Something went wrong. Try again.
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991001011021031041051061071081091101111121131141151161171181191201211221231241251261271281291301311321331341351361371381391401411421431441451461471481491501511521531541551561571581591601611621631641651661671681691701711721731741751761771781791801811821831841851861871881891901911921931941951961971981992002012022032042052062072082092102112122132142152162172182192202212222232242252262272282292302312322332342352362372382392402412422432442452462472482492502512522532542552562572582592602612622632642652662672682692702712722732742752762772782792802812822832842852862872882892902912922932942952962972982993003013023033043053063073083093103113123133143153163173183193203213223233243253263273283293303313323333343353363373383393403413423433443453463473483493503513523533543553563573583593603613623633643653663673683693703713723733743753763773783793803813823833843853863873883893903913923933943953963973983994004014024034044054064074084094104114124134144154164174184194204214224234244254264274284294304314324334344354364374384394404414424434444454464474484494504514524534544554564574584594604614624634644654664674684694704714724734744754764774784794804814824834844854864874884894904914924934944954964974984995005015025035045055065075085095105115125135145155165175185195205215225235245255265275285295305315325335345355365375385395405415425435445455465475485495505515525535545555565575585595605615625635645655665675685695705715725735745755765775785795805815825835845855865875885895905915925935945955965975985996006016026036046056066076086096106116126136146156166176186196206216226236246256266276286296306316326336346356366376386396406416426436446456466476486496506516526536546556566576586596606616626636646656666676686696706716726736746756766776786796806816826836846856866876886896906916926936946956966976986997007017027037047057067077087097107117127137147157167177187197207217227237247257267277287297307317327337347357367377387397407417427437447457467477487497507517527537547557567577587597607617627637647657667677687697707717727737747757767777787797807817827837847857867877887897907917927937947957967977987998008018028038048058068078088098108118128138148158168178188198208218228238248258268278288298308318328338348358368378388398408418428438448458468478488498508518528538548558568578588598608618628638648658668678688698708718728738748758768778788798808818828838848858868878888898908918928938948958968978988999009019029039049059069079089099109119129139149159169179189199209219229239249259269279289299309319329339349359369379389399409419429439449459469479489499509519529539549559569579589599609619629639649659669679689699709719729739749759769779789799809819829839849859869879889899909919929939949959969979989991000100110021003100410051006100710081009101010111012101310141015101610171018101910201021102210231024102510261027102810291030103110321033103410351036103710381039104010411042104310441045104610471048104910501051105210531054105510561057105810591060106110621063106410651066106710681069107010711072107310741075107610771078107910801081108210831084108510861087108810891090109110921093109410951096109710981099110011011102110311041105110611071108110911101111111211131114111511161117111811191120112111221123112411251126112711281129113011311132113311341135113611371138113911401141114211431144114511461147114811491150115111521153115411551156115711581159116011611162116311641165116611671168116911701171117211731174117511761177117811791180118111821183118411851186118711881189119011911192119311941195119611971198119912001201120212031204120512061207120812091210121112121213121412151216121712181219122012211222122312241225122612271228122912301231123212331234123512361237123812391240124112421243124412451246124712481249125012511252125312541255125612571258125912601261126212631264126512661267126812691270127112721273127412751276127712781279128012811282128312841285128612871288128912901291129212931294129512961297129812991300130113021303130413051306130713081309131013111312131313141315131613171318131913201321132213231324132513261327132813291330133113321333133413351336133713381339134013411342134313441345134613471348134913501351135213531354135513561357135813591360136113621363136413651366136713681369137013711372137313741375137613771378137913801381138213831384138513861387138813891390139113921393139413951396139713981399140014011402140314041405140614071408140914101411141214131414141514161417141814191420142114221423142414251426142714281429143014311432143314341435143614371438143914401441144214431444144514461447144814491450145114521453145414551456145714581459146014611462146314641465146614671468146914701471147214731474147514761477147814791480148114821483148414851486148714881489149014911492149314941495149614971498149915001501150215031504150515061507150815091510151115121513151415151516151715181519152015211522152315241525152615271528152915301531153215331534153515361537153815391540154115421543154415451546154715481549155015511552155315541555155615571558155915601561156215631564156515661567156815691570157115721573157415751576157715781579158015811582158315841585158615871588158915901591159215931594159515961597159815991600160116021603160416051606160716081609161016111612161316141615161616171618161916201621162216231624162516261627162816291630163116321633163416351636163716381639164016411642164316441645164616471648164916501651165216531654165516561657165816591660166116621663166416651666166716681669167016711672167316741675167616771678167916801681168216831684168516861687168816891690169116921693169416951696169716981699170017011702170317041705170617071708170917101711171217131714171517161717171817191720172117221723172417251726172717281729173017311732173317341735173617371738173917401741174217431744174517461747174817491750175117521753175417551756175717581759176017611762176317641765176617671768176917701771177217731774177517761777177817791780178117821783178417851786178717881789179017911792179317941795179617971798179918001801180218031804180518061807180818091810181118121813181418151816181718181819182018211822182318241825182618271828182918301831183218331834183518361837183818391840184118421843184418451846184718481849185018511852185318541855185618571858185918601861186218631864186518661867186818691870187118721873187418751876187718781879188018811882188318841885188618871888188918901891189218931894189518961897189818991900190119021903190419051906190719081909191019111912191319141915191619171918191919201921192219231924192519261927192819291930193119321933193419351936193719381939194019411942194319441945194619471948194919501951195219531954195519561957195819591960196119621963196419651966196719681969197019711972197319741975197619771978197919801981198219831984198519861987198819891990199119921993199419951996199719981999200020012002200320042005200620072008200920102011201220132014201520162017201820192020202120222023202420252026202720282029203020312032203320342035203620372038203920402041204220432044204520462047204820492050205120522053205420552056205720582059206020612062206320642065206620672068206920702071207220732074207520762077207820792080208120822083208420852086208720882089209020912092209320942095209620972098209921002101210221032104210521062107210821092110211121122113211421152116211721182119212021212122212321242125212621272128212921302131213221332134213521362137213821392140214121422143214421452146214721482149215021512152215321542155215621572158215921602161216221632164216521662167216821692170217121722173217421752176217721782179218021812182218321842185218621872188218921902191219221932194219521962197219821992200220122022203220422052206220722082209221022112212221322142215221622172218221922202221222222232224222522262227222822292230223122322233223422352236223722382239224022412242224322442245224622472248224922502251225222532254225522562257225822592260226122622263226422652266226722682269227022712272227322742275227622772278227922802281228222832284228522862287228822892290229122922293229422952296229722982299230023012302230323042305230623072308230923102311231223132314231523162317231823192320232123222323232423252326232723282329233023312332233323342335233623372338233923402341234223432344234523462347234823492350235123522353235423552356235723582359236023612362236323642365236623672368236923702371237223732374237523762377237823792380238123822383238423852386238723882389239023912392239323942395239623972398239924002401240224032404240524062407240824092410241124122413241424152416241724182419242024212422242324242425242624272428242924302431243224332434243524362437243824392440244124422443244424452446244724482449245024512452245324542455245624572458245924602461246224632464246524662467246824692470247124722473247424752476247724782479248024812482248324842485248624872488248924902491249224932494249524962497249824992500250125022503250425052506250725082509251025112512251325142515251625172518251925202521252225232524252525262527252825292530253125322533253425352536253725382539254025412542254325442545254625472548254925502551255225532554255525562557255825592560256125622563256425652566256725682569257025712572257325742575257625772578257925802581258225832584258525862587258825892590259125922593259425952596259725982599260026012602260326042605260626072608260926102611261226132614261526162617261826192620262126222623262426252626262726282629263026312632263326342635263626372638263926402641264226432644264526462647264826492650265126522653265426552656265726582659266026612662266326642665266626672668266926702671267226732674267526762677267826792680268126822683268426852686268726882689269026912692269326942695269626972698269927002701270227032704270527062707270827092710271127122713271427152716271727182719272027212722272327242725272627272728272927302731273227332734273527362737273827392740274127422743274427452746274727482749275027512752275327542755275627572758275927602761276227632764276527662767276827692770277127722773277427752776277727782779278027812782278327842785278627872788278927902791279227932794279527962797279827992800280128022803280428052806280728082809281028112812281328142815281628172818281928202821282228232824282528262827282828292830283128322833283428352836283728382839284028412842284328442845284628472848284928502851285228532854285528562857285828592860286128622863286428652866286728682869287028712872287328742875287628772878287928802881288228832884288528862887288828892890289128922893289428952896289728982899290029012902290329042905290629072908290929102911291229132914291529162917291829192920292129222923292429252926292729282929293029312932293329342935293629372938293929402941294229432944294529462947294829492950295129522953295429552956295729582959296029612962296329642965296629672968296929702971297229732974297529762977297829792980298129822983298429852986298729882989299029912992299329942995299629972998299930003001300230033004300530063007300830093010301130123013301430153016301730183019302030213022302330243025302630273028302930303031303230333034303530363037303830393040304130423043304430453046304730483049305030513052305330543055305630573058305930603061306230633064306530663067306830693070307130723073307430753076307730783079308030813082308330843085308630873088308930903091309230933094309530963097309830993100310131023103310431053106310731083109311031113112311331143115311631173118311931203121312231233124312531263127312831293130313131323133313431353136313731383139314031413142314331443145314631473148314931503151315231533154315531563157315831593160316131623163316431653166316731683169317031713172317331743175317631773178317931803181318231833184318531863187318831893190319131923193319431953196319731983199320032013202320332043205320632073208320932103211321232133214321532163217321832193220322132223223322432253226322732283229323032313232323332343235323632373238323932403241324232433244324532463247324832493250325132523253325432553256325732583259326032613262326332643265326632673268326932703271327232733274327532763277327832793280328132823283328432853286328732883289329032913292329332943295329632973298329933003301330233033304330533063307330833093310331133123313331433153316331733183319332033213322332333243325332633273328332933303331333233333334333533363337333833393340334133423343334433453346334733483349335033513352335333543355335633573358335933603361336233633364336533663367336833693370337133723373337433753376337733783379338033813382338333843385338633873388338933903391339233933394339533963397339833993400340134023403340434053406340734083409341034113412341334143415341634173418341934203421342234233424342534263427342834293430343134323433343434353436343734383439344034413442344334443445344634473448344934503451345234533454345534563457345834593460346134623463346434653466346734683469347034713472347334743475347634773478347934803481348234833484348534863487348834893490349134923493349434953496349734983499350035013502350335043505350635073508350935103511351235133514351535163517351835193520352135223523352435253526352735283529353035313532353335343535353635373538353935403541354235433544354535463547354835493550355135523553355435553556355735583559356035613562356335643565356635673568356935703571357235733574357535763577357835793580358135823583358435853586358735883589359035913592359335943595359635973598359936003601360236033604360536063607360836093610361136123613361436153616361736183619362036213622362336243625362636273628362936303631363236333634363536363637363836393640364136423643364436453646364736483649365036513652365336543655365636573658365936603661366236633664366536663667366836693670367136723673367436753676367736783679368036813682368336843685368636873688368936903691369236933694369536963697369836993700370137023703370437053706370737083709371037113712371337143715371637173718371937203721372237233724372537263727372837293730373137323733373437353736373737383739374037413742374337443745374637473748374937503751375237533754375537563757375837593760376137623763376437653766376737683769377037713772377337743775377637773778377937803781378237833784378537863787378837893790379137923793379437953796379737983799380038013802380338043805380638073808380938103811381238133814381538163817381838193820382138223823382438253826382738283829383038313832383338343835383638373838383938403841384238433844384538463847384838493850385138523853385438553856385738583859386038613862386338643865386638673868386938703871387238733874387538763877387838793880388138823883388438853886388738883889389038913892389338943895389638973898389939003901390239033904390539063907390839093910391139123913391439153916391739183919392039213922392339243925392639273928392939303931393239333934393539363937393839393940394139423943394439453946394739483949395039513952395339543955395639573958395939603961396239633964396539663967396839693970397139723973397439753976397739783979398039813982398339843985398639873988398939903991399239933994399539963997399839994000400140024003400440054006400740084009401040114012401340144015401640174018401940204021402240234024402540264027402840294030403140324033403440354036403740384039404040414042404340444045404640474048404940504051405240534054405540564057405840594060406140624063406440654066406740684069407040714072407340744075407640774078407940804081408240834084408540864087408840894090409140924093409440954096409740984099410041014102410341044105410641074108410941104111411241134114411541164117411841194120412141224123412441254126412741284129413041314132413341344135413641374138413941404141414241434144414541464147414841494150415141524153415441554156415741584159416041614162416341644165416641674168416941704171417241734174417541764177417841794180418141824183418441854186418741884189419041914192419341944195419641974198419942004201420242034204420542064207420842094210421142124213421442154216421742184219422042214222422342244225422642274228422942304231423242334234423542364237423842394240424142424243424442454246424742484249425042514252425342544255425642574258425942604261426242634264426542664267426842694270427142724273427442754276427742784279428042814282428342844285428642874288428942904291429242934294429542964297429842994300430143024303430443054306430743084309431043114312431343144315431643174318431943204321432243234324432543264327432843294330433143324333433443354336433743384339434043414342434343444345434643474348434943504351435243534354435543564357435843594360436143624363436443654366436743684369437043714372437343744375437643774378437943804381438243834384438543864387438843894390439143924393439443954396439743984399440044014402440344044405440644074408440944104411441244134414441544164417441844194420442144224423442444254426442744284429443044314432443344344435443644374438443944404441444244434444444544464447444844494450445144524453445444554456445744584459446044614462446344644465446644674468446944704471447244734474447544764477447844794480448144824483448444854486448744884489449044914492449344944495449644974498449945004501450245034504450545064507450845094510451145124513451445154516451745184519452045214522452345244525452645274528452945304531453245334534453545364537453845394540454145424543454445454546454745484549455045514552455345544555455645574558455945604561456245634564456545664567456845694570457145724573457445754576457745784579458045814582458345844585458645874588458945904591459245934594459545964597459845994600460146024603460446054606460746084609461046114612461346144615461646174618461946204621462246234624462546264627462846294630463146324633463446354636463746384639464046414642464346444645464646474648464946504651465246534654465546564657465846594660466146624663466446654666466746684669467046714672467346744675467646774678467946804681468246834684468546864687468846894690469146924693469446954696469746984699470047014702470347044705470647074708470947104711471247134714471547164717471847194720472147224723472447254726472747284729473047314732473347344735473647374738473947404741474247434744474547464747474847494750475147524753475447554756475747584759476047614762476347644765476647674768476947704771477247734774477547764777477847794780478147824783478447854786478747884789479047914792479347944795479647974798479948004801480248034804480548064807480848094810481148124813481448154816481748184819482048214822482348244825482648274828482948304831483248334834483548364837483848394840484148424843484448454846484748484849485048514852485348544855485648574858485948604861486248634864486548664867486848694870487148724873487448754876487748784879488048814882488348844885488648874888488948904891489248934894489548964897489848994900490149024903490449054906490749084909491049114912491349144915491649174918491949204921492249234924492549264927492849294930493149324933493449354936493749384939494049414942494349444945494649474948494949504951495249534954495549564957495849594960496149624963496449654966496749684969497049714972497349744975497649774978497949804981498249834984498549864987498849894990499149924993499449954996499749984999500050015002500350045005500650075008500950105011501250135014501550165017501850195020502150225023502450255026502750285029503050315032503350345035503650375038503950405041504250435044504550465047504850495050505150525053505450555056505750585059506050615062506350645065506650675068506950705071507250735074507550765077507850795080508150825083508450855086508750885089509050915092509350945095509650975098509951005101510251035104510551065107510851095110511151125113511451155116511751185119512051215122512351245125512651275128512951305131513251335134513551365137513851395140514151425143514451455146514751485149515051515152515351545155515651575158515951605161516251635164516551665167516851695170517151725173517451755176517751785179518051815182518351845185518651875188518951905191519251935194519551965197519851995200520152025203520452055206520752085209521052115212521352145215521652175218521952205221522252235224522552265227522852295230523152325233523452355236523752385239524052415242524352445245524652475248524952505251525252535254525552565257525852595260526152625263526452655266526752685269527052715272527352745275527652775278527952805281528252835284528552865287528852895290529152925293529452955296529752985299530053015302530353045305530653075308530953105311531253135314531553165317531853195320532153225323532453255326532753285329533053315332533353345335533653375338533953405341534253435344534553465347534853495350535153525353535453555356535753585359536053615362536353645365536653675368536953705371537253735374537553765377537853795380538153825383538453855386538753885389539053915392539353945395539653975398539954005401540254035404540554065407540854095410541154125413541454155416541754185419542054215422542354245425542654275428542954305431543254335434543554365437543854395440544154425443544454455446544754485449545054515452545354545455545654575458545954605461546254635464546554665467546854695470547154725473547454755476547754785479548054815482548354845485548654875488548954905491549254935494549554965497549854995500550155025503550455055506550755085509551055115512551355145515551655175518551955205521552255235524552555265527552855295530553155325533553455355536553755385539554055415542554355445545554655475548554955505551555255535554555555565557555855595560556155625563556455655566556755685569557055715572557355745575557655775578557955805581558255835584558555865587558855895590559155925593559455955596559755985599560056015602560356045605560656075608560956105611561256135614561556165617561856195620562156225623562456255626562756285629563056315632563356345635563656375638563956405641564256435644564556465647564856495650565156525653565456555656565756585659566056615662566356645665566656675668566956705671567256735674567556765677567856795680568156825683568456855686568756885689569056915692569356945695569656975698569957005701570257035704570557065707570857095710571157125713571457155716571757185719572057215722572357245725572657275728572957305731573257335734573557365737573857395740574157425743574457455746574757485749575057515752575357545755575657575758575957605761576257635764576557665767576857695770577157725773577457755776577757785779578057815782578357845785578657875788578957905791579257935794579557965797579857995800580158025803580458055806580758085809581058115812581358145815581658175818581958205821582258235824582558265827582858295830583158325833583458355836583758385839584058415842584358445845584658475848584958505851585258535854585558565857585858595860586158625863586458655866586758685869587058715872587358745875587658775878587958805881588258835884588558865887588858895890589158925893589458955896589758985899590059015902590359045905590659075908590959105911591259135914591559165917591859195920592159225923592459255926592759285929593059315932593359345935593659375938593959405941594259435944594559465947594859495950595159525953595459555956595759585959596059615962596359645965596659675968596959705971597259735974597559765977597859795980598159825983598459855986598759885989599059915992599359945995599659975998599960006001600260036004600560066007600860096010601160126013601460156016601760186019602060216022602360246025602660276028602960306031603260336034603560366037603860396040604160426043604460456046604760486049605060516052605360546055605660576058605960606061606260636064606560666067606860696070607160726073607460756076607760786079608060816082608360846085608660876088608960906091609260936094609560966097609860996100610161026103610461056106610761086109611061116112611361146115611661176118611961206121612261236124612561266127612861296130613161326133613461356136613761386139614061416142614361446145614661476148614961506151615261536154615561566157615861596160616161626163616461656166616761686169617061716172617361746175617661776178617961806181618261836184618561866187618861896190619161926193619461956196619761986199620062016202620362046205620662076208620962106211621262136214621562166217621862196220622162226223622462256226622762286229623062316232623362346235623662376238623962406241624262436244624562466247624862496250625162526253625462556256625762586259626062616262626362646265626662676268626962706271627262736274627562766277627862796280628162826283628462856286628762886289629062916292629362946295629662976298629963006301630263036304630563066307630863096310631163126313631463156316631763186319632063216322632363246325632663276328632963306331633263336334633563366337633863396340634163426343634463456346634763486349635063516352635363546355635663576358635963606361636263636364636563666367636863696370637163726373637463756376637763786379638063816382638363846385638663876388638963906391639263936394639563966397639863996400640164026403640464056406640764086409641064116412641364146415641664176418641964206421642264236424642564266427642864296430643164326433643464356436643764386439644064416442644364446445644664476448644964506451645264536454645564566457645864596460646164626463646464656466646764686469647064716472647364746475647664776478647964806481648264836484648564866487648864896490649164926493649464956496649764986499650065016502650365046505650665076508650965106511651265136514651565166517651865196520652165226523652465256526652765286529653065316532653365346535653665376538653965406541654265436544654565466547654865496550655165526553655465556556655765586559656065616562656365646565656665676568656965706571657265736574657565766577657865796580658165826583658465856586658765886589659065916592659365946595659665976598659966006601660266036604660566066607660866096610661166126613661466156616661766186619662066216622662366246625662666276628662966306631663266336634663566366637663866396640664166426643664466456646664766486649665066516652665366546655665666576658665966606661666266636664666566666667666866696670667166726673667466756676667766786679668066816682668366846685668666876688668966906691669266936694669566966697669866996700670167026703670467056706670767086709671067116712671367146715671667176718671967206721672267236724672567266727672867296730673167326733673467356736673767386739674067416742674367446745674667476748674967506751675267536754675567566757675867596760676167626763676467656766676767686769677067716772677367746775677667776778677967806781678267836784678567866787678867896790679167926793679467956796679767986799680068016802680368046805680668076808680968106811681268136814681568166817681868196820682168226823682468256826682768286829683068316832683368346835683668376838683968406841684268436844684568466847684868496850685168526853685468556856685768586859686068616862686368646865686668676868686968706871687268736874687568766877687868796880688168826883688468856886688768886889689068916892689368946895689668976898689969006901690269036904690569066907690869096910691169126913691469156916691769186919692069216922692369246925692669276928692969306931693269336934693569366937693869396940694169426943694469456946694769486949695069516952695369546955695669576958695969606961696269636964696569666967696869696970697169726973697469756976697769786979698069816982698369846985698669876988698969906991699269936994699569966997699869997000700170027003700470057006700770087009701070117012701370147015701670177018701970207021702270237024702570267027702870297030703170327033703470357036703770387039704070417042704370447045704670477048704970507051705270537054705570567057705870597060706170627063706470657066706770687069707070717072707370747075707670777078707970807081708270837084708570867087708870897090709170927093709470957096709770987099710071017102710371047105710671077108710971107111711271137114711571167117711871197120712171227123712471257126712771287129713071317132713371347135713671377138713971407141714271437144714571467147714871497150715171527153715471557156715771587159716071617162716371647165716671677168716971707171717271737174717571767177717871797180718171827183718471857186718771887189719071917192719371947195719671977198719972007201720272037204720572067207720872097210721172127213721472157216721772187219722072217222722372247225722672277228722972307231723272337234723572367237723872397240724172427243724472457246724772487249725072517252725372547255725672577258725972607261726272637264726572667267726872697270727172727273727472757276727772787279728072817282728372847285728672877288728972907291729272937294729572967297729872997300730173027303730473057306730773087309731073117312731373147315731673177318731973207321732273237324732573267327732873297330733173327333733473357336733773387339734073417342734373447345734673477348734973507351735273537354735573567357735873597360736173627363736473657366736773687369737073717372737373747375737673777378737973807381738273837384738573867387738873897390739173927393739473957396739773987399740074017402740374047405740674077408740974107411741274137414741574167417741874197420742174227423742474257426742774287429743074317432743374347435743674377438743974407441744274437444744574467447744874497450745174527453745474557456745774587459746074617462746374647465746674677468746974707471747274737474747574767477747874797480748174827483748474857486748774887489749074917492749374947495749674977498749975007501750275037504750575067507750875097510751175127513751475157516751775187519752075217522752375247525752675277528752975307531753275337534753575367537753875397540754175427543754475457546754775487549755075517552755375547555755675577558755975607561756275637564756575667567756875697570757175727573757475757576757775787579758075817582758375847585758675877588758975907591759275937594759575967597759875997600760176027603760476057606760776087609761076117612761376147615761676177618761976207621762276237624762576267627762876297630763176327633763476357636763776387639764076417642764376447645764676477648764976507651765276537654765576567657765876597660766176627663766476657666766776687669767076717672767376747675767676777678767976807681768276837684768576867687768876897690769176927693769476957696769776987699770077017702770377047705770677077708770977107711771277137714771577167717771877197720772177227723772477257726772777287729773077317732773377347735773677377738773977407741774277437744774577467747774877497750775177527753775477557756775777587759776077617762776377647765776677677768776977707771777277737774777577767777777877797780778177827783778477857786778777887789779077917792779377947795779677977798779978007801780278037804780578067807780878097810781178127813781478157816781778187819782078217822782378247825782678277828782978307831783278337834783578367837783878397840784178427843784478457846784778487849785078517852785378547855785678577858785978607861786278637864786578667867786878697870787178727873787478757876787778787879788078817882788378847885788678877888788978907891789278937894789578967897789878997900790179027903790479057906790779087909791079117912791379147915791679177918791979207921792279237924792579267927792879297930793179327933793479357936793779387939794079417942794379447945794679477948794979507951795279537954795579567957795879597960796179627963796479657966796779687969797079717972797379747975797679777978797979807981798279837984798579867987798879897990799179927993799479957996799779987999800080018002800380048005800680078008800980108011801280138014801580168017801880198020802180228023802480258026802780288029803080318032803380348035803680378038803980408041804280438044804580468047804880498050805180528053805480558056805780588059806080618062806380648065806680678068806980708071807280738074807580768077807880798080808180828083808480858086808780888089809080918092809380948095809680978098809981008101810281038104810581068107810881098110811181128113811481158116811781188119812081218122812381248125812681278128812981308131813281338134813581368137813881398140814181428143814481458146814781488149815081518152815381548155815681578158815981608161816281638164816581668167816881698170817181728173817481758176817781788179818081818182818381848185818681878188818981908191819281938194819581968197819881998200820182028203820482058206820782088209821082118212821382148215821682178218821982208221822282238224822582268227822882298230823182328233823482358236823782388239824082418242824382448245824682478248824982508251825282538254825582568257825882598260826182628263826482658266826782688269827082718272827382748275827682778278827982808281828282838284828582868287828882898290829182928293829482958296829782988299830083018302830383048305830683078308830983108311831283138314831583168317831883198320832183228323832483258326832783288329833083318332833383348335833683378338833983408341834283438344834583468347834883498350835183528353835483558356835783588359836083618362836383648365836683678368836983708371837283738374837583768377837883798380838183828383838483858386838783888389839083918392839383948395839683978398839984008401840284038404840584068407840884098410841184128413841484158416841784188419842084218422842384248425842684278428842984308431843284338434843584368437843884398440844184428443844484458446844784488449845084518452845384548455845684578458845984608461846284638464846584668467846884698470847184728473847484758476847784788479848084818482848384848485848684878488848984908491849284938494849584968497849884998500850185028503850485058506850785088509851085118512851385148515851685178518851985208521852285238524852585268527852885298530853185328533853485358536853785388539854085418542854385448545854685478548854985508551855285538554855585568557855885598560856185628563856485658566856785688569857085718572857385748575857685778578857985808581858285838584858585868587858885898590859185928593859485958596859785988599860086018602860386048605860686078608860986108611861286138614861586168617861886198620862186228623862486258626862786288629863086318632863386348635863686378638863986408641864286438644864586468647864886498650865186528653865486558656865786588659866086618662866386648665866686678668866986708671867286738674867586768677867886798680868186828683868486858686868786888689869086918692869386948695869686978698869987008701870287038704870587068707870887098710871187128713871487158716871787188719872087218722872387248725872687278728872987308731873287338734873587368737873887398740874187428743874487458746874787488749875087518752875387548755875687578758875987608761876287638764876587668767876887698770877187728773877487758776877787788779878087818782878387848785878687878788878987908791879287938794879587968797879887998800880188028803880488058806880788088809881088118812881388148815881688178818881988208821882288238824882588268827882888298830883188328833883488358836883788388839884088418842884388448845884688478848884988508851885288538854885588568857885888598860886188628863886488658866886788688869887088718872887388748875887688778878887988808881888288838884888588868887888888898890889188928893889488958896889788988899890089018902890389048905890689078908890989108911891289138914891589168917891889198920892189228923892489258926892789288929893089318932893389348935893689378938893989408941894289438944894589468947894889498950895189528953895489558956895789588959896089618962896389648965896689678968896989708971897289738974897589768977897889798980898189828983898489858986898789888989899089918992899389948995899689978998899990009001900290039004900590069007900890099010901190129013901490159016901790189019902090219022902390249025902690279028902990309031903290339034903590369037903890399040904190429043904490459046904790489049905090519052905390549055905690579058905990609061906290639064906590669067906890699070907190729073907490759076907790789079908090819082908390849085908690879088908990909091909290939094909590969097909890999100910191029103910491059106910791089109911091119112911391149115911691179118911991209121912291239124912591269127912891299130913191329133913491359136913791389139914091419142914391449145914691479148914991509151915291539154915591569157915891599160916191629163916491659166916791689169917091719172917391749175917691779178917991809181918291839184918591869187918891899190919191929193919491959196919791989199920092019202920392049205920692079208920992109211921292139214921592169217921892199220922192229223922492259226922792289229923092319232923392349235923692379238923992409241924292439244924592469247924892499250925192529253925492559256925792589259926092619262926392649265926692679268926992709271927292739274927592769277927892799280928192829283928492859286928792889289929092919292929392949295929692979298929993009301930293039304930593069307930893099310931193129313931493159316931793189319932093219322932393249325932693279328932993309331933293339334933593369337933893399340934193429343934493459346934793489349935093519352935393549355935693579358935993609361936293639364936593669367936893699370937193729373937493759376937793789379938093819382938393849385938693879388938993909391939293939394939593969397939893999400940194029403940494059406940794089409941094119412941394149415941694179418941994209421942294239424942594269427942894299430943194329433943494359436943794389439944094419442944394449445944694479448944994509451945294539454945594569457945894599460946194629463946494659466946794689469947094719472947394749475947694779478947994809481948294839484948594869487948894899490949194929493949494959496949794989499950095019502950395049505950695079508950995109511951295139514951595169517951895199520952195229523952495259526952795289529953095319532953395349535953695379538953995409541954295439544954595469547954895499550955195529553955495559556955795589559956095619562956395649565956695679568956995709571957295739574957595769577957895799580958195829583958495859586958795889589959095919592959395949595959695979598959996009601960296039604960596069607960896099610961196129613961496159616961796189619962096219622962396249625962696279628962996309631963296339634963596369637963896399640964196429643964496459646964796489649965096519652965396549655965696579658965996609661966296639664966596669667966896699670967196729673967496759676967796789679968096819682968396849685968696879688968996909691969296939694969596969697969896999700970197029703970497059706970797089709971097119712971397149715971697179718971997209721972297239724972597269727972897299730973197329733973497359736973797389739974097419742974397449745974697479748974997509751975297539754975597569757975897599760976197629763976497659766976797689769977097719772977397749775977697779778977997809781978297839784978597869787978897899790979197929793979497959796979797989799980098019802980398049805980698079808980998109811981298139814981598169817981898199820982198229823982498259826982798289829983098319832983398349835983698379838983998409841984298439844984598469847984898499850985198529853985498559856985798589859986098619862986398649865986698679868986998709871987298739874987598769877987898799880988198829883988498859886988798889889989098919892989398949895989698979898989999009901990299039904990599069907990899099910991199129913991499159916991799189919992099219922992399249925992699279928992999309931993299339934993599369937993899399940994199429943994499459946994799489949995099519952995399549955995699579958995999609961996299639964996599669967996899699970997199729973997499759976997799789979998099819982998399849985998699879988998999909991999299939994999599969997999899991000010001100021000310004100051000610007100081000910010100111001210013100141001510016100171001810019100201002110022100231002410025100261002710028100291003010031100321003310034100351003610037100381003910040100411004210043100441004510046100471004810049100501005110052100531005410055100561005710058100591006010061100621006310064100651006610067100681006910070100711007210073100741007510076100771007810079100801008110082100831008410085100861008710088100891009010091100921009310094100951009610097100981009910100101011010210103101041010510106101071010810109101101011110112101131011410115101161011710118101191012010121101221012310124101251012610127101281012910130101311013210133101341013510136101371013810139101401014110142101431014410145101461014710148101491015010151101521015310154101551015610157101581015910160101611016210163101641016510166101671016810169101701017110172101731017410175101761017710178101791018010181101821018310184101851018610187101881018910190101911019210193101941019510196101971019810199102001020110202102031020410205102061020710208102091021010211102121021310214102151021610217102181021910220102211022210223102241022510226102271022810229102301023110232102331023410235102361023710238102391024010241102421024310244102451024610247102481024910250102511025210253102541025510256102571025810259102601026110262102631026410265102661026710268102691027010271102721027310274102751027610277102781027910280102811028210283102841028510286102871028810289102901029110292102931029410295102961029710298102991030010301103021030310304103051030610307103081030910310103111031210313103141031510316103171031810319103201032110322103231032410325103261032710328103291033010331103321033310334103351033610337103381033910340103411034210343103441034510346103471034810349103501035110352103531035410355103561035710358103591036010361103621036310364103651036610367103681036910370103711037210373103741037510376103771037810379103801038110382103831038410385103861038710388103891039010391103921039310394103951039610397103981039910400104011040210403104041040510406104071040810409104101041110412104131041410415104161041710418104191042010421104221042310424104251042610427104281042910430104311043210433104341043510436104371043810439104401044110442104431044410445104461044710448104491045010451104521045310454104551045610457104581045910460104611046210463104641046510466104671046810469104701047110472104731047410475104761047710478104791048010481104821048310484104851048610487104881048910490104911049210493104941049510496104971049810499105001050110502105031050410505105061050710508105091051010511105121051310514105151051610517105181051910520105211052210523105241052510526105271052810529105301053110532105331053410535105361053710538105391054010541105421054310544105451054610547105481054910550105511055210553105541055510556105571055810559105601056110562105631056410565105661056710568105691057010571105721057310574105751057610577105781057910580105811058210583105841058510586105871058810589105901059110592105931059410595105961059710598105991060010601106021060310604106051060610607106081060910610106111061210613106141061510616106171061810619106201062110622106231062410625106261062710628106291063010631106321063310634106351063610637106381063910640106411064210643106441064510646106471064810649106501065110652106531065410655106561065710658106591066010661106621066310664106651066610667106681066910670106711067210673106741067510676106771067810679106801068110682106831068410685106861068710688106891069010691106921069310694106951069610697106981069910700107011070210703107041070510706107071070810709107101071110712107131071410715107161071710718107191072010721107221072310724107251072610727107281072910730107311073210733107341073510736107371073810739107401074110742107431074410745107461074710748107491075010751107521075310754107551075610757107581075910760107611076210763107641076510766107671076810769107701077110772107731077410775107761077710778107791078010781107821078310784107851078610787107881078910790107911079210793107941079510796107971079810799108001080110802108031080410805108061080710808108091081010811108121081310814108151081610817108181081910820108211082210823108241082510826108271082810829108301083110832108331083410835108361083710838108391084010841108421084310844108451084610847108481084910850108511085210853108541085510856108571085810859108601086110862108631086410865108661086710868108691087010871108721087310874108751087610877108781087910880108811088210883108841088510886108871088810889108901089110892108931089410895108961089710898108991090010901109021090310904109051090610907109081090910910109111091210913109141091510916109171091810919109201092110922109231092410925109261092710928109291093010931109321093310934109351093610937109381093910940109411094210943109441094510946109471094810949109501095110952109531095410955109561095710958109591096010961109621096310964109651096610967109681096910970109711097210973109741097510976109771097810979109801098110982109831098410985109861098710988109891099010991109921099310994109951099610997109981099911000110011100211003110041100511006110071100811009110101101111012110131101411015110161101711018110191102011021110221102311024110251102611027110281102911030110311103211033110341103511036110371103811039110401104111042110431104411045110461104711048110491105011051110521105311054110551105611057110581105911060110611106211063110641106511066110671106811069110701107111072110731107411075110761107711078110791108011081110821108311084110851108611087110881108911090110911109211093110941109511096110971109811099111001110111102111031110411105111061110711108111091111011111111121111311114111151111611117111181111911120111211112211123111241112511126111271112811129111301113111132111331113411135111361113711138111391114011141111421114311144111451114611147111481114911150111511115211153111541115511156111571115811159111601116111162111631116411165111661116711168111691117011171111721117311174111751117611177111781117911180111811118211183111841118511186111871118811189111901119111192111931119411195111961119711198111991120011201112021120311204112051120611207112081120911210112111121211213112141121511216112171121811219112201122111222112231122411225112261122711228112291123011231112321123311234112351123611237112381123911240112411124211243112441124511246112471124811249112501125111252112531125411255112561125711258112591126011261112621126311264112651126611267112681126911270112711127211273112741127511276112771127811279112801128111282112831128411285112861128711288112891129011291112921129311294112951129611297112981129911300113011130211303113041130511306113071130811309113101131111312113131131411315113161131711318113191132011321113221132311324113251132611327113281132911330113311133211333113341133511336113371133811339113401134111342113431134411345113461134711348113491135011351113521135311354113551135611357113581135911360113611136211363113641136511366113671136811369113701137111372113731137411375113761137711378113791138011381113821138311384113851138611387113881138911390113911139211393113941139511396113971139811399114001140111402114031140411405114061140711408114091141011411114121141311414114151141611417114181141911420114211142211423114241142511426114271142811429114301143111432114331143411435114361143711438114391144011441114421144311444114451144611447114481144911450114511145211453114541145511456114571145811459114601146111462114631146411465114661146711468114691147011471114721147311474114751147611477114781147911480114811148211483114841148511486114871148811489114901149111492114931149411495114961149711498114991150011501115021150311504115051150611507115081150911510115111151211513115141151511516115171151811519115201152111522115231152411525115261152711528115291153011531115321153311534115351153611537115381153911540115411154211543115441154511546115471154811549115501155111552115531155411555115561155711558115591156011561115621156311564115651156611567115681156911570115711157211573115741157511576115771157811579115801158111582115831158411585115861158711588115891159011591115921159311594115951159611597115981159911600116011160211603116041160511606116071160811609116101161111612116131161411615116161161711618116191162011621116221162311624116251162611627116281162911630116311163211633116341163511636116371163811639116401164111642116431164411645116461164711648116491165011651116521165311654116551165611657116581165911660116611166211663116641166511666116671166811669116701167111672116731167411675116761167711678116791168011681116821168311684116851168611687116881168911690116911169211693116941169511696116971169811699117001170111702117031170411705117061170711708117091171011711117121171311714117151171611717117181171911720117211172211723117241172511726117271172811729117301173111732117331173411735117361173711738117391174011741117421174311744117451174611747117481174911750117511175211753117541175511756117571175811759117601176111762117631176411765117661176711768117691177011771117721177311774117751177611777117781177911780117811178211783117841178511786117871178811789117901179111792117931179411795117961179711798117991180011801118021180311804118051180611807118081180911810118111181211813118141181511816118171181811819118201182111822118231182411825118261182711828118291183011831118321183311834118351183611837118381183911840118411184211843118441184511846118471184811849118501185111852118531185411855118561185711858118591186011861118621186311864118651186611867118681186911870118711187211873118741187511876118771187811879118801188111882118831188411885118861188711888118891189011891118921189311894118951189611897118981189911900119011190211903119041190511906119071190811909119101191111912119131191411915119161191711918119191192011921119221192311924119251192611927119281192911930119311193211933119341193511936119371193811939119401194111942119431194411945119461194711948119491195011951119521195311954119551195611957119581195911960119611196211963119641196511966119671196811969119701197111972119731197411975119761197711978119791198011981119821198311984119851198611987119881198911990119911199211993119941199511996119971199811999120001200112002120031200412005120061200712008120091201012011120121201312014120151201612017120181201912020120211202212023120241202512026120271202812029120301203112032120331203412035120361203712038120391204012041120421204312044120451204612047120481204912050120511205212053120541205512056120571205812059120601206112062120631206412065120661206712068120691207012071120721207312074120751207612077120781207912080120811208212083120841208512086120871208812089120901209112092120931209412095120961209712098120991210012101121021210312104121051210612107121081210912110121111211212113121141211512116121171211812119121201212112122121231212412125121261212712128121291213012131121321213312134121351213612137121381213912140121411214212143121441214512146121471214812149121501215112152121531215412155121561215712158121591216012161121621216312164121651216612167121681216912170121711217212173121741217512176121771217812179121801218112182121831218412185121861218712188121891219012191121921219312194121951219612197121981219912200122011220212203122041220512206122071220812209122101221112212122131221412215122161221712218122191222012221122221222312224122251222612227122281222912230122311223212233122341223512236122371223812239122401224112242122431224412245122461224712248122491225012251122521225312254122551225612257122581225912260122611226212263122641226512266122671226812269122701227112272122731227412275122761227712278122791228012281122821228312284122851228612287122881228912290122911229212293122941229512296122971229812299123001230112302123031230412305123061230712308123091231012311123121231312314123151231612317123181231912320123211232212323123241232512326123271232812329123301233112332123331233412335123361233712338123391234012341123421234312344123451234612347123481234912350123511235212353123541235512356123571235812359123601236112362123631236412365123661236712368123691237012371123721237312374123751237612377123781237912380123811238212383123841238512386123871238812389123901239112392123931239412395123961239712398123991240012401124021240312404124051240612407124081240912410124111241212413124141241512416124171241812419124201242112422124231242412425124261242712428124291243012431124321243312434124351243612437124381243912440124411244212443124441244512446124471244812449124501245112452124531245412455124561245712458124591246012461124621246312464124651246612467124681246912470124711247212473124741247512476124771247812479124801248112482124831248412485124861248712488124891249012491124921249312494124951249612497124981249912500125011250212503125041250512506125071250812509125101251112512125131251412515125161251712518125191252012521125221252312524125251252612527125281252912530125311253212533125341253512536125371253812539125401254112542125431254412545125461254712548125491255012551125521255312554125551255612557125581255912560125611256212563125641256512566125671256812569125701257112572125731257412575125761257712578125791258012581125821258312584125851258612587125881258912590125911259212593125941259512596125971259812599126001260112602126031260412605126061260712608126091261012611126121261312614126151261612617126181261912620126211262212623126241262512626126271262812629126301263112632126331263412635126361263712638126391264012641126421264312644126451264612647126481264912650126511265212653126541265512656126571265812659126601266112662126631266412665126661266712668126691267012671126721267312674126751267612677126781267912680126811268212683126841268512686126871268812689126901269112692126931269412695126961269712698126991270012701127021270312704127051270612707127081270912710127111271212713127141271512716127171271812719127201272112722127231272412725127261272712728127291273012731127321273312734127351273612737127381273912740127411274212743127441274512746127471274812749127501275112752127531275412755127561275712758127591276012761127621276312764127651276612767127681276912770127711277212773127741277512776127771277812779127801278112782127831278412785127861278712788127891279012791127921279312794127951279612797127981279912800128011280212803128041280512806128071280812809128101281112812128131281412815128161281712818128191282012821128221282312824128251282612827128281282912830128311283212833128341283512836128371283812839128401284112842128431284412845128461284712848128491285012851128521285312854128551285612857128581285912860128611286212863128641286512866128671286812869128701287112872128731287412875128761287712878128791288012881128821288312884128851288612887128881288912890128911289212893128941289512896128971289812899129001290112902129031290412905129061290712908129091291012911129121291312914129151291612917129181291912920129211292212923129241292512926129271292812929129301293112932129331293412935129361293712938129391294012941129421294312944129451294612947129481294912950129511295212953129541295512956129571295812959129601296112962129631296412965129661296712968129691297012971129721297312974129751297612977129781297912980129811298212983129841298512986129871298812989129901299112992129931299412995129961299712998129991300013001130021300313004130051300613007130081300913010130111301213013130141301513016130171301813019130201302113022130231302413025130261302713028130291303013031130321303313034130351303613037130381303913040130411304213043130441304513046130471304813049130501305113052130531305413055130561305713058130591306013061130621306313064130651306613067130681306913070130711307213073130741307513076130771307813079130801308113082130831308413085130861308713088130891309013091130921309313094130951309613097130981309913100131011310213103131041310513106131071310813109131101311113112131131311413115131161311713118131191312013121131221312313124131251312613127131281312913130131311313213133131341313513136131371313813139131401314113142131431314413145131461314713148131491315013151131521315313154131551315613157131581315913160131611316213163131641316513166131671316813169131701317113172131731317413175131761317713178131791318013181131821318313184131851318613187131881318913190131911319213193131941319513196131971319813199132001320113202132031320413205132061320713208132091321013211132121321313214132151321613217132181321913220132211322213223132241322513226132271322813229132301323113232132331323413235132361323713238132391324013241132421324313244132451324613247132481324913250132511325213253132541325513256132571325813259132601326113262132631326413265132661326713268132691327013271132721327313274132751327613277132781327913280132811328213283132841328513286132871328813289132901329113292132931329413295132961329713298132991330013301133021330313304133051330613307133081330913310133111331213313133141331513316133171331813319133201332113322133231332413325133261332713328133291333013331133321333313334133351333613337133381333913340133411334213343133441334513346133471334813349133501335113352133531335413355133561335713358133591336013361133621336313364133651336613367133681336913370133711337213373133741337513376133771337813379133801338113382133831338413385133861338713388133891339013391133921339313394133951339613397133981339913400134011340213403134041340513406134071340813409134101341113412134131341413415134161341713418134191342013421134221342313424134251342613427134281342913430134311343213433134341343513436134371343813439134401344113442134431344413445134461344713448134491345013451134521345313454134551345613457134581345913460134611346213463134641346513466134671346813469134701347113472134731347413475134761347713478134791348013481134821348313484134851348613487134881348913490134911349213493134941349513496134971349813499135001350113502135031350413505135061350713508135091351013511135121351313514135151351613517135181351913520135211352213523135241352513526135271352813529135301353113532135331353413535135361353713538135391354013541135421354313544135451354613547135481354913550135511355213553135541355513556135571355813559135601356113562135631356413565135661356713568135691357013571135721357313574135751357613577135781357913580135811358213583135841358513586135871358813589135901359113592135931359413595135961359713598135991360013601136021360313604136051360613607136081360913610136111361213613136141361513616136171361813619136201362113622136231362413625136261362713628136291363013631136321363313634136351363613637136381363913640136411364213643136441364513646136471364813649136501365113652136531365413655136561365713658136591366013661136621366313664136651366613667136681366913670136711367213673136741367513676136771367813679136801368113682136831368413685136861368713688136891369013691136921369313694136951369613697136981369913700137011370213703137041370513706137071370813709137101371113712137131371413715137161371713718137191372013721137221372313724137251372613727137281372913730137311373213733137341373513736137371373813739137401374113742137431374413745137461374713748137491375013751137521375313754137551375613757137581375913760137611376213763137641376513766137671376813769137701377113772137731377413775137761377713778137791378013781137821378313784137851378613787137881378913790137911379213793137941379513796137971379813799138001380113802138031380413805138061380713808138091381013811138121381313814138151381613817138181381913820138211382213823138241382513826138271382813829138301383113832138331383413835138361383713838138391384013841138421384313844138451384613847138481384913850138511385213853138541385513856138571385813859138601386113862138631386413865138661386713868138691387013871138721387313874138751387613877138781387913880138811388213883138841388513886138871388813889138901389113892138931389413895138961389713898138991390013901139021390313904139051390613907139081390913910139111391213913139141391513916139171391813919139201392113922139231392413925139261392713928139291393013931139321393313934139351393613937139381393913940139411394213943139441394513946139471394813949139501395113952139531395413955139561395713958139591396013961139621396313964139651396613967139681396913970139711397213973139741397513976139771397813979139801398113982139831398413985139861398713988139891399013991139921399313994139951399613997139981399914000140011400214003140041400514006140071400814009140101401114012140131401414015140161401714018140191402014021140221402314024140251402614027140281402914030140311403214033140341403514036140371403814039140401404114042140431404414045140461404714048140491405014051140521405314054140551405614057140581405914060140611406214063140641406514066140671406814069140701407114072140731407414075140761407714078140791408014081140821408314084140851408614087140881408914090140911409214093140941409514096140971409814099141001410114102141031410414105141061410714108141091411014111141121411314114141151411614117141181411914120141211412214123141241412514126141271412814129141301413114132141331413414135141361413714138141391414014141141421414314144141451414614147141481414914150141511415214153141541415514156141571415814159141601416114162141631416414165141661416714168141691417014171141721417314174141751417614177141781417914180141811418214183141841418514186141871418814189141901419114192141931419414195141961419714198141991420014201142021420314204142051420614207142081420914210142111421214213142141421514216142171421814219142201422114222142231422414225142261422714228142291423014231142321423314234142351423614237142381423914240142411424214243142441424514246142471424814249142501425114252142531425414255142561425714258142591426014261142621426314264142651426614267142681426914270142711427214273142741427514276142771427814279142801428114282142831428414285142861428714288142891429014291142921429314294142951429614297142981429914300143011430214303143041430514306143071430814309143101431114312143131431414315143161431714318143191432014321143221432314324143251432614327143281432914330143311433214333143341433514336143371433814339143401434114342143431434414345143461434714348143491435014351143521435314354143551435614357143581435914360143611436214363143641436514366143671436814369143701437114372143731437414375143761437714378143791438014381143821438314384143851438614387143881438914390143911439214393143941439514396143971439814399144001440114402144031440414405144061440714408144091441014411144121441314414144151441614417144181441914420144211442214423144241442514426144271442814429144301443114432144331443414435144361443714438144391444014441144421444314444144451444614447144481444914450144511445214453144541445514456144571445814459144601446114462144631446414465144661446714468144691447014471144721447314474144751447614477144781447914480144811448214483144841448514486144871448814489144901449114492144931449414495144961449714498144991450014501145021450314504145051450614507145081450914510145111451214513145141451514516145171451814519145201452114522145231452414525145261452714528145291453014531145321453314534145351453614537145381453914540145411454214543145441454514546145471454814549145501455114552145531455414555145561455714558145591456014561145621456314564145651456614567145681456914570145711457214573145741457514576145771457814579145801458114582145831458414585145861458714588145891459014591145921459314594145951459614597145981459914600146011460214603146041460514606146071460814609146101461114612146131461414615146161461714618146191462014621146221462314624146251462614627146281462914630146311463214633146341463514636146371463814639146401464114642146431464414645146461464714648146491465014651146521465314654146551465614657146581465914660146611466214663146641466514666146671466814669146701467114672146731467414675146761467714678146791468014681146821468314684146851468614687146881468914690146911469214693146941469514696146971469814699147001470114702147031470414705147061470714708147091471014711147121471314714147151471614717147181471914720147211472214723147241472514726147271472814729147301473114732147331473414735147361473714738147391474014741147421474314744147451474614747147481474914750147511475214753147541475514756147571475814759147601476114762147631476414765147661476714768147691477014771147721477314774147751477614777147781477914780147811478214783147841478514786147871478814789147901479114792147931479414795147961479714798147991480014801148021480314804148051480614807148081480914810148111481214813148141481514816148171481814819148201482114822148231482414825148261482714828148291483014831148321483314834148351483614837148381483914840148411484214843148441484514846148471484814849148501485114852148531485414855148561485714858148591486014861148621486314864148651486614867148681486914870148711487214873148741487514876148771487814879148801488114882148831488414885148861488714888148891489014891148921489314894148951489614897148981489914900149011490214903149041490514906149071490814909149101491114912149131491414915149161491714918149191492014921149221492314924149251492614927149281492914930149311493214933149341493514936149371493814939149401494114942149431494414945149461494714948149491495014951149521495314954149551495614957149581495914960149611496214963149641496514966149671496814969149701497114972149731497414975149761497714978149791498014981149821498314984149851498614987149881498914990149911499214993149941499514996149971499814999150001500115002150031500415005150061500715008150091501015011150121501315014150151501615017150181501915020150211502215023150241502515026150271502815029150301503115032150331503415035150361503715038150391504015041150421504315044150451504615047150481504915050150511505215053150541505515056150571505815059150601506115062150631506415065150661506715068150691507015071150721507315074150751507615077150781507915080150811508215083150841508515086150871508815089150901509115092150931509415095150961509715098150991510015101151021510315104151051510615107151081510915110151111511215113151141511515116151171511815119151201512115122151231512415125151261512715128151291513015131151321513315134151351513615137151381513915140151411514215143151441514515146151471514815149151501515115152151531515415155151561515715158151591516015161151621516315164151651516615167151681516915170151711517215173151741517515176151771517815179151801518115182151831518415185151861518715188151891519015191151921519315194151951519615197151981519915200152011520215203152041520515206152071520815209152101521115212152131521415215152161521715218152191522015221152221522315224152251522615227152281522915230152311523215233152341523515236152371523815239152401524115242152431524415245152461524715248152491525015251152521525315254152551525615257152581525915260152611526215263152641526515266152671526815269152701527115272152731527415275152761527715278152791528015281152821528315284152851528615287152881528915290152911529215293152941529515296152971529815299153001530115302153031530415305153061530715308153091531015311153121531315314153151531615317153181531915320153211532215323153241532515326153271532815329153301533115332153331533415335153361533715338153391534015341153421534315344153451534615347153481534915350153511535215353153541535515356153571535815359153601536115362153631536415365153661536715368153691537015371153721537315374153751537615377153781537915380153811538215383153841538515386153871538815389153901539115392153931539415395153961539715398153991540015401154021540315404154051540615407154081540915410154111541215413154141541515416154171541815419154201542115422154231542415425154261542715428154291543015431154321543315434154351543615437154381543915440154411544215443154441544515446154471544815449154501545115452// SPDX-License-Identifier: GPL-2.0/* * Performance events core code: * * Copyright (C) 2008 Linutronix GmbH, Thomas Gleixner <tglx@kernel.org> * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> */
#include <linux/fs.h>#include <linux/mm.h>#include <linux/cpu.h>#include <linux/smp.h>#include <linux/idr.h>#include <linux/file.h>#include <linux/poll.h>#include <linux/slab.h>#include <linux/hash.h>#include <linux/tick.h>#include <linux/sysfs.h>#include <linux/dcache.h>#include <linux/percpu.h>#include <linux/ptrace.h>#include <linux/reboot.h>#include <linux/vmstat.h>#include <linux/device.h>#include <linux/export.h>#include <linux/vmalloc.h>#include <linux/hardirq.h>#include <linux/hugetlb.h>#include <linux/rculist.h>#include <linux/uaccess.h>#include <linux/syscalls.h>#include <linux/anon_inodes.h>#include <linux/kernel_stat.h>#include <linux/cgroup.h>#include <linux/perf_event.h>#include <linux/trace_events.h>#include <linux/hw_breakpoint.h>#include <linux/mm_types.h>#include <linux/module.h>#include <linux/mman.h>#include <linux/compat.h>#include <linux/bpf.h>#include <linux/filter.h>#include <linux/namei.h>#include <linux/parser.h>#include <linux/sched/clock.h>#include <linux/sched/mm.h>#include <linux/proc_ns.h>#include <linux/mount.h>#include <linux/min_heap.h>#include <linux/highmem.h>#include <linux/pgtable.h>#include <linux/buildid.h>#include <linux/task_work.h>#include <linux/percpu-rwsem.h>#include <linux/unwind_deferred.h>#include <linux/kvm_types.h>#include <linux/seq_file.h>
#include "internal.h"
#include <asm/irq_regs.h>
typedef int (*remote_function_f)(void *);
struct remote_function_call { struct task_struct *p; remote_function_f func; void *info; int ret;};
static void remote_function(void *data){ struct remote_function_call *tfc = data; struct task_struct *p = tfc->p;
if (p) { /* -EAGAIN */ if (task_cpu(p) != smp_processor_id()) return;
/* * Now that we're on right CPU with IRQs disabled, we can test * if we hit the right task without races. */
tfc->ret = -ESRCH; /* No such (running) process */ if (p != current) return; }
tfc->ret = tfc->func(tfc->info);}
/** * task_function_call - call a function on the cpu on which a task runs * @p: the task to evaluate * @func: the function to be called * @info: the function call argument * * Calls the function @func when the task is currently running. This might * be on the current CPU, which just calls the function directly. This will * retry due to any failures in smp_call_function_single(), such as if the * task_cpu() goes offline concurrently. * * returns @func return value or -ESRCH or -ENXIO when the process isn't running */static inttask_function_call(struct task_struct *p, remote_function_f func, void *info){ struct remote_function_call data = { .p = p, .func = func, .info = info, .ret = -EAGAIN, }; int ret;
for (;;) { ret = smp_call_function_single(task_cpu(p), remote_function, &data, 1); if (!ret) ret = data.ret;
if (ret != -EAGAIN) break;
cond_resched(); }
return ret;}
/** * cpu_function_call - call a function on the cpu * @cpu: target cpu to queue this function * @func: the function to be called * @info: the function call argument * * Calls the function @func on the remote cpu. * * returns: @func return value or -ENXIO when the cpu is offline */static int cpu_function_call(int cpu, remote_function_f func, void *info){ struct remote_function_call data = { .p = NULL, .func = func, .info = info, .ret = -ENXIO, /* No such CPU */ };
smp_call_function_single(cpu, remote_function, &data, 1);
return data.ret;}
enum event_type_t { EVENT_FLEXIBLE = 0x01, EVENT_PINNED = 0x02, EVENT_TIME = 0x04, EVENT_FROZEN = 0x08, /* see ctx_resched() for details */ EVENT_CPU = 0x10, EVENT_CGROUP = 0x20,
/* * EVENT_GUEST is set when scheduling in/out events between the host * and a guest with a mediated vPMU. Among other things, EVENT_GUEST * is used: * * - In for_each_epc() to skip PMUs that don't support events in a * MEDIATED_VPMU guest, i.e. don't need to be context switched. * - To indicate the start/end point of the events in a guest. Guest * running time is deducted for host-only (exclude_guest) events. */ EVENT_GUEST = 0x40, EVENT_FLAGS = EVENT_CGROUP | EVENT_GUEST, /* compound helpers */ EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED, EVENT_TIME_FROZEN = EVENT_TIME | EVENT_FROZEN,};
static inline void __perf_ctx_lock(struct perf_event_context *ctx){ raw_spin_lock(&ctx->lock); WARN_ON_ONCE(ctx->is_active & EVENT_FROZEN);}
static void perf_ctx_lock(struct perf_cpu_context *cpuctx, struct perf_event_context *ctx){ __perf_ctx_lock(&cpuctx->ctx); if (ctx) __perf_ctx_lock(ctx);}
static inline void __perf_ctx_unlock(struct perf_event_context *ctx){ /* * If ctx_sched_in() didn't again set any ALL flags, clean up * after ctx_sched_out() by clearing is_active. */ if (ctx->is_active & EVENT_FROZEN) { if (!(ctx->is_active & EVENT_ALL)) ctx->is_active = 0; else ctx->is_active &= ~EVENT_FROZEN; } raw_spin_unlock(&ctx->lock);}
static void perf_ctx_unlock(struct perf_cpu_context *cpuctx, struct perf_event_context *ctx){ if (ctx) __perf_ctx_unlock(ctx); __perf_ctx_unlock(&cpuctx->ctx);}
typedef struct { struct perf_cpu_context *cpuctx; struct perf_event_context *ctx;} class_perf_ctx_lock_t;
static inline void class_perf_ctx_lock_destructor(class_perf_ctx_lock_t *_T){ perf_ctx_unlock(_T->cpuctx, _T->ctx); }
static inline class_perf_ctx_lock_tclass_perf_ctx_lock_constructor(struct perf_cpu_context *cpuctx, struct perf_event_context *ctx){ perf_ctx_lock(cpuctx, ctx); return (class_perf_ctx_lock_t){ cpuctx, ctx }; }
#define TASK_TOMBSTONE ((void *)-1L)
static bool is_kernel_event(struct perf_event *event){ return READ_ONCE(event->owner) == TASK_TOMBSTONE;}
static DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context);
struct perf_event_context *perf_cpu_task_ctx(void){ lockdep_assert_irqs_disabled(); return this_cpu_ptr(&perf_cpu_context)->task_ctx;}
/* * On task ctx scheduling... * * When !ctx->nr_events a task context will not be scheduled. This means * we can disable the scheduler hooks (for performance) without leaving * pending task ctx state. * * This however results in two special cases: * * - removing the last event from a task ctx; this is relatively straight * forward and is done in __perf_remove_from_context. * * - adding the first event to a task ctx; this is tricky because we cannot * rely on ctx->is_active and therefore cannot use event_function_call(). * See perf_install_in_context(). * * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set. */
typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *, struct perf_event_context *, void *);
struct event_function_struct { struct perf_event *event; event_f func; void *data;};
static int event_function(void *info){ struct event_function_struct *efs = info; struct perf_event *event = efs->event; struct perf_event_context *ctx = event->ctx; struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct perf_event_context *task_ctx = cpuctx->task_ctx; int ret = 0;
lockdep_assert_irqs_disabled();
perf_ctx_lock(cpuctx, task_ctx); /* * Since we do the IPI call without holding ctx->lock things can have * changed, double check we hit the task we set out to hit. */ if (ctx->task) { if (ctx->task != current) { ret = -ESRCH; goto unlock; }
/* * We only use event_function_call() on established contexts, * and event_function() is only ever called when active (or * rather, we'll have bailed in task_function_call() or the * above ctx->task != current test), therefore we must have * ctx->is_active here. */ WARN_ON_ONCE(!ctx->is_active); /* * And since we have ctx->is_active, cpuctx->task_ctx must * match. */ WARN_ON_ONCE(task_ctx != ctx); } else { WARN_ON_ONCE(&cpuctx->ctx != ctx); }
efs->func(event, cpuctx, ctx, efs->data);unlock: perf_ctx_unlock(cpuctx, task_ctx);
return ret;}
static void event_function_call(struct perf_event *event, event_f func, void *data){ struct perf_event_context *ctx = event->ctx; struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */ struct perf_cpu_context *cpuctx; struct event_function_struct efs = { .event = event, .func = func, .data = data, };
if (!event->parent) { /* * If this is a !child event, we must hold ctx::mutex to * stabilize the event->ctx relation. See * perf_event_ctx_lock(). */ lockdep_assert_held(&ctx->mutex); }
if (!task) { cpu_function_call(event->cpu, event_function, &efs); return; }
if (task == TASK_TOMBSTONE) return;
again: if (!task_function_call(task, event_function, &efs)) return;
local_irq_disable(); cpuctx = this_cpu_ptr(&perf_cpu_context); perf_ctx_lock(cpuctx, ctx); /* * Reload the task pointer, it might have been changed by * a concurrent perf_event_context_sched_out(). */ task = ctx->task; if (task == TASK_TOMBSTONE) goto unlock; if (ctx->is_active) { perf_ctx_unlock(cpuctx, ctx); local_irq_enable(); goto again; } func(event, NULL, ctx, data);unlock: perf_ctx_unlock(cpuctx, ctx); local_irq_enable();}
/* * Similar to event_function_call() + event_function(), but hard assumes IRQs * are already disabled and we're on the right CPU. */static void event_function_local(struct perf_event *event, event_f func, void *data){ struct perf_event_context *ctx = event->ctx; struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct task_struct *task = READ_ONCE(ctx->task); struct perf_event_context *task_ctx = NULL;
lockdep_assert_irqs_disabled();
if (task) { if (task == TASK_TOMBSTONE) return;
task_ctx = ctx; }
perf_ctx_lock(cpuctx, task_ctx);
task = ctx->task; if (task == TASK_TOMBSTONE) goto unlock;
if (task) { /* * We must be either inactive or active and the right task, * otherwise we're screwed, since we cannot IPI to somewhere * else. */ if (ctx->is_active) { if (WARN_ON_ONCE(task != current)) goto unlock;
if (WARN_ON_ONCE(cpuctx->task_ctx != ctx)) goto unlock; } } else { WARN_ON_ONCE(&cpuctx->ctx != ctx); }
func(event, cpuctx, ctx, data);unlock: perf_ctx_unlock(cpuctx, task_ctx);}
#define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\ PERF_FLAG_FD_OUTPUT |\ PERF_FLAG_PID_CGROUP |\ PERF_FLAG_FD_CLOEXEC)
/* * branch priv levels that need permission checks */#define PERF_SAMPLE_BRANCH_PERM_PLM \ (PERF_SAMPLE_BRANCH_KERNEL |\ PERF_SAMPLE_BRANCH_HV)
/* * perf_sched_events : >0 events exist */
static void perf_sched_delayed(struct work_struct *work);DEFINE_STATIC_KEY_FALSE(perf_sched_events);static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed);static DEFINE_MUTEX(perf_sched_mutex);static atomic_t perf_sched_count;
static DEFINE_PER_CPU(struct pmu_event_list, pmu_sb_events);
static atomic_t nr_mmap_events __read_mostly;static atomic_t nr_comm_events __read_mostly;static atomic_t nr_namespaces_events __read_mostly;static atomic_t nr_task_events __read_mostly;static atomic_t nr_freq_events __read_mostly;static atomic_t nr_switch_events __read_mostly;static atomic_t nr_ksymbol_events __read_mostly;static atomic_t nr_bpf_events __read_mostly;static atomic_t nr_cgroup_events __read_mostly;static atomic_t nr_text_poke_events __read_mostly;static atomic_t nr_build_id_events __read_mostly;
static LIST_HEAD(pmus);static DEFINE_MUTEX(pmus_lock);static struct srcu_struct pmus_srcu;static cpumask_var_t perf_online_mask;static cpumask_var_t perf_online_core_mask;static cpumask_var_t perf_online_die_mask;static cpumask_var_t perf_online_cluster_mask;static cpumask_var_t perf_online_pkg_mask;static cpumask_var_t perf_online_sys_mask;static struct kmem_cache *perf_event_cache;
#ifdef CONFIG_PERF_GUEST_MEDIATED_PMUstatic DEFINE_PER_CPU(bool, guest_ctx_loaded);
static __always_inline bool is_guest_mediated_pmu_loaded(void){ return __this_cpu_read(guest_ctx_loaded);}#elsestatic __always_inline bool is_guest_mediated_pmu_loaded(void){ return false;}#endif
/* * perf event paranoia level: * -1 - not paranoid at all * 0 - disallow raw tracepoint access for unpriv * 1 - disallow cpu events for unpriv * 2 - disallow kernel profiling for unpriv */int sysctl_perf_event_paranoid __read_mostly = 2;
/* Minimum for 512 kiB + 1 user control page. 'free' kiB per user. */static int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024);
/* * max perf event sample rate */#define DEFAULT_MAX_SAMPLE_RATE 100000#define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)#define DEFAULT_CPU_TIME_MAX_PERCENT 25
int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE;static int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT;
static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ);static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS;
static int perf_sample_allowed_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100;
static void update_perf_cpu_limits(void){ u64 tmp = perf_sample_period_ns;
tmp *= sysctl_perf_cpu_time_max_percent; tmp = div_u64(tmp, 100); if (!tmp) tmp = 1;
WRITE_ONCE(perf_sample_allowed_ns, tmp);}
static bool perf_rotate_context(struct perf_cpu_pmu_context *cpc);
static int perf_event_max_sample_rate_handler(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos){ int ret; int perf_cpu = sysctl_perf_cpu_time_max_percent; /* * If throttling is disabled don't allow the write: */ if (write && (perf_cpu == 100 || perf_cpu == 0)) return -EINVAL;
ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); if (ret || !write) return ret;
max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ); perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate; update_perf_cpu_limits();
return 0;}
static int perf_cpu_time_max_percent_handler(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos){ int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (ret || !write) return ret;
if (sysctl_perf_cpu_time_max_percent == 100 || sysctl_perf_cpu_time_max_percent == 0) { printk(KERN_WARNING "perf: Dynamic interrupt throttling disabled, can hang your system!\n"); WRITE_ONCE(perf_sample_allowed_ns, 0); } else { update_perf_cpu_limits(); }
return 0;}
static const struct ctl_table events_core_sysctl_table[] = { /* * User-space relies on this file as a feature check for * perf_events being enabled. It's an ABI, do not remove! */ { .procname = "perf_event_paranoid", .data = &sysctl_perf_event_paranoid, .maxlen = sizeof(sysctl_perf_event_paranoid), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "perf_event_mlock_kb", .data = &sysctl_perf_event_mlock, .maxlen = sizeof(sysctl_perf_event_mlock), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "perf_event_max_sample_rate", .data = &sysctl_perf_event_sample_rate, .maxlen = sizeof(sysctl_perf_event_sample_rate), .mode = 0644, .proc_handler = perf_event_max_sample_rate_handler, .extra1 = SYSCTL_ONE, }, { .procname = "perf_cpu_time_max_percent", .data = &sysctl_perf_cpu_time_max_percent, .maxlen = sizeof(sysctl_perf_cpu_time_max_percent), .mode = 0644, .proc_handler = perf_cpu_time_max_percent_handler, .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_ONE_HUNDRED, },};
static int __init init_events_core_sysctls(void){ register_sysctl_init("kernel", events_core_sysctl_table); return 0;}core_initcall(init_events_core_sysctls);
/* * perf samples are done in some very critical code paths (NMIs). * If they take too much CPU time, the system can lock up and not * get any real work done. This will drop the sample rate when * we detect that events are taking too long. */#define NR_ACCUMULATED_SAMPLES 128static DEFINE_PER_CPU(u64, running_sample_length);
static u64 __report_avg;static u64 __report_allowed;
static void perf_duration_warn(struct irq_work *w){ printk_ratelimited(KERN_INFO "perf: interrupt took too long (%lld > %lld), lowering " "kernel.perf_event_max_sample_rate to %d\n", __report_avg, __report_allowed, sysctl_perf_event_sample_rate);}
static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn);
void perf_sample_event_took(u64 sample_len_ns){ u64 max_len = READ_ONCE(perf_sample_allowed_ns); u64 running_len; u64 avg_len; u32 max;
if (max_len == 0) return;
/* Decay the counter by 1 average sample. */ running_len = __this_cpu_read(running_sample_length); running_len -= running_len/NR_ACCUMULATED_SAMPLES; running_len += sample_len_ns; __this_cpu_write(running_sample_length, running_len);
/* * Note: this will be biased artificially low until we have * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us * from having to maintain a count. */ avg_len = running_len/NR_ACCUMULATED_SAMPLES; if (avg_len <= max_len) return;
__report_avg = avg_len; __report_allowed = max_len;
/* * Compute a throttle threshold 25% below the current duration. */ avg_len += avg_len / 4; max = (TICK_NSEC / 100) * sysctl_perf_cpu_time_max_percent; if (avg_len < max) max /= (u32)avg_len; else max = 1;
WRITE_ONCE(perf_sample_allowed_ns, avg_len); WRITE_ONCE(max_samples_per_tick, max);
sysctl_perf_event_sample_rate = max * HZ; perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
if (!irq_work_queue(&perf_duration_work)) { early_printk("perf: interrupt took too long (%lld > %lld), lowering " "kernel.perf_event_max_sample_rate to %d\n", __report_avg, __report_allowed, sysctl_perf_event_sample_rate); }}
static atomic64_t perf_event_id;
static void update_context_time(struct perf_event_context *ctx);static u64 perf_event_time(struct perf_event *event);
void __weak perf_event_print_debug(void) { }
static inline u64 perf_clock(void){ return local_clock();}
static inline u64 perf_event_clock(struct perf_event *event){ return event->clock();}
/* * State based event timekeeping... * * The basic idea is to use event->state to determine which (if any) time * fields to increment with the current delta. This means we only need to * update timestamps when we change state or when they are explicitly requested * (read). * * Event groups make things a little more complicated, but not terribly so. The * rules for a group are that if the group leader is OFF the entire group is * OFF, irrespective of what the group member states are. This results in * __perf_effective_state(). * * A further ramification is that when a group leader flips between OFF and * !OFF, we need to update all group member times. * * * NOTE: perf_event_time() is based on the (cgroup) context time, and thus we * need to make sure the relevant context time is updated before we try and * update our timestamps. */
static __always_inline enum perf_event_state__perf_effective_state(struct perf_event *event){ struct perf_event *leader = event->group_leader;
if (leader->state <= PERF_EVENT_STATE_OFF) return leader->state;
return event->state;}
static __always_inline void__perf_update_times(struct perf_event *event, u64 now, u64 *enabled, u64 *running){ enum perf_event_state state = __perf_effective_state(event); u64 delta = now - event->tstamp;
*enabled = event->total_time_enabled; if (state >= PERF_EVENT_STATE_INACTIVE) *enabled += delta;
*running = event->total_time_running; if (state >= PERF_EVENT_STATE_ACTIVE) *running += delta;}
static void perf_event_update_time(struct perf_event *event){ u64 now = perf_event_time(event);
__perf_update_times(event, now, &event->total_time_enabled, &event->total_time_running); event->tstamp = now;}
static void perf_event_update_sibling_time(struct perf_event *leader){ struct perf_event *sibling;
for_each_sibling_event(sibling, leader) perf_event_update_time(sibling);}
static voidperf_event_set_state(struct perf_event *event, enum perf_event_state state){ if (event->state == state) return;
perf_event_update_time(event); /* * If a group leader gets enabled/disabled all its siblings * are affected too. */ if ((event->state < 0) ^ (state < 0)) perf_event_update_sibling_time(event);
WRITE_ONCE(event->state, state);}
/* * UP store-release, load-acquire */
#define __store_release(ptr, val) \do { \ barrier(); \ WRITE_ONCE(*(ptr), (val)); \} while (0)
#define __load_acquire(ptr) \({ \ __unqual_scalar_typeof(*(ptr)) ___p = READ_ONCE(*(ptr)); \ barrier(); \ ___p; \})
static bool perf_skip_pmu_ctx(struct perf_event_pmu_context *pmu_ctx, enum event_type_t event_type){ if ((event_type & EVENT_CGROUP) && !pmu_ctx->nr_cgroups) return true; if ((event_type & EVENT_GUEST) && !(pmu_ctx->pmu->capabilities & PERF_PMU_CAP_MEDIATED_VPMU)) return true; return false;}
#define for_each_epc(_epc, _ctx, _pmu, _event_type) \ list_for_each_entry(_epc, &((_ctx)->pmu_ctx_list), pmu_ctx_entry) \ if (perf_skip_pmu_ctx(_epc, _event_type)) \ continue; \ else if (_pmu && _epc->pmu != _pmu) \ continue; \ else
static void perf_ctx_disable(struct perf_event_context *ctx, enum event_type_t event_type){ struct perf_event_pmu_context *pmu_ctx;
for_each_epc(pmu_ctx, ctx, NULL, event_type) perf_pmu_disable(pmu_ctx->pmu);}
static void perf_ctx_enable(struct perf_event_context *ctx, enum event_type_t event_type){ struct perf_event_pmu_context *pmu_ctx;
for_each_epc(pmu_ctx, ctx, NULL, event_type) perf_pmu_enable(pmu_ctx->pmu);}
static void ctx_sched_out(struct perf_event_context *ctx, struct pmu *pmu, enum event_type_t event_type);static void ctx_sched_in(struct perf_event_context *ctx, struct pmu *pmu, enum event_type_t event_type);
static inline void update_perf_time_ctx(struct perf_time_ctx *time, u64 now, bool adv){ if (adv) time->time += now - time->stamp; time->stamp = now;
/* * The above: time' = time + (now - timestamp), can be re-arranged * into: time` = now + (time - timestamp), which gives a single value * offset to compute future time without locks on. * * See perf_event_time_now(), which can be used from NMI context where * it's (obviously) not possible to acquire ctx->lock in order to read * both the above values in a consistent manner. */ WRITE_ONCE(time->offset, time->time - time->stamp);}
static_assert(offsetof(struct perf_event_context, timeguest) - offsetof(struct perf_event_context, time) == sizeof(struct perf_time_ctx));
#define T_TOTAL 0#define T_GUEST 1
static inline u64 __perf_event_time_ctx(struct perf_event *event, struct perf_time_ctx *times){ u64 time = times[T_TOTAL].time;
if (event->attr.exclude_guest) time -= times[T_GUEST].time;
return time;}
static inline u64 __perf_event_time_ctx_now(struct perf_event *event, struct perf_time_ctx *times, u64 now){ if (is_guest_mediated_pmu_loaded() && event->attr.exclude_guest) { /* * (now + times[total].offset) - (now + times[guest].offset) := * times[total].offset - times[guest].offset */ return READ_ONCE(times[T_TOTAL].offset) - READ_ONCE(times[T_GUEST].offset); }
return now + READ_ONCE(times[T_TOTAL].offset);}
#ifdef CONFIG_CGROUP_PERF
static inline boolperf_cgroup_match(struct perf_event *event){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
/* @event doesn't care about cgroup */ if (!event->cgrp) return true;
/* wants specific cgroup scope but @cpuctx isn't associated with any */ if (!cpuctx->cgrp) return false;
/* * Cgroup scoping is recursive. An event enabled for a cgroup is * also enabled for all its descendant cgroups. If @cpuctx's * cgroup is a descendant of @event's (the test covers identity * case), it's a match. */ return cgroup_is_descendant(cpuctx->cgrp->css.cgroup, event->cgrp->css.cgroup);}
static inline void perf_detach_cgroup(struct perf_event *event){ css_put(&event->cgrp->css); event->cgrp = NULL;}
static inline int is_cgroup_event(struct perf_event *event){ return event->cgrp != NULL;}
static_assert(offsetof(struct perf_cgroup_info, timeguest) - offsetof(struct perf_cgroup_info, time) == sizeof(struct perf_time_ctx));
static inline u64 perf_cgroup_event_time(struct perf_event *event){ struct perf_cgroup_info *t;
t = per_cpu_ptr(event->cgrp->info, event->cpu); return __perf_event_time_ctx(event, &t->time);}
static inline u64 perf_cgroup_event_time_now(struct perf_event *event, u64 now){ struct perf_cgroup_info *t;
t = per_cpu_ptr(event->cgrp->info, event->cpu); if (!__load_acquire(&t->active)) return __perf_event_time_ctx(event, &t->time);
return __perf_event_time_ctx_now(event, &t->time, now);}
static inline void __update_cgrp_guest_time(struct perf_cgroup_info *info, u64 now, bool adv){ update_perf_time_ctx(&info->timeguest, now, adv);}
static inline void update_cgrp_time(struct perf_cgroup_info *info, u64 now){ update_perf_time_ctx(&info->time, now, true); if (is_guest_mediated_pmu_loaded()) __update_cgrp_guest_time(info, now, true);}
static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx, bool final){ struct perf_cgroup *cgrp = cpuctx->cgrp; struct cgroup_subsys_state *css; struct perf_cgroup_info *info;
if (cgrp) { u64 now = perf_clock();
for (css = &cgrp->css; css; css = css->parent) { cgrp = container_of(css, struct perf_cgroup, css); info = this_cpu_ptr(cgrp->info);
update_cgrp_time(info, now); if (final) __store_release(&info->active, 0); } }}
static inline void update_cgrp_time_from_event(struct perf_event *event){ struct perf_cgroup_info *info;
/* * ensure we access cgroup data only when needed and * when we know the cgroup is pinned (css_get) */ if (!is_cgroup_event(event)) return;
info = this_cpu_ptr(event->cgrp->info); /* * Do not update time when cgroup is not active */ if (info->active) update_cgrp_time(info, perf_clock());}
static inline voidperf_cgroup_set_timestamp(struct perf_cpu_context *cpuctx, bool guest){ struct perf_event_context *ctx = &cpuctx->ctx; struct perf_cgroup *cgrp = cpuctx->cgrp; struct perf_cgroup_info *info; struct cgroup_subsys_state *css;
/* * ctx->lock held by caller * ensure we do not access cgroup data * unless we have the cgroup pinned (css_get) */ if (!cgrp) return;
WARN_ON_ONCE(!ctx->nr_cgroups);
for (css = &cgrp->css; css; css = css->parent) { cgrp = container_of(css, struct perf_cgroup, css); info = this_cpu_ptr(cgrp->info); if (guest) { __update_cgrp_guest_time(info, ctx->time.stamp, false); } else { update_perf_time_ctx(&info->time, ctx->time.stamp, false); __store_release(&info->active, 1); } }}
/* * reschedule events based on the cgroup constraint of task. */static void perf_cgroup_switch(struct task_struct *task){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct perf_cgroup *cgrp;
/* * cpuctx->cgrp is set when the first cgroup event enabled, * and is cleared when the last cgroup event disabled. */ if (READ_ONCE(cpuctx->cgrp) == NULL) return;
cgrp = perf_cgroup_from_task(task, NULL); if (READ_ONCE(cpuctx->cgrp) == cgrp) return;
guard(perf_ctx_lock)(cpuctx, cpuctx->task_ctx); /* * Re-check, could've raced vs perf_remove_from_context(). */ if (READ_ONCE(cpuctx->cgrp) == NULL) return;
WARN_ON_ONCE(cpuctx->ctx.nr_cgroups == 0); perf_ctx_disable(&cpuctx->ctx, EVENT_CGROUP);
ctx_sched_out(&cpuctx->ctx, NULL, EVENT_ALL|EVENT_CGROUP); /* * must not be done before ctxswout due * to update_cgrp_time_from_cpuctx() in * ctx_sched_out() */ cpuctx->cgrp = cgrp; /* * set cgrp before ctxsw in to allow * perf_cgroup_set_timestamp() in ctx_sched_in() * to not have to pass task around */ ctx_sched_in(&cpuctx->ctx, NULL, EVENT_ALL|EVENT_CGROUP);
perf_ctx_enable(&cpuctx->ctx, EVENT_CGROUP);}
static int perf_cgroup_ensure_storage(struct perf_event *event, struct cgroup_subsys_state *css){ struct perf_cpu_context *cpuctx; struct perf_event **storage; int cpu, heap_size, ret = 0;
/* * Allow storage to have sufficient space for an iterator for each * possibly nested cgroup plus an iterator for events with no cgroup. */ for (heap_size = 1; css; css = css->parent) heap_size++;
for_each_possible_cpu(cpu) { cpuctx = per_cpu_ptr(&perf_cpu_context, cpu); if (heap_size <= cpuctx->heap_size) continue;
storage = kmalloc_node(heap_size * sizeof(struct perf_event *), GFP_KERNEL, cpu_to_node(cpu)); if (!storage) { ret = -ENOMEM; break; }
raw_spin_lock_irq(&cpuctx->ctx.lock); if (cpuctx->heap_size < heap_size) { swap(cpuctx->heap, storage); if (storage == cpuctx->heap_default) storage = NULL; cpuctx->heap_size = heap_size; } raw_spin_unlock_irq(&cpuctx->ctx.lock);
kfree(storage); }
return ret;}
static inline int perf_cgroup_connect(int fd, struct perf_event *event, struct perf_event_attr *attr, struct perf_event *group_leader){ struct perf_cgroup *cgrp; struct cgroup_subsys_state *css; CLASS(fd, f)(fd); int ret = 0;
if (fd_empty(f)) return -EBADF;
css = css_tryget_online_from_dir(fd_file(f)->f_path.dentry, &perf_event_cgrp_subsys); if (IS_ERR(css)) return PTR_ERR(css);
ret = perf_cgroup_ensure_storage(event, css); if (ret) return ret;
cgrp = container_of(css, struct perf_cgroup, css); event->cgrp = cgrp;
/* * all events in a group must monitor * the same cgroup because a task belongs * to only one perf cgroup at a time */ if (group_leader && group_leader->cgrp != cgrp) { perf_detach_cgroup(event); ret = -EINVAL; } return ret;}
static inline voidperf_cgroup_event_enable(struct perf_event *event, struct perf_event_context *ctx){ struct perf_cpu_context *cpuctx;
if (!is_cgroup_event(event)) return;
event->pmu_ctx->nr_cgroups++;
/* * Because cgroup events are always per-cpu events, * @ctx == &cpuctx->ctx. */ cpuctx = container_of(ctx, struct perf_cpu_context, ctx);
if (ctx->nr_cgroups++) return;
cpuctx->cgrp = perf_cgroup_from_task(current, ctx);}
static inline voidperf_cgroup_event_disable(struct perf_event *event, struct perf_event_context *ctx){ struct perf_cpu_context *cpuctx;
if (!is_cgroup_event(event)) return;
event->pmu_ctx->nr_cgroups--;
/* * Because cgroup events are always per-cpu events, * @ctx == &cpuctx->ctx. */ cpuctx = container_of(ctx, struct perf_cpu_context, ctx);
if (--ctx->nr_cgroups) return;
cpuctx->cgrp = NULL;}
#else /* !CONFIG_CGROUP_PERF */
static inline boolperf_cgroup_match(struct perf_event *event){ return true;}
static inline void perf_detach_cgroup(struct perf_event *event){}
static inline int is_cgroup_event(struct perf_event *event){ return 0;}
static inline void update_cgrp_time_from_event(struct perf_event *event){}
static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx, bool final){}
static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, struct perf_event_attr *attr, struct perf_event *group_leader){ return -EINVAL;}
static inline voidperf_cgroup_set_timestamp(struct perf_cpu_context *cpuctx, bool guest){}
static inline u64 perf_cgroup_event_time(struct perf_event *event){ return 0;}
static inline u64 perf_cgroup_event_time_now(struct perf_event *event, u64 now){ return 0;}
static inline voidperf_cgroup_event_enable(struct perf_event *event, struct perf_event_context *ctx){}
static inline voidperf_cgroup_event_disable(struct perf_event *event, struct perf_event_context *ctx){}
static void perf_cgroup_switch(struct task_struct *task){}#endif
/* * set default to be dependent on timer tick just * like original code */#define PERF_CPU_HRTIMER (1000 / HZ)/* * function must be called with interrupts disabled */static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr){ struct perf_cpu_pmu_context *cpc; bool rotations;
lockdep_assert_irqs_disabled();
cpc = container_of(hr, struct perf_cpu_pmu_context, hrtimer); rotations = perf_rotate_context(cpc);
raw_spin_lock(&cpc->hrtimer_lock); if (rotations) hrtimer_forward_now(hr, cpc->hrtimer_interval); else cpc->hrtimer_active = 0; raw_spin_unlock(&cpc->hrtimer_lock);
return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART;}
static void __perf_mux_hrtimer_init(struct perf_cpu_pmu_context *cpc, int cpu){ struct hrtimer *timer = &cpc->hrtimer; struct pmu *pmu = cpc->epc.pmu; u64 interval;
/* * check default is sane, if not set then force to * default interval (1/tick) */ interval = pmu->hrtimer_interval_ms; if (interval < 1) interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER;
cpc->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);
raw_spin_lock_init(&cpc->hrtimer_lock); hrtimer_setup(timer, perf_mux_hrtimer_handler, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);}
static int perf_mux_hrtimer_restart(struct perf_cpu_pmu_context *cpc){ struct hrtimer *timer = &cpc->hrtimer; unsigned long flags;
raw_spin_lock_irqsave(&cpc->hrtimer_lock, flags); if (!cpc->hrtimer_active) { cpc->hrtimer_active = 1; hrtimer_forward_now(timer, cpc->hrtimer_interval); hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED_HARD); } raw_spin_unlock_irqrestore(&cpc->hrtimer_lock, flags);
return 0;}
static int perf_mux_hrtimer_restart_ipi(void *arg){ return perf_mux_hrtimer_restart(arg);}
static __always_inline struct perf_cpu_pmu_context *this_cpc(struct pmu *pmu){ return *this_cpu_ptr(pmu->cpu_pmu_context);}
void perf_pmu_disable(struct pmu *pmu){ int *count = &this_cpc(pmu)->pmu_disable_count; if (!(*count)++) pmu->pmu_disable(pmu);}
void perf_pmu_enable(struct pmu *pmu){ int *count = &this_cpc(pmu)->pmu_disable_count; if (!--(*count)) pmu->pmu_enable(pmu);}
static void perf_assert_pmu_disabled(struct pmu *pmu){ int *count = &this_cpc(pmu)->pmu_disable_count; WARN_ON_ONCE(*count == 0);}
static inline void perf_pmu_read(struct perf_event *event){ if (event->state == PERF_EVENT_STATE_ACTIVE) event->pmu->read(event);}
static void get_ctx(struct perf_event_context *ctx){ refcount_inc(&ctx->refcount);}
static void free_ctx(struct rcu_head *head){ struct perf_event_context *ctx;
ctx = container_of(head, struct perf_event_context, rcu_head); kfree(ctx);}
static void put_ctx(struct perf_event_context *ctx){ if (refcount_dec_and_test(&ctx->refcount)) { if (ctx->parent_ctx) put_ctx(ctx->parent_ctx); if (ctx->task && ctx->task != TASK_TOMBSTONE) put_task_struct(ctx->task); call_rcu(&ctx->rcu_head, free_ctx); } else { smp_mb__after_atomic(); /* pairs with wait_var_event() */ if (ctx->task == TASK_TOMBSTONE) wake_up_var(&ctx->refcount); }}
/* * Because of perf_event::ctx migration in sys_perf_event_open::move_group and * perf_pmu_migrate_context() we need some magic. * * Those places that change perf_event::ctx will hold both * perf_event_ctx::mutex of the 'old' and 'new' ctx value. * * Lock ordering is by mutex address. There are two other sites where * perf_event_context::mutex nests and those are: * * - perf_event_exit_task_context() [ child , 0 ] * perf_event_exit_event() * put_event() [ parent, 1 ] * * - perf_event_init_context() [ parent, 0 ] * inherit_task_group() * inherit_group() * inherit_event() * perf_event_alloc() * perf_init_event() * perf_try_init_event() [ child , 1 ] * * While it appears there is an obvious deadlock here -- the parent and child * nesting levels are inverted between the two. This is in fact safe because * life-time rules separate them. That is an exiting task cannot fork, and a * spawning task cannot (yet) exit. * * But remember that these are parent<->child context relations, and * migration does not affect children, therefore these two orderings should not * interact. * * The change in perf_event::ctx does not affect children (as claimed above) * because the sys_perf_event_open() case will install a new event and break * the ctx parent<->child relation, and perf_pmu_migrate_context() is only * concerned with cpuctx and that doesn't have children. * * The places that change perf_event::ctx will issue: * * perf_remove_from_context(); * synchronize_rcu(); * perf_install_in_context(); * * to affect the change. The remove_from_context() + synchronize_rcu() should * quiesce the event, after which we can install it in the new location. This * means that only external vectors (perf_fops, prctl) can perturb the event * while in transit. Therefore all such accessors should also acquire * perf_event_context::mutex to serialize against this. * * However; because event->ctx can change while we're waiting to acquire * ctx->mutex we must be careful and use the below perf_event_ctx_lock() * function. * * Lock order: * exec_update_lock * task_struct::perf_event_mutex * perf_event_context::mutex * perf_event::child_mutex; * perf_event_context::lock * mmap_lock * perf_event::mmap_mutex * perf_buffer::aux_mutex * perf_addr_filters_head::lock * * cpu_hotplug_lock * pmus_lock * cpuctx->mutex / perf_event_context::mutex */static struct perf_event_context *perf_event_ctx_lock_nested(struct perf_event *event, int nesting){ struct perf_event_context *ctx;
again: rcu_read_lock(); ctx = READ_ONCE(event->ctx); if (!refcount_inc_not_zero(&ctx->refcount)) { rcu_read_unlock(); goto again; } rcu_read_unlock();
mutex_lock_nested(&ctx->mutex, nesting); if (event->ctx != ctx) { mutex_unlock(&ctx->mutex); put_ctx(ctx); goto again; }
return ctx;}
static inline struct perf_event_context *perf_event_ctx_lock(struct perf_event *event){ return perf_event_ctx_lock_nested(event, 0);}
static void perf_event_ctx_unlock(struct perf_event *event, struct perf_event_context *ctx){ mutex_unlock(&ctx->mutex); put_ctx(ctx);}
/* * This must be done under the ctx->lock, such as to serialize against * context_equiv(), therefore we cannot call put_ctx() since that might end up * calling scheduler related locks and ctx->lock nests inside those. */static __must_check struct perf_event_context *unclone_ctx(struct perf_event_context *ctx){ struct perf_event_context *parent_ctx = ctx->parent_ctx;
lockdep_assert_held(&ctx->lock);
if (parent_ctx) ctx->parent_ctx = NULL; ctx->generation++;
return parent_ctx;}
static u32 perf_event_pid_type(struct perf_event *event, struct task_struct *p, enum pid_type type){ u32 nr; /* * only top level events have the pid namespace they were created in */ if (event->parent) event = event->parent;
nr = __task_pid_nr_ns(p, type, event->ns); /* avoid -1 if it is idle thread or runs in another ns */ if (!nr && !pid_alive(p)) nr = -1; return nr;}
static u32 perf_event_pid(struct perf_event *event, struct task_struct *p){ return perf_event_pid_type(event, p, PIDTYPE_TGID);}
static u32 perf_event_tid(struct perf_event *event, struct task_struct *p){ return perf_event_pid_type(event, p, PIDTYPE_PID);}
/* * If we inherit events we want to return the parent event id * to userspace. */static u64 primary_event_id(struct perf_event *event){ u64 id = event->id;
if (event->parent) id = event->parent->id;
return id;}
/* * Get the perf_event_context for a task and lock it. * * This has to cope with the fact that until it is locked, * the context could get moved to another task. */static struct perf_event_context *perf_lock_task_context(struct task_struct *task, unsigned long *flags){ struct perf_event_context *ctx;
retry: /* * One of the few rules of preemptible RCU is that one cannot do * rcu_read_unlock() while holding a scheduler (or nested) lock when * part of the read side critical section was irqs-enabled -- see * rcu_read_unlock_special(). * * Since ctx->lock nests under rq->lock we must ensure the entire read * side critical section has interrupts disabled. */ local_irq_save(*flags); rcu_read_lock(); ctx = rcu_dereference(task->perf_event_ctxp); if (ctx) { /* * If this context is a clone of another, it might * get swapped for another underneath us by * perf_event_task_sched_out, though the * rcu_read_lock() protects us from any context * getting freed. Lock the context and check if it * got swapped before we could get the lock, and retry * if so. If we locked the right context, then it * can't get swapped on us any more. */ raw_spin_lock(&ctx->lock); if (ctx != rcu_dereference(task->perf_event_ctxp)) { raw_spin_unlock(&ctx->lock); rcu_read_unlock(); local_irq_restore(*flags); goto retry; }
if (ctx->task == TASK_TOMBSTONE || !refcount_inc_not_zero(&ctx->refcount)) { raw_spin_unlock(&ctx->lock); ctx = NULL; } else { WARN_ON_ONCE(ctx->task != task); } } rcu_read_unlock(); if (!ctx) local_irq_restore(*flags); return ctx;}
/* * Get the context for a task and increment its pin_count so it * can't get swapped to another task. This also increments its * reference count so that the context can't get freed. */static struct perf_event_context *perf_pin_task_context(struct task_struct *task){ struct perf_event_context *ctx; unsigned long flags;
ctx = perf_lock_task_context(task, &flags); if (ctx) { ++ctx->pin_count; raw_spin_unlock_irqrestore(&ctx->lock, flags); } return ctx;}
static void perf_unpin_context(struct perf_event_context *ctx){ unsigned long flags;
raw_spin_lock_irqsave(&ctx->lock, flags); --ctx->pin_count; raw_spin_unlock_irqrestore(&ctx->lock, flags);}
/* * Update the record of the current time in a context. */static void __update_context_time(struct perf_event_context *ctx, bool adv){ lockdep_assert_held(&ctx->lock);
update_perf_time_ctx(&ctx->time, perf_clock(), adv);}
static void __update_context_guest_time(struct perf_event_context *ctx, bool adv){ lockdep_assert_held(&ctx->lock);
/* must be called after __update_context_time(); */ update_perf_time_ctx(&ctx->timeguest, ctx->time.stamp, adv);}
static void update_context_time(struct perf_event_context *ctx){ __update_context_time(ctx, true); if (is_guest_mediated_pmu_loaded()) __update_context_guest_time(ctx, true);}
static u64 perf_event_time(struct perf_event *event){ struct perf_event_context *ctx = event->ctx;
if (unlikely(!ctx)) return 0;
if (is_cgroup_event(event)) return perf_cgroup_event_time(event);
return __perf_event_time_ctx(event, &ctx->time);}
static u64 perf_event_time_now(struct perf_event *event, u64 now){ struct perf_event_context *ctx = event->ctx;
if (unlikely(!ctx)) return 0;
if (is_cgroup_event(event)) return perf_cgroup_event_time_now(event, now);
if (!(__load_acquire(&ctx->is_active) & EVENT_TIME)) return __perf_event_time_ctx(event, &ctx->time);
return __perf_event_time_ctx_now(event, &ctx->time, now);}
static enum event_type_t get_event_type(struct perf_event *event){ struct perf_event_context *ctx = event->ctx; enum event_type_t event_type;
lockdep_assert_held(&ctx->lock);
/* * It's 'group type', really, because if our group leader is * pinned, so are we. */ if (event->group_leader != event) event = event->group_leader;
event_type = event->attr.pinned ? EVENT_PINNED : EVENT_FLEXIBLE; if (!ctx->task) event_type |= EVENT_CPU;
return event_type;}
/* * Helper function to initialize event group nodes. */static void init_event_group(struct perf_event *event){ RB_CLEAR_NODE(&event->group_node); event->group_index = 0;}
/* * Extract pinned or flexible groups from the context * based on event attrs bits. */static struct perf_event_groups *get_event_groups(struct perf_event *event, struct perf_event_context *ctx){ if (event->attr.pinned) return &ctx->pinned_groups; else return &ctx->flexible_groups;}
/* * Helper function to initializes perf_event_group trees. */static void perf_event_groups_init(struct perf_event_groups *groups){ groups->tree = RB_ROOT; groups->index = 0;}
static inline struct cgroup *event_cgroup(const struct perf_event *event){ struct cgroup *cgroup = NULL;
#ifdef CONFIG_CGROUP_PERF if (event->cgrp) cgroup = event->cgrp->css.cgroup;#endif
return cgroup;}
/* * Compare function for event groups; * * Implements complex key that first sorts by CPU and then by virtual index * which provides ordering when rotating groups for the same CPU. */static __always_inline intperf_event_groups_cmp(const int left_cpu, const struct pmu *left_pmu, const struct cgroup *left_cgroup, const u64 left_group_index, const struct perf_event *right){ if (left_cpu < right->cpu) return -1; if (left_cpu > right->cpu) return 1;
if (left_pmu) { if (left_pmu < right->pmu_ctx->pmu) return -1; if (left_pmu > right->pmu_ctx->pmu) return 1; }
#ifdef CONFIG_CGROUP_PERF { const struct cgroup *right_cgroup = event_cgroup(right);
if (left_cgroup != right_cgroup) { if (!left_cgroup) { /* * Left has no cgroup but right does, no * cgroups come first. */ return -1; } if (!right_cgroup) { /* * Right has no cgroup but left does, no * cgroups come first. */ return 1; } /* Two dissimilar cgroups, order by id. */ if (cgroup_id(left_cgroup) < cgroup_id(right_cgroup)) return -1;
return 1; } }#endif
if (left_group_index < right->group_index) return -1; if (left_group_index > right->group_index) return 1;
return 0;}
#define __node_2_pe(node) \ rb_entry((node), struct perf_event, group_node)
static inline bool __group_less(struct rb_node *a, const struct rb_node *b){ struct perf_event *e = __node_2_pe(a); return perf_event_groups_cmp(e->cpu, e->pmu_ctx->pmu, event_cgroup(e), e->group_index, __node_2_pe(b)) < 0;}
struct __group_key { int cpu; struct pmu *pmu; struct cgroup *cgroup;};
static inline int __group_cmp(const void *key, const struct rb_node *node){ const struct __group_key *a = key; const struct perf_event *b = __node_2_pe(node);
/* partial/subtree match: @cpu, @pmu, @cgroup; ignore: @group_index */ return perf_event_groups_cmp(a->cpu, a->pmu, a->cgroup, b->group_index, b);}
static inline int__group_cmp_ignore_cgroup(const void *key, const struct rb_node *node){ const struct __group_key *a = key; const struct perf_event *b = __node_2_pe(node);
/* partial/subtree match: @cpu, @pmu, ignore: @cgroup, @group_index */ return perf_event_groups_cmp(a->cpu, a->pmu, event_cgroup(b), b->group_index, b);}
/* * Insert @event into @groups' tree; using * {@event->cpu, @event->pmu_ctx->pmu, event_cgroup(@event), ++@groups->index} * as key. This places it last inside the {cpu,pmu,cgroup} subtree. */static voidperf_event_groups_insert(struct perf_event_groups *groups, struct perf_event *event){ event->group_index = ++groups->index;
rb_add(&event->group_node, &groups->tree, __group_less);}
/* * Helper function to insert event into the pinned or flexible groups. */static voidadd_event_to_groups(struct perf_event *event, struct perf_event_context *ctx){ struct perf_event_groups *groups;
groups = get_event_groups(event, ctx); perf_event_groups_insert(groups, event);}
/* * Delete a group from a tree. */static voidperf_event_groups_delete(struct perf_event_groups *groups, struct perf_event *event){ WARN_ON_ONCE(RB_EMPTY_NODE(&event->group_node) || RB_EMPTY_ROOT(&groups->tree));
rb_erase(&event->group_node, &groups->tree); init_event_group(event);}
/* * Helper function to delete event from its groups. */static voiddel_event_from_groups(struct perf_event *event, struct perf_event_context *ctx){ struct perf_event_groups *groups;
groups = get_event_groups(event, ctx); perf_event_groups_delete(groups, event);}
/* * Get the leftmost event in the {cpu,pmu,cgroup} subtree. */static struct perf_event *perf_event_groups_first(struct perf_event_groups *groups, int cpu, struct pmu *pmu, struct cgroup *cgrp){ struct __group_key key = { .cpu = cpu, .pmu = pmu, .cgroup = cgrp, }; struct rb_node *node;
node = rb_find_first(&key, &groups->tree, __group_cmp); if (node) return __node_2_pe(node);
return NULL;}
static struct perf_event *perf_event_groups_next(struct perf_event *event, struct pmu *pmu){ struct __group_key key = { .cpu = event->cpu, .pmu = pmu, .cgroup = event_cgroup(event), }; struct rb_node *next;
next = rb_next_match(&key, &event->group_node, __group_cmp); if (next) return __node_2_pe(next);
return NULL;}
#define perf_event_groups_for_cpu_pmu(event, groups, cpu, pmu) \ for (event = perf_event_groups_first(groups, cpu, pmu, NULL); \ event; event = perf_event_groups_next(event, pmu))
/* * Iterate through the whole groups tree. */#define perf_event_groups_for_each(event, groups) \ for (event = rb_entry_safe(rb_first(&((groups)->tree)), \ typeof(*event), group_node); event; \ event = rb_entry_safe(rb_next(&event->group_node), \ typeof(*event), group_node))
/* * Does the event attribute request inherit with PERF_SAMPLE_READ */static inline bool has_inherit_and_sample_read(struct perf_event_attr *attr){ return attr->inherit && (attr->sample_type & PERF_SAMPLE_READ);}
/* * Add an event from the lists for its context. * Must be called with ctx->mutex and ctx->lock held. */static voidlist_add_event(struct perf_event *event, struct perf_event_context *ctx){ lockdep_assert_held(&ctx->lock);
WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT); event->attach_state |= PERF_ATTACH_CONTEXT;
event->tstamp = perf_event_time(event);
/* * If we're a stand alone event or group leader, we go to the context * list, group events are kept attached to the group so that * perf_group_detach can, at all times, locate all siblings. */ if (event->group_leader == event) { event->group_caps = event->event_caps; add_event_to_groups(event, ctx); }
list_add_rcu(&event->event_entry, &ctx->event_list); ctx->nr_events++; if (event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT) ctx->nr_user++; if (event->attr.inherit_stat) ctx->nr_stat++; if (has_inherit_and_sample_read(&event->attr)) local_inc(&ctx->nr_no_switch_fast);
if (event->state > PERF_EVENT_STATE_OFF) perf_cgroup_event_enable(event, ctx);
ctx->generation++; event->pmu_ctx->nr_events++;}
/* * Initialize event state based on the perf_event_attr::disabled. */static inline void perf_event__state_init(struct perf_event *event){ event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF : PERF_EVENT_STATE_INACTIVE;}
static int __perf_event_read_size(u64 read_format, int nr_siblings){ int entry = sizeof(u64); /* value */ int size = 0; int nr = 1;
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) size += sizeof(u64);
if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) size += sizeof(u64);
if (read_format & PERF_FORMAT_ID) entry += sizeof(u64);
if (read_format & PERF_FORMAT_LOST) entry += sizeof(u64);
if (read_format & PERF_FORMAT_GROUP) { nr += nr_siblings; size += sizeof(u64); }
/* * Since perf_event_validate_size() limits this to 16k and inhibits * adding more siblings, this will never overflow. */ return size + nr * entry;}
static void __perf_event_header_size(struct perf_event *event, u64 sample_type){ struct perf_sample_data *data; u16 size = 0;
if (sample_type & PERF_SAMPLE_IP) size += sizeof(data->ip);
if (sample_type & PERF_SAMPLE_ADDR) size += sizeof(data->addr);
if (sample_type & PERF_SAMPLE_PERIOD) size += sizeof(data->period);
if (sample_type & PERF_SAMPLE_WEIGHT_TYPE) size += sizeof(data->weight.full);
if (sample_type & PERF_SAMPLE_READ) size += event->read_size;
if (sample_type & PERF_SAMPLE_DATA_SRC) size += sizeof(data->data_src.val);
if (sample_type & PERF_SAMPLE_TRANSACTION) size += sizeof(data->txn);
if (sample_type & PERF_SAMPLE_PHYS_ADDR) size += sizeof(data->phys_addr);
if (sample_type & PERF_SAMPLE_CGROUP) size += sizeof(data->cgroup);
if (sample_type & PERF_SAMPLE_DATA_PAGE_SIZE) size += sizeof(data->data_page_size);
if (sample_type & PERF_SAMPLE_CODE_PAGE_SIZE) size += sizeof(data->code_page_size);
event->header_size = size;}
/* * Called at perf_event creation and when events are attached/detached from a * group. */static void perf_event__header_size(struct perf_event *event){ event->read_size = __perf_event_read_size(event->attr.read_format, event->group_leader->nr_siblings); __perf_event_header_size(event, event->attr.sample_type);}
static void perf_event__id_header_size(struct perf_event *event){ struct perf_sample_data *data; u64 sample_type = event->attr.sample_type; u16 size = 0;
if (sample_type & PERF_SAMPLE_TID) size += sizeof(data->tid_entry);
if (sample_type & PERF_SAMPLE_TIME) size += sizeof(data->time);
if (sample_type & PERF_SAMPLE_IDENTIFIER) size += sizeof(data->id);
if (sample_type & PERF_SAMPLE_ID) size += sizeof(data->id);
if (sample_type & PERF_SAMPLE_STREAM_ID) size += sizeof(data->stream_id);
if (sample_type & PERF_SAMPLE_CPU) size += sizeof(data->cpu_entry);
event->id_header_size = size;}
/* * Check that adding an event to the group does not result in anybody * overflowing the 64k event limit imposed by the output buffer. * * Specifically, check that the read_size for the event does not exceed 16k, * read_size being the one term that grows with groups size. Since read_size * depends on per-event read_format, also (re)check the existing events. * * This leaves 48k for the constant size fields and things like callchains, * branch stacks and register sets. */static bool perf_event_validate_size(struct perf_event *event){ struct perf_event *sibling, *group_leader = event->group_leader;
if (__perf_event_read_size(event->attr.read_format, group_leader->nr_siblings + 1) > 16*1024) return false;
if (__perf_event_read_size(group_leader->attr.read_format, group_leader->nr_siblings + 1) > 16*1024) return false;
/* * When creating a new group leader, group_leader->ctx is initialized * after the size has been validated, but we cannot safely use * for_each_sibling_event() until group_leader->ctx is set. A new group * leader cannot have any siblings yet, so we can safely skip checking * the non-existent siblings. */ if (event == group_leader) return true;
for_each_sibling_event(sibling, group_leader) { if (__perf_event_read_size(sibling->attr.read_format, group_leader->nr_siblings + 1) > 16*1024) return false; }
return true;}
static void perf_group_attach(struct perf_event *event){ struct perf_event *group_leader = event->group_leader, *pos;
lockdep_assert_held(&event->ctx->lock);
/* * We can have double attach due to group movement (move_group) in * perf_event_open(). */ if (event->attach_state & PERF_ATTACH_GROUP) return;
event->attach_state |= PERF_ATTACH_GROUP;
if (group_leader == event) return;
WARN_ON_ONCE(group_leader->ctx != event->ctx);
group_leader->group_caps &= event->event_caps;
list_add_tail(&event->sibling_list, &group_leader->sibling_list); group_leader->nr_siblings++; group_leader->group_generation++;
perf_event__header_size(group_leader);
for_each_sibling_event(pos, group_leader) perf_event__header_size(pos);}
/* * Remove an event from the lists for its context. * Must be called with ctx->mutex and ctx->lock held. */static voidlist_del_event(struct perf_event *event, struct perf_event_context *ctx){ WARN_ON_ONCE(event->ctx != ctx); lockdep_assert_held(&ctx->lock);
/* * We can have double detach due to exit/hot-unplug + close. */ if (!(event->attach_state & PERF_ATTACH_CONTEXT)) return;
event->attach_state &= ~PERF_ATTACH_CONTEXT;
ctx->nr_events--; if (event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT) ctx->nr_user--; if (event->attr.inherit_stat) ctx->nr_stat--; if (has_inherit_and_sample_read(&event->attr)) local_dec(&ctx->nr_no_switch_fast);
list_del_rcu(&event->event_entry);
if (event->group_leader == event) del_event_from_groups(event, ctx);
ctx->generation++; event->pmu_ctx->nr_events--;}
static intperf_aux_output_match(struct perf_event *event, struct perf_event *aux_event){ if (!has_aux(aux_event)) return 0;
if (!event->pmu->aux_output_match) return 0;
return event->pmu->aux_output_match(aux_event);}
static void put_event(struct perf_event *event);static void __event_disable(struct perf_event *event, struct perf_event_context *ctx, enum perf_event_state state);
static void perf_put_aux_event(struct perf_event *event){ struct perf_event_context *ctx = event->ctx; struct perf_event *iter;
/* * If event uses aux_event tear down the link */ if (event->aux_event) { iter = event->aux_event; event->aux_event = NULL; put_event(iter); return; }
/* * If the event is an aux_event, tear down all links to * it from other events. */ for_each_sibling_event(iter, event) { if (iter->aux_event != event) continue;
iter->aux_event = NULL; put_event(event);
/* * If it's ACTIVE, schedule it out and put it into ERROR * state so that we don't try to schedule it again. Note * that perf_event_enable() will clear the ERROR status. */ __event_disable(iter, ctx, PERF_EVENT_STATE_ERROR); }}
static bool perf_need_aux_event(struct perf_event *event){ return event->attr.aux_output || has_aux_action(event);}
static int perf_get_aux_event(struct perf_event *event, struct perf_event *group_leader){ /* * Our group leader must be an aux event if we want to be * an aux_output. This way, the aux event will precede its * aux_output events in the group, and therefore will always * schedule first. */ if (!group_leader) return 0;
/* * aux_output and aux_sample_size are mutually exclusive. */ if (event->attr.aux_output && event->attr.aux_sample_size) return 0;
if (event->attr.aux_output && !perf_aux_output_match(event, group_leader)) return 0;
if ((event->attr.aux_pause || event->attr.aux_resume) && !(group_leader->pmu->capabilities & PERF_PMU_CAP_AUX_PAUSE)) return 0;
if (event->attr.aux_sample_size && !group_leader->pmu->snapshot_aux) return 0;
if (!atomic_long_inc_not_zero(&group_leader->refcount)) return 0;
/* * Link aux_outputs to their aux event; this is undone in * perf_group_detach() by perf_put_aux_event(). When the * group in torn down, the aux_output events loose their * link to the aux_event and can't schedule any more. */ event->aux_event = group_leader;
return 1;}
static inline struct list_head *get_event_list(struct perf_event *event){ return event->attr.pinned ? &event->pmu_ctx->pinned_active : &event->pmu_ctx->flexible_active;}
static void perf_group_detach(struct perf_event *event){ struct perf_event *leader = event->group_leader; struct perf_event *sibling, *tmp; struct perf_event_context *ctx = event->ctx;
lockdep_assert_held(&ctx->lock);
/* * We can have double detach due to exit/hot-unplug + close. */ if (!(event->attach_state & PERF_ATTACH_GROUP)) return;
event->attach_state &= ~PERF_ATTACH_GROUP;
perf_put_aux_event(event);
/* * If this is a sibling, remove it from its group. */ if (leader != event) { list_del_init(&event->sibling_list); event->group_leader->nr_siblings--; event->group_leader->group_generation++; goto out; }
/* * If this was a group event with sibling events then * upgrade the siblings to singleton events by adding them * to whatever list we are on. */ list_for_each_entry_safe(sibling, tmp, &event->sibling_list, sibling_list) {
/* * Events that have PERF_EV_CAP_SIBLING require being part of * a group and cannot exist on their own, schedule them out * and move them into the ERROR state. Also see * _perf_event_enable(), it will not be able to recover this * ERROR state. */ if (sibling->event_caps & PERF_EV_CAP_SIBLING) __event_disable(sibling, ctx, PERF_EVENT_STATE_ERROR);
sibling->group_leader = sibling; list_del_init(&sibling->sibling_list);
/* Inherit group flags from the previous leader */ sibling->group_caps = event->group_caps;
if (sibling->attach_state & PERF_ATTACH_CONTEXT) { add_event_to_groups(sibling, event->ctx);
if (sibling->state == PERF_EVENT_STATE_ACTIVE) list_add_tail(&sibling->active_list, get_event_list(sibling)); }
WARN_ON_ONCE(sibling->ctx != event->ctx); }
out: for_each_sibling_event(tmp, leader) perf_event__header_size(tmp);
perf_event__header_size(leader);}
static void perf_child_detach(struct perf_event *event){ struct perf_event *parent_event = event->parent;
if (!(event->attach_state & PERF_ATTACH_CHILD)) return;
event->attach_state &= ~PERF_ATTACH_CHILD;
if (WARN_ON_ONCE(!parent_event)) return;
/* * Can't check this from an IPI, the holder is likey another CPU. * lockdep_assert_held(&parent_event->child_mutex); */
list_del_init(&event->child_list);}
static bool is_orphaned_event(struct perf_event *event){ return event->state == PERF_EVENT_STATE_DEAD;}
static inline intevent_filter_match(struct perf_event *event){ return (event->cpu == -1 || event->cpu == smp_processor_id()) && perf_cgroup_match(event);}
static inline bool is_event_in_freq_mode(struct perf_event *event){ return event->attr.freq && event->attr.sample_freq;}
static voidevent_sched_out(struct perf_event *event, struct perf_event_context *ctx){ struct perf_event_pmu_context *epc = event->pmu_ctx; struct perf_cpu_pmu_context *cpc = this_cpc(epc->pmu); enum perf_event_state state = PERF_EVENT_STATE_INACTIVE;
// XXX cpc serialization, probably per-cpu IRQ disabled
WARN_ON_ONCE(event->ctx != ctx); lockdep_assert_held(&ctx->lock);
if (event->state != PERF_EVENT_STATE_ACTIVE) return;
/* * Asymmetry; we only schedule events _IN_ through ctx_sched_in(), but * we can schedule events _OUT_ individually through things like * __perf_remove_from_context(). */ list_del_init(&event->active_list);
perf_pmu_disable(event->pmu);
event->pmu->del(event, 0); event->oncpu = -1;
if (event->pending_disable) { event->pending_disable = 0; perf_cgroup_event_disable(event, ctx); state = PERF_EVENT_STATE_OFF; }
perf_event_set_state(event, state);
if (!is_software_event(event)) cpc->active_oncpu--; if (is_event_in_freq_mode(event)) { ctx->nr_freq--; epc->nr_freq--; } if (event->attr.exclusive || !cpc->active_oncpu) cpc->exclusive = 0;
perf_pmu_enable(event->pmu);}
static voidgroup_sched_out(struct perf_event *group_event, struct perf_event_context *ctx){ struct perf_event *event;
if (group_event->state != PERF_EVENT_STATE_ACTIVE) return;
perf_assert_pmu_disabled(group_event->pmu_ctx->pmu);
event_sched_out(group_event, ctx);
/* * Schedule out siblings (if any): */ for_each_sibling_event(event, group_event) event_sched_out(event, ctx);}
static inline void__ctx_time_update(struct perf_cpu_context *cpuctx, struct perf_event_context *ctx, bool final, enum event_type_t event_type){ if (ctx->is_active & EVENT_TIME) { if (ctx->is_active & EVENT_FROZEN) return;
update_context_time(ctx); /* vPMU should not stop time */ update_cgrp_time_from_cpuctx(cpuctx, !(event_type & EVENT_GUEST) && final); }}
static inline voidctx_time_update(struct perf_cpu_context *cpuctx, struct perf_event_context *ctx){ __ctx_time_update(cpuctx, ctx, false, 0);}
/* * To be used inside perf_ctx_lock() / perf_ctx_unlock(). Lasts until perf_ctx_unlock(). */static inline voidctx_time_freeze(struct perf_cpu_context *cpuctx, struct perf_event_context *ctx){ ctx_time_update(cpuctx, ctx); if (ctx->is_active & EVENT_TIME) ctx->is_active |= EVENT_FROZEN;}
static inline voidctx_time_update_event(struct perf_event_context *ctx, struct perf_event *event){ if (ctx->is_active & EVENT_TIME) { if (ctx->is_active & EVENT_FROZEN) return; update_context_time(ctx); update_cgrp_time_from_event(event); }}
#define DETACH_GROUP 0x01UL#define DETACH_CHILD 0x02UL#define DETACH_EXIT 0x04UL#define DETACH_REVOKE 0x08UL#define DETACH_DEAD 0x10UL
/* * Cross CPU call to remove a performance event * * We disable the event on the hardware level first. After that we * remove it from the context list. */static void__perf_remove_from_context(struct perf_event *event, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx, void *info){ struct perf_event_pmu_context *pmu_ctx = event->pmu_ctx; enum perf_event_state state = PERF_EVENT_STATE_OFF; unsigned long flags = (unsigned long)info;
ctx_time_update(cpuctx, ctx);
/* * Ensure event_sched_out() switches to OFF, at the very least * this avoids raising perf_pending_task() at this time. */ if (flags & DETACH_EXIT) state = PERF_EVENT_STATE_EXIT; if (flags & DETACH_REVOKE) state = PERF_EVENT_STATE_REVOKED; if (flags & DETACH_DEAD) state = PERF_EVENT_STATE_DEAD;
event_sched_out(event, ctx);
if (event->state > PERF_EVENT_STATE_OFF) perf_cgroup_event_disable(event, ctx);
perf_event_set_state(event, min(event->state, state));
if (flags & DETACH_GROUP) perf_group_detach(event); if (flags & DETACH_CHILD) perf_child_detach(event); list_del_event(event, ctx);
if (!pmu_ctx->nr_events) { pmu_ctx->rotate_necessary = 0;
if (ctx->task && ctx->is_active) { struct perf_cpu_pmu_context *cpc = this_cpc(pmu_ctx->pmu);
WARN_ON_ONCE(cpc->task_epc && cpc->task_epc != pmu_ctx); cpc->task_epc = NULL; } }
if (!ctx->nr_events && ctx->is_active) { if (ctx == &cpuctx->ctx) update_cgrp_time_from_cpuctx(cpuctx, true);
ctx->is_active = 0; if (ctx->task) { WARN_ON_ONCE(cpuctx->task_ctx != ctx); cpuctx->task_ctx = NULL; } }}
/* * Remove the event from a task's (or a CPU's) list of events. * * If event->ctx is a cloned context, callers must make sure that * every task struct that event->ctx->task could possibly point to * remains valid. This is OK when called from perf_release since * that only calls us on the top-level context, which can't be a clone. * When called from perf_event_exit_task, it's OK because the * context has been detached from its task. */static void perf_remove_from_context(struct perf_event *event, unsigned long flags){ struct perf_event_context *ctx = event->ctx;
lockdep_assert_held(&ctx->mutex);
/* * Because of perf_event_exit_task(), perf_remove_from_context() ought * to work in the face of TASK_TOMBSTONE, unlike every other * event_function_call() user. */ raw_spin_lock_irq(&ctx->lock); if (!ctx->is_active) { __perf_remove_from_context(event, this_cpu_ptr(&perf_cpu_context), ctx, (void *)flags); raw_spin_unlock_irq(&ctx->lock); return; } raw_spin_unlock_irq(&ctx->lock);
event_function_call(event, __perf_remove_from_context, (void *)flags);}
static void __event_disable(struct perf_event *event, struct perf_event_context *ctx, enum perf_event_state state){ event_sched_out(event, ctx); perf_cgroup_event_disable(event, ctx); perf_event_set_state(event, state);}
/* * Cross CPU call to disable a performance event */static void __perf_event_disable(struct perf_event *event, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx, void *info){ if (event->state < PERF_EVENT_STATE_INACTIVE) return;
perf_pmu_disable(event->pmu_ctx->pmu); ctx_time_update_event(ctx, event);
/* * When disabling a group leader, the whole group becomes ineligible * to run, so schedule out the full group. */ if (event == event->group_leader) group_sched_out(event, ctx);
/* * But only mark the leader OFF; the siblings will remain * INACTIVE. */ __event_disable(event, ctx, PERF_EVENT_STATE_OFF);
perf_pmu_enable(event->pmu_ctx->pmu);}
/* * Disable an event. * * If event->ctx is a cloned context, callers must make sure that * every task struct that event->ctx->task could possibly point to * remains valid. This condition is satisfied when called through * perf_event_for_each_child or perf_event_for_each because they * hold the top-level event's child_mutex, so any descendant that * goes to exit will block in perf_event_exit_event(). * * When called from perf_pending_disable it's OK because event->ctx * is the current context on this CPU and preemption is disabled, * hence we can't get into perf_event_task_sched_out for this context. */static void _perf_event_disable(struct perf_event *event){ struct perf_event_context *ctx = event->ctx;
raw_spin_lock_irq(&ctx->lock); if (event->state <= PERF_EVENT_STATE_OFF) { raw_spin_unlock_irq(&ctx->lock); return; } raw_spin_unlock_irq(&ctx->lock);
event_function_call(event, __perf_event_disable, NULL);}
void perf_event_disable_local(struct perf_event *event){ event_function_local(event, __perf_event_disable, NULL);}
/* * Strictly speaking kernel users cannot create groups and therefore this * interface does not need the perf_event_ctx_lock() magic. */void perf_event_disable(struct perf_event *event){ struct perf_event_context *ctx;
ctx = perf_event_ctx_lock(event); _perf_event_disable(event); perf_event_ctx_unlock(event, ctx);}EXPORT_SYMBOL_GPL(perf_event_disable);
void perf_event_disable_inatomic(struct perf_event *event){ event->pending_disable = 1; irq_work_queue(&event->pending_disable_irq);}
#define MAX_INTERRUPTS (~0ULL)
static void perf_log_throttle(struct perf_event *event, int enable);static void perf_log_itrace_start(struct perf_event *event);
static void perf_event_unthrottle(struct perf_event *event, bool start){ if (event->state != PERF_EVENT_STATE_ACTIVE) return;
event->hw.interrupts = 0; if (start) event->pmu->start(event, 0); if (event == event->group_leader) perf_log_throttle(event, 1);}
static void perf_event_throttle(struct perf_event *event){ if (event->state != PERF_EVENT_STATE_ACTIVE) return;
event->hw.interrupts = MAX_INTERRUPTS; event->pmu->stop(event, 0); if (event == event->group_leader) perf_log_throttle(event, 0);}
static void perf_event_unthrottle_group(struct perf_event *event, bool skip_start_event){ struct perf_event *sibling, *leader = event->group_leader;
perf_event_unthrottle(leader, skip_start_event ? leader != event : true); for_each_sibling_event(sibling, leader) perf_event_unthrottle(sibling, skip_start_event ? sibling != event : true);}
static void perf_event_throttle_group(struct perf_event *event){ struct perf_event *sibling, *leader = event->group_leader;
perf_event_throttle(leader); for_each_sibling_event(sibling, leader) perf_event_throttle(sibling);}
static intevent_sched_in(struct perf_event *event, struct perf_event_context *ctx){ struct perf_event_pmu_context *epc = event->pmu_ctx; struct perf_cpu_pmu_context *cpc = this_cpc(epc->pmu); int ret = 0;
WARN_ON_ONCE(event->ctx != ctx);
lockdep_assert_held(&ctx->lock);
if (event->state <= PERF_EVENT_STATE_OFF) return 0;
WRITE_ONCE(event->oncpu, smp_processor_id()); /* * Order event::oncpu write to happen before the ACTIVE state is * visible. This allows perf_event_{stop,read}() to observe the correct * ->oncpu if it sees ACTIVE. */ smp_wmb(); perf_event_set_state(event, PERF_EVENT_STATE_ACTIVE);
/* * Unthrottle events, since we scheduled we might have missed several * ticks already, also for a heavily scheduling task there is little * guarantee it'll get a tick in a timely manner. */ if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) perf_event_unthrottle(event, false);
perf_pmu_disable(event->pmu);
perf_log_itrace_start(event);
if (event->pmu->add(event, PERF_EF_START)) { perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE); event->oncpu = -1; ret = -EAGAIN; goto out; }
if (!is_software_event(event)) cpc->active_oncpu++; if (is_event_in_freq_mode(event)) { ctx->nr_freq++; epc->nr_freq++; } if (event->attr.exclusive) cpc->exclusive = 1;
out: perf_pmu_enable(event->pmu);
return ret;}
static intgroup_sched_in(struct perf_event *group_event, struct perf_event_context *ctx){ struct perf_event *event, *partial_group = NULL; struct pmu *pmu = group_event->pmu_ctx->pmu;
if (group_event->state == PERF_EVENT_STATE_OFF) return 0;
pmu->start_txn(pmu, PERF_PMU_TXN_ADD);
if (event_sched_in(group_event, ctx)) goto error;
/* * Schedule in siblings as one group (if any): */ for_each_sibling_event(event, group_event) { if (event_sched_in(event, ctx)) { partial_group = event; goto group_error; } }
if (!pmu->commit_txn(pmu)) return 0;
group_error: /* * Groups can be scheduled in as one unit only, so undo any * partial group before returning: * The events up to the failed event are scheduled out normally. */ for_each_sibling_event(event, group_event) { if (event == partial_group) break;
event_sched_out(event, ctx); } event_sched_out(group_event, ctx);
error: pmu->cancel_txn(pmu); return -EAGAIN;}
/* * Work out whether we can put this event group on the CPU now. */static int group_can_go_on(struct perf_event *event, int can_add_hw){ struct perf_event_pmu_context *epc = event->pmu_ctx; struct perf_cpu_pmu_context *cpc = this_cpc(epc->pmu);
/* * Groups consisting entirely of software events can always go on. */ if (event->group_caps & PERF_EV_CAP_SOFTWARE) return 1; /* * If an exclusive group is already on, no other hardware * events can go on. */ if (cpc->exclusive) return 0; /* * If this group is exclusive and there are already * events on the CPU, it can't go on. */ if (event->attr.exclusive && !list_empty(get_event_list(event))) return 0; /* * Otherwise, try to add it if all previous groups were able * to go on. */ return can_add_hw;}
static void add_event_to_ctx(struct perf_event *event, struct perf_event_context *ctx){ list_add_event(event, ctx); perf_group_attach(event);}
static void task_ctx_sched_out(struct perf_event_context *ctx, struct pmu *pmu, enum event_type_t event_type){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
if (!cpuctx->task_ctx) return;
if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) return;
ctx_sched_out(ctx, pmu, event_type);}
static void perf_event_sched_in(struct perf_cpu_context *cpuctx, struct perf_event_context *ctx, struct pmu *pmu, enum event_type_t event_type){ ctx_sched_in(&cpuctx->ctx, pmu, EVENT_PINNED | event_type); if (ctx) ctx_sched_in(ctx, pmu, EVENT_PINNED | event_type); ctx_sched_in(&cpuctx->ctx, pmu, EVENT_FLEXIBLE | event_type); if (ctx) ctx_sched_in(ctx, pmu, EVENT_FLEXIBLE | event_type);}
/* * We want to maintain the following priority of scheduling: * - CPU pinned (EVENT_CPU | EVENT_PINNED) * - task pinned (EVENT_PINNED) * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE) * - task flexible (EVENT_FLEXIBLE). * * In order to avoid unscheduling and scheduling back in everything every * time an event is added, only do it for the groups of equal priority and * below. * * This can be called after a batch operation on task events, in which case * event_type is a bit mask of the types of events involved. For CPU events, * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE. */static void ctx_resched(struct perf_cpu_context *cpuctx, struct perf_event_context *task_ctx, struct pmu *pmu, enum event_type_t event_type){ bool cpu_event = !!(event_type & EVENT_CPU); struct perf_event_pmu_context *epc;
/* * If pinned groups are involved, flexible groups also need to be * scheduled out. */ if (event_type & EVENT_PINNED) event_type |= EVENT_FLEXIBLE;
event_type &= EVENT_ALL;
for_each_epc(epc, &cpuctx->ctx, pmu, 0) perf_pmu_disable(epc->pmu);
if (task_ctx) { for_each_epc(epc, task_ctx, pmu, 0) perf_pmu_disable(epc->pmu);
task_ctx_sched_out(task_ctx, pmu, event_type); }
/* * Decide which cpu ctx groups to schedule out based on the types * of events that caused rescheduling: * - EVENT_CPU: schedule out corresponding groups; * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups; * - otherwise, do nothing more. */ if (cpu_event) ctx_sched_out(&cpuctx->ctx, pmu, event_type); else if (event_type & EVENT_PINNED) ctx_sched_out(&cpuctx->ctx, pmu, EVENT_FLEXIBLE);
perf_event_sched_in(cpuctx, task_ctx, pmu, 0);
for_each_epc(epc, &cpuctx->ctx, pmu, 0) perf_pmu_enable(epc->pmu);
if (task_ctx) { for_each_epc(epc, task_ctx, pmu, 0) perf_pmu_enable(epc->pmu); }}
void perf_pmu_resched(struct pmu *pmu){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct perf_event_context *task_ctx = cpuctx->task_ctx;
perf_ctx_lock(cpuctx, task_ctx); ctx_resched(cpuctx, task_ctx, pmu, EVENT_ALL|EVENT_CPU); perf_ctx_unlock(cpuctx, task_ctx);}
/* * Cross CPU call to install and enable a performance event * * Very similar to remote_function() + event_function() but cannot assume that * things like ctx->is_active and cpuctx->task_ctx are set. */static int __perf_install_in_context(void *info){ struct perf_event *event = info; struct perf_event_context *ctx = event->ctx; struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct perf_event_context *task_ctx = cpuctx->task_ctx; bool reprogram = true; int ret = 0;
raw_spin_lock(&cpuctx->ctx.lock); if (ctx->task) { raw_spin_lock(&ctx->lock); task_ctx = ctx;
reprogram = (ctx->task == current);
/* * If the task is running, it must be running on this CPU, * otherwise we cannot reprogram things. * * If its not running, we don't care, ctx->lock will * serialize against it becoming runnable. */ if (task_curr(ctx->task) && !reprogram) { ret = -ESRCH; goto unlock; }
WARN_ON_ONCE(reprogram && cpuctx->task_ctx && cpuctx->task_ctx != ctx); } else if (task_ctx) { raw_spin_lock(&task_ctx->lock); }
#ifdef CONFIG_CGROUP_PERF if (event->state > PERF_EVENT_STATE_OFF && is_cgroup_event(event)) { /* * If the current cgroup doesn't match the event's * cgroup, we should not try to schedule it. */ struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx); reprogram = cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup); }#endif
if (reprogram) { ctx_time_freeze(cpuctx, ctx); add_event_to_ctx(event, ctx); ctx_resched(cpuctx, task_ctx, event->pmu_ctx->pmu, get_event_type(event)); } else { add_event_to_ctx(event, ctx); }
unlock: perf_ctx_unlock(cpuctx, task_ctx);
return ret;}
static bool exclusive_event_installable(struct perf_event *event, struct perf_event_context *ctx);
/* * Attach a performance event to a context. * * Very similar to event_function_call, see comment there. */static voidperf_install_in_context(struct perf_event_context *ctx, struct perf_event *event, int cpu){ struct task_struct *task = READ_ONCE(ctx->task);
lockdep_assert_held(&ctx->mutex);
WARN_ON_ONCE(!exclusive_event_installable(event, ctx));
if (event->cpu != -1) WARN_ON_ONCE(event->cpu != cpu);
/* * Ensures that if we can observe event->ctx, both the event and ctx * will be 'complete'. See perf_iterate_sb_cpu(). */ smp_store_release(&event->ctx, ctx);
/* * perf_event_attr::disabled events will not run and can be initialized * without IPI. Except when this is the first event for the context, in * that case we need the magic of the IPI to set ctx->is_active. * * The IOC_ENABLE that is sure to follow the creation of a disabled * event will issue the IPI and reprogram the hardware. */ if (__perf_effective_state(event) == PERF_EVENT_STATE_OFF && ctx->nr_events && !is_cgroup_event(event)) { raw_spin_lock_irq(&ctx->lock); if (ctx->task == TASK_TOMBSTONE) { raw_spin_unlock_irq(&ctx->lock); return; } add_event_to_ctx(event, ctx); raw_spin_unlock_irq(&ctx->lock); return; }
if (!task) { cpu_function_call(cpu, __perf_install_in_context, event); return; }
/* * Should not happen, we validate the ctx is still alive before calling. */ if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) return;
/* * Installing events is tricky because we cannot rely on ctx->is_active * to be set in case this is the nr_events 0 -> 1 transition. * * Instead we use task_curr(), which tells us if the task is running. * However, since we use task_curr() outside of rq::lock, we can race * against the actual state. This means the result can be wrong. * * If we get a false positive, we retry, this is harmless. * * If we get a false negative, things are complicated. If we are after * perf_event_context_sched_in() ctx::lock will serialize us, and the * value must be correct. If we're before, it doesn't matter since * perf_event_context_sched_in() will program the counter. * * However, this hinges on the remote context switch having observed * our task->perf_event_ctxp[] store, such that it will in fact take * ctx::lock in perf_event_context_sched_in(). * * We do this by task_function_call(), if the IPI fails to hit the task * we know any future context switch of task must see the * perf_event_ctpx[] store. */
/* * This smp_mb() orders the task->perf_event_ctxp[] store with the * task_cpu() load, such that if the IPI then does not find the task * running, a future context switch of that task must observe the * store. */ smp_mb();again: if (!task_function_call(task, __perf_install_in_context, event)) return;
raw_spin_lock_irq(&ctx->lock); task = ctx->task; if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) { /* * Cannot happen because we already checked above (which also * cannot happen), and we hold ctx->mutex, which serializes us * against perf_event_exit_task_context(). */ raw_spin_unlock_irq(&ctx->lock); return; } /* * If the task is not running, ctx->lock will avoid it becoming so, * thus we can safely install the event. */ if (task_curr(task)) { raw_spin_unlock_irq(&ctx->lock); goto again; } add_event_to_ctx(event, ctx); raw_spin_unlock_irq(&ctx->lock);}
/* * Cross CPU call to enable a performance event */static void __perf_event_enable(struct perf_event *event, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx, void *info){ struct perf_event *leader = event->group_leader; struct perf_event_context *task_ctx;
if (event->state >= PERF_EVENT_STATE_INACTIVE || event->state <= PERF_EVENT_STATE_ERROR) return;
ctx_time_freeze(cpuctx, ctx);
perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE); perf_cgroup_event_enable(event, ctx);
if (!ctx->is_active) return;
if (!event_filter_match(event)) return;
/* * If the event is in a group and isn't the group leader, * then don't put it on unless the group is on. */ if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) return;
task_ctx = cpuctx->task_ctx; if (ctx->task) WARN_ON_ONCE(task_ctx != ctx);
ctx_resched(cpuctx, task_ctx, event->pmu_ctx->pmu, get_event_type(event));}
/* * Enable an event. * * If event->ctx is a cloned context, callers must make sure that * every task struct that event->ctx->task could possibly point to * remains valid. This condition is satisfied when called through * perf_event_for_each_child or perf_event_for_each as described * for perf_event_disable. */static void _perf_event_enable(struct perf_event *event){ struct perf_event_context *ctx = event->ctx;
raw_spin_lock_irq(&ctx->lock); if (event->state >= PERF_EVENT_STATE_INACTIVE || event->state < PERF_EVENT_STATE_ERROR) {out: raw_spin_unlock_irq(&ctx->lock); return; }
/* * If the event is in error state, clear that first. * * That way, if we see the event in error state below, we know that it * has gone back into error state, as distinct from the task having * been scheduled away before the cross-call arrived. */ if (event->state == PERF_EVENT_STATE_ERROR) { /* * Detached SIBLING events cannot leave ERROR state. */ if (event->event_caps & PERF_EV_CAP_SIBLING && event->group_leader == event) goto out;
event->state = PERF_EVENT_STATE_OFF; } raw_spin_unlock_irq(&ctx->lock);
event_function_call(event, __perf_event_enable, NULL);}
/* * See perf_event_disable(); */void perf_event_enable(struct perf_event *event){ struct perf_event_context *ctx;
ctx = perf_event_ctx_lock(event); _perf_event_enable(event); perf_event_ctx_unlock(event, ctx);}EXPORT_SYMBOL_GPL(perf_event_enable);
struct stop_event_data { struct perf_event *event; unsigned int restart;};
static int __perf_event_stop(void *info){ struct stop_event_data *sd = info; struct perf_event *event = sd->event;
/* if it's already INACTIVE, do nothing */ if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE) return 0;
/* matches smp_wmb() in event_sched_in() */ smp_rmb();
/* * There is a window with interrupts enabled before we get here, * so we need to check again lest we try to stop another CPU's event. */ if (READ_ONCE(event->oncpu) != smp_processor_id()) return -EAGAIN;
event->pmu->stop(event, PERF_EF_UPDATE);
/* * May race with the actual stop (through perf_pmu_output_stop()), * but it is only used for events with AUX ring buffer, and such * events will refuse to restart because of rb::aux_mmap_count==0, * see comments in perf_aux_output_begin(). * * Since this is happening on an event-local CPU, no trace is lost * while restarting. */ if (sd->restart) event->pmu->start(event, 0);
return 0;}
static int perf_event_stop(struct perf_event *event, int restart){ struct stop_event_data sd = { .event = event, .restart = restart, }; int ret = 0;
do { if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE) return 0;
/* matches smp_wmb() in event_sched_in() */ smp_rmb();
/* * We only want to restart ACTIVE events, so if the event goes * inactive here (event->oncpu==-1), there's nothing more to do; * fall through with ret==-ENXIO. */ ret = cpu_function_call(READ_ONCE(event->oncpu), __perf_event_stop, &sd); } while (ret == -EAGAIN);
return ret;}
/* * In order to contain the amount of racy and tricky in the address filter * configuration management, it is a two part process: * * (p1) when userspace mappings change as a result of (1) or (2) or (3) below, * we update the addresses of corresponding vmas in * event::addr_filter_ranges array and bump the event::addr_filters_gen; * (p2) when an event is scheduled in (pmu::add), it calls * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync() * if the generation has changed since the previous call. * * If (p1) happens while the event is active, we restart it to force (p2). * * (1) perf_addr_filters_apply(): adjusting filters' offsets based on * pre-existing mappings, called once when new filters arrive via SET_FILTER * ioctl; * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly * registered mapping, called for every new mmap(), with mm::mmap_lock down * for reading; * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process * of exec. */void perf_event_addr_filters_sync(struct perf_event *event){ struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
if (!has_addr_filter(event)) return;
raw_spin_lock(&ifh->lock); if (event->addr_filters_gen != event->hw.addr_filters_gen) { event->pmu->addr_filters_sync(event); event->hw.addr_filters_gen = event->addr_filters_gen; } raw_spin_unlock(&ifh->lock);}EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync);
static int _perf_event_refresh(struct perf_event *event, int refresh){ /* * not supported on inherited events */ if (event->attr.inherit || !is_sampling_event(event)) return -EINVAL;
atomic_add(refresh, &event->event_limit); _perf_event_enable(event);
return 0;}
/* * See perf_event_disable() */int perf_event_refresh(struct perf_event *event, int refresh){ struct perf_event_context *ctx; int ret;
ctx = perf_event_ctx_lock(event); ret = _perf_event_refresh(event, refresh); perf_event_ctx_unlock(event, ctx);
return ret;}EXPORT_SYMBOL_GPL(perf_event_refresh);
static int perf_event_modify_breakpoint(struct perf_event *bp, struct perf_event_attr *attr){ int err;
_perf_event_disable(bp);
err = modify_user_hw_breakpoint_check(bp, attr, true);
if (!bp->attr.disabled) _perf_event_enable(bp);
return err;}
/* * Copy event-type-independent attributes that may be modified. */static void perf_event_modify_copy_attr(struct perf_event_attr *to, const struct perf_event_attr *from){ to->sig_data = from->sig_data;}
static int perf_event_modify_attr(struct perf_event *event, struct perf_event_attr *attr){ int (*func)(struct perf_event *, struct perf_event_attr *); struct perf_event *child; int err;
if (event->attr.type != attr->type) return -EINVAL;
switch (event->attr.type) { case PERF_TYPE_BREAKPOINT: func = perf_event_modify_breakpoint; break; default: /* Place holder for future additions. */ return -EOPNOTSUPP; }
WARN_ON_ONCE(event->ctx->parent_ctx);
mutex_lock(&event->child_mutex); /* * Event-type-independent attributes must be copied before event-type * modification, which will validate that final attributes match the * source attributes after all relevant attributes have been copied. */ perf_event_modify_copy_attr(&event->attr, attr); err = func(event, attr); if (err) goto out; list_for_each_entry(child, &event->child_list, child_list) { perf_event_modify_copy_attr(&child->attr, attr); err = func(child, attr); if (err) goto out; }out: mutex_unlock(&event->child_mutex); return err;}
static void __pmu_ctx_sched_out(struct perf_event_pmu_context *pmu_ctx, enum event_type_t event_type){ struct perf_event_context *ctx = pmu_ctx->ctx; struct perf_event *event, *tmp; struct pmu *pmu = pmu_ctx->pmu;
if (ctx->task && !(ctx->is_active & EVENT_ALL)) { struct perf_cpu_pmu_context *cpc = this_cpc(pmu);
WARN_ON_ONCE(cpc->task_epc && cpc->task_epc != pmu_ctx); cpc->task_epc = NULL; }
if (!(event_type & EVENT_ALL)) return;
perf_pmu_disable(pmu); if (event_type & EVENT_PINNED) { list_for_each_entry_safe(event, tmp, &pmu_ctx->pinned_active, active_list) group_sched_out(event, ctx); }
if (event_type & EVENT_FLEXIBLE) { list_for_each_entry_safe(event, tmp, &pmu_ctx->flexible_active, active_list) group_sched_out(event, ctx); /* * Since we cleared EVENT_FLEXIBLE, also clear * rotate_necessary, is will be reset by * ctx_flexible_sched_in() when needed. */ pmu_ctx->rotate_necessary = 0; } perf_pmu_enable(pmu);}
/* * Be very careful with the @pmu argument since this will change ctx state. * The @pmu argument works for ctx_resched(), because that is symmetric in * ctx_sched_out() / ctx_sched_in() usage and the ctx state ends up invariant. * * However, if you were to be asymmetrical, you could end up with messed up * state, eg. ctx->is_active cleared even though most EPCs would still actually * be active. */static voidctx_sched_out(struct perf_event_context *ctx, struct pmu *pmu, enum event_type_t event_type){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); enum event_type_t active_type = event_type & ~EVENT_FLAGS; struct perf_event_pmu_context *pmu_ctx; int is_active = ctx->is_active;
lockdep_assert_held(&ctx->lock);
if (likely(!ctx->nr_events)) { /* * See __perf_remove_from_context(). */ WARN_ON_ONCE(ctx->is_active); if (ctx->task) WARN_ON_ONCE(cpuctx->task_ctx); return; }
/* * Always update time if it was set; not only when it changes. * Otherwise we can 'forget' to update time for any but the last * context we sched out. For example: * * ctx_sched_out(.event_type = EVENT_FLEXIBLE) * ctx_sched_out(.event_type = EVENT_PINNED) * * would only update time for the pinned events. */ __ctx_time_update(cpuctx, ctx, ctx == &cpuctx->ctx, event_type);
/* * CPU-release for the below ->is_active store, * see __load_acquire() in perf_event_time_now() */ barrier(); ctx->is_active &= ~active_type;
if (!(ctx->is_active & EVENT_ALL)) { /* * For FROZEN, preserve TIME|FROZEN such that perf_event_time_now() * does not observe a hole. perf_ctx_unlock() will clean up. */ if (ctx->is_active & EVENT_FROZEN) ctx->is_active &= EVENT_TIME_FROZEN; else ctx->is_active = 0; }
if (ctx->task) { WARN_ON_ONCE(cpuctx->task_ctx != ctx); if (!(ctx->is_active & EVENT_ALL)) cpuctx->task_ctx = NULL; }
if (event_type & EVENT_GUEST) { /* * Schedule out all exclude_guest events of PMU * with PERF_PMU_CAP_MEDIATED_VPMU. */ is_active = EVENT_ALL; __update_context_guest_time(ctx, false); perf_cgroup_set_timestamp(cpuctx, true); barrier(); } else { is_active ^= ctx->is_active; /* changed bits */ }
for_each_epc(pmu_ctx, ctx, pmu, event_type) __pmu_ctx_sched_out(pmu_ctx, is_active);}
/* * Test whether two contexts are equivalent, i.e. whether they have both been * cloned from the same version of the same context. * * Equivalence is measured using a generation number in the context that is * incremented on each modification to it; see unclone_ctx(), list_add_event() * and list_del_event(). */static int context_equiv(struct perf_event_context *ctx1, struct perf_event_context *ctx2){ lockdep_assert_held(&ctx1->lock); lockdep_assert_held(&ctx2->lock);
/* Pinning disables the swap optimization */ if (ctx1->pin_count || ctx2->pin_count) return 0;
/* If ctx1 is the parent of ctx2 */ if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen) return 1;
/* If ctx2 is the parent of ctx1 */ if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation) return 1;
/* * If ctx1 and ctx2 have the same parent; we flatten the parent * hierarchy, see perf_event_init_context(). */ if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx && ctx1->parent_gen == ctx2->parent_gen) return 1;
/* Unmatched */ return 0;}
static void __perf_event_sync_stat(struct perf_event *event, struct perf_event *next_event){ u64 value;
if (!event->attr.inherit_stat) return;
/* * Update the event value, we cannot use perf_event_read() * because we're in the middle of a context switch and have IRQs * disabled, which upsets smp_call_function_single(), however * we know the event must be on the current CPU, therefore we * don't need to use it. */ perf_pmu_read(event);
perf_event_update_time(event);
/* * In order to keep per-task stats reliable we need to flip the event * values when we flip the contexts. */ value = local64_read(&next_event->count); value = local64_xchg(&event->count, value); local64_set(&next_event->count, value);
swap(event->total_time_enabled, next_event->total_time_enabled); swap(event->total_time_running, next_event->total_time_running);
/* * Since we swizzled the values, update the user visible data too. */ perf_event_update_userpage(event); perf_event_update_userpage(next_event);}
static void perf_event_sync_stat(struct perf_event_context *ctx, struct perf_event_context *next_ctx){ struct perf_event *event, *next_event;
if (!ctx->nr_stat) return;
update_context_time(ctx);
event = list_first_entry(&ctx->event_list, struct perf_event, event_entry);
next_event = list_first_entry(&next_ctx->event_list, struct perf_event, event_entry);
while (&event->event_entry != &ctx->event_list && &next_event->event_entry != &next_ctx->event_list) {
__perf_event_sync_stat(event, next_event);
event = list_next_entry(event, event_entry); next_event = list_next_entry(next_event, event_entry); }}
static void perf_ctx_sched_task_cb(struct perf_event_context *ctx, struct task_struct *task, bool sched_in){ struct perf_event_pmu_context *pmu_ctx; struct perf_cpu_pmu_context *cpc;
list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) { cpc = this_cpc(pmu_ctx->pmu);
if (cpc->sched_cb_usage && pmu_ctx->pmu->sched_task) pmu_ctx->pmu->sched_task(pmu_ctx, task, sched_in); }}
static voidperf_event_context_sched_out(struct task_struct *task, struct task_struct *next){ struct perf_event_context *ctx = task->perf_event_ctxp; struct perf_event_context *next_ctx; struct perf_event_context *parent, *next_parent; int do_switch = 1;
if (likely(!ctx)) return;
rcu_read_lock(); next_ctx = rcu_dereference(next->perf_event_ctxp); if (!next_ctx) goto unlock;
parent = rcu_dereference(ctx->parent_ctx); next_parent = rcu_dereference(next_ctx->parent_ctx);
/* If neither context have a parent context; they cannot be clones. */ if (!parent && !next_parent) goto unlock;
if (next_parent == ctx || next_ctx == parent || next_parent == parent) { /* * Looks like the two contexts are clones, so we might be * able to optimize the context switch. We lock both * contexts and check that they are clones under the * lock (including re-checking that neither has been * uncloned in the meantime). It doesn't matter which * order we take the locks because no other cpu could * be trying to lock both of these tasks. */ raw_spin_lock(&ctx->lock); raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); if (context_equiv(ctx, next_ctx)) {
perf_ctx_disable(ctx, 0);
/* PMIs are disabled; ctx->nr_no_switch_fast is stable. */ if (local_read(&ctx->nr_no_switch_fast) || local_read(&next_ctx->nr_no_switch_fast)) { /* * Must not swap out ctx when there's pending * events that rely on the ctx->task relation. * * Likewise, when a context contains inherit + * SAMPLE_READ events they should be switched * out using the slow path so that they are * treated as if they were distinct contexts. */ raw_spin_unlock(&next_ctx->lock); rcu_read_unlock(); goto inside_switch; }
WRITE_ONCE(ctx->task, next); WRITE_ONCE(next_ctx->task, task);
perf_ctx_sched_task_cb(ctx, task, false);
perf_ctx_enable(ctx, 0);
/* * RCU_INIT_POINTER here is safe because we've not * modified the ctx and the above modification of * ctx->task is immaterial since this value is * always verified under ctx->lock which we're now * holding. */ RCU_INIT_POINTER(task->perf_event_ctxp, next_ctx); RCU_INIT_POINTER(next->perf_event_ctxp, ctx);
do_switch = 0;
perf_event_sync_stat(ctx, next_ctx); } raw_spin_unlock(&next_ctx->lock); raw_spin_unlock(&ctx->lock); }unlock: rcu_read_unlock();
if (do_switch) { raw_spin_lock(&ctx->lock); perf_ctx_disable(ctx, 0);
inside_switch: perf_ctx_sched_task_cb(ctx, task, false); task_ctx_sched_out(ctx, NULL, EVENT_ALL);
perf_ctx_enable(ctx, 0); raw_spin_unlock(&ctx->lock); }}
static DEFINE_PER_CPU(struct list_head, sched_cb_list);static DEFINE_PER_CPU(int, perf_sched_cb_usages);
void perf_sched_cb_dec(struct pmu *pmu){ struct perf_cpu_pmu_context *cpc = this_cpc(pmu);
this_cpu_dec(perf_sched_cb_usages); barrier();
if (!--cpc->sched_cb_usage) list_del(&cpc->sched_cb_entry);}
void perf_sched_cb_inc(struct pmu *pmu){ struct perf_cpu_pmu_context *cpc = this_cpc(pmu);
if (!cpc->sched_cb_usage++) list_add(&cpc->sched_cb_entry, this_cpu_ptr(&sched_cb_list));
barrier(); this_cpu_inc(perf_sched_cb_usages);}
/* * This function provides the context switch callback to the lower code * layer. It is invoked ONLY when the context switch callback is enabled. * * This callback is relevant even to per-cpu events; for example multi event * PEBS requires this to provide PID/TID information. This requires we flush * all queued PEBS records before we context switch to a new task. */static void __perf_pmu_sched_task(struct perf_cpu_pmu_context *cpc, struct task_struct *task, bool sched_in){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct pmu *pmu;
pmu = cpc->epc.pmu;
/* software PMUs will not have sched_task */ if (WARN_ON_ONCE(!pmu->sched_task)) return;
perf_ctx_lock(cpuctx, cpuctx->task_ctx); perf_pmu_disable(pmu);
pmu->sched_task(cpc->task_epc, task, sched_in);
perf_pmu_enable(pmu); perf_ctx_unlock(cpuctx, cpuctx->task_ctx);}
static void perf_pmu_sched_task(struct task_struct *prev, struct task_struct *next, bool sched_in){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct perf_cpu_pmu_context *cpc;
/* cpuctx->task_ctx will be handled in perf_event_context_sched_in/out */ if (prev == next || cpuctx->task_ctx) return;
list_for_each_entry(cpc, this_cpu_ptr(&sched_cb_list), sched_cb_entry) __perf_pmu_sched_task(cpc, sched_in ? next : prev, sched_in);}
static void perf_event_switch(struct task_struct *task, struct task_struct *next_prev, bool sched_in);
/* * Called from scheduler to remove the events of the current task, * with interrupts disabled. * * We stop each event and update the event value in event->count. * * This does not protect us against NMI, but disable() * sets the disabled bit in the control field of event _before_ * accessing the event control register. If a NMI hits, then it will * not restart the event. */void __perf_event_task_sched_out(struct task_struct *task, struct task_struct *next){ if (__this_cpu_read(perf_sched_cb_usages)) perf_pmu_sched_task(task, next, false);
if (atomic_read(&nr_switch_events)) perf_event_switch(task, next, false);
perf_event_context_sched_out(task, next);
/* * if cgroup events exist on this CPU, then we need * to check if we have to switch out PMU state. * cgroup event are system-wide mode only */ perf_cgroup_switch(next);}
static bool perf_less_group_idx(const void *l, const void *r, void __always_unused *args){ const struct perf_event *le = *(const struct perf_event **)l; const struct perf_event *re = *(const struct perf_event **)r;
return le->group_index < re->group_index;}
DEFINE_MIN_HEAP(struct perf_event *, perf_event_min_heap);
static const struct min_heap_callbacks perf_min_heap = { .less = perf_less_group_idx, .swp = NULL,};
static void __heap_add(struct perf_event_min_heap *heap, struct perf_event *event){ struct perf_event **itrs = heap->data;
if (event) { itrs[heap->nr] = event; heap->nr++; }}
static void __link_epc(struct perf_event_pmu_context *pmu_ctx){ struct perf_cpu_pmu_context *cpc;
if (!pmu_ctx->ctx->task) return;
cpc = this_cpc(pmu_ctx->pmu); WARN_ON_ONCE(cpc->task_epc && cpc->task_epc != pmu_ctx); cpc->task_epc = pmu_ctx;}
static noinline int visit_groups_merge(struct perf_event_context *ctx, struct perf_event_groups *groups, int cpu, struct pmu *pmu, int (*func)(struct perf_event *, void *), void *data){#ifdef CONFIG_CGROUP_PERF struct cgroup_subsys_state *css = NULL;#endif struct perf_cpu_context *cpuctx = NULL; /* Space for per CPU and/or any CPU event iterators. */ struct perf_event *itrs[2]; struct perf_event_min_heap event_heap; struct perf_event **evt; int ret;
if (pmu->filter && pmu->filter(pmu, cpu)) return 0;
if (!ctx->task) { cpuctx = this_cpu_ptr(&perf_cpu_context); event_heap = (struct perf_event_min_heap){ .data = cpuctx->heap, .nr = 0, .size = cpuctx->heap_size, };
lockdep_assert_held(&cpuctx->ctx.lock);
#ifdef CONFIG_CGROUP_PERF if (cpuctx->cgrp) css = &cpuctx->cgrp->css;#endif } else { event_heap = (struct perf_event_min_heap){ .data = itrs, .nr = 0, .size = ARRAY_SIZE(itrs), }; /* Events not within a CPU context may be on any CPU. */ __heap_add(&event_heap, perf_event_groups_first(groups, -1, pmu, NULL)); } evt = event_heap.data;
__heap_add(&event_heap, perf_event_groups_first(groups, cpu, pmu, NULL));
#ifdef CONFIG_CGROUP_PERF for (; css; css = css->parent) __heap_add(&event_heap, perf_event_groups_first(groups, cpu, pmu, css->cgroup));#endif
if (event_heap.nr) { __link_epc((*evt)->pmu_ctx); perf_assert_pmu_disabled((*evt)->pmu_ctx->pmu); }
min_heapify_all_inline(&event_heap, &perf_min_heap, NULL);
while (event_heap.nr) { ret = func(*evt, data); if (ret) return ret;
*evt = perf_event_groups_next(*evt, pmu); if (*evt) min_heap_sift_down_inline(&event_heap, 0, &perf_min_heap, NULL); else min_heap_pop_inline(&event_heap, &perf_min_heap, NULL); }
return 0;}
/* * Because the userpage is strictly per-event (there is no concept of context, * so there cannot be a context indirection), every userpage must be updated * when context time starts :-( * * IOW, we must not miss EVENT_TIME edges. */static inline bool event_update_userpage(struct perf_event *event){ if (likely(!refcount_read(&event->mmap_count))) return false;
perf_event_update_time(event); perf_event_update_userpage(event);
return true;}
static inline void group_update_userpage(struct perf_event *group_event){ struct perf_event *event;
if (!event_update_userpage(group_event)) return;
for_each_sibling_event(event, group_event) event_update_userpage(event);}
struct merge_sched_data { int can_add_hw; enum event_type_t event_type;};
static int merge_sched_in(struct perf_event *event, void *data){ struct perf_event_context *ctx = event->ctx; struct merge_sched_data *msd = data;
if (event->state <= PERF_EVENT_STATE_OFF) return 0;
if (!event_filter_match(event)) return 0;
/* * Don't schedule in any host events from PMU with * PERF_PMU_CAP_MEDIATED_VPMU, while a guest is running. */ if (is_guest_mediated_pmu_loaded() && event->pmu_ctx->pmu->capabilities & PERF_PMU_CAP_MEDIATED_VPMU && !(msd->event_type & EVENT_GUEST)) return 0;
if (group_can_go_on(event, msd->can_add_hw)) { if (!group_sched_in(event, ctx)) list_add_tail(&event->active_list, get_event_list(event)); }
if (event->state == PERF_EVENT_STATE_INACTIVE) { msd->can_add_hw = 0; if (event->attr.pinned) { perf_cgroup_event_disable(event, ctx); perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
if (*perf_event_fasync(event)) event->pending_kill = POLL_ERR;
event->pending_wakeup = 1; irq_work_queue(&event->pending_irq); } else { struct perf_cpu_pmu_context *cpc = this_cpc(event->pmu_ctx->pmu);
event->pmu_ctx->rotate_necessary = 1; perf_mux_hrtimer_restart(cpc); group_update_userpage(event); } }
return 0;}
static void pmu_groups_sched_in(struct perf_event_context *ctx, struct perf_event_groups *groups, struct pmu *pmu, enum event_type_t event_type){ struct merge_sched_data msd = { .can_add_hw = 1, .event_type = event_type, }; visit_groups_merge(ctx, groups, smp_processor_id(), pmu, merge_sched_in, &msd);}
static void __pmu_ctx_sched_in(struct perf_event_pmu_context *pmu_ctx, enum event_type_t event_type){ struct perf_event_context *ctx = pmu_ctx->ctx;
if (event_type & EVENT_PINNED) pmu_groups_sched_in(ctx, &ctx->pinned_groups, pmu_ctx->pmu, event_type); if (event_type & EVENT_FLEXIBLE) pmu_groups_sched_in(ctx, &ctx->flexible_groups, pmu_ctx->pmu, event_type);}
static voidctx_sched_in(struct perf_event_context *ctx, struct pmu *pmu, enum event_type_t event_type){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); enum event_type_t active_type = event_type & ~EVENT_FLAGS; struct perf_event_pmu_context *pmu_ctx; int is_active = ctx->is_active;
lockdep_assert_held(&ctx->lock);
if (likely(!ctx->nr_events)) return;
if (!(is_active & EVENT_TIME)) { /* EVENT_TIME should be active while the guest runs */ WARN_ON_ONCE(event_type & EVENT_GUEST); /* start ctx time */ __update_context_time(ctx, false); perf_cgroup_set_timestamp(cpuctx, false); /* * CPU-release for the below ->is_active store, * see __load_acquire() in perf_event_time_now() */ barrier(); }
ctx->is_active |= active_type | EVENT_TIME; if (ctx->task) { if (!(is_active & EVENT_ALL)) cpuctx->task_ctx = ctx; else WARN_ON_ONCE(cpuctx->task_ctx != ctx); }
if (event_type & EVENT_GUEST) { /* * Schedule in the required exclude_guest events of PMU * with PERF_PMU_CAP_MEDIATED_VPMU. */ is_active = event_type & EVENT_ALL;
/* * Update ctx time to set the new start time for * the exclude_guest events. */ update_context_time(ctx); update_cgrp_time_from_cpuctx(cpuctx, false); barrier(); } else { is_active ^= ctx->is_active; /* changed bits */ }
/* * First go through the list and put on any pinned groups * in order to give them the best chance of going on. */ if (is_active & EVENT_PINNED) { for_each_epc(pmu_ctx, ctx, pmu, event_type) __pmu_ctx_sched_in(pmu_ctx, EVENT_PINNED | (event_type & EVENT_GUEST)); }
/* Then walk through the lower prio flexible groups */ if (is_active & EVENT_FLEXIBLE) { for_each_epc(pmu_ctx, ctx, pmu, event_type) __pmu_ctx_sched_in(pmu_ctx, EVENT_FLEXIBLE | (event_type & EVENT_GUEST)); }}
static void perf_event_context_sched_in(struct task_struct *task){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct perf_event_context *ctx;
rcu_read_lock(); ctx = rcu_dereference(task->perf_event_ctxp); if (!ctx) goto rcu_unlock;
if (cpuctx->task_ctx == ctx) { perf_ctx_lock(cpuctx, ctx); perf_ctx_disable(ctx, 0);
perf_ctx_sched_task_cb(ctx, task, true);
perf_ctx_enable(ctx, 0); perf_ctx_unlock(cpuctx, ctx); goto rcu_unlock; }
perf_ctx_lock(cpuctx, ctx); /* * We must check ctx->nr_events while holding ctx->lock, such * that we serialize against perf_install_in_context(). */ if (!ctx->nr_events) goto unlock;
perf_ctx_disable(ctx, 0); /* * We want to keep the following priority order: * cpu pinned (that don't need to move), task pinned, * cpu flexible, task flexible. * * However, if task's ctx is not carrying any pinned * events, no need to flip the cpuctx's events around. */ if (!RB_EMPTY_ROOT(&ctx->pinned_groups.tree)) { perf_ctx_disable(&cpuctx->ctx, 0); ctx_sched_out(&cpuctx->ctx, NULL, EVENT_FLEXIBLE); }
perf_event_sched_in(cpuctx, ctx, NULL, 0);
perf_ctx_sched_task_cb(cpuctx->task_ctx, task, true);
if (!RB_EMPTY_ROOT(&ctx->pinned_groups.tree)) perf_ctx_enable(&cpuctx->ctx, 0);
perf_ctx_enable(ctx, 0);
unlock: perf_ctx_unlock(cpuctx, ctx);rcu_unlock: rcu_read_unlock();}
/* * Called from scheduler to add the events of the current task * with interrupts disabled. * * We restore the event value and then enable it. * * This does not protect us against NMI, but enable() * sets the enabled bit in the control field of event _before_ * accessing the event control register. If a NMI hits, then it will * keep the event running. */void __perf_event_task_sched_in(struct task_struct *prev, struct task_struct *task){ perf_event_context_sched_in(task);
if (atomic_read(&nr_switch_events)) perf_event_switch(task, prev, true);
if (__this_cpu_read(perf_sched_cb_usages)) perf_pmu_sched_task(prev, task, true);}
static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count){ u64 frequency = event->attr.sample_freq; u64 sec = NSEC_PER_SEC; u64 divisor, dividend;
int count_fls, nsec_fls, frequency_fls, sec_fls;
count_fls = fls64(count); nsec_fls = fls64(nsec); frequency_fls = fls64(frequency); sec_fls = 30;
/* * We got @count in @nsec, with a target of sample_freq HZ * the target period becomes: * * @count * 10^9 * period = ------------------- * @nsec * sample_freq * */
/* * Reduce accuracy by one bit such that @a and @b converge * to a similar magnitude. */#define REDUCE_FLS(a, b) \do { \ if (a##_fls > b##_fls) { \ a >>= 1; \ a##_fls--; \ } else { \ b >>= 1; \ b##_fls--; \ } \} while (0)
/* * Reduce accuracy until either term fits in a u64, then proceed with * the other, so that finally we can do a u64/u64 division. */ while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) { REDUCE_FLS(nsec, frequency); REDUCE_FLS(sec, count); }
if (count_fls + sec_fls > 64) { divisor = nsec * frequency;
while (count_fls + sec_fls > 64) { REDUCE_FLS(count, sec); divisor >>= 1; }
dividend = count * sec; } else { dividend = count * sec;
while (nsec_fls + frequency_fls > 64) { REDUCE_FLS(nsec, frequency); dividend >>= 1; }
divisor = nsec * frequency; }
if (!divisor) return dividend;
return div64_u64(dividend, divisor);}
static DEFINE_PER_CPU(int, perf_throttled_count);static DEFINE_PER_CPU(u64, perf_throttled_seq);
static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable){ struct hw_perf_event *hwc = &event->hw; s64 period, sample_period; s64 delta;
period = perf_calculate_period(event, nsec, count);
delta = (s64)(period - hwc->sample_period); if (delta >= 0) delta += 7; else delta -= 7; delta /= 8; /* low pass filter */
sample_period = hwc->sample_period + delta;
if (!sample_period) sample_period = 1;
hwc->sample_period = sample_period;
if (local64_read(&hwc->period_left) > 8*sample_period) { if (disable) event->pmu->stop(event, PERF_EF_UPDATE);
local64_set(&hwc->period_left, 0);
if (disable) event->pmu->start(event, PERF_EF_RELOAD); }}
static void perf_adjust_freq_unthr_events(struct list_head *event_list){ struct perf_event *event; struct hw_perf_event *hwc; u64 now, period = TICK_NSEC; s64 delta;
list_for_each_entry(event, event_list, active_list) { if (event->state != PERF_EVENT_STATE_ACTIVE) continue;
// XXX use visit thingy to avoid the -1,cpu match if (!event_filter_match(event)) continue;
hwc = &event->hw;
if (hwc->interrupts == MAX_INTERRUPTS) perf_event_unthrottle_group(event, is_event_in_freq_mode(event));
if (!is_event_in_freq_mode(event)) continue;
/* * stop the event and update event->count */ event->pmu->stop(event, PERF_EF_UPDATE);
now = local64_read(&event->count); delta = now - hwc->freq_count_stamp; hwc->freq_count_stamp = now;
/* * restart the event * reload only if value has changed * we have stopped the event so tell that * to perf_adjust_period() to avoid stopping it * twice. */ if (delta > 0) perf_adjust_period(event, period, delta, false);
event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); }}
/* * combine freq adjustment with unthrottling to avoid two passes over the * events. At the same time, make sure, having freq events does not change * the rate of unthrottling as that would introduce bias. */static voidperf_adjust_freq_unthr_context(struct perf_event_context *ctx, bool unthrottle){ struct perf_event_pmu_context *pmu_ctx;
/* * only need to iterate over all events iff: * - context have events in frequency mode (needs freq adjust) * - there are events to unthrottle on this cpu */ if (!(ctx->nr_freq || unthrottle)) return;
raw_spin_lock(&ctx->lock);
list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) { if (!(pmu_ctx->nr_freq || unthrottle)) continue; if (!perf_pmu_ctx_is_active(pmu_ctx)) continue; if (pmu_ctx->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) continue;
perf_pmu_disable(pmu_ctx->pmu); perf_adjust_freq_unthr_events(&pmu_ctx->pinned_active); perf_adjust_freq_unthr_events(&pmu_ctx->flexible_active); perf_pmu_enable(pmu_ctx->pmu); }
raw_spin_unlock(&ctx->lock);}
/* * Move @event to the tail of the @ctx's elegible events. */static void rotate_ctx(struct perf_event_context *ctx, struct perf_event *event){ /* * Rotate the first entry last of non-pinned groups. Rotation might be * disabled by the inheritance code. */ if (ctx->rotate_disable) return;
perf_event_groups_delete(&ctx->flexible_groups, event); perf_event_groups_insert(&ctx->flexible_groups, event);}
/* pick an event from the flexible_groups to rotate */static inline struct perf_event *ctx_event_to_rotate(struct perf_event_pmu_context *pmu_ctx){ struct perf_event *event; struct rb_node *node; struct rb_root *tree; struct __group_key key = { .pmu = pmu_ctx->pmu, };
/* pick the first active flexible event */ event = list_first_entry_or_null(&pmu_ctx->flexible_active, struct perf_event, active_list); if (event) goto out;
/* if no active flexible event, pick the first event */ tree = &pmu_ctx->ctx->flexible_groups.tree;
if (!pmu_ctx->ctx->task) { key.cpu = smp_processor_id();
node = rb_find_first(&key, tree, __group_cmp_ignore_cgroup); if (node) event = __node_2_pe(node); goto out; }
key.cpu = -1; node = rb_find_first(&key, tree, __group_cmp_ignore_cgroup); if (node) { event = __node_2_pe(node); goto out; }
key.cpu = smp_processor_id(); node = rb_find_first(&key, tree, __group_cmp_ignore_cgroup); if (node) event = __node_2_pe(node);
out: /* * Unconditionally clear rotate_necessary; if ctx_flexible_sched_in() * finds there are unschedulable events, it will set it again. */ pmu_ctx->rotate_necessary = 0;
return event;}
static bool perf_rotate_context(struct perf_cpu_pmu_context *cpc){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct perf_event_pmu_context *cpu_epc, *task_epc = NULL; struct perf_event *cpu_event = NULL, *task_event = NULL; int cpu_rotate, task_rotate; struct pmu *pmu;
/* * Since we run this from IRQ context, nobody can install new * events, thus the event count values are stable. */
cpu_epc = &cpc->epc; pmu = cpu_epc->pmu; task_epc = cpc->task_epc;
cpu_rotate = cpu_epc->rotate_necessary; task_rotate = task_epc ? task_epc->rotate_necessary : 0;
if (!(cpu_rotate || task_rotate)) return false;
perf_ctx_lock(cpuctx, cpuctx->task_ctx); perf_pmu_disable(pmu);
if (task_rotate) task_event = ctx_event_to_rotate(task_epc); if (cpu_rotate) cpu_event = ctx_event_to_rotate(cpu_epc);
/* * As per the order given at ctx_resched() first 'pop' task flexible * and then, if needed CPU flexible. */ if (task_event || (task_epc && cpu_event)) { update_context_time(task_epc->ctx); __pmu_ctx_sched_out(task_epc, EVENT_FLEXIBLE); }
if (cpu_event) { update_context_time(&cpuctx->ctx); __pmu_ctx_sched_out(cpu_epc, EVENT_FLEXIBLE); rotate_ctx(&cpuctx->ctx, cpu_event); __pmu_ctx_sched_in(cpu_epc, EVENT_FLEXIBLE); }
if (task_event) rotate_ctx(task_epc->ctx, task_event);
if (task_event || (task_epc && cpu_event)) __pmu_ctx_sched_in(task_epc, EVENT_FLEXIBLE);
perf_pmu_enable(pmu); perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
return true;}
void perf_event_task_tick(void){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct perf_event_context *ctx; int throttled;
lockdep_assert_irqs_disabled();
__this_cpu_inc(perf_throttled_seq); throttled = __this_cpu_xchg(perf_throttled_count, 0); tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
perf_adjust_freq_unthr_context(&cpuctx->ctx, !!throttled);
rcu_read_lock(); ctx = rcu_dereference(current->perf_event_ctxp); if (ctx) perf_adjust_freq_unthr_context(ctx, !!throttled); rcu_read_unlock();}
static int event_enable_on_exec(struct perf_event *event, struct perf_event_context *ctx){ if (!event->attr.enable_on_exec) return 0;
event->attr.enable_on_exec = 0; if (event->state >= PERF_EVENT_STATE_INACTIVE) return 0;
perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE);
return 1;}
/* * Enable all of a task's events that have been marked enable-on-exec. * This expects task == current. */static void perf_event_enable_on_exec(struct perf_event_context *ctx){ struct perf_event_context *clone_ctx = NULL; enum event_type_t event_type = 0; struct perf_cpu_context *cpuctx; struct perf_event *event; unsigned long flags; int enabled = 0;
local_irq_save(flags); if (WARN_ON_ONCE(current->perf_event_ctxp != ctx)) goto out;
if (!ctx->nr_events) goto out;
cpuctx = this_cpu_ptr(&perf_cpu_context); perf_ctx_lock(cpuctx, ctx); ctx_time_freeze(cpuctx, ctx);
list_for_each_entry(event, &ctx->event_list, event_entry) { enabled |= event_enable_on_exec(event, ctx); event_type |= get_event_type(event); }
/* * Unclone and reschedule this context if we enabled any event. */ if (enabled) { clone_ctx = unclone_ctx(ctx); ctx_resched(cpuctx, ctx, NULL, event_type); } perf_ctx_unlock(cpuctx, ctx);
out: local_irq_restore(flags);
if (clone_ctx) put_ctx(clone_ctx);}
static void perf_remove_from_owner(struct perf_event *event);static void perf_event_exit_event(struct perf_event *event, struct perf_event_context *ctx, struct task_struct *task, unsigned long detach_flags);
/* * Removes all events from the current task that have been marked * remove-on-exec, and feeds their values back to parent events. */static void perf_event_remove_on_exec(struct perf_event_context *ctx){ struct perf_event_context *clone_ctx = NULL; struct perf_event *event, *next; unsigned long flags; bool modified = false;
mutex_lock(&ctx->mutex);
if (WARN_ON_ONCE(ctx->task != current)) goto unlock;
list_for_each_entry_safe(event, next, &ctx->event_list, event_entry) { if (!event->attr.remove_on_exec) continue;
if (!is_kernel_event(event)) perf_remove_from_owner(event);
modified = true;
perf_event_exit_event(event, ctx, ctx->task, DETACH_GROUP); }
raw_spin_lock_irqsave(&ctx->lock, flags); if (modified) clone_ctx = unclone_ctx(ctx); raw_spin_unlock_irqrestore(&ctx->lock, flags);
unlock: mutex_unlock(&ctx->mutex);
if (clone_ctx) put_ctx(clone_ctx);}
struct perf_read_data { struct perf_event *event; bool group; int ret;};
static inline const struct cpumask *perf_scope_cpu_topology_cpumask(unsigned int scope, int cpu);
static int __perf_event_read_cpu(struct perf_event *event, int event_cpu){ int local_cpu = smp_processor_id(); u16 local_pkg, event_pkg;
if ((unsigned)event_cpu >= nr_cpu_ids) return event_cpu;
if (event->group_caps & PERF_EV_CAP_READ_SCOPE) { const struct cpumask *cpumask = perf_scope_cpu_topology_cpumask(event->pmu->scope, event_cpu);
if (cpumask && cpumask_test_cpu(local_cpu, cpumask)) return local_cpu; }
if (event->group_caps & PERF_EV_CAP_READ_ACTIVE_PKG) { event_pkg = topology_physical_package_id(event_cpu); local_pkg = topology_physical_package_id(local_cpu);
if (event_pkg == local_pkg) return local_cpu; }
return event_cpu;}
/* * Cross CPU call to read the hardware event */static void __perf_event_read(void *info){ struct perf_read_data *data = info; struct perf_event *sub, *event = data->event; struct perf_event_context *ctx = event->ctx; struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct pmu *pmu;
/* * If this is a task context, we need to check whether it is * the current task context of this cpu. If not it has been * scheduled out before the smp call arrived. In that case * event->count would have been updated to a recent sample * when the event was scheduled out. */ if (ctx->task && cpuctx->task_ctx != ctx) return;
guard(raw_spinlock)(&ctx->lock); ctx_time_update_event(ctx, event);
perf_event_update_time(event); if (data->group) perf_event_update_sibling_time(event);
if (event->state != PERF_EVENT_STATE_ACTIVE) return;
if (!data->group) { perf_pmu_read(event); data->ret = 0; return; }
pmu = event->pmu_ctx->pmu; pmu->start_txn(pmu, PERF_PMU_TXN_READ);
perf_pmu_read(event); for_each_sibling_event(sub, event) perf_pmu_read(sub);
data->ret = pmu->commit_txn(pmu);}
static inline u64 perf_event_count(struct perf_event *event, bool self){ if (self) return local64_read(&event->count);
return local64_read(&event->count) + atomic64_read(&event->child_count);}
static void calc_timer_values(struct perf_event *event, u64 *now, u64 *enabled, u64 *running){ u64 ctx_time;
*now = perf_clock(); ctx_time = perf_event_time_now(event, *now); __perf_update_times(event, ctx_time, enabled, running);}
/* * NMI-safe method to read a local event, that is an event that * is: * - either for the current task, or for this CPU * - does not have inherit set, for inherited task events * will not be local and we cannot read them atomically * - must not have a pmu::count method */int perf_event_read_local(struct perf_event *event, u64 *value, u64 *enabled, u64 *running){ unsigned long flags; int event_oncpu; int event_cpu; int ret = 0;
/* * Disabling interrupts avoids all counter scheduling (context * switches, timer based rotation and IPIs). */ local_irq_save(flags);
/* * It must not be an event with inherit set, we cannot read * all child counters from atomic context. */ if (event->attr.inherit) { ret = -EOPNOTSUPP; goto out; }
/* If this is a per-task event, it must be for current */ if ((event->attach_state & PERF_ATTACH_TASK) && event->hw.target != current) { ret = -EINVAL; goto out; }
/* * Get the event CPU numbers, and adjust them to local if the event is * a per-package event that can be read locally */ event_oncpu = __perf_event_read_cpu(event, event->oncpu); event_cpu = __perf_event_read_cpu(event, event->cpu);
/* If this is a per-CPU event, it must be for this CPU */ if (!(event->attach_state & PERF_ATTACH_TASK) && event_cpu != smp_processor_id()) { ret = -EINVAL; goto out; }
/* If this is a pinned event it must be running on this CPU */ if (event->attr.pinned && event_oncpu != smp_processor_id()) { ret = -EBUSY; goto out; }
/* * If the event is currently on this CPU, its either a per-task event, * or local to this CPU. Furthermore it means its ACTIVE (otherwise * oncpu == -1). */ if (event_oncpu == smp_processor_id()) event->pmu->read(event);
*value = local64_read(&event->count); if (enabled || running) { u64 __enabled, __running, __now;
calc_timer_values(event, &__now, &__enabled, &__running); if (enabled) *enabled = __enabled; if (running) *running = __running; }out: local_irq_restore(flags);
return ret;}
static int perf_event_read(struct perf_event *event, bool group){ enum perf_event_state state = READ_ONCE(event->state); int event_cpu, ret = 0;
/* * If event is enabled and currently active on a CPU, update the * value in the event structure: */again: if (state == PERF_EVENT_STATE_ACTIVE) { struct perf_read_data data;
/* * Orders the ->state and ->oncpu loads such that if we see * ACTIVE we must also see the right ->oncpu. * * Matches the smp_wmb() from event_sched_in(). */ smp_rmb();
event_cpu = READ_ONCE(event->oncpu); if ((unsigned)event_cpu >= nr_cpu_ids) return 0;
data = (struct perf_read_data){ .event = event, .group = group, .ret = 0, };
preempt_disable(); event_cpu = __perf_event_read_cpu(event, event_cpu);
/* * Purposely ignore the smp_call_function_single() return * value. * * If event_cpu isn't a valid CPU it means the event got * scheduled out and that will have updated the event count. * * Therefore, either way, we'll have an up-to-date event count * after this. */ (void)smp_call_function_single(event_cpu, __perf_event_read, &data, 1); preempt_enable(); ret = data.ret;
} else if (state == PERF_EVENT_STATE_INACTIVE) { struct perf_event_context *ctx = event->ctx; unsigned long flags;
raw_spin_lock_irqsave(&ctx->lock, flags); state = event->state; if (state != PERF_EVENT_STATE_INACTIVE) { raw_spin_unlock_irqrestore(&ctx->lock, flags); goto again; }
/* * May read while context is not active (e.g., thread is * blocked), in that case we cannot update context time */ ctx_time_update_event(ctx, event);
perf_event_update_time(event); if (group) perf_event_update_sibling_time(event); raw_spin_unlock_irqrestore(&ctx->lock, flags); }
return ret;}
/* * Initialize the perf_event context in a task_struct: */static void __perf_event_init_context(struct perf_event_context *ctx){ raw_spin_lock_init(&ctx->lock); mutex_init(&ctx->mutex); INIT_LIST_HEAD(&ctx->pmu_ctx_list); perf_event_groups_init(&ctx->pinned_groups); perf_event_groups_init(&ctx->flexible_groups); INIT_LIST_HEAD(&ctx->event_list); refcount_set(&ctx->refcount, 1);}
static void__perf_init_event_pmu_context(struct perf_event_pmu_context *epc, struct pmu *pmu){ epc->pmu = pmu; INIT_LIST_HEAD(&epc->pmu_ctx_entry); INIT_LIST_HEAD(&epc->pinned_active); INIT_LIST_HEAD(&epc->flexible_active); atomic_set(&epc->refcount, 1);}
static struct perf_event_context *alloc_perf_context(struct task_struct *task){ struct perf_event_context *ctx;
ctx = kzalloc_obj(struct perf_event_context); if (!ctx) return NULL;
__perf_event_init_context(ctx); if (task) ctx->task = get_task_struct(task);
return ctx;}
static struct task_struct *find_lively_task_by_vpid(pid_t vpid){ struct task_struct *task;
rcu_read_lock(); if (!vpid) task = current; else task = find_task_by_vpid(vpid); if (task) get_task_struct(task); rcu_read_unlock();
if (!task) return ERR_PTR(-ESRCH);
return task;}
/* * Returns a matching context with refcount and pincount. */static struct perf_event_context *find_get_context(struct task_struct *task, struct perf_event *event){ struct perf_event_context *ctx, *clone_ctx = NULL; struct perf_cpu_context *cpuctx; unsigned long flags; int err;
if (!task) { /* Must be root to operate on a CPU event: */ err = perf_allow_cpu(); if (err) return ERR_PTR(err);
cpuctx = per_cpu_ptr(&perf_cpu_context, event->cpu); ctx = &cpuctx->ctx; get_ctx(ctx); raw_spin_lock_irqsave(&ctx->lock, flags); ++ctx->pin_count; raw_spin_unlock_irqrestore(&ctx->lock, flags);
return ctx; }
err = -EINVAL;retry: ctx = perf_lock_task_context(task, &flags); if (ctx) { clone_ctx = unclone_ctx(ctx); ++ctx->pin_count;
raw_spin_unlock_irqrestore(&ctx->lock, flags);
if (clone_ctx) put_ctx(clone_ctx); } else { ctx = alloc_perf_context(task); err = -ENOMEM; if (!ctx) goto errout;
err = 0; mutex_lock(&task->perf_event_mutex); /* * If it has already passed perf_event_exit_task(). * we must see PF_EXITING, it takes this mutex too. */ if (task->flags & PF_EXITING) err = -ESRCH; else if (task->perf_event_ctxp) err = -EAGAIN; else { get_ctx(ctx); ++ctx->pin_count; rcu_assign_pointer(task->perf_event_ctxp, ctx); } mutex_unlock(&task->perf_event_mutex);
if (unlikely(err)) { put_ctx(ctx);
if (err == -EAGAIN) goto retry; goto errout; } }
return ctx;
errout: return ERR_PTR(err);}
static struct perf_event_pmu_context *find_get_pmu_context(struct pmu *pmu, struct perf_event_context *ctx, struct perf_event *event){ struct perf_event_pmu_context *new = NULL, *pos = NULL, *epc;
if (!ctx->task) { /* * perf_pmu_migrate_context() / __perf_pmu_install_event() * relies on the fact that find_get_pmu_context() cannot fail * for CPU contexts. */ struct perf_cpu_pmu_context *cpc;
cpc = *per_cpu_ptr(pmu->cpu_pmu_context, event->cpu); epc = &cpc->epc; raw_spin_lock_irq(&ctx->lock); if (!epc->ctx) { /* * One extra reference for the pmu; see perf_pmu_free(). */ atomic_set(&epc->refcount, 2); epc->embedded = 1; list_add(&epc->pmu_ctx_entry, &ctx->pmu_ctx_list); epc->ctx = ctx; } else { WARN_ON_ONCE(epc->ctx != ctx); atomic_inc(&epc->refcount); } raw_spin_unlock_irq(&ctx->lock); return epc; }
new = kzalloc_obj(*epc); if (!new) return ERR_PTR(-ENOMEM);
__perf_init_event_pmu_context(new, pmu);
/* * XXX * * lockdep_assert_held(&ctx->mutex); * * can't because perf_event_init_task() doesn't actually hold the * child_ctx->mutex. */
raw_spin_lock_irq(&ctx->lock); list_for_each_entry(epc, &ctx->pmu_ctx_list, pmu_ctx_entry) { if (epc->pmu == pmu) { WARN_ON_ONCE(epc->ctx != ctx); atomic_inc(&epc->refcount); goto found_epc; } /* Make sure the pmu_ctx_list is sorted by PMU type: */ if (!pos && epc->pmu->type > pmu->type) pos = epc; }
epc = new; new = NULL;
if (!pos) list_add_tail(&epc->pmu_ctx_entry, &ctx->pmu_ctx_list); else list_add(&epc->pmu_ctx_entry, pos->pmu_ctx_entry.prev);
epc->ctx = ctx;
found_epc: raw_spin_unlock_irq(&ctx->lock); kfree(new);
return epc;}
static void get_pmu_ctx(struct perf_event_pmu_context *epc){ WARN_ON_ONCE(!atomic_inc_not_zero(&epc->refcount));}
static void free_cpc_rcu(struct rcu_head *head){ struct perf_cpu_pmu_context *cpc = container_of(head, typeof(*cpc), epc.rcu_head);
kfree(cpc);}
static void free_epc_rcu(struct rcu_head *head){ struct perf_event_pmu_context *epc = container_of(head, typeof(*epc), rcu_head);
kfree(epc);}
static void put_pmu_ctx(struct perf_event_pmu_context *epc){ struct perf_event_context *ctx = epc->ctx; unsigned long flags;
/* * XXX * * lockdep_assert_held(&ctx->mutex); * * can't because of the call-site in _free_event()/put_event() * which isn't always called under ctx->mutex. */ if (!atomic_dec_and_raw_lock_irqsave(&epc->refcount, &ctx->lock, flags)) return;
WARN_ON_ONCE(list_empty(&epc->pmu_ctx_entry));
list_del_init(&epc->pmu_ctx_entry); epc->ctx = NULL;
WARN_ON_ONCE(!list_empty(&epc->pinned_active)); WARN_ON_ONCE(!list_empty(&epc->flexible_active));
raw_spin_unlock_irqrestore(&ctx->lock, flags);
if (epc->embedded) { call_rcu(&epc->rcu_head, free_cpc_rcu); return; }
call_rcu(&epc->rcu_head, free_epc_rcu);}
static void perf_event_free_filter(struct perf_event *event);
static void free_event_rcu(struct rcu_head *head){ struct perf_event *event = container_of(head, typeof(*event), rcu_head);
if (event->ns) put_pid_ns(event->ns); perf_event_free_filter(event); kfree(event->addr_filter_ranges); kmem_cache_free(perf_event_cache, event);}
static void ring_buffer_attach(struct perf_event *event, struct perf_buffer *rb);
static void detach_sb_event(struct perf_event *event){ struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);
raw_spin_lock(&pel->lock); list_del_rcu(&event->sb_list); raw_spin_unlock(&pel->lock);}
static bool is_sb_event(struct perf_event *event){ struct perf_event_attr *attr = &event->attr;
if (event->parent) return false;
if (event->attach_state & PERF_ATTACH_TASK) return false;
if (attr->mmap || attr->mmap_data || attr->mmap2 || attr->comm || attr->comm_exec || attr->task || attr->ksymbol || attr->context_switch || attr->text_poke || attr->bpf_event) return true;
return false;}
static void unaccount_pmu_sb_event(struct perf_event *event){ if (is_sb_event(event)) detach_sb_event(event);}
#ifdef CONFIG_NO_HZ_FULLstatic DEFINE_SPINLOCK(nr_freq_lock);#endif
static void unaccount_freq_event_nohz(void){#ifdef CONFIG_NO_HZ_FULL spin_lock(&nr_freq_lock); if (atomic_dec_and_test(&nr_freq_events)) tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS); spin_unlock(&nr_freq_lock);#endif}
static void unaccount_freq_event(void){ if (tick_nohz_full_enabled()) unaccount_freq_event_nohz(); else atomic_dec(&nr_freq_events);}
static struct perf_ctx_data *alloc_perf_ctx_data(struct kmem_cache *ctx_cache, bool global, gfp_t gfp_flags){ struct perf_ctx_data *cd;
cd = kzalloc_obj(*cd, gfp_flags); if (!cd) return NULL;
cd->data = kmem_cache_zalloc(ctx_cache, gfp_flags); if (!cd->data) { kfree(cd); return NULL; }
cd->global = global; cd->ctx_cache = ctx_cache; refcount_set(&cd->refcount, 1);
return cd;}
static void free_perf_ctx_data(struct perf_ctx_data *cd){ kmem_cache_free(cd->ctx_cache, cd->data); kfree(cd);}
static void __free_perf_ctx_data_rcu(struct rcu_head *rcu_head){ struct perf_ctx_data *cd;
cd = container_of(rcu_head, struct perf_ctx_data, rcu_head); free_perf_ctx_data(cd);}
static inline void perf_free_ctx_data_rcu(struct perf_ctx_data *cd){ call_rcu(&cd->rcu_head, __free_perf_ctx_data_rcu);}
static intattach_task_ctx_data(struct task_struct *task, struct kmem_cache *ctx_cache, bool global, gfp_t gfp_flags){ struct perf_ctx_data *cd, *old = NULL;
cd = alloc_perf_ctx_data(ctx_cache, global, gfp_flags); if (!cd) return -ENOMEM;
for (;;) { if (try_cmpxchg(&task->perf_ctx_data, &old, cd)) { if (old) perf_free_ctx_data_rcu(old); /* * Above try_cmpxchg() pairs with try_cmpxchg() from * detach_task_ctx_data() such that * if we race with perf_event_exit_task(), we must * observe PF_EXITING. */ if (task->flags & PF_EXITING) { /* detach_task_ctx_data() may free it already */ if (try_cmpxchg(&task->perf_ctx_data, &cd, NULL)) perf_free_ctx_data_rcu(cd); } return 0; }
if (!old) { /* * After seeing a dead @old, we raced with * removal and lost, try again to install @cd. */ continue; }
if (refcount_inc_not_zero(&old->refcount)) { free_perf_ctx_data(cd); /* unused */ return 0; }
/* * @old is a dead object, refcount==0 is stable, try and * replace it with @cd. */ } return 0;}
static void __detach_global_ctx_data(void);DEFINE_STATIC_PERCPU_RWSEM(global_ctx_data_rwsem);static refcount_t global_ctx_data_ref;
static intattach_global_ctx_data(struct kmem_cache *ctx_cache){ struct task_struct *g, *p; struct perf_ctx_data *cd; int ret;
if (refcount_inc_not_zero(&global_ctx_data_ref)) return 0;
guard(percpu_write)(&global_ctx_data_rwsem); if (refcount_inc_not_zero(&global_ctx_data_ref)) return 0;again: /* Allocate everything */ scoped_guard (rcu) { for_each_process_thread(g, p) { if (p->flags & PF_EXITING) continue; cd = rcu_dereference(p->perf_ctx_data); if (cd && !cd->global) { cd->global = 1; if (!refcount_inc_not_zero(&cd->refcount)) cd = NULL; } if (!cd) { /* * Try to allocate context quickly before * traversing the whole thread list again. */ if (!attach_task_ctx_data(p, ctx_cache, true, GFP_NOWAIT)) continue; get_task_struct(p); goto alloc; } } }
refcount_set(&global_ctx_data_ref, 1);
return 0;alloc: ret = attach_task_ctx_data(p, ctx_cache, true, GFP_KERNEL); put_task_struct(p); if (ret) { __detach_global_ctx_data(); return ret; } goto again;}
static intattach_perf_ctx_data(struct perf_event *event){ struct task_struct *task = event->hw.target; struct kmem_cache *ctx_cache = event->pmu->task_ctx_cache; int ret;
if (!ctx_cache) return -ENOMEM;
if (task) return attach_task_ctx_data(task, ctx_cache, false, GFP_KERNEL);
ret = attach_global_ctx_data(ctx_cache); if (ret) return ret;
event->attach_state |= PERF_ATTACH_GLOBAL_DATA; return 0;}
static voiddetach_task_ctx_data(struct task_struct *p){ struct perf_ctx_data *cd;
scoped_guard (rcu) { cd = rcu_dereference(p->perf_ctx_data); if (!cd || !refcount_dec_and_test(&cd->refcount)) return; }
/* * The old ctx_data may be lost because of the race. * Nothing is required to do for the case. * See attach_task_ctx_data(). */ if (try_cmpxchg((struct perf_ctx_data **)&p->perf_ctx_data, &cd, NULL)) perf_free_ctx_data_rcu(cd);}
static void __detach_global_ctx_data(void){ struct task_struct *g, *p; struct perf_ctx_data *cd;
scoped_guard (rcu) { for_each_process_thread(g, p) { cd = rcu_dereference(p->perf_ctx_data); if (cd && cd->global) { cd->global = 0; detach_task_ctx_data(p); } } }}
static void detach_global_ctx_data(void){ if (refcount_dec_not_one(&global_ctx_data_ref)) return;
guard(percpu_write)(&global_ctx_data_rwsem); if (!refcount_dec_and_test(&global_ctx_data_ref)) return;
/* remove everything */ __detach_global_ctx_data();}
static void detach_perf_ctx_data(struct perf_event *event){ struct task_struct *task = event->hw.target;
event->attach_state &= ~PERF_ATTACH_TASK_DATA;
if (task) return detach_task_ctx_data(task);
if (event->attach_state & PERF_ATTACH_GLOBAL_DATA) { detach_global_ctx_data(); event->attach_state &= ~PERF_ATTACH_GLOBAL_DATA; }}
static void unaccount_event(struct perf_event *event){ bool dec = false;
if (event->parent) return;
if (event->attach_state & (PERF_ATTACH_TASK | PERF_ATTACH_SCHED_CB)) dec = true; if (event->attr.mmap || event->attr.mmap_data) atomic_dec(&nr_mmap_events); if (event->attr.build_id) atomic_dec(&nr_build_id_events); if (event->attr.comm) atomic_dec(&nr_comm_events); if (event->attr.namespaces) atomic_dec(&nr_namespaces_events); if (event->attr.cgroup) atomic_dec(&nr_cgroup_events); if (event->attr.task) atomic_dec(&nr_task_events); if (event->attr.freq) unaccount_freq_event(); if (event->attr.context_switch) { dec = true; atomic_dec(&nr_switch_events); } if (is_cgroup_event(event)) dec = true; if (has_branch_stack(event)) dec = true; if (event->attr.ksymbol) atomic_dec(&nr_ksymbol_events); if (event->attr.bpf_event) atomic_dec(&nr_bpf_events); if (event->attr.text_poke) atomic_dec(&nr_text_poke_events);
if (dec) { if (!atomic_add_unless(&perf_sched_count, -1, 1)) schedule_delayed_work(&perf_sched_work, HZ); }
unaccount_pmu_sb_event(event);}
static void perf_sched_delayed(struct work_struct *work){ mutex_lock(&perf_sched_mutex); if (atomic_dec_and_test(&perf_sched_count)) static_branch_disable(&perf_sched_events); mutex_unlock(&perf_sched_mutex);}
/* * The following implement mutual exclusion of events on "exclusive" pmus * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled * at a time, so we disallow creating events that might conflict, namely: * * 1) cpu-wide events in the presence of per-task events, * 2) per-task events in the presence of cpu-wide events, * 3) two matching events on the same perf_event_context. * * The former two cases are handled in the allocation path (perf_event_alloc(), * _free_event()), the latter -- before the first perf_install_in_context(). */static int exclusive_event_init(struct perf_event *event){ struct pmu *pmu = event->pmu;
if (!is_exclusive_pmu(pmu)) return 0;
/* * Prevent co-existence of per-task and cpu-wide events on the * same exclusive pmu. * * Negative pmu::exclusive_cnt means there are cpu-wide * events on this "exclusive" pmu, positive means there are * per-task events. * * Since this is called in perf_event_alloc() path, event::ctx * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK * to mean "per-task event", because unlike other attach states it * never gets cleared. */ if (event->attach_state & PERF_ATTACH_TASK) { if (!atomic_inc_unless_negative(&pmu->exclusive_cnt)) return -EBUSY; } else { if (!atomic_dec_unless_positive(&pmu->exclusive_cnt)) return -EBUSY; }
event->attach_state |= PERF_ATTACH_EXCLUSIVE;
return 0;}
static void exclusive_event_destroy(struct perf_event *event){ struct pmu *pmu = event->pmu;
/* see comment in exclusive_event_init() */ if (event->attach_state & PERF_ATTACH_TASK) atomic_dec(&pmu->exclusive_cnt); else atomic_inc(&pmu->exclusive_cnt);
event->attach_state &= ~PERF_ATTACH_EXCLUSIVE;}
static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2){ if ((e1->pmu == e2->pmu) && (e1->cpu == e2->cpu || e1->cpu == -1 || e2->cpu == -1)) return true; return false;}
static bool exclusive_event_installable(struct perf_event *event, struct perf_event_context *ctx){ struct perf_event *iter_event; struct pmu *pmu = event->pmu;
lockdep_assert_held(&ctx->mutex);
if (!is_exclusive_pmu(pmu)) return true;
list_for_each_entry(iter_event, &ctx->event_list, event_entry) { if (exclusive_event_match(iter_event, event)) return false; }
return true;}
static void perf_free_addr_filters(struct perf_event *event);
/* vs perf_event_alloc() error */static void __free_event(struct perf_event *event){ struct pmu *pmu = event->pmu;
security_perf_event_free(event);
if (event->attach_state & PERF_ATTACH_CALLCHAIN) put_callchain_buffers();
if (event->attach_state & PERF_ATTACH_EXCLUSIVE) exclusive_event_destroy(event);
if (is_cgroup_event(event)) perf_detach_cgroup(event);
if (event->attach_state & PERF_ATTACH_TASK_DATA) detach_perf_ctx_data(event);
if (event->destroy) event->destroy(event);
/* * Must be after ->destroy(), due to uprobe_perf_close() using * hw.target. */ if (event->hw.target) put_task_struct(event->hw.target);
if (event->pmu_ctx) { /* * put_pmu_ctx() needs an event->ctx reference, because of * epc->ctx. */ WARN_ON_ONCE(!pmu); WARN_ON_ONCE(!event->ctx); WARN_ON_ONCE(event->pmu_ctx->ctx != event->ctx); put_pmu_ctx(event->pmu_ctx); }
/* * perf_event_free_task() relies on put_ctx() being 'last', in * particular all task references must be cleaned up. */ if (event->ctx) put_ctx(event->ctx);
if (pmu) { module_put(pmu->module); scoped_guard (spinlock, &pmu->events_lock) { list_del(&event->pmu_list); wake_up_var(pmu); } }
call_rcu(&event->rcu_head, free_event_rcu);}
static void mediated_pmu_unaccount_event(struct perf_event *event);
DEFINE_FREE(__free_event, struct perf_event *, if (_T) __free_event(_T))
/* vs perf_event_alloc() success */static void _free_event(struct perf_event *event){ irq_work_sync(&event->pending_irq); irq_work_sync(&event->pending_disable_irq);
unaccount_event(event); mediated_pmu_unaccount_event(event);
if (event->rb) { /* * Can happen when we close an event with re-directed output. * * Since we have a 0 refcount, perf_mmap_close() will skip * over us; possibly making our ring_buffer_put() the last. */ mutex_lock(&event->mmap_mutex); ring_buffer_attach(event, NULL); mutex_unlock(&event->mmap_mutex); }
perf_event_free_bpf_prog(event); perf_free_addr_filters(event);
__free_event(event);}
/* * Used to free events which have a known refcount of 1, such as in error paths * of inherited events. */static void free_event(struct perf_event *event){ if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1, "unexpected event refcount: %ld; ptr=%p\n", atomic_long_read(&event->refcount), event)) { /* leak to avoid use-after-free */ return; }
_free_event(event);}
/* * Remove user event from the owner task. */static void perf_remove_from_owner(struct perf_event *event){ struct task_struct *owner;
rcu_read_lock(); /* * Matches the smp_store_release() in perf_event_exit_task(). If we * observe !owner it means the list deletion is complete and we can * indeed free this event, otherwise we need to serialize on * owner->perf_event_mutex. */ owner = READ_ONCE(event->owner); if (owner) { /* * Since delayed_put_task_struct() also drops the last * task reference we can safely take a new reference * while holding the rcu_read_lock(). */ get_task_struct(owner); } rcu_read_unlock();
if (owner) { /* * If we're here through perf_event_exit_task() we're already * holding ctx->mutex which would be an inversion wrt. the * normal lock order. * * However we can safely take this lock because its the child * ctx->mutex. */ mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING);
/* * We have to re-check the event->owner field, if it is cleared * we raced with perf_event_exit_task(), acquiring the mutex * ensured they're done, and we can proceed with freeing the * event. */ if (event->owner) { list_del_init(&event->owner_entry); smp_store_release(&event->owner, NULL); } mutex_unlock(&owner->perf_event_mutex); put_task_struct(owner); }}
static void put_event(struct perf_event *event){ struct perf_event *parent;
if (!atomic_long_dec_and_test(&event->refcount)) return;
parent = event->parent; _free_event(event);
/* Matches the refcount bump in inherit_event() */ if (parent) put_event(parent);}
/* * Kill an event dead; while event:refcount will preserve the event * object, it will not preserve its functionality. Once the last 'user' * gives up the object, we'll destroy the thing. */int perf_event_release_kernel(struct perf_event *event){ struct perf_event_context *ctx = event->ctx; struct perf_event *child, *tmp;
/* * If we got here through err_alloc: free_event(event); we will not * have attached to a context yet. */ if (!ctx) { WARN_ON_ONCE(event->attach_state & (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP)); goto no_ctx; }
if (!is_kernel_event(event)) perf_remove_from_owner(event);
ctx = perf_event_ctx_lock(event); WARN_ON_ONCE(ctx->parent_ctx);
/* * Mark this event as STATE_DEAD, there is no external reference to it * anymore. * * Anybody acquiring event->child_mutex after the below loop _must_ * also see this, most importantly inherit_event() which will avoid * placing more children on the list. * * Thus this guarantees that we will in fact observe and kill _ALL_ * child events. */ if (event->state > PERF_EVENT_STATE_REVOKED) { perf_remove_from_context(event, DETACH_GROUP|DETACH_DEAD); } else { event->state = PERF_EVENT_STATE_DEAD; }
perf_event_ctx_unlock(event, ctx);
again: mutex_lock(&event->child_mutex); list_for_each_entry(child, &event->child_list, child_list) { /* * Cannot change, child events are not migrated, see the * comment with perf_event_ctx_lock_nested(). */ ctx = READ_ONCE(child->ctx); /* * Since child_mutex nests inside ctx::mutex, we must jump * through hoops. We start by grabbing a reference on the ctx. * * Since the event cannot get freed while we hold the * child_mutex, the context must also exist and have a !0 * reference count. */ get_ctx(ctx);
/* * Now that we have a ctx ref, we can drop child_mutex, and * acquire ctx::mutex without fear of it going away. Then we * can re-acquire child_mutex. */ mutex_unlock(&event->child_mutex); mutex_lock(&ctx->mutex); mutex_lock(&event->child_mutex);
/* * Now that we hold ctx::mutex and child_mutex, revalidate our * state, if child is still the first entry, it didn't get freed * and we can continue doing so. */ tmp = list_first_entry_or_null(&event->child_list, struct perf_event, child_list); if (tmp == child) { perf_remove_from_context(child, DETACH_GROUP | DETACH_CHILD); } else { child = NULL; }
mutex_unlock(&event->child_mutex); mutex_unlock(&ctx->mutex);
if (child) { /* Last reference unless ->pending_task work is pending */ put_event(child); } put_ctx(ctx);
goto again; } mutex_unlock(&event->child_mutex);
no_ctx: /* * Last reference unless ->pending_task work is pending on this event * or any of its children. */ put_event(event); return 0;}EXPORT_SYMBOL_GPL(perf_event_release_kernel);
/* * Called when the last reference to the file is gone. */static int perf_release(struct inode *inode, struct file *file){ perf_event_release_kernel(file->private_data); return 0;}
static u64 __perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running){ struct perf_event *child; u64 total = 0;
*enabled = 0; *running = 0;
mutex_lock(&event->child_mutex);
(void)perf_event_read(event, false); total += perf_event_count(event, false);
*enabled += event->total_time_enabled + atomic64_read(&event->child_total_time_enabled); *running += event->total_time_running + atomic64_read(&event->child_total_time_running);
list_for_each_entry(child, &event->child_list, child_list) { (void)perf_event_read(child, false); total += perf_event_count(child, false); *enabled += child->total_time_enabled; *running += child->total_time_running; } mutex_unlock(&event->child_mutex);
return total;}
u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running){ struct perf_event_context *ctx; u64 count;
ctx = perf_event_ctx_lock(event); count = __perf_event_read_value(event, enabled, running); perf_event_ctx_unlock(event, ctx);
return count;}EXPORT_SYMBOL_GPL(perf_event_read_value);
static int __perf_read_group_add(struct perf_event *leader, u64 read_format, u64 *values){ struct perf_event_context *ctx = leader->ctx; struct perf_event *sub, *parent; unsigned long flags; int n = 1; /* skip @nr */ int ret;
ret = perf_event_read(leader, true); if (ret) return ret;
raw_spin_lock_irqsave(&ctx->lock, flags); /* * Verify the grouping between the parent and child (inherited) * events is still in tact. * * Specifically: * - leader->ctx->lock pins leader->sibling_list * - parent->child_mutex pins parent->child_list * - parent->ctx->mutex pins parent->sibling_list * * Because parent->ctx != leader->ctx (and child_list nests inside * ctx->mutex), group destruction is not atomic between children, also * see perf_event_release_kernel(). Additionally, parent can grow the * group. * * Therefore it is possible to have parent and child groups in a * different configuration and summing over such a beast makes no sense * what so ever. * * Reject this. */ parent = leader->parent; if (parent && (parent->group_generation != leader->group_generation || parent->nr_siblings != leader->nr_siblings)) { ret = -ECHILD; goto unlock; }
/* * Since we co-schedule groups, {enabled,running} times of siblings * will be identical to those of the leader, so we only publish one * set. */ if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { values[n++] += leader->total_time_enabled + atomic64_read(&leader->child_total_time_enabled); }
if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { values[n++] += leader->total_time_running + atomic64_read(&leader->child_total_time_running); }
/* * Write {count,id} tuples for every sibling. */ values[n++] += perf_event_count(leader, false); if (read_format & PERF_FORMAT_ID) values[n++] = primary_event_id(leader); if (read_format & PERF_FORMAT_LOST) values[n++] = atomic64_read(&leader->lost_samples);
for_each_sibling_event(sub, leader) { values[n++] += perf_event_count(sub, false); if (read_format & PERF_FORMAT_ID) values[n++] = primary_event_id(sub); if (read_format & PERF_FORMAT_LOST) values[n++] = atomic64_read(&sub->lost_samples); }
unlock: raw_spin_unlock_irqrestore(&ctx->lock, flags); return ret;}
static int perf_read_group(struct perf_event *event, u64 read_format, char __user *buf){ struct perf_event *leader = event->group_leader, *child; struct perf_event_context *ctx = leader->ctx; int ret; u64 *values;
lockdep_assert_held(&ctx->mutex);
values = kzalloc(event->read_size, GFP_KERNEL); if (!values) return -ENOMEM;
values[0] = 1 + leader->nr_siblings;
mutex_lock(&leader->child_mutex);
ret = __perf_read_group_add(leader, read_format, values); if (ret) goto unlock;
list_for_each_entry(child, &leader->child_list, child_list) { ret = __perf_read_group_add(child, read_format, values); if (ret) goto unlock; }
mutex_unlock(&leader->child_mutex);
ret = event->read_size; if (copy_to_user(buf, values, event->read_size)) ret = -EFAULT; goto out;
unlock: mutex_unlock(&leader->child_mutex);out: kfree(values); return ret;}
static int perf_read_one(struct perf_event *event, u64 read_format, char __user *buf){ u64 enabled, running; u64 values[5]; int n = 0;
values[n++] = __perf_event_read_value(event, &enabled, &running); if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) values[n++] = enabled; if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) values[n++] = running; if (read_format & PERF_FORMAT_ID) values[n++] = primary_event_id(event); if (read_format & PERF_FORMAT_LOST) values[n++] = atomic64_read(&event->lost_samples);
if (copy_to_user(buf, values, n * sizeof(u64))) return -EFAULT;
return n * sizeof(u64);}
static bool is_event_hup(struct perf_event *event){ bool no_children;
if (event->state > PERF_EVENT_STATE_EXIT) return false;
mutex_lock(&event->child_mutex); no_children = list_empty(&event->child_list); mutex_unlock(&event->child_mutex); return no_children;}
/* * Read the performance event - simple non blocking version for now */static ssize_t__perf_read(struct perf_event *event, char __user *buf, size_t count){ u64 read_format = event->attr.read_format; int ret;
/* * Return end-of-file for a read on an event that is in * error state (i.e. because it was pinned but it couldn't be * scheduled on to the CPU at some point). */ if (event->state == PERF_EVENT_STATE_ERROR) return 0;
if (count < event->read_size) return -ENOSPC;
WARN_ON_ONCE(event->ctx->parent_ctx); if (read_format & PERF_FORMAT_GROUP) ret = perf_read_group(event, read_format, buf); else ret = perf_read_one(event, read_format, buf);
return ret;}
static ssize_tperf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos){ struct perf_event *event = file->private_data; struct perf_event_context *ctx; int ret;
ret = security_perf_event_read(event); if (ret) return ret;
ctx = perf_event_ctx_lock(event); ret = __perf_read(event, buf, count); perf_event_ctx_unlock(event, ctx);
return ret;}
static __poll_t perf_poll(struct file *file, poll_table *wait){ struct perf_event *event = file->private_data; struct perf_buffer *rb; __poll_t events = EPOLLHUP;
if (event->state <= PERF_EVENT_STATE_REVOKED) return EPOLLERR;
poll_wait(file, &event->waitq, wait);
if (event->state <= PERF_EVENT_STATE_REVOKED) return EPOLLERR;
if (is_event_hup(event)) return events;
if (unlikely(READ_ONCE(event->state) == PERF_EVENT_STATE_ERROR && event->attr.pinned)) return EPOLLERR;
/* * Pin the event->rb by taking event->mmap_mutex; otherwise * perf_event_set_output() can swizzle our rb and make us miss wakeups. */ mutex_lock(&event->mmap_mutex); rb = event->rb; if (rb) events = atomic_xchg(&rb->poll, 0); mutex_unlock(&event->mmap_mutex); return events;}
static void _perf_event_reset(struct perf_event *event){ (void)perf_event_read(event, false); local64_set(&event->count, 0); perf_event_update_userpage(event);}
/* Assume it's not an event with inherit set. */u64 perf_event_pause(struct perf_event *event, bool reset){ struct perf_event_context *ctx; u64 count;
ctx = perf_event_ctx_lock(event); WARN_ON_ONCE(event->attr.inherit); _perf_event_disable(event); count = local64_read(&event->count); if (reset) local64_set(&event->count, 0); perf_event_ctx_unlock(event, ctx);
return count;}EXPORT_SYMBOL_GPL(perf_event_pause);
#ifdef CONFIG_PERF_GUEST_MEDIATED_PMUstatic atomic_t nr_include_guest_events __read_mostly;
static atomic_t nr_mediated_pmu_vms __read_mostly;static DEFINE_MUTEX(perf_mediated_pmu_mutex);
/* !exclude_guest event of PMU with PERF_PMU_CAP_MEDIATED_VPMU */static inline bool is_include_guest_event(struct perf_event *event){ if ((event->pmu->capabilities & PERF_PMU_CAP_MEDIATED_VPMU) && !event->attr.exclude_guest) return true;
return false;}
static int mediated_pmu_account_event(struct perf_event *event){ if (!is_include_guest_event(event)) return 0;
if (atomic_inc_not_zero(&nr_include_guest_events)) return 0;
guard(mutex)(&perf_mediated_pmu_mutex); if (atomic_read(&nr_mediated_pmu_vms)) return -EOPNOTSUPP;
atomic_inc(&nr_include_guest_events); return 0;}
static void mediated_pmu_unaccount_event(struct perf_event *event){ if (!is_include_guest_event(event)) return;
if (WARN_ON_ONCE(!atomic_read(&nr_include_guest_events))) return;
atomic_dec(&nr_include_guest_events);}
/* * Currently invoked at VM creation to * - Check whether there are existing !exclude_guest events of PMU with * PERF_PMU_CAP_MEDIATED_VPMU * - Set nr_mediated_pmu_vms to prevent !exclude_guest event creation on * PMUs with PERF_PMU_CAP_MEDIATED_VPMU * * No impact for the PMU without PERF_PMU_CAP_MEDIATED_VPMU. The perf * still owns all the PMU resources. */int perf_create_mediated_pmu(void){ if (atomic_inc_not_zero(&nr_mediated_pmu_vms)) return 0;
guard(mutex)(&perf_mediated_pmu_mutex); if (atomic_read(&nr_include_guest_events)) return -EBUSY;
atomic_inc(&nr_mediated_pmu_vms); return 0;}EXPORT_SYMBOL_FOR_KVM(perf_create_mediated_pmu);
void perf_release_mediated_pmu(void){ if (WARN_ON_ONCE(!atomic_read(&nr_mediated_pmu_vms))) return;
atomic_dec(&nr_mediated_pmu_vms);}EXPORT_SYMBOL_FOR_KVM(perf_release_mediated_pmu);
/* When loading a guest's mediated PMU, schedule out all exclude_guest events. */void perf_load_guest_context(void){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
lockdep_assert_irqs_disabled();
guard(perf_ctx_lock)(cpuctx, cpuctx->task_ctx);
if (WARN_ON_ONCE(__this_cpu_read(guest_ctx_loaded))) return;
perf_ctx_disable(&cpuctx->ctx, EVENT_GUEST); ctx_sched_out(&cpuctx->ctx, NULL, EVENT_GUEST); if (cpuctx->task_ctx) { perf_ctx_disable(cpuctx->task_ctx, EVENT_GUEST); task_ctx_sched_out(cpuctx->task_ctx, NULL, EVENT_GUEST); }
perf_ctx_enable(&cpuctx->ctx, EVENT_GUEST); if (cpuctx->task_ctx) perf_ctx_enable(cpuctx->task_ctx, EVENT_GUEST);
__this_cpu_write(guest_ctx_loaded, true);}EXPORT_SYMBOL_GPL(perf_load_guest_context);
void perf_put_guest_context(void){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
lockdep_assert_irqs_disabled();
guard(perf_ctx_lock)(cpuctx, cpuctx->task_ctx);
if (WARN_ON_ONCE(!__this_cpu_read(guest_ctx_loaded))) return;
perf_ctx_disable(&cpuctx->ctx, EVENT_GUEST); if (cpuctx->task_ctx) perf_ctx_disable(cpuctx->task_ctx, EVENT_GUEST);
perf_event_sched_in(cpuctx, cpuctx->task_ctx, NULL, EVENT_GUEST);
if (cpuctx->task_ctx) perf_ctx_enable(cpuctx->task_ctx, EVENT_GUEST); perf_ctx_enable(&cpuctx->ctx, EVENT_GUEST);
__this_cpu_write(guest_ctx_loaded, false);}EXPORT_SYMBOL_GPL(perf_put_guest_context);#elsestatic int mediated_pmu_account_event(struct perf_event *event) { return 0; }static void mediated_pmu_unaccount_event(struct perf_event *event) {}#endif
/* * Holding the top-level event's child_mutex means that any * descendant process that has inherited this event will block * in perf_event_exit_event() if it goes to exit, thus satisfying the * task existence requirements of perf_event_enable/disable. */static void perf_event_for_each_child(struct perf_event *event, void (*func)(struct perf_event *)){ struct perf_event *child;
WARN_ON_ONCE(event->ctx->parent_ctx);
mutex_lock(&event->child_mutex); func(event); list_for_each_entry(child, &event->child_list, child_list) func(child); mutex_unlock(&event->child_mutex);}
static void perf_event_for_each(struct perf_event *event, void (*func)(struct perf_event *)){ struct perf_event_context *ctx = event->ctx; struct perf_event *sibling;
lockdep_assert_held(&ctx->mutex);
event = event->group_leader;
perf_event_for_each_child(event, func); for_each_sibling_event(sibling, event) perf_event_for_each_child(sibling, func);}
static void __perf_event_period(struct perf_event *event, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx, void *info){ u64 value = *((u64 *)info); bool active;
if (event->attr.freq) { event->attr.sample_freq = value; } else { event->attr.sample_period = value; event->hw.sample_period = value; }
active = (event->state == PERF_EVENT_STATE_ACTIVE); if (active) { perf_pmu_disable(event->pmu); event->pmu->stop(event, PERF_EF_UPDATE); }
local64_set(&event->hw.period_left, 0);
if (active) { event->pmu->start(event, PERF_EF_RELOAD); /* * Once the period is force-reset, the event starts immediately. * But the event/group could be throttled. Unthrottle the * event/group now to avoid the next tick trying to unthrottle * while we already re-started the event/group. */ if (event->hw.interrupts == MAX_INTERRUPTS) perf_event_unthrottle_group(event, true); perf_pmu_enable(event->pmu); }}
static int perf_event_check_period(struct perf_event *event, u64 value){ return event->pmu->check_period(event, value);}
static int _perf_event_period(struct perf_event *event, u64 value){ if (!is_sampling_event(event)) return -EINVAL;
if (!value) return -EINVAL;
if (event->attr.freq) { if (value > sysctl_perf_event_sample_rate) return -EINVAL; } else { if (perf_event_check_period(event, value)) return -EINVAL; if (value & (1ULL << 63)) return -EINVAL; }
event_function_call(event, __perf_event_period, &value);
return 0;}
int perf_event_period(struct perf_event *event, u64 value){ struct perf_event_context *ctx; int ret;
ctx = perf_event_ctx_lock(event); ret = _perf_event_period(event, value); perf_event_ctx_unlock(event, ctx);
return ret;}EXPORT_SYMBOL_GPL(perf_event_period);
static const struct file_operations perf_fops;
static inline bool is_perf_file(struct fd f){ return !fd_empty(f) && fd_file(f)->f_op == &perf_fops;}
static int perf_event_set_output(struct perf_event *event, struct perf_event *output_event);static int perf_event_set_filter(struct perf_event *event, void __user *arg);static int perf_copy_attr(struct perf_event_attr __user *uattr, struct perf_event_attr *attr);static int __perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie);
static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg){ void (*func)(struct perf_event *); u32 flags = arg;
if (event->state <= PERF_EVENT_STATE_REVOKED) return -ENODEV;
switch (cmd) { case PERF_EVENT_IOC_ENABLE: func = _perf_event_enable; break; case PERF_EVENT_IOC_DISABLE: func = _perf_event_disable; break; case PERF_EVENT_IOC_RESET: func = _perf_event_reset; break;
case PERF_EVENT_IOC_REFRESH: return _perf_event_refresh(event, arg);
case PERF_EVENT_IOC_PERIOD: { u64 value;
if (copy_from_user(&value, (u64 __user *)arg, sizeof(value))) return -EFAULT;
return _perf_event_period(event, value); } case PERF_EVENT_IOC_ID: { u64 id = primary_event_id(event);
if (copy_to_user((void __user *)arg, &id, sizeof(id))) return -EFAULT; return 0; }
case PERF_EVENT_IOC_SET_OUTPUT: { CLASS(fd, output)(arg); // arg == -1 => empty struct perf_event *output_event = NULL; if (arg != -1) { if (!is_perf_file(output)) return -EBADF; output_event = fd_file(output)->private_data; } return perf_event_set_output(event, output_event); }
case PERF_EVENT_IOC_SET_FILTER: return perf_event_set_filter(event, (void __user *)arg);
case PERF_EVENT_IOC_SET_BPF: { struct bpf_prog *prog; int err;
prog = bpf_prog_get(arg); if (IS_ERR(prog)) return PTR_ERR(prog);
err = __perf_event_set_bpf_prog(event, prog, 0); if (err) { bpf_prog_put(prog); return err; }
return 0; }
case PERF_EVENT_IOC_PAUSE_OUTPUT: { struct perf_buffer *rb;
rcu_read_lock(); rb = rcu_dereference(event->rb); if (!rb || !rb->nr_pages) { rcu_read_unlock(); return -EINVAL; } rb_toggle_paused(rb, !!arg); rcu_read_unlock(); return 0; }
case PERF_EVENT_IOC_QUERY_BPF: return perf_event_query_prog_array(event, (void __user *)arg);
case PERF_EVENT_IOC_MODIFY_ATTRIBUTES: { struct perf_event_attr new_attr; int err = perf_copy_attr((struct perf_event_attr __user *)arg, &new_attr);
if (err) return err;
return perf_event_modify_attr(event, &new_attr); } default: return -ENOTTY; }
if (flags & PERF_IOC_FLAG_GROUP) perf_event_for_each(event, func); else perf_event_for_each_child(event, func);
return 0;}
static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg){ struct perf_event *event = file->private_data; struct perf_event_context *ctx; long ret;
/* Treat ioctl like writes as it is likely a mutating operation. */ ret = security_perf_event_write(event); if (ret) return ret;
ctx = perf_event_ctx_lock(event); ret = _perf_ioctl(event, cmd, arg); perf_event_ctx_unlock(event, ctx);
return ret;}
#ifdef CONFIG_COMPATstatic long perf_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg){ switch (_IOC_NR(cmd)) { case _IOC_NR(PERF_EVENT_IOC_SET_FILTER): case _IOC_NR(PERF_EVENT_IOC_ID): case _IOC_NR(PERF_EVENT_IOC_QUERY_BPF): case _IOC_NR(PERF_EVENT_IOC_MODIFY_ATTRIBUTES): /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */ if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) { cmd &= ~IOCSIZE_MASK; cmd |= sizeof(void *) << IOCSIZE_SHIFT; } break; } return perf_ioctl(file, cmd, arg);}#else# define perf_compat_ioctl NULL#endif
int perf_event_task_enable(void){ struct perf_event_context *ctx; struct perf_event *event;
mutex_lock(¤t->perf_event_mutex); list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { ctx = perf_event_ctx_lock(event); perf_event_for_each_child(event, _perf_event_enable); perf_event_ctx_unlock(event, ctx); } mutex_unlock(¤t->perf_event_mutex);
return 0;}
int perf_event_task_disable(void){ struct perf_event_context *ctx; struct perf_event *event;
mutex_lock(¤t->perf_event_mutex); list_for_each_entry(event, ¤t->perf_event_list, owner_entry) { ctx = perf_event_ctx_lock(event); perf_event_for_each_child(event, _perf_event_disable); perf_event_ctx_unlock(event, ctx); } mutex_unlock(¤t->perf_event_mutex);
return 0;}
static int perf_event_index(struct perf_event *event){ if (event->hw.state & PERF_HES_STOPPED) return 0;
if (event->state != PERF_EVENT_STATE_ACTIVE) return 0;
return event->pmu->event_idx(event);}
static void perf_event_init_userpage(struct perf_event *event){ struct perf_event_mmap_page *userpg; struct perf_buffer *rb;
rcu_read_lock(); rb = rcu_dereference(event->rb); if (!rb) goto unlock;
userpg = rb->user_page;
/* Allow new userspace to detect that bit 0 is deprecated */ userpg->cap_bit0_is_deprecated = 1; userpg->size = offsetof(struct perf_event_mmap_page, __reserved); userpg->data_offset = PAGE_SIZE; userpg->data_size = perf_data_size(rb);
unlock: rcu_read_unlock();}
void __weak arch_perf_update_userpage( struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now){}
/* * Callers need to ensure there can be no nesting of this function, otherwise * the seqlock logic goes bad. We can not serialize this because the arch * code calls this from NMI context. */void perf_event_update_userpage(struct perf_event *event){ struct perf_event_mmap_page *userpg; struct perf_buffer *rb; u64 enabled, running, now;
rcu_read_lock(); rb = rcu_dereference(event->rb); if (!rb) goto unlock;
/* * Disable preemption to guarantee consistent time stamps are stored to * the user page. */ preempt_disable();
/* * Compute total_time_enabled, total_time_running based on snapshot * values taken when the event was last scheduled in. * * We cannot simply call update_context_time() because doing so would * lead to deadlock when called from NMI context. */ calc_timer_values(event, &now, &enabled, &running);
userpg = rb->user_page;
++userpg->lock; barrier(); userpg->index = perf_event_index(event); userpg->offset = perf_event_count(event, false); if (userpg->index) userpg->offset -= local64_read(&event->hw.prev_count);
userpg->time_enabled = enabled + atomic64_read(&event->child_total_time_enabled);
userpg->time_running = running + atomic64_read(&event->child_total_time_running);
arch_perf_update_userpage(event, userpg, now);
barrier(); ++userpg->lock; preempt_enable();unlock: rcu_read_unlock();}EXPORT_SYMBOL_GPL(perf_event_update_userpage);
static void ring_buffer_attach(struct perf_event *event, struct perf_buffer *rb){ struct perf_buffer *old_rb = NULL; unsigned long flags;
WARN_ON_ONCE(event->parent);
if (event->rb) { /* * Should be impossible, we set this when removing * event->rb_entry and wait/clear when adding event->rb_entry. */ WARN_ON_ONCE(event->rcu_pending);
old_rb = event->rb; spin_lock_irqsave(&old_rb->event_lock, flags); list_del_rcu(&event->rb_entry); spin_unlock_irqrestore(&old_rb->event_lock, flags);
event->rcu_batches = get_state_synchronize_rcu(); event->rcu_pending = 1; }
if (rb) { if (event->rcu_pending) { cond_synchronize_rcu(event->rcu_batches); event->rcu_pending = 0; }
spin_lock_irqsave(&rb->event_lock, flags); list_add_rcu(&event->rb_entry, &rb->event_list); spin_unlock_irqrestore(&rb->event_lock, flags); }
/* * Avoid racing with perf_mmap_close(AUX): stop the event * before swizzling the event::rb pointer; if it's getting * unmapped, its aux_mmap_count will be 0 and it won't * restart. See the comment in __perf_pmu_output_stop(). * * Data will inevitably be lost when set_output is done in * mid-air, but then again, whoever does it like this is * not in for the data anyway. */ if (has_aux(event)) perf_event_stop(event, 0);
rcu_assign_pointer(event->rb, rb);
if (old_rb) { ring_buffer_put(old_rb); /* * Since we detached before setting the new rb, so that we * could attach the new rb, we could have missed a wakeup. * Provide it now. */ wake_up_all(&event->waitq); }}
static void ring_buffer_wakeup(struct perf_event *event){ struct perf_buffer *rb;
if (event->parent) event = event->parent;
rcu_read_lock(); rb = rcu_dereference(event->rb); if (rb) { list_for_each_entry_rcu(event, &rb->event_list, rb_entry) wake_up_all(&event->waitq); } rcu_read_unlock();}
struct perf_buffer *ring_buffer_get(struct perf_event *event){ struct perf_buffer *rb;
if (event->parent) event = event->parent;
rcu_read_lock(); rb = rcu_dereference(event->rb); if (rb) { if (!refcount_inc_not_zero(&rb->refcount)) rb = NULL; } rcu_read_unlock();
return rb;}
void ring_buffer_put(struct perf_buffer *rb){ if (!refcount_dec_and_test(&rb->refcount)) return;
WARN_ON_ONCE(!list_empty(&rb->event_list));
call_rcu(&rb->rcu_head, rb_free_rcu);}
typedef void (*mapped_f)(struct perf_event *event, struct mm_struct *mm);
#define get_mapped(event, func) \({ struct pmu *pmu; \ mapped_f f = NULL; \ guard(rcu)(); \ pmu = READ_ONCE(event->pmu); \ if (pmu) \ f = pmu->func; \ f; \})
static void perf_mmap_open(struct vm_area_struct *vma){ struct perf_event *event = vma->vm_file->private_data; mapped_f mapped = get_mapped(event, event_mapped);
refcount_inc(&event->mmap_count); refcount_inc(&event->rb->mmap_count);
if (vma->vm_pgoff) refcount_inc(&event->rb->aux_mmap_count);
if (mapped) mapped(event, vma->vm_mm);}
static void perf_pmu_output_stop(struct perf_event *event);static void perf_mmap_unaccount(struct vm_area_struct *vma, struct perf_buffer *rb);
/* * A buffer can be mmap()ed multiple times; either directly through the same * event, or through other events by use of perf_event_set_output(). * * In order to undo the VM accounting done by perf_mmap() we need to destroy * the buffer here, where we still have a VM context. This means we need * to detach all events redirecting to us. */static void perf_mmap_close(struct vm_area_struct *vma){ struct perf_event *event = vma->vm_file->private_data; mapped_f unmapped = get_mapped(event, event_unmapped); struct perf_buffer *rb = ring_buffer_get(event); struct user_struct *mmap_user = rb->mmap_user; bool detach_rest = false;
/* FIXIES vs perf_pmu_unregister() */ if (unmapped) unmapped(event, vma->vm_mm);
/* * The AUX buffer is strictly a sub-buffer, serialize using aux_mutex * to avoid complications. */ if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff && refcount_dec_and_mutex_lock(&rb->aux_mmap_count, &rb->aux_mutex)) { /* * Stop all AUX events that are writing to this buffer, * so that we can free its AUX pages and corresponding PMU * data. Note that after rb::aux_mmap_count dropped to zero, * they won't start any more (see perf_aux_output_begin()). */ perf_pmu_output_stop(event);
/* now it's safe to free the pages */ atomic_long_sub(rb->aux_nr_pages - rb->aux_mmap_locked, &mmap_user->locked_vm); atomic64_sub(rb->aux_mmap_locked, &vma->vm_mm->pinned_vm);
/* this has to be the last one */ rb_free_aux(rb); WARN_ON_ONCE(refcount_read(&rb->aux_refcount));
mutex_unlock(&rb->aux_mutex); }
if (refcount_dec_and_test(&rb->mmap_count)) detach_rest = true;
if (!refcount_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) goto out_put;
ring_buffer_attach(event, NULL); mutex_unlock(&event->mmap_mutex);
/* If there's still other mmap()s of this buffer, we're done. */ if (!detach_rest) goto out_put;
/* * No other mmap()s, detach from all other events that might redirect * into the now unreachable buffer. Somewhat complicated by the * fact that rb::event_lock otherwise nests inside mmap_mutex. */again: rcu_read_lock(); list_for_each_entry_rcu(event, &rb->event_list, rb_entry) { if (!atomic_long_inc_not_zero(&event->refcount)) { /* * This event is en-route to free_event() which will * detach it and remove it from the list. */ continue; } rcu_read_unlock();
mutex_lock(&event->mmap_mutex); /* * Check we didn't race with perf_event_set_output() which can * swizzle the rb from under us while we were waiting to * acquire mmap_mutex. * * If we find a different rb; ignore this event, a next * iteration will no longer find it on the list. We have to * still restart the iteration to make sure we're not now * iterating the wrong list. */ if (event->rb == rb) ring_buffer_attach(event, NULL);
mutex_unlock(&event->mmap_mutex); put_event(event);
/* * Restart the iteration; either we're on the wrong list or * destroyed its integrity by doing a deletion. */ goto again; } rcu_read_unlock();
/* * It could be there's still a few 0-ref events on the list; they'll * get cleaned up by free_event() -- they'll also still have their * ref on the rb and will free it whenever they are done with it. * * Aside from that, this buffer is 'fully' detached and unmapped, * undo the VM accounting. */ perf_mmap_unaccount(vma, rb);
out_put: ring_buffer_put(rb); /* could be last */}
static vm_fault_t perf_mmap_pfn_mkwrite(struct vm_fault *vmf){ /* The first page is the user control page, others are read-only. */ return vmf->pgoff == 0 ? 0 : VM_FAULT_SIGBUS;}
static int perf_mmap_may_split(struct vm_area_struct *vma, unsigned long addr){ /* * Forbid splitting perf mappings to prevent refcount leaks due to * the resulting non-matching offsets and sizes. See open()/close(). */ return -EINVAL;}
static const struct vm_operations_struct perf_mmap_vmops = { .open = perf_mmap_open, .close = perf_mmap_close, /* non mergeable */ .pfn_mkwrite = perf_mmap_pfn_mkwrite, .may_split = perf_mmap_may_split,};
static int map_range(struct perf_buffer *rb, struct vm_area_struct *vma){ unsigned long nr_pages = vma_pages(vma); int err = 0; unsigned long pagenum;
guard(mutex)(&rb->aux_mutex);
/* * We map this as a VM_PFNMAP VMA. * * This is not ideal as this is designed broadly for mappings of PFNs * referencing memory-mapped I/O ranges or non-system RAM i.e. for which * !pfn_valid(pfn). * * We are mapping kernel-allocated memory (memory we manage ourselves) * which would more ideally be mapped using vm_insert_page() or a * similar mechanism, that is as a VM_MIXEDMAP mapping. * * However this won't work here, because: * * 1. It uses vma->vm_page_prot, but this field has not been completely * setup at the point of the f_op->mmp() hook, so we are unable to * indicate that this should be mapped CoW in order that the * mkwrite() hook can be invoked to make the first page R/W and the * rest R/O as desired. * * 2. Anything other than a VM_PFNMAP of valid PFNs will result in * vm_normal_page() returning a struct page * pointer, which means * vm_ops->page_mkwrite() will be invoked rather than * vm_ops->pfn_mkwrite(), and this means we have to set page->mapping * to work around retry logic in the fault handler, however this * field is no longer allowed to be used within struct page. * * 3. Having a struct page * made available in the fault logic also * means that the page gets put on the rmap and becomes * inappropriately accessible and subject to map and ref counting. * * Ideally we would have a mechanism that could explicitly express our * desires, but this is not currently the case, so we instead use * VM_PFNMAP. * * We manage the lifetime of these mappings with internal refcounts (see * perf_mmap_open() and perf_mmap_close()) so we ensure the lifetime of * this mapping is maintained correctly. */ for (pagenum = 0; pagenum < nr_pages; pagenum++) { unsigned long va = vma->vm_start + PAGE_SIZE * pagenum; struct page *page = perf_mmap_to_page(rb, vma->vm_pgoff + pagenum);
if (page == NULL) { err = -EINVAL; break; }
/* Map readonly, perf_mmap_pfn_mkwrite() called on write fault. */ err = remap_pfn_range(vma, va, page_to_pfn(page), PAGE_SIZE, vm_get_page_prot(vma->vm_flags & ~VM_SHARED)); if (err) break; }
#ifdef CONFIG_MMU /* Clear any partial mappings on error. */ if (err) zap_vma_range(vma, vma->vm_start, nr_pages * PAGE_SIZE);#endif
return err;}
static bool perf_mmap_calc_limits(struct vm_area_struct *vma, long *user_extra, long *extra){ unsigned long user_locked, user_lock_limit, locked, lock_limit; struct user_struct *user = current_user();
user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); /* Increase the limit linearly with more CPUs */ user_lock_limit *= num_online_cpus();
user_locked = atomic_long_read(&user->locked_vm);
/* * sysctl_perf_event_mlock may have changed, so that * user->locked_vm > user_lock_limit */ if (user_locked > user_lock_limit) user_locked = user_lock_limit; user_locked += *user_extra;
if (user_locked > user_lock_limit) { /* * charge locked_vm until it hits user_lock_limit; * charge the rest from pinned_vm */ *extra = user_locked - user_lock_limit; *user_extra -= *extra; }
lock_limit = rlimit(RLIMIT_MEMLOCK); lock_limit >>= PAGE_SHIFT; locked = atomic64_read(&vma->vm_mm->pinned_vm) + *extra;
return locked <= lock_limit || !perf_is_paranoid() || capable(CAP_IPC_LOCK);}
static void perf_mmap_account(struct vm_area_struct *vma, long user_extra, long extra){ struct user_struct *user = current_user();
atomic_long_add(user_extra, &user->locked_vm); atomic64_add(extra, &vma->vm_mm->pinned_vm);}
static void perf_mmap_unaccount(struct vm_area_struct *vma, struct perf_buffer *rb){ struct user_struct *user = rb->mmap_user;
atomic_long_sub((perf_data_size(rb) >> PAGE_SHIFT) + 1 - rb->mmap_locked, &user->locked_vm); atomic64_sub(rb->mmap_locked, &vma->vm_mm->pinned_vm);}
static int perf_mmap_rb(struct vm_area_struct *vma, struct perf_event *event, unsigned long nr_pages){ long extra = 0, user_extra = nr_pages; struct perf_buffer *rb; int rb_flags = 0;
nr_pages -= 1;
/* * If we have rb pages ensure they're a power-of-two number, so we * can do bitmasks instead of modulo. */ if (nr_pages != 0 && !is_power_of_2(nr_pages)) return -EINVAL;
WARN_ON_ONCE(event->ctx->parent_ctx);
if (event->rb) { if (data_page_nr(event->rb) != nr_pages) return -EINVAL;
/* * If this event doesn't have mmap_count, we're attempting to * create an alias of another event's mmap(); this would mean * both events will end up scribbling the same user_page; * which makes no sense. */ if (!refcount_read(&event->mmap_count)) return -EBUSY;
if (refcount_inc_not_zero(&event->rb->mmap_count)) { /* * Success -- managed to mmap() the same buffer * multiple times. */ perf_mmap_account(vma, user_extra, extra); refcount_inc(&event->mmap_count); return 0; }
/* * Raced against perf_mmap_close()'s * refcount_dec_and_mutex_lock() remove the * event and continue as if !event->rb */ ring_buffer_attach(event, NULL); }
if (!perf_mmap_calc_limits(vma, &user_extra, &extra)) return -EPERM;
if (vma->vm_flags & VM_WRITE) rb_flags |= RING_BUFFER_WRITABLE;
rb = rb_alloc(nr_pages, event->attr.watermark ? event->attr.wakeup_watermark : 0, event->cpu, rb_flags);
if (!rb) return -ENOMEM;
rb->mmap_locked = extra;
ring_buffer_attach(event, rb);
perf_event_update_time(event); perf_event_init_userpage(event); perf_event_update_userpage(event);
perf_mmap_account(vma, user_extra, extra); refcount_set(&event->mmap_count, 1);
return 0;}
static int perf_mmap_aux(struct vm_area_struct *vma, struct perf_event *event, unsigned long nr_pages){ long extra = 0, user_extra = nr_pages; u64 aux_offset, aux_size; struct perf_buffer *rb; int ret, rb_flags = 0;
rb = event->rb; if (!rb) return -EINVAL;
guard(mutex)(&rb->aux_mutex);
/* * AUX area mapping: if rb->aux_nr_pages != 0, it's already * mapped, all subsequent mappings should have the same size * and offset. Must be above the normal perf buffer. */ aux_offset = READ_ONCE(rb->user_page->aux_offset); aux_size = READ_ONCE(rb->user_page->aux_size);
if (aux_offset < perf_data_size(rb) + PAGE_SIZE) return -EINVAL;
if (aux_offset != vma->vm_pgoff << PAGE_SHIFT) return -EINVAL;
/* already mapped with a different offset */ if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff) return -EINVAL;
if (aux_size != nr_pages * PAGE_SIZE) return -EINVAL;
/* already mapped with a different size */ if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages) return -EINVAL;
if (!is_power_of_2(nr_pages)) return -EINVAL;
if (!refcount_inc_not_zero(&rb->mmap_count)) return -EINVAL;
if (rb_has_aux(rb)) { refcount_inc(&rb->aux_mmap_count);
} else { if (!perf_mmap_calc_limits(vma, &user_extra, &extra)) { refcount_dec(&rb->mmap_count); return -EPERM; }
WARN_ON(!rb && event->rb);
if (vma->vm_flags & VM_WRITE) rb_flags |= RING_BUFFER_WRITABLE;
ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, event->attr.aux_watermark, rb_flags); if (ret) { refcount_dec(&rb->mmap_count); return ret; }
refcount_set(&rb->aux_mmap_count, 1); rb->aux_mmap_locked = extra; }
perf_mmap_account(vma, user_extra, extra); refcount_inc(&event->mmap_count);
return 0;}
static int perf_mmap(struct file *file, struct vm_area_struct *vma){ struct perf_event *event = file->private_data; unsigned long vma_size, nr_pages; mapped_f mapped; int ret;
/* * Don't allow mmap() of inherited per-task counters. This would * create a performance issue due to all children writing to the * same rb. */ if (event->cpu == -1 && event->attr.inherit) return -EINVAL;
if (!(vma->vm_flags & VM_SHARED)) return -EINVAL;
ret = security_perf_event_read(event); if (ret) return ret;
vma_size = vma->vm_end - vma->vm_start; nr_pages = vma_size / PAGE_SIZE;
if (nr_pages > INT_MAX) return -ENOMEM;
if (vma_size != PAGE_SIZE * nr_pages) return -EINVAL;
scoped_guard (mutex, &event->mmap_mutex) { /* * This relies on __pmu_detach_event() taking mmap_mutex after marking * the event REVOKED. Either we observe the state, or __pmu_detach_event() * will detach the rb created here. */ if (event->state <= PERF_EVENT_STATE_REVOKED) return -ENODEV;
if (vma->vm_pgoff == 0) ret = perf_mmap_rb(vma, event, nr_pages); else ret = perf_mmap_aux(vma, event, nr_pages); if (ret) return ret;
/* * Since pinned accounting is per vm we cannot allow fork() to copy our * vma. */ vm_flags_set(vma, VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP); vma->vm_ops = &perf_mmap_vmops;
mapped = get_mapped(event, event_mapped); if (mapped) mapped(event, vma->vm_mm);
/* * Try to map it into the page table. On fail undo the above, * as the callsite expects full cleanup in this case and * therefore does not invoke vmops::close(). */ ret = map_range(event->rb, vma); if (likely(!ret)) return 0;
/* Error path */
/* * If this is the first mmap(), then event->mmap_count should * be stable at 1. It is only modified by: * perf_mmap_{open,close}() and perf_mmap(). * * The former are not possible because this mmap() hasn't been * successful yet, and the latter is serialized by * event->mmap_mutex which we still hold (note that mmap_lock * is not strictly sufficient here, because the event fd can * be passed to another process through trivial means like * fork(), leading to concurrent mmap() from different mm). * * Make sure to remove event->rb before releasing * event->mmap_mutex, such that any concurrent mmap() will not * attempt use this failed buffer. */ if (refcount_read(&event->mmap_count) == 1) { /* * Minimal perf_mmap_close(); there can't be AUX or * other events on account of this being the first. */ mapped = get_mapped(event, event_unmapped); if (mapped) mapped(event, vma->vm_mm); perf_mmap_unaccount(vma, event->rb); ring_buffer_attach(event, NULL); /* drops last rb->refcount */ refcount_set(&event->mmap_count, 0); return ret; }
/* * Otherwise this is an already existing buffer, and there is * no race vs first exposure, so fall-through and call * perf_mmap_close(). */ }
perf_mmap_close(vma); return ret;}
static int perf_fasync(int fd, struct file *filp, int on){ struct inode *inode = file_inode(filp); struct perf_event *event = filp->private_data; int retval;
if (event->state <= PERF_EVENT_STATE_REVOKED) return -ENODEV;
inode_lock(inode); retval = fasync_helper(fd, filp, on, &event->fasync); inode_unlock(inode);
if (retval < 0) return retval;
return 0;}
static void perf_show_fdinfo(struct seq_file *m, struct file *f){ struct perf_event *event = f->private_data; struct perf_event_context *ctx; struct mutex *child_mutex;
ctx = perf_event_ctx_lock(event); child_mutex = event->parent ? &event->parent->child_mutex : &event->child_mutex; mutex_lock(child_mutex);
seq_printf(m, "perf_event_attr.type:\t%u\n", event->orig_type); if (event->pmu) seq_printf(m, "pmu_type:\t%u\n", event->pmu->type); seq_printf(m, "perf_event_attr.config:\t0x%llx\n", (unsigned long long)event->attr.config); seq_printf(m, "perf_event_attr.config1:\t0x%llx\n", (unsigned long long)event->attr.config1); seq_printf(m, "perf_event_attr.config2:\t0x%llx\n", (unsigned long long)event->attr.config2); seq_printf(m, "perf_event_attr.config3:\t0x%llx\n", (unsigned long long)event->attr.config3); seq_printf(m, "perf_event_attr.config4:\t0x%llx\n", (unsigned long long)event->attr.config4);
mutex_unlock(child_mutex); perf_event_ctx_unlock(event, ctx);}
static const struct file_operations perf_fops = { .release = perf_release, .read = perf_read, .poll = perf_poll, .unlocked_ioctl = perf_ioctl, .compat_ioctl = perf_compat_ioctl, .mmap = perf_mmap, .fasync = perf_fasync, .show_fdinfo = perf_show_fdinfo,};
/* * Perf event wakeup * * If there's data, ensure we set the poll() state and publish everything * to user-space before waking everybody up. */
void perf_event_wakeup(struct perf_event *event){ ring_buffer_wakeup(event);
if (event->pending_kill) { kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill); event->pending_kill = 0; }}
static void perf_sigtrap(struct perf_event *event){ /* * Both perf_pending_task() and perf_pending_irq() can race with the * task exiting. */ if (current->flags & PF_EXITING) return;
/* * We'd expect this to only occur if the irq_work is delayed and either * ctx->task or current has changed in the meantime. This can be the * case on architectures that do not implement arch_irq_work_raise(). */ if (WARN_ON_ONCE(event->ctx->task != current)) return;
send_sig_perf((void __user *)event->pending_addr, event->orig_type, event->attr.sig_data);}
/* * Deliver the pending work in-event-context or follow the context. */static void __perf_pending_disable(struct perf_event *event){ int cpu = READ_ONCE(event->oncpu);
/* * If the event isn't running; we done. event_sched_out() will have * taken care of things. */ if (cpu < 0) return;
/* * Yay, we hit home and are in the context of the event. */ if (cpu == smp_processor_id()) { if (event->pending_disable) { event->pending_disable = 0; perf_event_disable_local(event); } return; }
/* * CPU-A CPU-B * * perf_event_disable_inatomic() * @pending_disable = 1; * irq_work_queue(); * * sched-out * @pending_disable = 0; * * sched-in * perf_event_disable_inatomic() * @pending_disable = 1; * irq_work_queue(); // FAILS * * irq_work_run() * perf_pending_disable() * * But the event runs on CPU-B and wants disabling there. */ irq_work_queue_on(&event->pending_disable_irq, cpu);}
static void perf_pending_disable(struct irq_work *entry){ struct perf_event *event = container_of(entry, struct perf_event, pending_disable_irq); int rctx;
/* * If we 'fail' here, that's OK, it means recursion is already disabled * and we won't recurse 'further'. */ rctx = perf_swevent_get_recursion_context(); __perf_pending_disable(event); if (rctx >= 0) perf_swevent_put_recursion_context(rctx);}
static void perf_pending_irq(struct irq_work *entry){ struct perf_event *event = container_of(entry, struct perf_event, pending_irq); int rctx;
/* * If we 'fail' here, that's OK, it means recursion is already disabled * and we won't recurse 'further'. */ rctx = perf_swevent_get_recursion_context();
/* * The wakeup isn't bound to the context of the event -- it can happen * irrespective of where the event is. */ if (event->pending_wakeup) { event->pending_wakeup = 0; perf_event_wakeup(event); }
if (rctx >= 0) perf_swevent_put_recursion_context(rctx);}
static void perf_pending_task(struct callback_head *head){ struct perf_event *event = container_of(head, struct perf_event, pending_task); int rctx;
/* * If we 'fail' here, that's OK, it means recursion is already disabled * and we won't recurse 'further'. */ rctx = perf_swevent_get_recursion_context();
if (event->pending_work) { event->pending_work = 0; perf_sigtrap(event); local_dec(&event->ctx->nr_no_switch_fast); } put_event(event);
if (rctx >= 0) perf_swevent_put_recursion_context(rctx);}
#ifdef CONFIG_GUEST_PERF_EVENTSstruct perf_guest_info_callbacks __rcu *perf_guest_cbs;
DEFINE_STATIC_CALL_RET0(__perf_guest_state, *perf_guest_cbs->state);DEFINE_STATIC_CALL_RET0(__perf_guest_get_ip, *perf_guest_cbs->get_ip);DEFINE_STATIC_CALL_RET0(__perf_guest_handle_intel_pt_intr, *perf_guest_cbs->handle_intel_pt_intr);DEFINE_STATIC_CALL_RET0(__perf_guest_handle_mediated_pmi, *perf_guest_cbs->handle_mediated_pmi);
void perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs){ if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs))) return;
rcu_assign_pointer(perf_guest_cbs, cbs); static_call_update(__perf_guest_state, cbs->state); static_call_update(__perf_guest_get_ip, cbs->get_ip);
/* Implementing ->handle_intel_pt_intr is optional. */ if (cbs->handle_intel_pt_intr) static_call_update(__perf_guest_handle_intel_pt_intr, cbs->handle_intel_pt_intr);
if (cbs->handle_mediated_pmi) static_call_update(__perf_guest_handle_mediated_pmi, cbs->handle_mediated_pmi);}EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
void perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs){ if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs) != cbs)) return;
rcu_assign_pointer(perf_guest_cbs, NULL); static_call_update(__perf_guest_state, (void *)&__static_call_return0); static_call_update(__perf_guest_get_ip, (void *)&__static_call_return0); static_call_update(__perf_guest_handle_intel_pt_intr, (void *)&__static_call_return0); static_call_update(__perf_guest_handle_mediated_pmi, (void *)&__static_call_return0); synchronize_rcu();}EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);#endif
static bool should_sample_guest(struct perf_event *event){ return !event->attr.exclude_guest && perf_guest_state();}
unsigned long perf_misc_flags(struct perf_event *event, struct pt_regs *regs){ if (should_sample_guest(event)) return perf_arch_guest_misc_flags(regs);
return perf_arch_misc_flags(regs);}
unsigned long perf_instruction_pointer(struct perf_event *event, struct pt_regs *regs){ if (should_sample_guest(event)) return perf_guest_get_ip();
return perf_arch_instruction_pointer(regs);}
static voidperf_output_sample_regs(struct perf_output_handle *handle, struct pt_regs *regs, u64 mask){ int bit; DECLARE_BITMAP(_mask, 64);
bitmap_from_u64(_mask, mask); for_each_set_bit(bit, _mask, sizeof(mask) * BITS_PER_BYTE) { u64 val;
val = perf_reg_value(regs, bit); perf_output_put(handle, val); }}
static void perf_sample_regs_user(struct perf_regs *regs_user, struct pt_regs *regs){ if (user_mode(regs)) { regs_user->abi = perf_reg_abi(current); regs_user->regs = regs; } else if (is_user_task(current)) { perf_get_regs_user(regs_user, regs); } else { regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; regs_user->regs = NULL; }}
static void perf_sample_regs_intr(struct perf_regs *regs_intr, struct pt_regs *regs){ regs_intr->regs = regs; regs_intr->abi = perf_reg_abi(current);}
/* * Get remaining task size from user stack pointer. * * It'd be better to take stack vma map and limit this more * precisely, but there's no way to get it safely under interrupt, * so using TASK_SIZE as limit. */static u64 perf_ustack_task_size(struct pt_regs *regs){ unsigned long addr = perf_user_stack_pointer(regs);
if (!addr || addr >= TASK_SIZE) return 0;
return TASK_SIZE - addr;}
static u16perf_sample_ustack_size(u16 stack_size, u16 header_size, struct pt_regs *regs){ u64 task_size;
/* No regs, no stack pointer, no dump. */ if (!regs) return 0;
/* No mm, no stack, no dump. */ if (!current->mm) return 0;
/* * Check if we fit in with the requested stack size into the: * - TASK_SIZE * If we don't, we limit the size to the TASK_SIZE. * * - remaining sample size * If we don't, we customize the stack size to * fit in to the remaining sample size. */
task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs)); stack_size = min(stack_size, (u16) task_size);
/* Current header size plus static size and dynamic size. */ header_size += 2 * sizeof(u64);
/* Do we fit in with the current stack dump size? */ if ((u16) (header_size + stack_size) < header_size) { /* * If we overflow the maximum size for the sample, * we customize the stack dump size to fit in. */ stack_size = USHRT_MAX - header_size - sizeof(u64); stack_size = round_up(stack_size, sizeof(u64)); }
return stack_size;}
static voidperf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size, struct pt_regs *regs){ /* Case of a kernel thread, nothing to dump */ if (!regs) { u64 size = 0; perf_output_put(handle, size); } else { unsigned long sp; unsigned int rem; u64 dyn_size;
/* * We dump: * static size * - the size requested by user or the best one we can fit * in to the sample max size * data * - user stack dump data * dynamic size * - the actual dumped size */
/* Static size. */ perf_output_put(handle, dump_size);
/* Data. */ sp = perf_user_stack_pointer(regs); rem = __output_copy_user(handle, (void *) sp, dump_size); dyn_size = dump_size - rem;
perf_output_skip(handle, rem);
/* Dynamic size. */ perf_output_put(handle, dyn_size); }}
static unsigned long perf_prepare_sample_aux(struct perf_event *event, struct perf_sample_data *data, size_t size){ struct perf_event *sampler = event->aux_event; struct perf_buffer *rb;
data->aux_size = 0;
if (!sampler) goto out;
if (WARN_ON_ONCE(READ_ONCE(sampler->state) != PERF_EVENT_STATE_ACTIVE)) goto out;
if (WARN_ON_ONCE(READ_ONCE(sampler->oncpu) != smp_processor_id())) goto out;
rb = ring_buffer_get(sampler); if (!rb) goto out;
/* * If this is an NMI hit inside sampling code, don't take * the sample. See also perf_aux_sample_output(). */ if (READ_ONCE(rb->aux_in_sampling)) { data->aux_size = 0; } else { size = min_t(size_t, size, perf_aux_size(rb)); data->aux_size = ALIGN(size, sizeof(u64)); } ring_buffer_put(rb);
out: return data->aux_size;}
static long perf_pmu_snapshot_aux(struct perf_buffer *rb, struct perf_event *event, struct perf_output_handle *handle, unsigned long size){ unsigned long flags; long ret;
/* * Normal ->start()/->stop() callbacks run in IRQ mode in scheduler * paths. If we start calling them in NMI context, they may race with * the IRQ ones, that is, for example, re-starting an event that's just * been stopped, which is why we're using a separate callback that * doesn't change the event state. * * IRQs need to be disabled to prevent IPIs from racing with us. */ local_irq_save(flags); /* * Guard against NMI hits inside the critical section; * see also perf_prepare_sample_aux(). */ WRITE_ONCE(rb->aux_in_sampling, 1); barrier();
ret = event->pmu->snapshot_aux(event, handle, size);
barrier(); WRITE_ONCE(rb->aux_in_sampling, 0); local_irq_restore(flags);
return ret;}
static void perf_aux_sample_output(struct perf_event *event, struct perf_output_handle *handle, struct perf_sample_data *data){ struct perf_event *sampler = event->aux_event; struct perf_buffer *rb; unsigned long pad; long size;
if (WARN_ON_ONCE(!sampler || !data->aux_size)) return;
rb = ring_buffer_get(sampler); if (!rb) return;
size = perf_pmu_snapshot_aux(rb, sampler, handle, data->aux_size);
/* * An error here means that perf_output_copy() failed (returned a * non-zero surplus that it didn't copy), which in its current * enlightened implementation is not possible. If that changes, we'd * like to know. */ if (WARN_ON_ONCE(size < 0)) goto out_put;
/* * The pad comes from ALIGN()ing data->aux_size up to u64 in * perf_prepare_sample_aux(), so should not be more than that. */ pad = data->aux_size - size; if (WARN_ON_ONCE(pad >= sizeof(u64))) pad = 8;
if (pad) { u64 zero = 0; perf_output_copy(handle, &zero, pad); }
out_put: ring_buffer_put(rb);}
/* * A set of common sample data types saved even for non-sample records * when event->attr.sample_id_all is set. */#define PERF_SAMPLE_ID_ALL (PERF_SAMPLE_TID | PERF_SAMPLE_TIME | \ PERF_SAMPLE_ID | PERF_SAMPLE_STREAM_ID | \ PERF_SAMPLE_CPU | PERF_SAMPLE_IDENTIFIER)
static void __perf_event_header__init_id(struct perf_sample_data *data, struct perf_event *event, u64 sample_type){ data->type = event->attr.sample_type; data->sample_flags |= data->type & PERF_SAMPLE_ID_ALL;
if (sample_type & PERF_SAMPLE_TID) { /* namespace issues */ data->tid_entry.pid = perf_event_pid(event, current); data->tid_entry.tid = perf_event_tid(event, current); }
if (sample_type & PERF_SAMPLE_TIME) data->time = perf_event_clock(event);
if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER)) data->id = primary_event_id(event);
if (sample_type & PERF_SAMPLE_STREAM_ID) data->stream_id = event->id;
if (sample_type & PERF_SAMPLE_CPU) { data->cpu_entry.cpu = raw_smp_processor_id(); data->cpu_entry.reserved = 0; }}
void perf_event_header__init_id(struct perf_event_header *header, struct perf_sample_data *data, struct perf_event *event){ if (event->attr.sample_id_all) { header->size += event->id_header_size; __perf_event_header__init_id(data, event, event->attr.sample_type); }}
static void __perf_event__output_id_sample(struct perf_output_handle *handle, struct perf_sample_data *data){ u64 sample_type = data->type;
if (sample_type & PERF_SAMPLE_TID) perf_output_put(handle, data->tid_entry);
if (sample_type & PERF_SAMPLE_TIME) perf_output_put(handle, data->time);
if (sample_type & PERF_SAMPLE_ID) perf_output_put(handle, data->id);
if (sample_type & PERF_SAMPLE_STREAM_ID) perf_output_put(handle, data->stream_id);
if (sample_type & PERF_SAMPLE_CPU) perf_output_put(handle, data->cpu_entry);
if (sample_type & PERF_SAMPLE_IDENTIFIER) perf_output_put(handle, data->id);}
void perf_event__output_id_sample(struct perf_event *event, struct perf_output_handle *handle, struct perf_sample_data *sample){ if (event->attr.sample_id_all) __perf_event__output_id_sample(handle, sample);}
static void perf_output_read_one(struct perf_output_handle *handle, struct perf_event *event, u64 enabled, u64 running){ u64 read_format = event->attr.read_format; u64 values[5]; int n = 0;
values[n++] = perf_event_count(event, has_inherit_and_sample_read(&event->attr)); if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { values[n++] = enabled + atomic64_read(&event->child_total_time_enabled); } if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { values[n++] = running + atomic64_read(&event->child_total_time_running); } if (read_format & PERF_FORMAT_ID) values[n++] = primary_event_id(event); if (read_format & PERF_FORMAT_LOST) values[n++] = atomic64_read(&event->lost_samples);
__output_copy(handle, values, n * sizeof(u64));}
static void perf_output_read_group(struct perf_output_handle *handle, struct perf_event *event, u64 enabled, u64 running){ struct perf_event *leader = event->group_leader, *sub; u64 read_format = event->attr.read_format; unsigned long flags; u64 values[6]; int n = 0; bool self = has_inherit_and_sample_read(&event->attr);
/* * Disabling interrupts avoids all counter scheduling * (context switches, timer based rotation and IPIs). */ local_irq_save(flags);
values[n++] = 1 + leader->nr_siblings;
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) values[n++] = enabled;
if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) values[n++] = running;
if ((leader != event) && !handle->skip_read) perf_pmu_read(leader);
values[n++] = perf_event_count(leader, self); if (read_format & PERF_FORMAT_ID) values[n++] = primary_event_id(leader); if (read_format & PERF_FORMAT_LOST) values[n++] = atomic64_read(&leader->lost_samples);
__output_copy(handle, values, n * sizeof(u64));
for_each_sibling_event(sub, leader) { n = 0;
if ((sub != event) && !handle->skip_read) perf_pmu_read(sub);
values[n++] = perf_event_count(sub, self); if (read_format & PERF_FORMAT_ID) values[n++] = primary_event_id(sub); if (read_format & PERF_FORMAT_LOST) values[n++] = atomic64_read(&sub->lost_samples);
__output_copy(handle, values, n * sizeof(u64)); }
local_irq_restore(flags);}
#define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ PERF_FORMAT_TOTAL_TIME_RUNNING)
/* * XXX PERF_SAMPLE_READ vs inherited events seems difficult. * * The problem is that its both hard and excessively expensive to iterate the * child list, not to mention that its impossible to IPI the children running * on another CPU, from interrupt/NMI context. * * Instead the combination of PERF_SAMPLE_READ and inherit will track per-thread * counts rather than attempting to accumulate some value across all children on * all cores. */static void perf_output_read(struct perf_output_handle *handle, struct perf_event *event){ u64 enabled = 0, running = 0, now; u64 read_format = event->attr.read_format;
/* * Compute total_time_enabled, total_time_running based on snapshot * values taken when the event was last scheduled in. * * We cannot simply call update_context_time() because doing so would * lead to deadlock when called from NMI context. */ if (read_format & PERF_FORMAT_TOTAL_TIMES) calc_timer_values(event, &now, &enabled, &running);
if (event->attr.read_format & PERF_FORMAT_GROUP) perf_output_read_group(handle, event, enabled, running); else perf_output_read_one(handle, event, enabled, running);}
void perf_output_sample(struct perf_output_handle *handle, struct perf_event_header *header, struct perf_sample_data *data, struct perf_event *event){ u64 sample_type = data->type;
if (data->sample_flags & PERF_SAMPLE_READ) handle->skip_read = 1;
perf_output_put(handle, *header);
if (sample_type & PERF_SAMPLE_IDENTIFIER) perf_output_put(handle, data->id);
if (sample_type & PERF_SAMPLE_IP) perf_output_put(handle, data->ip);
if (sample_type & PERF_SAMPLE_TID) perf_output_put(handle, data->tid_entry);
if (sample_type & PERF_SAMPLE_TIME) perf_output_put(handle, data->time);
if (sample_type & PERF_SAMPLE_ADDR) perf_output_put(handle, data->addr);
if (sample_type & PERF_SAMPLE_ID) perf_output_put(handle, data->id);
if (sample_type & PERF_SAMPLE_STREAM_ID) perf_output_put(handle, data->stream_id);
if (sample_type & PERF_SAMPLE_CPU) perf_output_put(handle, data->cpu_entry);
if (sample_type & PERF_SAMPLE_PERIOD) perf_output_put(handle, data->period);
if (sample_type & PERF_SAMPLE_READ) perf_output_read(handle, event);
if (sample_type & PERF_SAMPLE_CALLCHAIN) { int size = 1;
size += data->callchain->nr; size *= sizeof(u64); __output_copy(handle, data->callchain, size); }
if (sample_type & PERF_SAMPLE_RAW) { struct perf_raw_record *raw = data->raw;
if (raw) { struct perf_raw_frag *frag = &raw->frag;
perf_output_put(handle, raw->size); do { if (frag->copy) { __output_custom(handle, frag->copy, frag->data, frag->size); } else { __output_copy(handle, frag->data, frag->size); } if (perf_raw_frag_last(frag)) break; frag = frag->next; } while (1); if (frag->pad) __output_skip(handle, NULL, frag->pad); } else { struct { u32 size; u32 data; } raw = { .size = sizeof(u32), .data = 0, }; perf_output_put(handle, raw); } }
if (sample_type & PERF_SAMPLE_BRANCH_STACK) { if (data->br_stack) { size_t size;
size = data->br_stack->nr * sizeof(struct perf_branch_entry);
perf_output_put(handle, data->br_stack->nr); if (branch_sample_hw_index(event)) perf_output_put(handle, data->br_stack->hw_idx); perf_output_copy(handle, data->br_stack->entries, size); /* * Add the extension space which is appended * right after the struct perf_branch_stack. */ if (data->br_stack_cntr) { size = data->br_stack->nr * sizeof(u64); perf_output_copy(handle, data->br_stack_cntr, size); } } else { /* * we always store at least the value of nr */ u64 nr = 0; perf_output_put(handle, nr); } }
if (sample_type & PERF_SAMPLE_REGS_USER) { u64 abi = data->regs_user.abi;
/* * If there are no regs to dump, notice it through * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). */ perf_output_put(handle, abi);
if (abi) { u64 mask = event->attr.sample_regs_user; perf_output_sample_regs(handle, data->regs_user.regs, mask); } }
if (sample_type & PERF_SAMPLE_STACK_USER) { perf_output_sample_ustack(handle, data->stack_user_size, data->regs_user.regs); }
if (sample_type & PERF_SAMPLE_WEIGHT_TYPE) perf_output_put(handle, data->weight.full);
if (sample_type & PERF_SAMPLE_DATA_SRC) perf_output_put(handle, data->data_src.val);
if (sample_type & PERF_SAMPLE_TRANSACTION) perf_output_put(handle, data->txn);
if (sample_type & PERF_SAMPLE_REGS_INTR) { u64 abi = data->regs_intr.abi; /* * If there are no regs to dump, notice it through * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE). */ perf_output_put(handle, abi);
if (abi) { u64 mask = event->attr.sample_regs_intr;
perf_output_sample_regs(handle, data->regs_intr.regs, mask); } }
if (sample_type & PERF_SAMPLE_PHYS_ADDR) perf_output_put(handle, data->phys_addr);
if (sample_type & PERF_SAMPLE_CGROUP) perf_output_put(handle, data->cgroup);
if (sample_type & PERF_SAMPLE_DATA_PAGE_SIZE) perf_output_put(handle, data->data_page_size);
if (sample_type & PERF_SAMPLE_CODE_PAGE_SIZE) perf_output_put(handle, data->code_page_size);
if (sample_type & PERF_SAMPLE_AUX) { perf_output_put(handle, data->aux_size);
if (data->aux_size) perf_aux_sample_output(event, handle, data); }
if (!event->attr.watermark) { int wakeup_events = event->attr.wakeup_events;
if (wakeup_events) { struct perf_buffer *rb = handle->rb; int events = local_inc_return(&rb->events);
if (events >= wakeup_events) { local_sub(wakeup_events, &rb->events); local_inc(&rb->wakeup); } } }}
static u64 perf_virt_to_phys(u64 virt){ u64 phys_addr = 0;
if (!virt) return 0;
if (virt >= TASK_SIZE) { /* If it's vmalloc()d memory, leave phys_addr as 0 */ if (virt_addr_valid((void *)(uintptr_t)virt) && !(virt >= VMALLOC_START && virt < VMALLOC_END)) phys_addr = (u64)virt_to_phys((void *)(uintptr_t)virt); } else { /* * Walking the pages tables for user address. * Interrupts are disabled, so it prevents any tear down * of the page tables. * Try IRQ-safe get_user_page_fast_only first. * If failed, leave phys_addr as 0. */ if (is_user_task(current)) { struct page *p;
pagefault_disable(); if (get_user_page_fast_only(virt, 0, &p)) { phys_addr = page_to_phys(p) + virt % PAGE_SIZE; put_page(p); } pagefault_enable(); } }
return phys_addr;}
/* * Return the pagetable size of a given virtual address. */static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr){ u64 size = 0;
#ifdef CONFIG_HAVE_GUP_FAST pgd_t *pgdp, pgd; p4d_t *p4dp, p4d; pud_t *pudp, pud; pmd_t *pmdp, pmd; pte_t *ptep, pte;
pgdp = pgd_offset(mm, addr); pgd = pgdp_get(pgdp); if (pgd_none(pgd)) return 0;
if (pgd_leaf(pgd)) return pgd_leaf_size(pgd);
p4dp = p4d_offset_lockless(pgdp, pgd, addr); p4d = p4dp_get(p4dp); if (!p4d_present(p4d)) return 0;
if (p4d_leaf(p4d)) return p4d_leaf_size(p4d);
pudp = pud_offset_lockless(p4dp, p4d, addr); pud = pudp_get(pudp); if (!pud_present(pud)) return 0;
if (pud_leaf(pud)) return pud_leaf_size(pud);
pmdp = pmd_offset_lockless(pudp, pud, addr);again: pmd = pmdp_get_lockless(pmdp); if (!pmd_present(pmd)) return 0;
if (pmd_leaf(pmd)) return pmd_leaf_size(pmd);
ptep = pte_offset_map(&pmd, addr); if (!ptep) goto again;
pte = ptep_get_lockless(ptep); if (pte_present(pte)) size = __pte_leaf_size(pmd, pte); pte_unmap(ptep);#endif /* CONFIG_HAVE_GUP_FAST */
return size;}
static u64 perf_get_page_size(unsigned long addr){ struct mm_struct *mm; unsigned long flags; u64 size;
if (!addr) return 0;
/* * Software page-table walkers must disable IRQs, * which prevents any tear down of the page tables. */ local_irq_save(flags);
mm = current->mm; if (!mm) { /* * For kernel threads and the like, use init_mm so that * we can find kernel memory. */ mm = &init_mm; }
size = perf_get_pgtable_size(mm, addr);
local_irq_restore(flags);
return size;}
static struct perf_callchain_entry __empty_callchain = { .nr = 0, };
static struct unwind_work perf_unwind_work;
struct perf_callchain_entry *perf_callchain(struct perf_event *event, struct pt_regs *regs){ bool kernel = !event->attr.exclude_callchain_kernel; bool user = !event->attr.exclude_callchain_user && is_user_task(current); /* Disallow cross-task user callchains. */ bool crosstask = event->ctx->task && event->ctx->task != current; bool defer_user = IS_ENABLED(CONFIG_UNWIND_USER) && user && event->attr.defer_callchain; const u32 max_stack = event->attr.sample_max_stack; struct perf_callchain_entry *callchain; u64 defer_cookie;
if (!current->mm) user = false;
if (!kernel && !user) return &__empty_callchain;
if (!(user && defer_user && !crosstask && unwind_deferred_request(&perf_unwind_work, &defer_cookie) >= 0)) defer_cookie = 0;
callchain = get_perf_callchain(regs, kernel, user, max_stack, crosstask, true, defer_cookie);
return callchain ?: &__empty_callchain;}
static __always_inline u64 __cond_set(u64 flags, u64 s, u64 d){ return d * !!(flags & s);}
void perf_prepare_sample(struct perf_sample_data *data, struct perf_event *event, struct pt_regs *regs){ u64 sample_type = event->attr.sample_type; u64 filtered_sample_type;
/* * Add the sample flags that are dependent to others. And clear the * sample flags that have already been done by the PMU driver. */ filtered_sample_type = sample_type; filtered_sample_type |= __cond_set(sample_type, PERF_SAMPLE_CODE_PAGE_SIZE, PERF_SAMPLE_IP); filtered_sample_type |= __cond_set(sample_type, PERF_SAMPLE_DATA_PAGE_SIZE | PERF_SAMPLE_PHYS_ADDR, PERF_SAMPLE_ADDR); filtered_sample_type |= __cond_set(sample_type, PERF_SAMPLE_STACK_USER, PERF_SAMPLE_REGS_USER); filtered_sample_type &= ~data->sample_flags;
if (filtered_sample_type == 0) { /* Make sure it has the correct data->type for output */ data->type = event->attr.sample_type; return; }
__perf_event_header__init_id(data, event, filtered_sample_type);
if (filtered_sample_type & PERF_SAMPLE_IP) { data->ip = perf_instruction_pointer(event, regs); data->sample_flags |= PERF_SAMPLE_IP; }
if (filtered_sample_type & PERF_SAMPLE_CALLCHAIN) perf_sample_save_callchain(data, event, regs);
if (filtered_sample_type & PERF_SAMPLE_RAW) { data->raw = NULL; data->dyn_size += sizeof(u64); data->sample_flags |= PERF_SAMPLE_RAW; }
if (filtered_sample_type & PERF_SAMPLE_BRANCH_STACK) { data->br_stack = NULL; data->dyn_size += sizeof(u64); data->sample_flags |= PERF_SAMPLE_BRANCH_STACK; }
if (filtered_sample_type & PERF_SAMPLE_REGS_USER) perf_sample_regs_user(&data->regs_user, regs);
/* * It cannot use the filtered_sample_type here as REGS_USER can be set * by STACK_USER (using __cond_set() above) and we don't want to update * the dyn_size if it's not requested by users. */ if ((sample_type & ~data->sample_flags) & PERF_SAMPLE_REGS_USER) { /* regs dump ABI info */ int size = sizeof(u64);
if (data->regs_user.regs) { u64 mask = event->attr.sample_regs_user; size += hweight64(mask) * sizeof(u64); }
data->dyn_size += size; data->sample_flags |= PERF_SAMPLE_REGS_USER; }
if (filtered_sample_type & PERF_SAMPLE_STACK_USER) { /* * Either we need PERF_SAMPLE_STACK_USER bit to be always * processed as the last one or have additional check added * in case new sample type is added, because we could eat * up the rest of the sample size. */ u16 stack_size = event->attr.sample_stack_user; u16 header_size = perf_sample_data_size(data, event); u16 size = sizeof(u64);
stack_size = perf_sample_ustack_size(stack_size, header_size, data->regs_user.regs);
/* * If there is something to dump, add space for the dump * itself and for the field that tells the dynamic size, * which is how many have been actually dumped. */ if (stack_size) size += sizeof(u64) + stack_size;
data->stack_user_size = stack_size; data->dyn_size += size; data->sample_flags |= PERF_SAMPLE_STACK_USER; }
if (filtered_sample_type & PERF_SAMPLE_WEIGHT_TYPE) { data->weight.full = 0; data->sample_flags |= PERF_SAMPLE_WEIGHT_TYPE; }
if (filtered_sample_type & PERF_SAMPLE_DATA_SRC) { data->data_src.val = PERF_MEM_NA; data->sample_flags |= PERF_SAMPLE_DATA_SRC; }
if (filtered_sample_type & PERF_SAMPLE_TRANSACTION) { data->txn = 0; data->sample_flags |= PERF_SAMPLE_TRANSACTION; }
if (filtered_sample_type & PERF_SAMPLE_ADDR) { data->addr = 0; data->sample_flags |= PERF_SAMPLE_ADDR; }
if (filtered_sample_type & PERF_SAMPLE_REGS_INTR) { /* regs dump ABI info */ int size = sizeof(u64);
perf_sample_regs_intr(&data->regs_intr, regs);
if (data->regs_intr.regs) { u64 mask = event->attr.sample_regs_intr;
size += hweight64(mask) * sizeof(u64); }
data->dyn_size += size; data->sample_flags |= PERF_SAMPLE_REGS_INTR; }
if (filtered_sample_type & PERF_SAMPLE_PHYS_ADDR) { data->phys_addr = perf_virt_to_phys(data->addr); data->sample_flags |= PERF_SAMPLE_PHYS_ADDR; }
#ifdef CONFIG_CGROUP_PERF if (filtered_sample_type & PERF_SAMPLE_CGROUP) { struct cgroup *cgrp;
/* protected by RCU */ cgrp = task_css_check(current, perf_event_cgrp_id, 1)->cgroup; data->cgroup = cgroup_id(cgrp); data->sample_flags |= PERF_SAMPLE_CGROUP; }#endif
/* * PERF_DATA_PAGE_SIZE requires PERF_SAMPLE_ADDR. If the user doesn't * require PERF_SAMPLE_ADDR, kernel implicitly retrieve the data->addr, * but the value will not dump to the userspace. */ if (filtered_sample_type & PERF_SAMPLE_DATA_PAGE_SIZE) { data->data_page_size = perf_get_page_size(data->addr); data->sample_flags |= PERF_SAMPLE_DATA_PAGE_SIZE; }
if (filtered_sample_type & PERF_SAMPLE_CODE_PAGE_SIZE) { data->code_page_size = perf_get_page_size(data->ip); data->sample_flags |= PERF_SAMPLE_CODE_PAGE_SIZE; }
if (filtered_sample_type & PERF_SAMPLE_AUX) { u64 size; u16 header_size = perf_sample_data_size(data, event);
header_size += sizeof(u64); /* size */
/* * Given the 16bit nature of header::size, an AUX sample can * easily overflow it, what with all the preceding sample bits. * Make sure this doesn't happen by using up to U16_MAX bytes * per sample in total (rounded down to 8 byte boundary). */ size = min_t(size_t, U16_MAX - header_size, event->attr.aux_sample_size); size = rounddown(size, 8); size = perf_prepare_sample_aux(event, data, size);
WARN_ON_ONCE(size + header_size > U16_MAX); data->dyn_size += size + sizeof(u64); /* size above */ data->sample_flags |= PERF_SAMPLE_AUX; }}
void perf_prepare_header(struct perf_event_header *header, struct perf_sample_data *data, struct perf_event *event, struct pt_regs *regs){ header->type = PERF_RECORD_SAMPLE; header->size = perf_sample_data_size(data, event); header->misc = perf_misc_flags(event, regs);
/* * If you're adding more sample types here, you likely need to do * something about the overflowing header::size, like repurpose the * lowest 3 bits of size, which should be always zero at the moment. * This raises a more important question, do we really need 512k sized * samples and why, so good argumentation is in order for whatever you * do here next. */ WARN_ON_ONCE(header->size & 7);}
static void __perf_event_aux_pause(struct perf_event *event, bool pause){ if (pause) { if (!event->hw.aux_paused) { event->hw.aux_paused = 1; event->pmu->stop(event, PERF_EF_PAUSE); } } else { if (event->hw.aux_paused) { event->hw.aux_paused = 0; event->pmu->start(event, PERF_EF_RESUME); } }}
static void perf_event_aux_pause(struct perf_event *event, bool pause){ struct perf_buffer *rb;
if (WARN_ON_ONCE(!event)) return;
rb = ring_buffer_get(event); if (!rb) return;
scoped_guard (irqsave) { /* * Guard against self-recursion here. Another event could trip * this same from NMI context. */ if (READ_ONCE(rb->aux_in_pause_resume)) break;
WRITE_ONCE(rb->aux_in_pause_resume, 1); barrier(); __perf_event_aux_pause(event, pause); barrier(); WRITE_ONCE(rb->aux_in_pause_resume, 0); } ring_buffer_put(rb);}
static __always_inline int__perf_event_output(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs, int (*output_begin)(struct perf_output_handle *, struct perf_sample_data *, struct perf_event *, unsigned int)){ struct perf_output_handle handle; struct perf_event_header header; int err;
/* protect the callchain buffers */ rcu_read_lock();
perf_prepare_sample(data, event, regs); perf_prepare_header(&header, data, event, regs);
err = output_begin(&handle, data, event, header.size); if (err) goto exit;
perf_output_sample(&handle, &header, data, event);
perf_output_end(&handle);
exit: rcu_read_unlock(); return err;}
voidperf_event_output_forward(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs){ __perf_event_output(event, data, regs, perf_output_begin_forward);}
voidperf_event_output_backward(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs){ __perf_event_output(event, data, regs, perf_output_begin_backward);}
intperf_event_output(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs){ return __perf_event_output(event, data, regs, perf_output_begin);}
/* * read event_id */
struct perf_read_event { struct perf_event_header header;
u32 pid; u32 tid;};
static voidperf_event_read_event(struct perf_event *event, struct task_struct *task){ struct perf_output_handle handle; struct perf_sample_data sample; struct perf_read_event read_event = { .header = { .type = PERF_RECORD_READ, .misc = 0, .size = sizeof(read_event) + event->read_size, }, .pid = perf_event_pid(event, task), .tid = perf_event_tid(event, task), }; int ret;
perf_event_header__init_id(&read_event.header, &sample, event); ret = perf_output_begin(&handle, &sample, event, read_event.header.size); if (ret) return;
perf_output_put(&handle, read_event); perf_output_read(&handle, event); perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);}
typedef void (perf_iterate_f)(struct perf_event *event, void *data);
static voidperf_iterate_ctx(struct perf_event_context *ctx, perf_iterate_f output, void *data, bool all){ struct perf_event *event;
list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { if (!all) { if (event->state < PERF_EVENT_STATE_INACTIVE) continue; if (!event_filter_match(event)) continue; }
output(event, data); }}
static void perf_iterate_sb_cpu(perf_iterate_f output, void *data){ struct pmu_event_list *pel = this_cpu_ptr(&pmu_sb_events); struct perf_event *event;
list_for_each_entry_rcu(event, &pel->list, sb_list) { /* * Skip events that are not fully formed yet; ensure that * if we observe event->ctx, both event and ctx will be * complete enough. See perf_install_in_context(). */ if (!smp_load_acquire(&event->ctx)) continue;
if (event->state < PERF_EVENT_STATE_INACTIVE) continue; if (!event_filter_match(event)) continue; output(event, data); }}
/* * Iterate all events that need to receive side-band events. * * For new callers; ensure that account_pmu_sb_event() includes * your event, otherwise it might not get delivered. */static voidperf_iterate_sb(perf_iterate_f output, void *data, struct perf_event_context *task_ctx){ struct perf_event_context *ctx;
rcu_read_lock(); preempt_disable();
/* * If we have task_ctx != NULL we only notify the task context itself. * The task_ctx is set only for EXIT events before releasing task * context. */ if (task_ctx) { perf_iterate_ctx(task_ctx, output, data, false); goto done; }
perf_iterate_sb_cpu(output, data);
ctx = rcu_dereference(current->perf_event_ctxp); if (ctx) perf_iterate_ctx(ctx, output, data, false);done: preempt_enable(); rcu_read_unlock();}
/* * Clear all file-based filters at exec, they'll have to be * re-instated when/if these objects are mmapped again. */static void perf_event_addr_filters_exec(struct perf_event *event, void *data){ struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); struct perf_addr_filter *filter; unsigned int restart = 0, count = 0; unsigned long flags;
if (!has_addr_filter(event)) return;
raw_spin_lock_irqsave(&ifh->lock, flags); list_for_each_entry(filter, &ifh->list, entry) { if (filter->path.dentry) { event->addr_filter_ranges[count].start = 0; event->addr_filter_ranges[count].size = 0; restart++; }
count++; }
if (restart) event->addr_filters_gen++; raw_spin_unlock_irqrestore(&ifh->lock, flags);
if (restart) perf_event_stop(event, 1);}
void perf_event_exec(void){ struct perf_event_context *ctx;
ctx = perf_pin_task_context(current); if (!ctx) return;
perf_event_enable_on_exec(ctx); perf_event_remove_on_exec(ctx); scoped_guard(rcu) perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL, true);
perf_unpin_context(ctx); put_ctx(ctx);}
struct remote_output { struct perf_buffer *rb; int err;};
static void __perf_event_output_stop(struct perf_event *event, void *data){ struct perf_event *parent = event->parent; struct remote_output *ro = data; struct perf_buffer *rb = ro->rb; struct stop_event_data sd = { .event = event, };
if (!has_aux(event)) return;
if (!parent) parent = event;
/* * In case of inheritance, it will be the parent that links to the * ring-buffer, but it will be the child that's actually using it. * * We are using event::rb to determine if the event should be stopped, * however this may race with ring_buffer_attach() (through set_output), * which will make us skip the event that actually needs to be stopped. * So ring_buffer_attach() has to stop an aux event before re-assigning * its rb pointer. */ if (rcu_dereference(parent->rb) == rb) ro->err = __perf_event_stop(&sd);}
static int __perf_pmu_output_stop(void *info){ struct perf_event *event = info; struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct remote_output ro = { .rb = event->rb, };
rcu_read_lock(); perf_iterate_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro, false); if (cpuctx->task_ctx) perf_iterate_ctx(cpuctx->task_ctx, __perf_event_output_stop, &ro, false); rcu_read_unlock();
return ro.err;}
static void perf_pmu_output_stop(struct perf_event *event){ struct perf_event *iter; int err, cpu;
restart: rcu_read_lock(); list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) { /* * For per-CPU events, we need to make sure that neither they * nor their children are running; for cpu==-1 events it's * sufficient to stop the event itself if it's active, since * it can't have children. */ cpu = iter->cpu; if (cpu == -1) cpu = READ_ONCE(iter->oncpu);
if (cpu == -1) continue;
err = cpu_function_call(cpu, __perf_pmu_output_stop, event); if (err == -EAGAIN) { rcu_read_unlock(); goto restart; } } rcu_read_unlock();}
/* * task tracking -- fork/exit * * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task */
struct perf_task_event { struct task_struct *task; struct perf_event_context *task_ctx;
struct { struct perf_event_header header;
u32 pid; u32 ppid; u32 tid; u32 ptid; u64 time; } event_id;};
static int perf_event_task_match(struct perf_event *event){ return event->attr.comm || event->attr.mmap || event->attr.mmap2 || event->attr.mmap_data || event->attr.task;}
static void perf_event_task_output(struct perf_event *event, void *data){ struct perf_task_event *task_event = data; struct perf_output_handle handle; struct perf_sample_data sample; struct task_struct *task = task_event->task; int ret, size = task_event->event_id.header.size;
if (!perf_event_task_match(event)) return;
perf_event_header__init_id(&task_event->event_id.header, &sample, event);
ret = perf_output_begin(&handle, &sample, event, task_event->event_id.header.size); if (ret) goto out;
task_event->event_id.pid = perf_event_pid(event, task); task_event->event_id.tid = perf_event_tid(event, task);
if (task_event->event_id.header.type == PERF_RECORD_EXIT) { task_event->event_id.ppid = perf_event_pid(event, task->real_parent); task_event->event_id.ptid = perf_event_pid(event, task->real_parent); } else { /* PERF_RECORD_FORK */ task_event->event_id.ppid = perf_event_pid(event, current); task_event->event_id.ptid = perf_event_tid(event, current); }
task_event->event_id.time = perf_event_clock(event);
perf_output_put(&handle, task_event->event_id);
perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);out: task_event->event_id.header.size = size;}
static void perf_event_task(struct task_struct *task, struct perf_event_context *task_ctx, int new){ struct perf_task_event task_event;
if (!atomic_read(&nr_comm_events) && !atomic_read(&nr_mmap_events) && !atomic_read(&nr_task_events)) return;
task_event = (struct perf_task_event){ .task = task, .task_ctx = task_ctx, .event_id = { .header = { .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, .misc = 0, .size = sizeof(task_event.event_id), }, /* .pid */ /* .ppid */ /* .tid */ /* .ptid */ /* .time */ }, };
perf_iterate_sb(perf_event_task_output, &task_event, task_ctx);}
/* * Allocate data for a new task when profiling system-wide * events which require PMU specific data */static voidperf_event_alloc_task_data(struct task_struct *child, struct task_struct *parent){ struct kmem_cache *ctx_cache = NULL; struct perf_ctx_data *cd;
if (!refcount_read(&global_ctx_data_ref)) return;
scoped_guard (rcu) { cd = rcu_dereference(parent->perf_ctx_data); if (cd) ctx_cache = cd->ctx_cache; }
if (!ctx_cache) return;
guard(percpu_read)(&global_ctx_data_rwsem); scoped_guard (rcu) { cd = rcu_dereference(child->perf_ctx_data); if (!cd) { /* * A system-wide event may be unaccount, * when attaching the perf_ctx_data. */ if (!refcount_read(&global_ctx_data_ref)) return; goto attach; }
if (!cd->global) { cd->global = 1; refcount_inc(&cd->refcount); } }
return;attach: attach_task_ctx_data(child, ctx_cache, true, GFP_KERNEL);}
void perf_event_fork(struct task_struct *task){ perf_event_task(task, NULL, 1); perf_event_namespaces(task); perf_event_alloc_task_data(task, current);}
/* * comm tracking */
struct perf_comm_event { struct task_struct *task; char *comm; int comm_size;
struct { struct perf_event_header header;
u32 pid; u32 tid; } event_id;};
static int perf_event_comm_match(struct perf_event *event){ return event->attr.comm;}
static void perf_event_comm_output(struct perf_event *event, void *data){ struct perf_comm_event *comm_event = data; struct perf_output_handle handle; struct perf_sample_data sample; int size = comm_event->event_id.header.size; int ret;
if (!perf_event_comm_match(event)) return;
perf_event_header__init_id(&comm_event->event_id.header, &sample, event); ret = perf_output_begin(&handle, &sample, event, comm_event->event_id.header.size);
if (ret) goto out;
comm_event->event_id.pid = perf_event_pid(event, comm_event->task); comm_event->event_id.tid = perf_event_tid(event, comm_event->task);
perf_output_put(&handle, comm_event->event_id); __output_copy(&handle, comm_event->comm, comm_event->comm_size);
perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);out: comm_event->event_id.header.size = size;}
static void perf_event_comm_event(struct perf_comm_event *comm_event){ char comm[TASK_COMM_LEN]; unsigned int size;
memset(comm, 0, sizeof(comm)); strscpy(comm, comm_event->task->comm); size = ALIGN(strlen(comm)+1, sizeof(u64));
comm_event->comm = comm; comm_event->comm_size = size;
comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
perf_iterate_sb(perf_event_comm_output, comm_event, NULL);}
void perf_event_comm(struct task_struct *task, bool exec){ struct perf_comm_event comm_event;
if (!atomic_read(&nr_comm_events)) return;
comm_event = (struct perf_comm_event){ .task = task, /* .comm */ /* .comm_size */ .event_id = { .header = { .type = PERF_RECORD_COMM, .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, /* .size */ }, /* .pid */ /* .tid */ }, };
perf_event_comm_event(&comm_event);}
/* * namespaces tracking */
struct perf_namespaces_event { struct task_struct *task;
struct { struct perf_event_header header;
u32 pid; u32 tid; u64 nr_namespaces; struct perf_ns_link_info link_info[NR_NAMESPACES]; } event_id;};
static int perf_event_namespaces_match(struct perf_event *event){ return event->attr.namespaces;}
static void perf_event_namespaces_output(struct perf_event *event, void *data){ struct perf_namespaces_event *namespaces_event = data; struct perf_output_handle handle; struct perf_sample_data sample; u16 header_size = namespaces_event->event_id.header.size; int ret;
if (!perf_event_namespaces_match(event)) return;
perf_event_header__init_id(&namespaces_event->event_id.header, &sample, event); ret = perf_output_begin(&handle, &sample, event, namespaces_event->event_id.header.size); if (ret) goto out;
namespaces_event->event_id.pid = perf_event_pid(event, namespaces_event->task); namespaces_event->event_id.tid = perf_event_tid(event, namespaces_event->task);
perf_output_put(&handle, namespaces_event->event_id);
perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);out: namespaces_event->event_id.header.size = header_size;}
static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info, struct task_struct *task, const struct proc_ns_operations *ns_ops){ struct path ns_path; struct inode *ns_inode; int error;
error = ns_get_path(&ns_path, task, ns_ops); if (!error) { ns_inode = ns_path.dentry->d_inode; ns_link_info->dev = new_encode_dev(ns_inode->i_sb->s_dev); ns_link_info->ino = ns_inode->i_ino; path_put(&ns_path); }}
void perf_event_namespaces(struct task_struct *task){ struct perf_namespaces_event namespaces_event; struct perf_ns_link_info *ns_link_info;
if (!atomic_read(&nr_namespaces_events)) return;
namespaces_event = (struct perf_namespaces_event){ .task = task, .event_id = { .header = { .type = PERF_RECORD_NAMESPACES, .misc = 0, .size = sizeof(namespaces_event.event_id), }, /* .pid */ /* .tid */ .nr_namespaces = NR_NAMESPACES, /* .link_info[NR_NAMESPACES] */ }, };
ns_link_info = namespaces_event.event_id.link_info;
perf_fill_ns_link_info(&ns_link_info[MNT_NS_INDEX], task, &mntns_operations);
#ifdef CONFIG_USER_NS perf_fill_ns_link_info(&ns_link_info[USER_NS_INDEX], task, &userns_operations);#endif#ifdef CONFIG_NET_NS perf_fill_ns_link_info(&ns_link_info[NET_NS_INDEX], task, &netns_operations);#endif#ifdef CONFIG_UTS_NS perf_fill_ns_link_info(&ns_link_info[UTS_NS_INDEX], task, &utsns_operations);#endif#ifdef CONFIG_IPC_NS perf_fill_ns_link_info(&ns_link_info[IPC_NS_INDEX], task, &ipcns_operations);#endif#ifdef CONFIG_PID_NS perf_fill_ns_link_info(&ns_link_info[PID_NS_INDEX], task, &pidns_operations);#endif#ifdef CONFIG_CGROUPS perf_fill_ns_link_info(&ns_link_info[CGROUP_NS_INDEX], task, &cgroupns_operations);#endif
perf_iterate_sb(perf_event_namespaces_output, &namespaces_event, NULL);}
/* * cgroup tracking */#ifdef CONFIG_CGROUP_PERF
struct perf_cgroup_event { char *path; int path_size; struct { struct perf_event_header header; u64 id; char path[]; } event_id;};
static int perf_event_cgroup_match(struct perf_event *event){ return event->attr.cgroup;}
static void perf_event_cgroup_output(struct perf_event *event, void *data){ struct perf_cgroup_event *cgroup_event = data; struct perf_output_handle handle; struct perf_sample_data sample; u16 header_size = cgroup_event->event_id.header.size; int ret;
if (!perf_event_cgroup_match(event)) return;
perf_event_header__init_id(&cgroup_event->event_id.header, &sample, event); ret = perf_output_begin(&handle, &sample, event, cgroup_event->event_id.header.size); if (ret) goto out;
perf_output_put(&handle, cgroup_event->event_id); __output_copy(&handle, cgroup_event->path, cgroup_event->path_size);
perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);out: cgroup_event->event_id.header.size = header_size;}
static void perf_event_cgroup(struct cgroup *cgrp){ struct perf_cgroup_event cgroup_event; char path_enomem[16] = "//enomem"; char *pathname; size_t size;
if (!atomic_read(&nr_cgroup_events)) return;
cgroup_event = (struct perf_cgroup_event){ .event_id = { .header = { .type = PERF_RECORD_CGROUP, .misc = 0, .size = sizeof(cgroup_event.event_id), }, .id = cgroup_id(cgrp), }, };
pathname = kmalloc(PATH_MAX, GFP_KERNEL); if (pathname == NULL) { cgroup_event.path = path_enomem; } else { /* just to be sure to have enough space for alignment */ cgroup_path(cgrp, pathname, PATH_MAX - sizeof(u64)); cgroup_event.path = pathname; }
/* * Since our buffer works in 8 byte units we need to align our string * size to a multiple of 8. However, we must guarantee the tail end is * zero'd out to avoid leaking random bits to userspace. */ size = strlen(cgroup_event.path) + 1; while (!IS_ALIGNED(size, sizeof(u64))) cgroup_event.path[size++] = '\0';
cgroup_event.event_id.header.size += size; cgroup_event.path_size = size;
perf_iterate_sb(perf_event_cgroup_output, &cgroup_event, NULL);
kfree(pathname);}
#endif
/* * mmap tracking */
struct perf_mmap_event { struct vm_area_struct *vma;
const char *file_name; int file_size; int maj, min; u64 ino; u64 ino_generation; u32 prot, flags; u8 build_id[BUILD_ID_SIZE_MAX]; u32 build_id_size;
struct { struct perf_event_header header;
u32 pid; u32 tid; u64 start; u64 len; u64 pgoff; } event_id;};
static int perf_event_mmap_match(struct perf_event *event, void *data){ struct perf_mmap_event *mmap_event = data; struct vm_area_struct *vma = mmap_event->vma; int executable = vma->vm_flags & VM_EXEC;
return (!executable && event->attr.mmap_data) || (executable && (event->attr.mmap || event->attr.mmap2));}
static void perf_event_mmap_output(struct perf_event *event, void *data){ struct perf_mmap_event *mmap_event = data; struct perf_output_handle handle; struct perf_sample_data sample; int size = mmap_event->event_id.header.size; u32 type = mmap_event->event_id.header.type; bool use_build_id; int ret;
if (!perf_event_mmap_match(event, data)) return;
if (event->attr.mmap2) { mmap_event->event_id.header.type = PERF_RECORD_MMAP2; mmap_event->event_id.header.size += sizeof(mmap_event->maj); mmap_event->event_id.header.size += sizeof(mmap_event->min); mmap_event->event_id.header.size += sizeof(mmap_event->ino); mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation); mmap_event->event_id.header.size += sizeof(mmap_event->prot); mmap_event->event_id.header.size += sizeof(mmap_event->flags); }
perf_event_header__init_id(&mmap_event->event_id.header, &sample, event); ret = perf_output_begin(&handle, &sample, event, mmap_event->event_id.header.size); if (ret) goto out;
mmap_event->event_id.pid = perf_event_pid(event, current); mmap_event->event_id.tid = perf_event_tid(event, current);
use_build_id = event->attr.build_id && mmap_event->build_id_size;
if (event->attr.mmap2 && use_build_id) mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_BUILD_ID;
perf_output_put(&handle, mmap_event->event_id);
if (event->attr.mmap2) { if (use_build_id) { u8 size[4] = { (u8) mmap_event->build_id_size, 0, 0, 0 };
__output_copy(&handle, size, 4); __output_copy(&handle, mmap_event->build_id, BUILD_ID_SIZE_MAX); } else { perf_output_put(&handle, mmap_event->maj); perf_output_put(&handle, mmap_event->min); perf_output_put(&handle, mmap_event->ino); perf_output_put(&handle, mmap_event->ino_generation); } perf_output_put(&handle, mmap_event->prot); perf_output_put(&handle, mmap_event->flags); }
__output_copy(&handle, mmap_event->file_name, mmap_event->file_size);
perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);out: mmap_event->event_id.header.size = size; mmap_event->event_id.header.type = type;}
static void perf_event_mmap_event(struct perf_mmap_event *mmap_event){ struct vm_area_struct *vma = mmap_event->vma; struct file *file = vma->vm_file; int maj = 0, min = 0; u64 ino = 0, gen = 0; u32 prot = 0, flags = 0; unsigned int size; char tmp[16]; char *buf = NULL; char *name = NULL;
if (vma->vm_flags & VM_READ) prot |= PROT_READ; if (vma->vm_flags & VM_WRITE) prot |= PROT_WRITE; if (vma->vm_flags & VM_EXEC) prot |= PROT_EXEC;
if (vma->vm_flags & VM_MAYSHARE) flags = MAP_SHARED; else flags = MAP_PRIVATE;
if (vma->vm_flags & VM_LOCKED) flags |= MAP_LOCKED; if (is_vm_hugetlb_page(vma)) flags |= MAP_HUGETLB;
if (file) { const struct inode *inode; dev_t dev;
buf = kmalloc(PATH_MAX, GFP_KERNEL); if (!buf) { name = "//enomem"; goto cpy_name; } /* * d_path() works from the end of the rb backwards, so we * need to add enough zero bytes after the string to handle * the 64bit alignment we do later. */ name = d_path(file_user_path(file), buf, PATH_MAX - sizeof(u64)); if (IS_ERR(name)) { name = "//toolong"; goto cpy_name; } inode = file_user_inode(vma->vm_file); dev = inode->i_sb->s_dev; ino = inode->i_ino; gen = inode->i_generation; maj = MAJOR(dev); min = MINOR(dev);
goto got_name; } else { if (vma->vm_ops && vma->vm_ops->name) name = (char *) vma->vm_ops->name(vma); if (!name) name = (char *)arch_vma_name(vma); if (!name) { if (vma_is_initial_heap(vma)) name = "[heap]"; else if (vma_is_initial_stack(vma)) name = "[stack]"; else name = "//anon"; } }
cpy_name: strscpy(tmp, name); name = tmp;got_name: /* * Since our buffer works in 8 byte units we need to align our string * size to a multiple of 8. However, we must guarantee the tail end is * zero'd out to avoid leaking random bits to userspace. */ size = strlen(name)+1; while (!IS_ALIGNED(size, sizeof(u64))) name[size++] = '\0';
mmap_event->file_name = name; mmap_event->file_size = size; mmap_event->maj = maj; mmap_event->min = min; mmap_event->ino = ino; mmap_event->ino_generation = gen; mmap_event->prot = prot; mmap_event->flags = flags;
if (!(vma->vm_flags & VM_EXEC)) mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA;
mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
if (atomic_read(&nr_build_id_events)) build_id_parse_nofault(vma, mmap_event->build_id, &mmap_event->build_id_size);
perf_iterate_sb(perf_event_mmap_output, mmap_event, NULL);
kfree(buf);}
/* * Check whether inode and address range match filter criteria. */static bool perf_addr_filter_match(struct perf_addr_filter *filter, struct file *file, unsigned long offset, unsigned long size){ /* d_inode(NULL) won't be equal to any mapped user-space file */ if (!filter->path.dentry) return false;
if (d_inode(filter->path.dentry) != file_user_inode(file)) return false;
if (filter->offset > offset + size) return false;
if (filter->offset + filter->size < offset) return false;
return true;}
static bool perf_addr_filter_vma_adjust(struct perf_addr_filter *filter, struct vm_area_struct *vma, struct perf_addr_filter_range *fr){ unsigned long vma_size = vma->vm_end - vma->vm_start; unsigned long off = vma->vm_pgoff << PAGE_SHIFT; struct file *file = vma->vm_file;
if (!perf_addr_filter_match(filter, file, off, vma_size)) return false;
if (filter->offset < off) { fr->start = vma->vm_start; fr->size = min(vma_size, filter->size - (off - filter->offset)); } else { fr->start = vma->vm_start + filter->offset - off; fr->size = min(vma->vm_end - fr->start, filter->size); }
return true;}
static void __perf_addr_filters_adjust(struct perf_event *event, void *data){ struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); struct vm_area_struct *vma = data; struct perf_addr_filter *filter; unsigned int restart = 0, count = 0; unsigned long flags;
if (!has_addr_filter(event)) return;
if (!vma->vm_file) return;
raw_spin_lock_irqsave(&ifh->lock, flags); list_for_each_entry(filter, &ifh->list, entry) { if (perf_addr_filter_vma_adjust(filter, vma, &event->addr_filter_ranges[count])) restart++;
count++; }
if (restart) event->addr_filters_gen++; raw_spin_unlock_irqrestore(&ifh->lock, flags);
if (restart) perf_event_stop(event, 1);}
/* * Adjust all task's events' filters to the new vma */static void perf_addr_filters_adjust(struct vm_area_struct *vma){ struct perf_event_context *ctx;
/* * Data tracing isn't supported yet and as such there is no need * to keep track of anything that isn't related to executable code: */ if (!(vma->vm_flags & VM_EXEC)) return;
rcu_read_lock(); ctx = rcu_dereference(current->perf_event_ctxp); if (ctx) perf_iterate_ctx(ctx, __perf_addr_filters_adjust, vma, true); rcu_read_unlock();}
void perf_event_mmap(struct vm_area_struct *vma){ struct perf_mmap_event mmap_event;
if (!atomic_read(&nr_mmap_events)) return;
mmap_event = (struct perf_mmap_event){ .vma = vma, /* .file_name */ /* .file_size */ .event_id = { .header = { .type = PERF_RECORD_MMAP, .misc = PERF_RECORD_MISC_USER, /* .size */ }, /* .pid */ /* .tid */ .start = vma->vm_start, .len = vma->vm_end - vma->vm_start, .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT, }, /* .maj (attr_mmap2 only) */ /* .min (attr_mmap2 only) */ /* .ino (attr_mmap2 only) */ /* .ino_generation (attr_mmap2 only) */ /* .prot (attr_mmap2 only) */ /* .flags (attr_mmap2 only) */ };
perf_addr_filters_adjust(vma); perf_event_mmap_event(&mmap_event);}
void perf_event_aux_event(struct perf_event *event, unsigned long head, unsigned long size, u64 flags){ struct perf_output_handle handle; struct perf_sample_data sample; struct perf_aux_event { struct perf_event_header header; u64 offset; u64 size; u64 flags; } rec = { .header = { .type = PERF_RECORD_AUX, .misc = 0, .size = sizeof(rec), }, .offset = head, .size = size, .flags = flags, }; int ret;
perf_event_header__init_id(&rec.header, &sample, event); ret = perf_output_begin(&handle, &sample, event, rec.header.size);
if (ret) return;
perf_output_put(&handle, rec); perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);}
/* * Lost/dropped samples logging */void perf_log_lost_samples(struct perf_event *event, u64 lost){ struct perf_output_handle handle; struct perf_sample_data sample; int ret;
struct { struct perf_event_header header; u64 lost; } lost_samples_event = { .header = { .type = PERF_RECORD_LOST_SAMPLES, .misc = 0, .size = sizeof(lost_samples_event), }, .lost = lost, };
perf_event_header__init_id(&lost_samples_event.header, &sample, event);
ret = perf_output_begin(&handle, &sample, event, lost_samples_event.header.size); if (ret) return;
perf_output_put(&handle, lost_samples_event); perf_event__output_id_sample(event, &handle, &sample); perf_output_end(&handle);}
/* * context_switch tracking */
struct perf_switch_event { struct task_struct *task; struct task_struct *next_prev;
struct { struct perf_event_header header; u32 next_prev_pid; u32 next_prev_tid; } event_id;};
static int perf_event_switch_match(struct perf_event *event){ return event->attr.context_switch;}
static void perf_event_switch_output(struct perf_event *event, void *data){ struct perf_switch_event *se = data; struct perf_output_handle handle; struct perf_sample_data sample; int ret;
if (!perf_event_switch_match(event)) return;
/* Only CPU-wide events are allowed to see next/prev pid/tid */ if (event->ctx->task) { se->event_id.header.type = PERF_RECORD_SWITCH; se->event_id.header.size = sizeof(se->event_id.header); } else { se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE; se->event_id.header.size = sizeof(se->event_id); se->event_id.next_prev_pid = perf_event_pid(event, se->next_prev); se->event_id.next_prev_tid = perf_event_tid(event, se->next_prev); }
perf_event_header__init_id(&se->event_id.header, &sample, event);
ret = perf_output_begin(&handle, &sample, event, se->event_id.header.size); if (ret) return;
if (event->ctx->task) perf_output_put(&handle, se->event_id.header); else perf_output_put(&handle, se->event_id);
perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);}
static void perf_event_switch(struct task_struct *task, struct task_struct *next_prev, bool sched_in){ struct perf_switch_event switch_event;
/* N.B. caller checks nr_switch_events != 0 */
switch_event = (struct perf_switch_event){ .task = task, .next_prev = next_prev, .event_id = { .header = { /* .type */ .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, /* .size */ }, /* .next_prev_pid */ /* .next_prev_tid */ }, };
if (!sched_in && task_is_runnable(task)) { switch_event.event_id.header.misc |= PERF_RECORD_MISC_SWITCH_OUT_PREEMPT; }
perf_iterate_sb(perf_event_switch_output, &switch_event, NULL);}
/* * IRQ throttle logging */
static void perf_log_throttle(struct perf_event *event, int enable){ struct perf_output_handle handle; struct perf_sample_data sample; int ret;
struct { struct perf_event_header header; u64 time; u64 id; u64 stream_id; } throttle_event = { .header = { .type = PERF_RECORD_THROTTLE, .misc = 0, .size = sizeof(throttle_event), }, .time = perf_event_clock(event), .id = primary_event_id(event), .stream_id = event->id, };
if (enable) throttle_event.header.type = PERF_RECORD_UNTHROTTLE;
perf_event_header__init_id(&throttle_event.header, &sample, event);
ret = perf_output_begin(&handle, &sample, event, throttle_event.header.size); if (ret) return;
perf_output_put(&handle, throttle_event); perf_event__output_id_sample(event, &handle, &sample); perf_output_end(&handle);}
/* * ksymbol register/unregister tracking */
struct perf_ksymbol_event { const char *name; int name_len; struct { struct perf_event_header header; u64 addr; u32 len; u16 ksym_type; u16 flags; } event_id;};
static int perf_event_ksymbol_match(struct perf_event *event){ return event->attr.ksymbol;}
static void perf_event_ksymbol_output(struct perf_event *event, void *data){ struct perf_ksymbol_event *ksymbol_event = data; struct perf_output_handle handle; struct perf_sample_data sample; int ret;
if (!perf_event_ksymbol_match(event)) return;
perf_event_header__init_id(&ksymbol_event->event_id.header, &sample, event); ret = perf_output_begin(&handle, &sample, event, ksymbol_event->event_id.header.size); if (ret) return;
perf_output_put(&handle, ksymbol_event->event_id); __output_copy(&handle, ksymbol_event->name, ksymbol_event->name_len); perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);}
void perf_event_ksymbol(u16 ksym_type, u64 addr, u32 len, bool unregister, const char *sym){ struct perf_ksymbol_event ksymbol_event; char name[KSYM_NAME_LEN]; u16 flags = 0; int name_len;
if (!atomic_read(&nr_ksymbol_events)) return;
if (ksym_type >= PERF_RECORD_KSYMBOL_TYPE_MAX || ksym_type == PERF_RECORD_KSYMBOL_TYPE_UNKNOWN) goto err;
strscpy(name, sym); name_len = strlen(name) + 1; while (!IS_ALIGNED(name_len, sizeof(u64))) name[name_len++] = '\0'; BUILD_BUG_ON(KSYM_NAME_LEN % sizeof(u64));
if (unregister) flags |= PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER;
ksymbol_event = (struct perf_ksymbol_event){ .name = name, .name_len = name_len, .event_id = { .header = { .type = PERF_RECORD_KSYMBOL, .size = sizeof(ksymbol_event.event_id) + name_len, }, .addr = addr, .len = len, .ksym_type = ksym_type, .flags = flags, }, };
perf_iterate_sb(perf_event_ksymbol_output, &ksymbol_event, NULL); return;err: WARN_ONCE(1, "%s: Invalid KSYMBOL type 0x%x\n", __func__, ksym_type);}
/* * bpf program load/unload tracking */
struct perf_bpf_event { struct bpf_prog *prog; struct { struct perf_event_header header; u16 type; u16 flags; u32 id; u8 tag[BPF_TAG_SIZE]; } event_id;};
static int perf_event_bpf_match(struct perf_event *event){ return event->attr.bpf_event;}
static void perf_event_bpf_output(struct perf_event *event, void *data){ struct perf_bpf_event *bpf_event = data; struct perf_output_handle handle; struct perf_sample_data sample; int ret;
if (!perf_event_bpf_match(event)) return;
perf_event_header__init_id(&bpf_event->event_id.header, &sample, event); ret = perf_output_begin(&handle, &sample, event, bpf_event->event_id.header.size); if (ret) return;
perf_output_put(&handle, bpf_event->event_id); perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);}
static void perf_event_bpf_emit_ksymbols(struct bpf_prog *prog, enum perf_bpf_event_type type){ bool unregister = type == PERF_BPF_EVENT_PROG_UNLOAD; int i;
perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, (u64)(unsigned long)prog->bpf_func, prog->jited_len, unregister, prog->aux->ksym.name);
for (i = 1; i < prog->aux->func_cnt; i++) { struct bpf_prog *subprog = prog->aux->func[i];
perf_event_ksymbol( PERF_RECORD_KSYMBOL_TYPE_BPF, (u64)(unsigned long)subprog->bpf_func, subprog->jited_len, unregister, subprog->aux->ksym.name); }}
void perf_event_bpf_event(struct bpf_prog *prog, enum perf_bpf_event_type type, u16 flags){ struct perf_bpf_event bpf_event;
switch (type) { case PERF_BPF_EVENT_PROG_LOAD: case PERF_BPF_EVENT_PROG_UNLOAD: if (atomic_read(&nr_ksymbol_events)) perf_event_bpf_emit_ksymbols(prog, type); break; default: return; }
if (!atomic_read(&nr_bpf_events)) return;
bpf_event = (struct perf_bpf_event){ .prog = prog, .event_id = { .header = { .type = PERF_RECORD_BPF_EVENT, .size = sizeof(bpf_event.event_id), }, .type = type, .flags = flags, .id = prog->aux->id, }, };
BUILD_BUG_ON(BPF_TAG_SIZE % sizeof(u64));
memcpy(bpf_event.event_id.tag, prog->tag, BPF_TAG_SIZE); perf_iterate_sb(perf_event_bpf_output, &bpf_event, NULL);}
struct perf_callchain_deferred_event { struct unwind_stacktrace *trace; struct { struct perf_event_header header; u64 cookie; u64 nr; u64 ips[]; } event;};
static void perf_callchain_deferred_output(struct perf_event *event, void *data){ struct perf_callchain_deferred_event *deferred_event = data; struct perf_output_handle handle; struct perf_sample_data sample; int ret, size = deferred_event->event.header.size;
if (!event->attr.defer_output) return;
/* XXX do we really need sample_id_all for this ??? */ perf_event_header__init_id(&deferred_event->event.header, &sample, event);
ret = perf_output_begin(&handle, &sample, event, deferred_event->event.header.size); if (ret) goto out;
perf_output_put(&handle, deferred_event->event); for (int i = 0; i < deferred_event->trace->nr; i++) { u64 entry = deferred_event->trace->entries[i]; perf_output_put(&handle, entry); } perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);out: deferred_event->event.header.size = size;}
static void perf_unwind_deferred_callback(struct unwind_work *work, struct unwind_stacktrace *trace, u64 cookie){ struct perf_callchain_deferred_event deferred_event = { .trace = trace, .event = { .header = { .type = PERF_RECORD_CALLCHAIN_DEFERRED, .misc = PERF_RECORD_MISC_USER, .size = sizeof(deferred_event.event) + (trace->nr * sizeof(u64)), }, .cookie = cookie, .nr = trace->nr, }, };
perf_iterate_sb(perf_callchain_deferred_output, &deferred_event, NULL);}
struct perf_text_poke_event { const void *old_bytes; const void *new_bytes; size_t pad; u16 old_len; u16 new_len;
struct { struct perf_event_header header;
u64 addr; } event_id;};
static int perf_event_text_poke_match(struct perf_event *event){ return event->attr.text_poke;}
static void perf_event_text_poke_output(struct perf_event *event, void *data){ struct perf_text_poke_event *text_poke_event = data; struct perf_output_handle handle; struct perf_sample_data sample; u64 padding = 0; int ret;
if (!perf_event_text_poke_match(event)) return;
perf_event_header__init_id(&text_poke_event->event_id.header, &sample, event);
ret = perf_output_begin(&handle, &sample, event, text_poke_event->event_id.header.size); if (ret) return;
perf_output_put(&handle, text_poke_event->event_id); perf_output_put(&handle, text_poke_event->old_len); perf_output_put(&handle, text_poke_event->new_len);
__output_copy(&handle, text_poke_event->old_bytes, text_poke_event->old_len); __output_copy(&handle, text_poke_event->new_bytes, text_poke_event->new_len);
if (text_poke_event->pad) __output_copy(&handle, &padding, text_poke_event->pad);
perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);}
void perf_event_text_poke(const void *addr, const void *old_bytes, size_t old_len, const void *new_bytes, size_t new_len){ struct perf_text_poke_event text_poke_event; size_t tot, pad;
if (!atomic_read(&nr_text_poke_events)) return;
tot = sizeof(text_poke_event.old_len) + old_len; tot += sizeof(text_poke_event.new_len) + new_len; pad = ALIGN(tot, sizeof(u64)) - tot;
text_poke_event = (struct perf_text_poke_event){ .old_bytes = old_bytes, .new_bytes = new_bytes, .pad = pad, .old_len = old_len, .new_len = new_len, .event_id = { .header = { .type = PERF_RECORD_TEXT_POKE, .misc = PERF_RECORD_MISC_KERNEL, .size = sizeof(text_poke_event.event_id) + tot + pad, }, .addr = (unsigned long)addr, }, };
perf_iterate_sb(perf_event_text_poke_output, &text_poke_event, NULL);}
void perf_event_itrace_started(struct perf_event *event){ WRITE_ONCE(event->attach_state, event->attach_state | PERF_ATTACH_ITRACE);}
static void perf_log_itrace_start(struct perf_event *event){ struct perf_output_handle handle; struct perf_sample_data sample; struct perf_aux_event { struct perf_event_header header; u32 pid; u32 tid; } rec; int ret;
if (event->parent) event = event->parent;
if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) || event->attach_state & PERF_ATTACH_ITRACE) return;
rec.header.type = PERF_RECORD_ITRACE_START; rec.header.misc = 0; rec.header.size = sizeof(rec); rec.pid = perf_event_pid(event, current); rec.tid = perf_event_tid(event, current);
perf_event_header__init_id(&rec.header, &sample, event); ret = perf_output_begin(&handle, &sample, event, rec.header.size);
if (ret) return;
perf_output_put(&handle, rec); perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);}
void perf_report_aux_output_id(struct perf_event *event, u64 hw_id){ struct perf_output_handle handle; struct perf_sample_data sample; struct perf_aux_event { struct perf_event_header header; u64 hw_id; } rec; int ret;
if (event->parent) event = event->parent;
rec.header.type = PERF_RECORD_AUX_OUTPUT_HW_ID; rec.header.misc = 0; rec.header.size = sizeof(rec); rec.hw_id = hw_id;
perf_event_header__init_id(&rec.header, &sample, event); ret = perf_output_begin(&handle, &sample, event, rec.header.size);
if (ret) return;
perf_output_put(&handle, rec); perf_event__output_id_sample(event, &handle, &sample);
perf_output_end(&handle);}EXPORT_SYMBOL_GPL(perf_report_aux_output_id);
static int__perf_event_account_interrupt(struct perf_event *event, int throttle){ struct hw_perf_event *hwc = &event->hw; int ret = 0; u64 seq;
seq = __this_cpu_read(perf_throttled_seq); if (seq != hwc->interrupts_seq) { hwc->interrupts_seq = seq; hwc->interrupts = 1; } else { hwc->interrupts++; }
if (unlikely(throttle && hwc->interrupts >= max_samples_per_tick)) { __this_cpu_inc(perf_throttled_count); tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS); perf_event_throttle_group(event); ret = 1; }
if (event->attr.freq) { u64 now = perf_clock(); s64 delta = now - hwc->freq_time_stamp;
hwc->freq_time_stamp = now;
if (delta > 0 && delta < 2*TICK_NSEC) perf_adjust_period(event, delta, hwc->last_period, true); }
return ret;}
int perf_event_account_interrupt(struct perf_event *event){ return __perf_event_account_interrupt(event, 1);}
static inline bool sample_is_allowed(struct perf_event *event, struct pt_regs *regs){ /* * Due to interrupt latency (AKA "skid"), we may enter the * kernel before taking an overflow, even if the PMU is only * counting user events. */ if (event->attr.exclude_kernel && !user_mode(regs)) return false;
return true;}
#ifdef CONFIG_BPF_SYSCALLstatic int bpf_overflow_handler(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs){ struct bpf_perf_event_data_kern ctx = { .data = data, .event = event, }; struct bpf_prog *prog; int ret = 0;
ctx.regs = perf_arch_bpf_user_pt_regs(regs); if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) goto out; rcu_read_lock(); prog = READ_ONCE(event->prog); if (prog) { perf_prepare_sample(data, event, regs); ret = bpf_prog_run(prog, &ctx); } rcu_read_unlock();out: __this_cpu_dec(bpf_prog_active);
return ret;}
static inline int perf_event_set_bpf_handler(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie){ if (event->overflow_handler_context) /* hw breakpoint or kernel counter */ return -EINVAL;
if (event->prog) return -EEXIST;
if (prog->type != BPF_PROG_TYPE_PERF_EVENT) return -EINVAL;
if (event->attr.precise_ip && prog->call_get_stack && (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) || event->attr.exclude_callchain_kernel || event->attr.exclude_callchain_user)) { /* * On perf_event with precise_ip, calling bpf_get_stack() * may trigger unwinder warnings and occasional crashes. * bpf_get_[stack|stackid] works around this issue by using * callchain attached to perf_sample_data. If the * perf_event does not full (kernel and user) callchain * attached to perf_sample_data, do not allow attaching BPF * program that calls bpf_get_[stack|stackid]. */ return -EPROTO; }
event->prog = prog; event->bpf_cookie = bpf_cookie; return 0;}
static inline void perf_event_free_bpf_handler(struct perf_event *event){ struct bpf_prog *prog = event->prog;
if (!prog) return;
event->prog = NULL; bpf_prog_put(prog);}#elsestatic inline int bpf_overflow_handler(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs){ return 1;}
static inline int perf_event_set_bpf_handler(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie){ return -EOPNOTSUPP;}
static inline void perf_event_free_bpf_handler(struct perf_event *event){}#endif
/* * Generic event overflow handling, sampling. */
static int __perf_event_overflow(struct perf_event *event, int throttle, struct perf_sample_data *data, struct pt_regs *regs){ int events = atomic_read(&event->event_limit); int ret = 0;
/* * Non-sampling counters might still use the PMI to fold short * hardware counters, ignore those. */ if (unlikely(!is_sampling_event(event))) return 0;
ret = __perf_event_account_interrupt(event, throttle);
if (event->attr.aux_pause) perf_event_aux_pause(event->aux_event, true);
if (event->prog && event->prog->type == BPF_PROG_TYPE_PERF_EVENT && !bpf_overflow_handler(event, data, regs)) goto out;
/* * XXX event_limit might not quite work as expected on inherited * events */
event->pending_kill = POLL_IN; if (events && atomic_dec_and_test(&event->event_limit)) { ret = 1; event->pending_kill = POLL_HUP; perf_event_disable_inatomic(event); event->pmu->stop(event, 0); }
if (event->attr.sigtrap) { /* * The desired behaviour of sigtrap vs invalid samples is a bit * tricky; on the one hand, one should not loose the SIGTRAP if * it is the first event, on the other hand, we should also not * trigger the WARN or override the data address. */ bool valid_sample = sample_is_allowed(event, regs); unsigned int pending_id = 1; enum task_work_notify_mode notify_mode;
if (regs) pending_id = hash32_ptr((void *)instruction_pointer(regs)) ?: 1;
notify_mode = in_nmi() ? TWA_NMI_CURRENT : TWA_RESUME;
if (!event->pending_work && !task_work_add(current, &event->pending_task, notify_mode)) { event->pending_work = pending_id; local_inc(&event->ctx->nr_no_switch_fast); WARN_ON_ONCE(!atomic_long_inc_not_zero(&event->refcount));
event->pending_addr = 0; if (valid_sample && (data->sample_flags & PERF_SAMPLE_ADDR)) event->pending_addr = data->addr;
} else if (event->attr.exclude_kernel && valid_sample) { /* * Should not be able to return to user space without * consuming pending_work; with exceptions: * * 1. Where !exclude_kernel, events can overflow again * in the kernel without returning to user space. * * 2. Events that can overflow again before the IRQ- * work without user space progress (e.g. hrtimer). * To approximate progress (with false negatives), * check 32-bit hash of the current IP. */ WARN_ON_ONCE(event->pending_work != pending_id); } }
READ_ONCE(event->overflow_handler)(event, data, regs);
if (*perf_event_fasync(event) && event->pending_kill) { event->pending_wakeup = 1; irq_work_queue(&event->pending_irq); }out: if (event->attr.aux_resume) perf_event_aux_pause(event->aux_event, false);
return ret;}
int perf_event_overflow(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs){ /* * Entry point from hardware PMI, interrupts should be disabled here. * This serializes us against perf_event_remove_from_context() in * things like perf_event_release_kernel(). */ lockdep_assert_irqs_disabled();
return __perf_event_overflow(event, 1, data, regs);}
/* * Generic software event infrastructure */
struct swevent_htable { struct swevent_hlist *swevent_hlist; struct mutex hlist_mutex; int hlist_refcount;};static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
/* * We directly increment event->count and keep a second value in * event->hw.period_left to count intervals. This period event * is kept in the range [-sample_period, 0] so that we can use the * sign as trigger. */
u64 perf_swevent_set_period(struct perf_event *event){ struct hw_perf_event *hwc = &event->hw; u64 period = hwc->last_period; u64 nr, offset; s64 old, val;
hwc->last_period = hwc->sample_period;
old = local64_read(&hwc->period_left); do { val = old; if (val < 0) return 0;
nr = div64_u64(period + val, period); offset = nr * period; val -= offset; } while (!local64_try_cmpxchg(&hwc->period_left, &old, val));
return nr;}
static void perf_swevent_overflow(struct perf_event *event, u64 overflow, struct perf_sample_data *data, struct pt_regs *regs){ struct hw_perf_event *hwc = &event->hw; int throttle = 0;
if (!overflow) overflow = perf_swevent_set_period(event);
if (hwc->interrupts == MAX_INTERRUPTS) return;
for (; overflow; overflow--) { if (__perf_event_overflow(event, throttle, data, regs)) { /* * We inhibit the overflow from happening when * hwc->interrupts == MAX_INTERRUPTS. */ break; } throttle = 1; }}
static void perf_swevent_event(struct perf_event *event, u64 nr, struct perf_sample_data *data, struct pt_regs *regs){ struct hw_perf_event *hwc = &event->hw;
/* * This is: * - software preempt * - tracepoint preempt * - tp_target_task irq (ctx->lock) * - uprobes preempt/irq * - kprobes preempt/irq * - hw_breakpoint irq * * Any of these are sufficient to hold off RCU and thus ensure @event * exists. */ lockdep_assert_preemption_disabled(); local64_add(nr, &event->count);
if (!regs) return;
if (!is_sampling_event(event)) return;
/* * Serialize against event_function_call() IPIs like normal overflow * event handling. Specifically, must not allow * perf_event_release_kernel() -> perf_remove_from_context() to make * progress and 'release' the event from under us. */ guard(irqsave)(); if (event->state != PERF_EVENT_STATE_ACTIVE) return;
if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) { data->period = nr; return perf_swevent_overflow(event, 1, data, regs); } else data->period = event->hw.last_period;
if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq) return perf_swevent_overflow(event, 1, data, regs);
if (local64_add_negative(nr, &hwc->period_left)) return;
perf_swevent_overflow(event, 0, data, regs);}
int perf_exclude_event(struct perf_event *event, struct pt_regs *regs){ if (event->hw.state & PERF_HES_STOPPED) return 1;
if (regs) { if (event->attr.exclude_user && user_mode(regs)) return 1;
if (event->attr.exclude_kernel && !user_mode(regs)) return 1; }
return 0;}
static int perf_swevent_match(struct perf_event *event, enum perf_type_id type, u32 event_id, struct perf_sample_data *data, struct pt_regs *regs){ if (event->attr.type != type) return 0;
if (event->attr.config != event_id) return 0;
if (perf_exclude_event(event, regs)) return 0;
return 1;}
static inline u64 swevent_hash(u64 type, u32 event_id){ u64 val = event_id | (type << 32);
return hash_64(val, SWEVENT_HLIST_BITS);}
static inline struct hlist_head *__find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id){ u64 hash = swevent_hash(type, event_id);
return &hlist->heads[hash];}
/* For the read side: events when they trigger */static inline struct hlist_head *find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id){ struct swevent_hlist *hlist;
hlist = rcu_dereference(swhash->swevent_hlist); if (!hlist) return NULL;
return __find_swevent_head(hlist, type, event_id);}
/* For the event head insertion and removal in the hlist */static inline struct hlist_head *find_swevent_head(struct swevent_htable *swhash, struct perf_event *event){ struct swevent_hlist *hlist; u32 event_id = event->attr.config; u64 type = event->attr.type;
/* * Event scheduling is always serialized against hlist allocation * and release. Which makes the protected version suitable here. * The context lock guarantees that. */ hlist = rcu_dereference_protected(swhash->swevent_hlist, lockdep_is_held(&event->ctx->lock)); if (!hlist) return NULL;
return __find_swevent_head(hlist, type, event_id);}
static void do_perf_sw_event(enum perf_type_id type, u32 event_id, u64 nr, struct perf_sample_data *data, struct pt_regs *regs){ struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); struct perf_event *event; struct hlist_head *head;
rcu_read_lock(); head = find_swevent_head_rcu(swhash, type, event_id); if (!head) goto end;
hlist_for_each_entry_rcu(event, head, hlist_entry) { if (perf_swevent_match(event, type, event_id, data, regs)) perf_swevent_event(event, nr, data, regs); }end: rcu_read_unlock();}
DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]);
int perf_swevent_get_recursion_context(void){ return get_recursion_context(current->perf_recursion);}EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
void perf_swevent_put_recursion_context(int rctx){ put_recursion_context(current->perf_recursion, rctx);}
void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr){ struct perf_sample_data data;
if (WARN_ON_ONCE(!regs)) return;
perf_sample_data_init(&data, addr, 0); do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs);}
void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr){ int rctx;
preempt_disable_notrace(); rctx = perf_swevent_get_recursion_context(); if (unlikely(rctx < 0)) goto fail;
___perf_sw_event(event_id, nr, regs, addr);
perf_swevent_put_recursion_context(rctx);fail: preempt_enable_notrace();}
static void perf_swevent_read(struct perf_event *event){}
static int perf_swevent_add(struct perf_event *event, int flags){ struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable); struct hw_perf_event *hwc = &event->hw; struct hlist_head *head;
if (is_sampling_event(event)) { hwc->last_period = hwc->sample_period; perf_swevent_set_period(event); }
hwc->state = !(flags & PERF_EF_START);
head = find_swevent_head(swhash, event); if (WARN_ON_ONCE(!head)) return -EINVAL;
hlist_add_head_rcu(&event->hlist_entry, head); perf_event_update_userpage(event);
return 0;}
static void perf_swevent_del(struct perf_event *event, int flags){ hlist_del_rcu(&event->hlist_entry);}
static void perf_swevent_start(struct perf_event *event, int flags){ event->hw.state = 0;}
static void perf_swevent_stop(struct perf_event *event, int flags){ event->hw.state = PERF_HES_STOPPED;}
/* Deref the hlist from the update side */static inline struct swevent_hlist *swevent_hlist_deref(struct swevent_htable *swhash){ return rcu_dereference_protected(swhash->swevent_hlist, lockdep_is_held(&swhash->hlist_mutex));}
static void swevent_hlist_release(struct swevent_htable *swhash){ struct swevent_hlist *hlist = swevent_hlist_deref(swhash);
if (!hlist) return;
RCU_INIT_POINTER(swhash->swevent_hlist, NULL); kfree_rcu(hlist, rcu_head);}
static void swevent_hlist_put_cpu(int cpu){ struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
mutex_lock(&swhash->hlist_mutex);
if (!--swhash->hlist_refcount) swevent_hlist_release(swhash);
mutex_unlock(&swhash->hlist_mutex);}
static void swevent_hlist_put(void){ int cpu;
for_each_possible_cpu(cpu) swevent_hlist_put_cpu(cpu);}
static int swevent_hlist_get_cpu(int cpu){ struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu); int err = 0;
mutex_lock(&swhash->hlist_mutex); if (!swevent_hlist_deref(swhash) && cpumask_test_cpu(cpu, perf_online_mask)) { struct swevent_hlist *hlist;
hlist = kzalloc_obj(*hlist); if (!hlist) { err = -ENOMEM; goto exit; } rcu_assign_pointer(swhash->swevent_hlist, hlist); } swhash->hlist_refcount++;exit: mutex_unlock(&swhash->hlist_mutex);
return err;}
static int swevent_hlist_get(void){ int err, cpu, failed_cpu;
mutex_lock(&pmus_lock); for_each_possible_cpu(cpu) { err = swevent_hlist_get_cpu(cpu); if (err) { failed_cpu = cpu; goto fail; } } mutex_unlock(&pmus_lock); return 0;fail: for_each_possible_cpu(cpu) { if (cpu == failed_cpu) break; swevent_hlist_put_cpu(cpu); } mutex_unlock(&pmus_lock); return err;}
struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
static void sw_perf_event_destroy(struct perf_event *event){ u64 event_id = event->attr.config;
WARN_ON(event->parent);
static_key_slow_dec(&perf_swevent_enabled[event_id]); swevent_hlist_put();}
static struct pmu perf_cpu_clock; /* fwd declaration */static struct pmu perf_task_clock;
static int perf_swevent_init(struct perf_event *event){ u64 event_id = event->attr.config;
if (event->attr.type != PERF_TYPE_SOFTWARE) return -ENOENT;
/* * no branch sampling for software events */ if (has_branch_stack(event)) return -EOPNOTSUPP;
switch (event_id) { case PERF_COUNT_SW_CPU_CLOCK: event->attr.type = perf_cpu_clock.type; return -ENOENT; case PERF_COUNT_SW_TASK_CLOCK: event->attr.type = perf_task_clock.type; return -ENOENT;
default: break; }
if (event_id >= PERF_COUNT_SW_MAX) return -ENOENT;
if (!event->parent) { int err;
err = swevent_hlist_get(); if (err) return err;
static_key_slow_inc(&perf_swevent_enabled[event_id]); event->destroy = sw_perf_event_destroy; }
return 0;}
static struct pmu perf_swevent = { .task_ctx_nr = perf_sw_context,
.capabilities = PERF_PMU_CAP_NO_NMI,
.event_init = perf_swevent_init, .add = perf_swevent_add, .del = perf_swevent_del, .start = perf_swevent_start, .stop = perf_swevent_stop, .read = perf_swevent_read,};
#ifdef CONFIG_EVENT_TRACING
static void tp_perf_event_destroy(struct perf_event *event){ perf_trace_destroy(event);}
static int perf_tp_event_init(struct perf_event *event){ int err;
if (event->attr.type != PERF_TYPE_TRACEPOINT) return -ENOENT;
/* * no branch sampling for tracepoint events */ if (has_branch_stack(event)) return -EOPNOTSUPP;
err = perf_trace_init(event); if (err) return err;
event->destroy = tp_perf_event_destroy;
return 0;}
static struct pmu perf_tracepoint = { .task_ctx_nr = perf_sw_context,
.event_init = perf_tp_event_init, .add = perf_trace_add, .del = perf_trace_del, .start = perf_swevent_start, .stop = perf_swevent_stop, .read = perf_swevent_read,};
static int perf_tp_filter_match(struct perf_event *event, struct perf_raw_record *raw){ void *record = raw->frag.data;
/* only top level events have filters set */ if (event->parent) event = event->parent;
if (likely(!event->filter) || filter_match_preds(event->filter, record)) return 1; return 0;}
static int perf_tp_event_match(struct perf_event *event, struct perf_raw_record *raw, struct pt_regs *regs){ if (event->hw.state & PERF_HES_STOPPED) return 0; /* * If exclude_kernel, only trace user-space tracepoints (uprobes) */ if (event->attr.exclude_kernel && !user_mode(regs)) return 0;
if (!perf_tp_filter_match(event, raw)) return 0;
return 1;}
void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx, struct trace_event_call *call, u64 count, struct pt_regs *regs, struct hlist_head *head, struct task_struct *task){ if (bpf_prog_array_valid(call)) { *(struct pt_regs **)raw_data = regs; if (!trace_call_bpf(call, raw_data) || hlist_empty(head)) { perf_swevent_put_recursion_context(rctx); return; } } perf_tp_event(call->event.type, count, raw_data, size, regs, head, rctx, task);}EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit);
static void __perf_tp_event_target_task(u64 count, void *record, struct pt_regs *regs, struct perf_sample_data *data, struct perf_raw_record *raw, struct perf_event *event){ struct trace_entry *entry = record;
if (event->attr.config != entry->type) return; /* Cannot deliver synchronous signal to other task. */ if (event->attr.sigtrap) return; if (perf_tp_event_match(event, raw, regs)) { perf_sample_data_init(data, 0, 0); perf_sample_save_raw_data(data, event, raw); perf_swevent_event(event, count, data, regs); }}
static void perf_tp_event_target_task(u64 count, void *record, struct pt_regs *regs, struct perf_sample_data *data, struct perf_raw_record *raw, struct perf_event_context *ctx){ unsigned int cpu = smp_processor_id(); struct pmu *pmu = &perf_tracepoint; struct perf_event *event, *sibling;
perf_event_groups_for_cpu_pmu(event, &ctx->pinned_groups, cpu, pmu) { __perf_tp_event_target_task(count, record, regs, data, raw, event); for_each_sibling_event(sibling, event) __perf_tp_event_target_task(count, record, regs, data, raw, sibling); }
perf_event_groups_for_cpu_pmu(event, &ctx->flexible_groups, cpu, pmu) { __perf_tp_event_target_task(count, record, regs, data, raw, event); for_each_sibling_event(sibling, event) __perf_tp_event_target_task(count, record, regs, data, raw, sibling); }}
void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size, struct pt_regs *regs, struct hlist_head *head, int rctx, struct task_struct *task){ struct perf_sample_data data; struct perf_event *event;
/* * Per being a tracepoint, this runs with preemption disabled. */ lockdep_assert_preemption_disabled();
struct perf_raw_record raw = { .frag = { .size = entry_size, .data = record, }, };
perf_trace_buf_update(record, event_type);
hlist_for_each_entry_rcu(event, head, hlist_entry) { if (perf_tp_event_match(event, &raw, regs)) { /* * Here use the same on-stack perf_sample_data, * some members in data are event-specific and * need to be re-computed for different sweveents. * Re-initialize data->sample_flags safely to avoid * the problem that next event skips preparing data * because data->sample_flags is set. */ perf_sample_data_init(&data, 0, 0); perf_sample_save_raw_data(&data, event, &raw); perf_swevent_event(event, count, &data, regs); } }
/* * If we got specified a target task, also iterate its context and * deliver this event there too. */ if (task && task != current) { struct perf_event_context *ctx;
rcu_read_lock(); ctx = rcu_dereference(task->perf_event_ctxp); if (!ctx) goto unlock;
raw_spin_lock(&ctx->lock); perf_tp_event_target_task(count, record, regs, &data, &raw, ctx); raw_spin_unlock(&ctx->lock);unlock: rcu_read_unlock(); }
perf_swevent_put_recursion_context(rctx);}EXPORT_SYMBOL_GPL(perf_tp_event);
#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)/* * Flags in config, used by dynamic PMU kprobe and uprobe * The flags should match following PMU_FORMAT_ATTR(). * * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe * if not set, create kprobe/uprobe * * The following values specify a reference counter (or semaphore in the * terminology of tools like dtrace, systemtap, etc.) Userspace Statically * Defined Tracepoints (USDT). Currently, we use 40 bit for the offset. * * PERF_UPROBE_REF_CTR_OFFSET_BITS # of bits in config as th offset * PERF_UPROBE_REF_CTR_OFFSET_SHIFT # of bits to shift left */enum perf_probe_config { PERF_PROBE_CONFIG_IS_RETPROBE = 1U << 0, /* [k,u]retprobe */ PERF_UPROBE_REF_CTR_OFFSET_BITS = 32, PERF_UPROBE_REF_CTR_OFFSET_SHIFT = 64 - PERF_UPROBE_REF_CTR_OFFSET_BITS,};
PMU_FORMAT_ATTR(retprobe, "config:0");#endif
#ifdef CONFIG_KPROBE_EVENTSstatic struct attribute *kprobe_attrs[] = { &format_attr_retprobe.attr, NULL,};
static struct attribute_group kprobe_format_group = { .name = "format", .attrs = kprobe_attrs,};
static const struct attribute_group *kprobe_attr_groups[] = { &kprobe_format_group, NULL,};
static int perf_kprobe_event_init(struct perf_event *event);static struct pmu perf_kprobe = { .task_ctx_nr = perf_sw_context, .event_init = perf_kprobe_event_init, .add = perf_trace_add, .del = perf_trace_del, .start = perf_swevent_start, .stop = perf_swevent_stop, .read = perf_swevent_read, .attr_groups = kprobe_attr_groups,};
static int perf_kprobe_event_init(struct perf_event *event){ int err; bool is_retprobe;
if (event->attr.type != perf_kprobe.type) return -ENOENT;
if (!perfmon_capable()) return -EACCES;
/* * no branch sampling for probe events */ if (has_branch_stack(event)) return -EOPNOTSUPP;
is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE; err = perf_kprobe_init(event, is_retprobe); if (err) return err;
event->destroy = perf_kprobe_destroy;
return 0;}#endif /* CONFIG_KPROBE_EVENTS */
#ifdef CONFIG_UPROBE_EVENTSPMU_FORMAT_ATTR(ref_ctr_offset, "config:32-63");
static struct attribute *uprobe_attrs[] = { &format_attr_retprobe.attr, &format_attr_ref_ctr_offset.attr, NULL,};
static struct attribute_group uprobe_format_group = { .name = "format", .attrs = uprobe_attrs,};
static const struct attribute_group *uprobe_attr_groups[] = { &uprobe_format_group, NULL,};
static int perf_uprobe_event_init(struct perf_event *event);static struct pmu perf_uprobe = { .task_ctx_nr = perf_sw_context, .event_init = perf_uprobe_event_init, .add = perf_trace_add, .del = perf_trace_del, .start = perf_swevent_start, .stop = perf_swevent_stop, .read = perf_swevent_read, .attr_groups = uprobe_attr_groups,};
static int perf_uprobe_event_init(struct perf_event *event){ int err; unsigned long ref_ctr_offset; bool is_retprobe;
if (event->attr.type != perf_uprobe.type) return -ENOENT;
if (!capable(CAP_SYS_ADMIN)) return -EACCES;
/* * no branch sampling for probe events */ if (has_branch_stack(event)) return -EOPNOTSUPP;
is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE; ref_ctr_offset = event->attr.config >> PERF_UPROBE_REF_CTR_OFFSET_SHIFT; err = perf_uprobe_init(event, ref_ctr_offset, is_retprobe); if (err) return err;
event->destroy = perf_uprobe_destroy;
return 0;}#endif /* CONFIG_UPROBE_EVENTS */
static inline void perf_tp_register(void){ perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT);#ifdef CONFIG_KPROBE_EVENTS perf_pmu_register(&perf_kprobe, "kprobe", -1);#endif#ifdef CONFIG_UPROBE_EVENTS perf_pmu_register(&perf_uprobe, "uprobe", -1);#endif}
static void perf_event_free_filter(struct perf_event *event){ ftrace_profile_free_filter(event);}
/* * returns true if the event is a tracepoint, or a kprobe/upprobe created * with perf_event_open() */static inline bool perf_event_is_tracing(struct perf_event *event){ if (event->pmu == &perf_tracepoint) return true;#ifdef CONFIG_KPROBE_EVENTS if (event->pmu == &perf_kprobe) return true;#endif#ifdef CONFIG_UPROBE_EVENTS if (event->pmu == &perf_uprobe) return true;#endif return false;}
static int __perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie){ bool is_kprobe, is_uprobe, is_tracepoint, is_syscall_tp;
if (event->state <= PERF_EVENT_STATE_REVOKED) return -ENODEV;
if (!perf_event_is_tracing(event)) return perf_event_set_bpf_handler(event, prog, bpf_cookie);
is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_KPROBE; is_uprobe = event->tp_event->flags & TRACE_EVENT_FL_UPROBE; is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT; is_syscall_tp = is_syscall_trace_event(event->tp_event); if (!is_kprobe && !is_uprobe && !is_tracepoint && !is_syscall_tp) /* bpf programs can only be attached to u/kprobe or tracepoint */ return -EINVAL;
if (((is_kprobe || is_uprobe) && prog->type != BPF_PROG_TYPE_KPROBE) || (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT) || (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT)) return -EINVAL;
if (prog->type == BPF_PROG_TYPE_KPROBE && prog->sleepable && !is_uprobe) /* only uprobe programs are allowed to be sleepable */ return -EINVAL;
if (prog->type == BPF_PROG_TYPE_TRACEPOINT && prog->sleepable) { /* * Sleepable tracepoint programs can only attach to faultable * tracepoints. Currently only syscall tracepoints are faultable. */ if (!is_syscall_tp) return -EINVAL; }
/* Kprobe override only works for kprobes, not uprobes. */ if (prog->kprobe_override && !is_kprobe) return -EINVAL;
/* Writing to context allowed only for uprobes. */ if (prog->aux->kprobe_write_ctx && !is_uprobe) return -EINVAL;
if (is_tracepoint || is_syscall_tp) { int off = trace_event_get_offsets(event->tp_event);
if (prog->aux->max_ctx_offset > off) return -EACCES; }
return perf_event_attach_bpf_prog(event, prog, bpf_cookie);}
int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie){ struct perf_event_context *ctx; int ret;
ctx = perf_event_ctx_lock(event); ret = __perf_event_set_bpf_prog(event, prog, bpf_cookie); perf_event_ctx_unlock(event, ctx);
return ret;}
void perf_event_free_bpf_prog(struct perf_event *event){ if (!event->prog) return;
if (!perf_event_is_tracing(event)) { perf_event_free_bpf_handler(event); return; } perf_event_detach_bpf_prog(event);}
#else
static inline void perf_tp_register(void){}
static void perf_event_free_filter(struct perf_event *event){}
static int __perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie){ return -ENOENT;}
int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie){ return -ENOENT;}
void perf_event_free_bpf_prog(struct perf_event *event){}#endif /* CONFIG_EVENT_TRACING */
#ifdef CONFIG_HAVE_HW_BREAKPOINTvoid perf_bp_event(struct perf_event *bp, void *data){ struct perf_sample_data sample; struct pt_regs *regs = data;
/* * Exception context, will have interrupts disabled. */ lockdep_assert_irqs_disabled();
perf_sample_data_init(&sample, bp->attr.bp_addr, 0);
if (!bp->hw.state && !perf_exclude_event(bp, regs)) perf_swevent_event(bp, 1, &sample, regs);}#endif
/* * Allocate a new address filter */static struct perf_addr_filter *perf_addr_filter_new(struct perf_event *event, struct list_head *filters){ int node = cpu_to_node(event->cpu == -1 ? 0 : event->cpu); struct perf_addr_filter *filter;
filter = kzalloc_node(sizeof(*filter), GFP_KERNEL, node); if (!filter) return NULL;
INIT_LIST_HEAD(&filter->entry); list_add_tail(&filter->entry, filters);
return filter;}
static void free_filters_list(struct list_head *filters){ struct perf_addr_filter *filter, *iter;
list_for_each_entry_safe(filter, iter, filters, entry) { path_put(&filter->path); list_del(&filter->entry); kfree(filter); }}
/* * Free existing address filters and optionally install new ones */static void perf_addr_filters_splice(struct perf_event *event, struct list_head *head){ unsigned long flags; LIST_HEAD(list);
if (!has_addr_filter(event)) return;
/* don't bother with children, they don't have their own filters */ if (event->parent) return;
raw_spin_lock_irqsave(&event->addr_filters.lock, flags);
list_splice_init(&event->addr_filters.list, &list); if (head) list_splice(head, &event->addr_filters.list);
raw_spin_unlock_irqrestore(&event->addr_filters.lock, flags);
free_filters_list(&list);}
static void perf_free_addr_filters(struct perf_event *event){ /* * Used during free paths, there is no concurrency. */ if (list_empty(&event->addr_filters.list)) return;
perf_addr_filters_splice(event, NULL);}
/* * Scan through mm's vmas and see if one of them matches the * @filter; if so, adjust filter's address range. * Called with mm::mmap_lock down for reading. */static void perf_addr_filter_apply(struct perf_addr_filter *filter, struct mm_struct *mm, struct perf_addr_filter_range *fr){ struct vm_area_struct *vma; VMA_ITERATOR(vmi, mm, 0);
for_each_vma(vmi, vma) { if (!vma->vm_file) continue;
if (perf_addr_filter_vma_adjust(filter, vma, fr)) return; }}
/* * Update event's address range filters based on the * task's existing mappings, if any. */static void perf_event_addr_filters_apply(struct perf_event *event){ struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); struct task_struct *task = READ_ONCE(event->ctx->task); struct perf_addr_filter *filter; struct mm_struct *mm = NULL; unsigned int count = 0; unsigned long flags;
/* * We may observe TASK_TOMBSTONE, which means that the event tear-down * will stop on the parent's child_mutex that our caller is also holding */ if (task == TASK_TOMBSTONE) return;
if (ifh->nr_file_filters) { mm = get_task_mm(task); if (!mm) goto restart;
mmap_read_lock(mm); }
raw_spin_lock_irqsave(&ifh->lock, flags); list_for_each_entry(filter, &ifh->list, entry) { if (filter->path.dentry) { /* * Adjust base offset if the filter is associated to a * binary that needs to be mapped: */ event->addr_filter_ranges[count].start = 0; event->addr_filter_ranges[count].size = 0;
perf_addr_filter_apply(filter, mm, &event->addr_filter_ranges[count]); } else { event->addr_filter_ranges[count].start = filter->offset; event->addr_filter_ranges[count].size = filter->size; }
count++; }
event->addr_filters_gen++; raw_spin_unlock_irqrestore(&ifh->lock, flags);
if (ifh->nr_file_filters) { mmap_read_unlock(mm);
mmput(mm); }
restart: perf_event_stop(event, 1);}
/* * Address range filtering: limiting the data to certain * instruction address ranges. Filters are ioctl()ed to us from * userspace as ascii strings. * * Filter string format: * * ACTION RANGE_SPEC * where ACTION is one of the * * "filter": limit the trace to this region * * "start": start tracing from this address * * "stop": stop tracing at this address/region; * RANGE_SPEC is * * for kernel addresses: <start address>[/<size>] * * for object files: <start address>[/<size>]@</path/to/object/file> * * if <size> is not specified or is zero, the range is treated as a single * address; not valid for ACTION=="filter". */enum { IF_ACT_NONE = -1, IF_ACT_FILTER, IF_ACT_START, IF_ACT_STOP, IF_SRC_FILE, IF_SRC_KERNEL, IF_SRC_FILEADDR, IF_SRC_KERNELADDR,};
enum { IF_STATE_ACTION = 0, IF_STATE_SOURCE, IF_STATE_END,};
static const match_table_t if_tokens = { { IF_ACT_FILTER, "filter" }, { IF_ACT_START, "start" }, { IF_ACT_STOP, "stop" }, { IF_SRC_FILE, "%u/%u@%s" }, { IF_SRC_KERNEL, "%u/%u" }, { IF_SRC_FILEADDR, "%u@%s" }, { IF_SRC_KERNELADDR, "%u" }, { IF_ACT_NONE, NULL },};
/* * Address filter string parser */static intperf_event_parse_addr_filter(struct perf_event *event, char *fstr, struct list_head *filters){ struct perf_addr_filter *filter = NULL; char *start, *orig, *filename = NULL; substring_t args[MAX_OPT_ARGS]; int state = IF_STATE_ACTION, token; unsigned int kernel = 0; int ret = -EINVAL;
orig = fstr = kstrdup(fstr, GFP_KERNEL); if (!fstr) return -ENOMEM;
while ((start = strsep(&fstr, " ,\n")) != NULL) { static const enum perf_addr_filter_action_t actions[] = { [IF_ACT_FILTER] = PERF_ADDR_FILTER_ACTION_FILTER, [IF_ACT_START] = PERF_ADDR_FILTER_ACTION_START, [IF_ACT_STOP] = PERF_ADDR_FILTER_ACTION_STOP, }; ret = -EINVAL;
if (!*start) continue;
/* filter definition begins */ if (state == IF_STATE_ACTION) { filter = perf_addr_filter_new(event, filters); if (!filter) goto fail; }
token = match_token(start, if_tokens, args); switch (token) { case IF_ACT_FILTER: case IF_ACT_START: case IF_ACT_STOP: if (state != IF_STATE_ACTION) goto fail;
filter->action = actions[token]; state = IF_STATE_SOURCE; break;
case IF_SRC_KERNELADDR: case IF_SRC_KERNEL: kernel = 1; fallthrough;
case IF_SRC_FILEADDR: case IF_SRC_FILE: if (state != IF_STATE_SOURCE) goto fail;
*args[0].to = 0; ret = kstrtoul(args[0].from, 0, &filter->offset); if (ret) goto fail;
if (token == IF_SRC_KERNEL || token == IF_SRC_FILE) { *args[1].to = 0; ret = kstrtoul(args[1].from, 0, &filter->size); if (ret) goto fail; }
if (token == IF_SRC_FILE || token == IF_SRC_FILEADDR) { int fpos = token == IF_SRC_FILE ? 2 : 1;
kfree(filename); filename = match_strdup(&args[fpos]); if (!filename) { ret = -ENOMEM; goto fail; } }
state = IF_STATE_END; break;
default: goto fail; }
/* * Filter definition is fully parsed, validate and install it. * Make sure that it doesn't contradict itself or the event's * attribute. */ if (state == IF_STATE_END) { ret = -EINVAL;
/* * ACTION "filter" must have a non-zero length region * specified. */ if (filter->action == PERF_ADDR_FILTER_ACTION_FILTER && !filter->size) goto fail;
if (!kernel) { if (!filename) goto fail;
/* * For now, we only support file-based filters * in per-task events; doing so for CPU-wide * events requires additional context switching * trickery, since same object code will be * mapped at different virtual addresses in * different processes. */ ret = -EOPNOTSUPP; if (!event->ctx->task) goto fail;
/* look up the path and grab its inode */ ret = kern_path(filename, LOOKUP_FOLLOW, &filter->path); if (ret) goto fail;
ret = -EINVAL; if (!filter->path.dentry || !S_ISREG(d_inode(filter->path.dentry) ->i_mode)) goto fail;
event->addr_filters.nr_file_filters++; }
/* ready to consume more filters */ kfree(filename); filename = NULL; state = IF_STATE_ACTION; filter = NULL; kernel = 0; } }
if (state != IF_STATE_ACTION) goto fail;
kfree(filename); kfree(orig);
return 0;
fail: kfree(filename); free_filters_list(filters); kfree(orig);
return ret;}
static intperf_event_set_addr_filter(struct perf_event *event, char *filter_str){ LIST_HEAD(filters); int ret;
/* * Since this is called in perf_ioctl() path, we're already holding * ctx::mutex. */ lockdep_assert_held(&event->ctx->mutex);
if (WARN_ON_ONCE(event->parent)) return -EINVAL;
ret = perf_event_parse_addr_filter(event, filter_str, &filters); if (ret) goto fail_clear_files;
ret = event->pmu->addr_filters_validate(&filters); if (ret) goto fail_free_filters;
/* remove existing filters, if any */ perf_addr_filters_splice(event, &filters);
/* install new filters */ perf_event_for_each_child(event, perf_event_addr_filters_apply);
return ret;
fail_free_filters: free_filters_list(&filters);
fail_clear_files: event->addr_filters.nr_file_filters = 0;
return ret;}
static int perf_event_set_filter(struct perf_event *event, void __user *arg){ int ret = -EINVAL; char *filter_str;
filter_str = strndup_user(arg, PAGE_SIZE); if (IS_ERR(filter_str)) return PTR_ERR(filter_str);
#ifdef CONFIG_EVENT_TRACING if (perf_event_is_tracing(event)) { struct perf_event_context *ctx = event->ctx;
/* * Beware, here be dragons!! * * the tracepoint muck will deadlock against ctx->mutex, but * the tracepoint stuff does not actually need it. So * temporarily drop ctx->mutex. As per perf_event_ctx_lock() we * already have a reference on ctx. * * This can result in event getting moved to a different ctx, * but that does not affect the tracepoint state. */ mutex_unlock(&ctx->mutex); ret = ftrace_profile_set_filter(event, event->attr.config, filter_str); mutex_lock(&ctx->mutex); } else#endif if (has_addr_filter(event)) ret = perf_event_set_addr_filter(event, filter_str);
kfree(filter_str); return ret;}
/* * hrtimer based swevent callback */
static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer){ enum hrtimer_restart ret = HRTIMER_RESTART; struct perf_sample_data data; struct pt_regs *regs; struct perf_event *event; u64 period;
event = container_of(hrtimer, struct perf_event, hw.hrtimer);
if (event->state != PERF_EVENT_STATE_ACTIVE || event->hw.state & PERF_HES_STOPPED) return HRTIMER_NORESTART;
event->pmu->read(event);
perf_sample_data_init(&data, 0, event->hw.last_period); regs = get_irq_regs();
if (regs && !perf_exclude_event(event, regs)) { if (!(event->attr.exclude_idle && is_idle_task(current))) if (perf_event_overflow(event, &data, regs)) ret = HRTIMER_NORESTART; }
period = max_t(u64, 10000, event->hw.sample_period); hrtimer_forward_now(hrtimer, ns_to_ktime(period));
return ret;}
static void perf_swevent_start_hrtimer(struct perf_event *event){ struct hw_perf_event *hwc = &event->hw; s64 period;
if (!is_sampling_event(event)) return;
period = local64_read(&hwc->period_left); if (period) { if (period < 0) period = 10000;
local64_set(&hwc->period_left, 0); } else { period = max_t(u64, 10000, hwc->sample_period); } hrtimer_start(&hwc->hrtimer, ns_to_ktime(period), HRTIMER_MODE_REL_PINNED_HARD);}
static void perf_swevent_cancel_hrtimer(struct perf_event *event){ struct hw_perf_event *hwc = &event->hw;
/* * Careful: this function can be triggered in the hrtimer handler, * for cpu-clock events, so hrtimer_cancel() would cause a * deadlock. * * So use hrtimer_try_to_cancel() to try to stop the hrtimer, * and the cpu-clock handler also sets the PERF_HES_STOPPED flag, * which guarantees that perf_swevent_hrtimer() will stop the * hrtimer once it sees the PERF_HES_STOPPED flag. */ if (is_sampling_event(event) && (hwc->interrupts != MAX_INTERRUPTS)) { ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); local64_set(&hwc->period_left, ktime_to_ns(remaining));
hrtimer_try_to_cancel(&hwc->hrtimer); }}
static void perf_swevent_destroy_hrtimer(struct perf_event *event){ hrtimer_cancel(&event->hw.hrtimer);}
static void perf_swevent_init_hrtimer(struct perf_event *event){ struct hw_perf_event *hwc = &event->hw;
if (!is_sampling_event(event)) return;
hrtimer_setup(&hwc->hrtimer, perf_swevent_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); event->destroy = perf_swevent_destroy_hrtimer;
/* * Since hrtimers have a fixed rate, we can do a static freq->period * mapping and avoid the whole period adjust feedback stuff. */ if (event->attr.freq) { long freq = event->attr.sample_freq;
event->attr.sample_period = NSEC_PER_SEC / freq; hwc->sample_period = event->attr.sample_period; local64_set(&hwc->period_left, hwc->sample_period); hwc->last_period = hwc->sample_period; event->attr.freq = 0; }}
/* * Software event: cpu wall time clock */
static void cpu_clock_event_update(struct perf_event *event){ s64 prev; u64 now;
now = local_clock(); prev = local64_xchg(&event->hw.prev_count, now); local64_add(now - prev, &event->count);}
static void cpu_clock_event_start(struct perf_event *event, int flags){ event->hw.state = 0; local64_set(&event->hw.prev_count, local_clock()); perf_swevent_start_hrtimer(event);}
static void cpu_clock_event_stop(struct perf_event *event, int flags){ event->hw.state = PERF_HES_STOPPED; perf_swevent_cancel_hrtimer(event); if (flags & PERF_EF_UPDATE) cpu_clock_event_update(event);}
static int cpu_clock_event_add(struct perf_event *event, int flags){ if (flags & PERF_EF_START) cpu_clock_event_start(event, flags); perf_event_update_userpage(event);
return 0;}
static void cpu_clock_event_del(struct perf_event *event, int flags){ cpu_clock_event_stop(event, PERF_EF_UPDATE);}
static void cpu_clock_event_read(struct perf_event *event){ cpu_clock_event_update(event);}
static int cpu_clock_event_init(struct perf_event *event){ if (event->attr.type != perf_cpu_clock.type) return -ENOENT;
if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK) return -ENOENT;
/* * no branch sampling for software events */ if (has_branch_stack(event)) return -EOPNOTSUPP;
perf_swevent_init_hrtimer(event);
return 0;}
static struct pmu perf_cpu_clock = { .task_ctx_nr = perf_sw_context,
.capabilities = PERF_PMU_CAP_NO_NMI, .dev = PMU_NULL_DEV,
.event_init = cpu_clock_event_init, .add = cpu_clock_event_add, .del = cpu_clock_event_del, .start = cpu_clock_event_start, .stop = cpu_clock_event_stop, .read = cpu_clock_event_read,};
/* * Software event: task time clock */
static void task_clock_event_update(struct perf_event *event, u64 now){ u64 prev; s64 delta;
prev = local64_xchg(&event->hw.prev_count, now); delta = now - prev; local64_add(delta, &event->count);}
static void task_clock_event_start(struct perf_event *event, int flags){ event->hw.state = 0; local64_set(&event->hw.prev_count, event->ctx->time.time); perf_swevent_start_hrtimer(event);}
static void task_clock_event_stop(struct perf_event *event, int flags){ event->hw.state = PERF_HES_STOPPED; perf_swevent_cancel_hrtimer(event); if (flags & PERF_EF_UPDATE) task_clock_event_update(event, event->ctx->time.time);}
static int task_clock_event_add(struct perf_event *event, int flags){ if (flags & PERF_EF_START) task_clock_event_start(event, flags); perf_event_update_userpage(event);
return 0;}
static void task_clock_event_del(struct perf_event *event, int flags){ task_clock_event_stop(event, PERF_EF_UPDATE);}
static void task_clock_event_read(struct perf_event *event){ u64 now = perf_clock(); u64 delta = now - event->ctx->time.stamp; u64 time = event->ctx->time.time + delta;
task_clock_event_update(event, time);}
static int task_clock_event_init(struct perf_event *event){ if (event->attr.type != perf_task_clock.type) return -ENOENT;
if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK) return -ENOENT;
/* * no branch sampling for software events */ if (has_branch_stack(event)) return -EOPNOTSUPP;
perf_swevent_init_hrtimer(event);
return 0;}
static struct pmu perf_task_clock = { .task_ctx_nr = perf_sw_context,
.capabilities = PERF_PMU_CAP_NO_NMI, .dev = PMU_NULL_DEV,
.event_init = task_clock_event_init, .add = task_clock_event_add, .del = task_clock_event_del, .start = task_clock_event_start, .stop = task_clock_event_stop, .read = task_clock_event_read,};
static void perf_pmu_nop_void(struct pmu *pmu){}
static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags){}
static int perf_pmu_nop_int(struct pmu *pmu){ return 0;}
static int perf_event_nop_int(struct perf_event *event, u64 value){ return 0;}
static DEFINE_PER_CPU(unsigned int, nop_txn_flags);
static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags){ __this_cpu_write(nop_txn_flags, flags);
if (flags & ~PERF_PMU_TXN_ADD) return;
perf_pmu_disable(pmu);}
static int perf_pmu_commit_txn(struct pmu *pmu){ unsigned int flags = __this_cpu_read(nop_txn_flags);
__this_cpu_write(nop_txn_flags, 0);
if (flags & ~PERF_PMU_TXN_ADD) return 0;
perf_pmu_enable(pmu); return 0;}
static void perf_pmu_cancel_txn(struct pmu *pmu){ unsigned int flags = __this_cpu_read(nop_txn_flags);
__this_cpu_write(nop_txn_flags, 0);
if (flags & ~PERF_PMU_TXN_ADD) return;
perf_pmu_enable(pmu);}
static int perf_event_idx_default(struct perf_event *event){ return 0;}
/* * Let userspace know that this PMU supports address range filtering: */static ssize_t nr_addr_filters_show(struct device *dev, struct device_attribute *attr, char *page){ struct pmu *pmu = dev_get_drvdata(dev);
return sysfs_emit(page, "%d\n", pmu->nr_addr_filters);}DEVICE_ATTR_RO(nr_addr_filters);
static struct idr pmu_idr;
static ssize_ttype_show(struct device *dev, struct device_attribute *attr, char *page){ struct pmu *pmu = dev_get_drvdata(dev);
return sysfs_emit(page, "%d\n", pmu->type);}static DEVICE_ATTR_RO(type);
static ssize_tperf_event_mux_interval_ms_show(struct device *dev, struct device_attribute *attr, char *page){ struct pmu *pmu = dev_get_drvdata(dev);
return sysfs_emit(page, "%d\n", pmu->hrtimer_interval_ms);}
static DEFINE_MUTEX(mux_interval_mutex);
static ssize_tperf_event_mux_interval_ms_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count){ struct pmu *pmu = dev_get_drvdata(dev); int timer, cpu, ret;
ret = kstrtoint(buf, 0, &timer); if (ret) return ret;
if (timer < 1) return -EINVAL;
/* same value, noting to do */ if (timer == pmu->hrtimer_interval_ms) return count;
mutex_lock(&mux_interval_mutex); pmu->hrtimer_interval_ms = timer;
/* update all cpuctx for this PMU */ cpus_read_lock(); for_each_online_cpu(cpu) { struct perf_cpu_pmu_context *cpc; cpc = *per_cpu_ptr(pmu->cpu_pmu_context, cpu); cpc->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer);
cpu_function_call(cpu, perf_mux_hrtimer_restart_ipi, cpc); } cpus_read_unlock(); mutex_unlock(&mux_interval_mutex);
return count;}static DEVICE_ATTR_RW(perf_event_mux_interval_ms);
static inline const struct cpumask *perf_scope_cpu_topology_cpumask(unsigned int scope, int cpu){ switch (scope) { case PERF_PMU_SCOPE_CORE: return topology_sibling_cpumask(cpu); case PERF_PMU_SCOPE_DIE: return topology_die_cpumask(cpu); case PERF_PMU_SCOPE_CLUSTER: return topology_cluster_cpumask(cpu); case PERF_PMU_SCOPE_PKG: return topology_core_cpumask(cpu); case PERF_PMU_SCOPE_SYS_WIDE: return cpu_online_mask; }
return NULL;}
static inline struct cpumask *perf_scope_cpumask(unsigned int scope){ switch (scope) { case PERF_PMU_SCOPE_CORE: return perf_online_core_mask; case PERF_PMU_SCOPE_DIE: return perf_online_die_mask; case PERF_PMU_SCOPE_CLUSTER: return perf_online_cluster_mask; case PERF_PMU_SCOPE_PKG: return perf_online_pkg_mask; case PERF_PMU_SCOPE_SYS_WIDE: return perf_online_sys_mask; }
return NULL;}
static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr, char *buf){ struct pmu *pmu = dev_get_drvdata(dev); struct cpumask *mask = perf_scope_cpumask(pmu->scope);
if (mask) return cpumap_print_to_pagebuf(true, buf, mask); return 0;}
static DEVICE_ATTR_RO(cpumask);
static struct attribute *pmu_dev_attrs[] = { &dev_attr_type.attr, &dev_attr_perf_event_mux_interval_ms.attr, &dev_attr_nr_addr_filters.attr, &dev_attr_cpumask.attr, NULL,};
static umode_t pmu_dev_is_visible(struct kobject *kobj, struct attribute *a, int n){ struct device *dev = kobj_to_dev(kobj); struct pmu *pmu = dev_get_drvdata(dev);
if (n == 2 && !pmu->nr_addr_filters) return 0;
/* cpumask */ if (n == 3 && pmu->scope == PERF_PMU_SCOPE_NONE) return 0;
return a->mode;}
static struct attribute_group pmu_dev_attr_group = { .is_visible = pmu_dev_is_visible, .attrs = pmu_dev_attrs,};
static const struct attribute_group *pmu_dev_groups[] = { &pmu_dev_attr_group, NULL,};
static int pmu_bus_running;static const struct bus_type pmu_bus = { .name = "event_source", .dev_groups = pmu_dev_groups,};
static void pmu_dev_release(struct device *dev){ kfree(dev);}
static int pmu_dev_alloc(struct pmu *pmu){ int ret = -ENOMEM;
pmu->dev = kzalloc_obj(struct device); if (!pmu->dev) goto out;
pmu->dev->groups = pmu->attr_groups; device_initialize(pmu->dev);
dev_set_drvdata(pmu->dev, pmu); pmu->dev->bus = &pmu_bus; pmu->dev->parent = pmu->parent; pmu->dev->release = pmu_dev_release;
ret = dev_set_name(pmu->dev, "%s", pmu->name); if (ret) goto free_dev;
ret = device_add(pmu->dev); if (ret) goto free_dev;
if (pmu->attr_update) { ret = sysfs_update_groups(&pmu->dev->kobj, pmu->attr_update); if (ret) goto del_dev; }
out: return ret;
del_dev: device_del(pmu->dev);
free_dev: put_device(pmu->dev); pmu->dev = NULL; goto out;}
static struct lock_class_key cpuctx_mutex;static struct lock_class_key cpuctx_lock;
static bool idr_cmpxchg(struct idr *idr, unsigned long id, void *old, void *new){ void *tmp, *val = idr_find(idr, id);
if (val != old) return false;
tmp = idr_replace(idr, new, id); if (IS_ERR(tmp)) return false;
WARN_ON_ONCE(tmp != val); return true;}
static void perf_pmu_free(struct pmu *pmu){ if (pmu_bus_running && pmu->dev && pmu->dev != PMU_NULL_DEV) { if (pmu->nr_addr_filters) device_remove_file(pmu->dev, &dev_attr_nr_addr_filters); device_del(pmu->dev); put_device(pmu->dev); }
if (pmu->cpu_pmu_context) { int cpu;
for_each_possible_cpu(cpu) { struct perf_cpu_pmu_context *cpc;
cpc = *per_cpu_ptr(pmu->cpu_pmu_context, cpu); if (!cpc) continue; if (cpc->epc.embedded) { /* refcount managed */ put_pmu_ctx(&cpc->epc); continue; } kfree(cpc); } free_percpu(pmu->cpu_pmu_context); }}
DEFINE_FREE(pmu_unregister, struct pmu *, if (_T) perf_pmu_free(_T))
int perf_pmu_register(struct pmu *_pmu, const char *name, int type){ int cpu, max = PERF_TYPE_MAX;
struct pmu *pmu __free(pmu_unregister) = _pmu; guard(mutex)(&pmus_lock);
if (WARN_ONCE(!name, "Can not register anonymous pmu.\n")) return -EINVAL;
if (WARN_ONCE(pmu->scope >= PERF_PMU_MAX_SCOPE, "Can not register a pmu with an invalid scope.\n")) return -EINVAL;
pmu->name = name;
if (type >= 0) max = type;
CLASS(idr_alloc, pmu_type)(&pmu_idr, NULL, max, 0, GFP_KERNEL); if (pmu_type.id < 0) return pmu_type.id;
WARN_ON(type >= 0 && pmu_type.id != type);
pmu->type = pmu_type.id; atomic_set(&pmu->exclusive_cnt, 0);
if (pmu_bus_running && !pmu->dev) { int ret = pmu_dev_alloc(pmu); if (ret) return ret; }
pmu->cpu_pmu_context = alloc_percpu(struct perf_cpu_pmu_context *); if (!pmu->cpu_pmu_context) return -ENOMEM;
for_each_possible_cpu(cpu) { struct perf_cpu_pmu_context *cpc = kmalloc_node(sizeof(struct perf_cpu_pmu_context), GFP_KERNEL | __GFP_ZERO, cpu_to_node(cpu));
if (!cpc) return -ENOMEM;
*per_cpu_ptr(pmu->cpu_pmu_context, cpu) = cpc; __perf_init_event_pmu_context(&cpc->epc, pmu); __perf_mux_hrtimer_init(cpc, cpu); }
if (!pmu->start_txn) { if (pmu->pmu_enable) { /* * If we have pmu_enable/pmu_disable calls, install * transaction stubs that use that to try and batch * hardware accesses. */ pmu->start_txn = perf_pmu_start_txn; pmu->commit_txn = perf_pmu_commit_txn; pmu->cancel_txn = perf_pmu_cancel_txn; } else { pmu->start_txn = perf_pmu_nop_txn; pmu->commit_txn = perf_pmu_nop_int; pmu->cancel_txn = perf_pmu_nop_void; } }
if (!pmu->pmu_enable) { pmu->pmu_enable = perf_pmu_nop_void; pmu->pmu_disable = perf_pmu_nop_void; }
if (!pmu->check_period) pmu->check_period = perf_event_nop_int;
if (!pmu->event_idx) pmu->event_idx = perf_event_idx_default;
INIT_LIST_HEAD(&pmu->events); spin_lock_init(&pmu->events_lock);
/* * Now that the PMU is complete, make it visible to perf_try_init_event(). */ if (!idr_cmpxchg(&pmu_idr, pmu->type, NULL, pmu)) return -EINVAL; list_add_rcu(&pmu->entry, &pmus);
take_idr_id(pmu_type); _pmu = no_free_ptr(pmu); // let it rip return 0;}EXPORT_SYMBOL_GPL(perf_pmu_register);
static void __pmu_detach_event(struct pmu *pmu, struct perf_event *event, struct perf_event_context *ctx){ /* * De-schedule the event and mark it REVOKED. */ perf_event_exit_event(event, ctx, ctx->task, DETACH_REVOKE);
/* * All _free_event() bits that rely on event->pmu: * * Notably, perf_mmap() relies on the ordering here. */ scoped_guard (mutex, &event->mmap_mutex) { WARN_ON_ONCE(pmu->event_unmapped); /* * Mostly an empty lock sequence, such that perf_mmap(), which * relies on mmap_mutex, is sure to observe the state change. */ }
perf_event_free_bpf_prog(event); perf_free_addr_filters(event);
if (event->destroy) { event->destroy(event); event->destroy = NULL; }
if (event->pmu_ctx) { put_pmu_ctx(event->pmu_ctx); event->pmu_ctx = NULL; }
exclusive_event_destroy(event); module_put(pmu->module);
event->pmu = NULL; /* force fault instead of UAF */}
static void pmu_detach_event(struct pmu *pmu, struct perf_event *event){ struct perf_event_context *ctx;
ctx = perf_event_ctx_lock(event); __pmu_detach_event(pmu, event, ctx); perf_event_ctx_unlock(event, ctx);
scoped_guard (spinlock, &pmu->events_lock) list_del(&event->pmu_list);}
static struct perf_event *pmu_get_event(struct pmu *pmu){ struct perf_event *event;
guard(spinlock)(&pmu->events_lock); list_for_each_entry(event, &pmu->events, pmu_list) { if (atomic_long_inc_not_zero(&event->refcount)) return event; }
return NULL;}
static bool pmu_empty(struct pmu *pmu){ guard(spinlock)(&pmu->events_lock); return list_empty(&pmu->events);}
static void pmu_detach_events(struct pmu *pmu){ struct perf_event *event;
for (;;) { event = pmu_get_event(pmu); if (!event) break;
pmu_detach_event(pmu, event); put_event(event); }
/* * wait for pending _free_event()s */ wait_var_event(pmu, pmu_empty(pmu));}
int perf_pmu_unregister(struct pmu *pmu){ scoped_guard (mutex, &pmus_lock) { if (!idr_cmpxchg(&pmu_idr, pmu->type, pmu, NULL)) return -EINVAL;
list_del_rcu(&pmu->entry); }
/* * We dereference the pmu list under both SRCU and regular RCU, so * synchronize against both of those. * * Notably, the entirety of event creation, from perf_init_event() * (which will now fail, because of the above) until * perf_install_in_context() should be under SRCU such that * this synchronizes against event creation. This avoids trying to * detach events that are not fully formed. */ synchronize_srcu(&pmus_srcu); synchronize_rcu();
if (pmu->event_unmapped && !pmu_empty(pmu)) { /* * Can't force remove events when pmu::event_unmapped() * is used in perf_mmap_close(). */ guard(mutex)(&pmus_lock); idr_cmpxchg(&pmu_idr, pmu->type, NULL, pmu); list_add_rcu(&pmu->entry, &pmus); return -EBUSY; }
scoped_guard (mutex, &pmus_lock) idr_remove(&pmu_idr, pmu->type);
/* * PMU is removed from the pmus list, so no new events will * be created, now take care of the existing ones. */ pmu_detach_events(pmu);
/* * PMU is unused, make it go away. */ perf_pmu_free(pmu); return 0;}EXPORT_SYMBOL_GPL(perf_pmu_unregister);
static inline bool has_extended_regs(struct perf_event *event){ return (event->attr.sample_regs_user & PERF_REG_EXTENDED_MASK) || (event->attr.sample_regs_intr & PERF_REG_EXTENDED_MASK);}
static int perf_try_init_event(struct pmu *pmu, struct perf_event *event){ struct perf_event_context *ctx = NULL; int ret;
if (!try_module_get(pmu->module)) return -ENODEV;
/* * A number of pmu->event_init() methods iterate the sibling_list to, * for example, validate if the group fits on the PMU. Therefore, * if this is a sibling event, acquire the ctx->mutex to protect * the sibling_list. */ if (event->group_leader != event && pmu->task_ctx_nr != perf_sw_context) { /* * This ctx->mutex can nest when we're called through * inheritance. See the perf_event_ctx_lock_nested() comment. */ ctx = perf_event_ctx_lock_nested(event->group_leader, SINGLE_DEPTH_NESTING); BUG_ON(!ctx); }
event->pmu = pmu; ret = pmu->event_init(event);
if (ctx) perf_event_ctx_unlock(event->group_leader, ctx);
if (ret) goto err_pmu;
if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) && has_extended_regs(event)) { ret = -EOPNOTSUPP; goto err_destroy; }
if (pmu->capabilities & PERF_PMU_CAP_NO_EXCLUDE && event_has_any_exclude_flag(event)) { ret = -EINVAL; goto err_destroy; }
if (pmu->scope != PERF_PMU_SCOPE_NONE && event->cpu >= 0) { const struct cpumask *cpumask; struct cpumask *pmu_cpumask; int cpu;
cpumask = perf_scope_cpu_topology_cpumask(pmu->scope, event->cpu); pmu_cpumask = perf_scope_cpumask(pmu->scope);
ret = -ENODEV; if (!pmu_cpumask || !cpumask) goto err_destroy;
cpu = cpumask_any_and(pmu_cpumask, cpumask); if (cpu >= nr_cpu_ids) goto err_destroy;
event->event_caps |= PERF_EV_CAP_READ_SCOPE; }
return 0;
err_destroy: if (event->destroy) { event->destroy(event); event->destroy = NULL; }
err_pmu: event->pmu = NULL; module_put(pmu->module); return ret;}
static struct pmu *perf_init_event(struct perf_event *event){ bool extended_type = false; struct pmu *pmu; int type, ret;
guard(srcu)(&pmus_srcu); /* pmu idr/list access */
/* * Save original type before calling pmu->event_init() since certain * pmus overwrites event->attr.type to forward event to another pmu. */ event->orig_type = event->attr.type;
/* Try parent's PMU first: */ if (event->parent && event->parent->pmu) { pmu = event->parent->pmu; ret = perf_try_init_event(pmu, event); if (!ret) return pmu; }
/* * PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE * are often aliases for PERF_TYPE_RAW. */ type = event->attr.type; if (type == PERF_TYPE_HARDWARE || type == PERF_TYPE_HW_CACHE) { type = event->attr.config >> PERF_PMU_TYPE_SHIFT; if (!type) { type = PERF_TYPE_RAW; } else { extended_type = true; event->attr.config &= PERF_HW_EVENT_MASK; } }
again: scoped_guard (rcu) pmu = idr_find(&pmu_idr, type); if (pmu) { if (event->attr.type != type && type != PERF_TYPE_RAW && !(pmu->capabilities & PERF_PMU_CAP_EXTENDED_HW_TYPE)) return ERR_PTR(-ENOENT);
ret = perf_try_init_event(pmu, event); if (ret == -ENOENT && event->attr.type != type && !extended_type) { type = event->attr.type; goto again; }
if (ret) return ERR_PTR(ret);
return pmu; }
list_for_each_entry_rcu(pmu, &pmus, entry, lockdep_is_held(&pmus_srcu)) { ret = perf_try_init_event(pmu, event); if (!ret) return pmu;
if (ret != -ENOENT) return ERR_PTR(ret); }
return ERR_PTR(-ENOENT);}
static void attach_sb_event(struct perf_event *event){ struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);
raw_spin_lock(&pel->lock); list_add_rcu(&event->sb_list, &pel->list); raw_spin_unlock(&pel->lock);}
/* * We keep a list of all !task (and therefore per-cpu) events * that need to receive side-band records. * * This avoids having to scan all the various PMU per-cpu contexts * looking for them. */static void account_pmu_sb_event(struct perf_event *event){ if (is_sb_event(event)) attach_sb_event(event);}
/* Freq events need the tick to stay alive (see perf_event_task_tick). */static void account_freq_event_nohz(void){#ifdef CONFIG_NO_HZ_FULL /* Lock so we don't race with concurrent unaccount */ spin_lock(&nr_freq_lock); if (atomic_inc_return(&nr_freq_events) == 1) tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS); spin_unlock(&nr_freq_lock);#endif}
static void account_freq_event(void){ if (tick_nohz_full_enabled()) account_freq_event_nohz(); else atomic_inc(&nr_freq_events);}
static void account_event(struct perf_event *event){ bool inc = false;
if (event->parent) return;
if (event->attach_state & (PERF_ATTACH_TASK | PERF_ATTACH_SCHED_CB)) inc = true; if (event->attr.mmap || event->attr.mmap_data) atomic_inc(&nr_mmap_events); if (event->attr.build_id) atomic_inc(&nr_build_id_events); if (event->attr.comm) atomic_inc(&nr_comm_events); if (event->attr.namespaces) atomic_inc(&nr_namespaces_events); if (event->attr.cgroup) atomic_inc(&nr_cgroup_events); if (event->attr.task) atomic_inc(&nr_task_events); if (event->attr.freq) account_freq_event(); if (event->attr.context_switch) { atomic_inc(&nr_switch_events); inc = true; } if (has_branch_stack(event)) inc = true; if (is_cgroup_event(event)) inc = true; if (event->attr.ksymbol) atomic_inc(&nr_ksymbol_events); if (event->attr.bpf_event) atomic_inc(&nr_bpf_events); if (event->attr.text_poke) atomic_inc(&nr_text_poke_events);
if (inc) { /* * We need the mutex here because static_branch_enable() * must complete *before* the perf_sched_count increment * becomes visible. */ if (atomic_inc_not_zero(&perf_sched_count)) goto enabled;
mutex_lock(&perf_sched_mutex); if (!atomic_read(&perf_sched_count)) { static_branch_enable(&perf_sched_events); /* * Guarantee that all CPUs observe they key change and * call the perf scheduling hooks before proceeding to * install events that need them. */ synchronize_rcu(); } /* * Now that we have waited for the sync_sched(), allow further * increments to by-pass the mutex. */ atomic_inc(&perf_sched_count); mutex_unlock(&perf_sched_mutex); }enabled:
account_pmu_sb_event(event);}
/* * Allocate and initialize an event structure */static struct perf_event *perf_event_alloc(struct perf_event_attr *attr, int cpu, struct task_struct *task, struct perf_event *group_leader, struct perf_event *parent_event, perf_overflow_handler_t overflow_handler, void *context, int cgroup_fd){ struct pmu *pmu; struct hw_perf_event *hwc; long err = -EINVAL; int node;
if ((unsigned)cpu >= nr_cpu_ids) { if (!task || cpu != -1) return ERR_PTR(-EINVAL); } if (attr->sigtrap && !task) { /* Requires a task: avoid signalling random tasks. */ return ERR_PTR(-EINVAL); }
node = (cpu >= 0) ? cpu_to_node(cpu) : -1; struct perf_event *event __free(__free_event) = kmem_cache_alloc_node(perf_event_cache, GFP_KERNEL | __GFP_ZERO, node); if (!event) return ERR_PTR(-ENOMEM);
/* * Single events are their own group leaders, with an * empty sibling list: */ if (!group_leader) group_leader = event;
mutex_init(&event->child_mutex); INIT_LIST_HEAD(&event->child_list);
INIT_LIST_HEAD(&event->event_entry); INIT_LIST_HEAD(&event->sibling_list); INIT_LIST_HEAD(&event->active_list); init_event_group(event); INIT_LIST_HEAD(&event->rb_entry); INIT_LIST_HEAD(&event->active_entry); INIT_LIST_HEAD(&event->addr_filters.list); INIT_HLIST_NODE(&event->hlist_entry); INIT_LIST_HEAD(&event->pmu_list);
init_waitqueue_head(&event->waitq); init_irq_work(&event->pending_irq, perf_pending_irq); event->pending_disable_irq = IRQ_WORK_INIT_HARD(perf_pending_disable); init_task_work(&event->pending_task, perf_pending_task);
mutex_init(&event->mmap_mutex); raw_spin_lock_init(&event->addr_filters.lock);
atomic_long_set(&event->refcount, 1); event->cpu = cpu; event->attr = *attr; event->group_leader = group_leader; event->pmu = NULL; event->oncpu = -1;
event->parent = parent_event;
event->ns = get_pid_ns(task_active_pid_ns(current)); event->id = atomic64_inc_return(&perf_event_id);
event->state = PERF_EVENT_STATE_INACTIVE;
if (parent_event) event->event_caps = parent_event->event_caps;
if (task) { event->attach_state = PERF_ATTACH_TASK; /* * XXX pmu::event_init needs to know what task to account to * and we cannot use the ctx information because we need the * pmu before we get a ctx. */ event->hw.target = get_task_struct(task); }
event->clock = &local_clock; if (parent_event) event->clock = parent_event->clock;
if (!overflow_handler && parent_event) { overflow_handler = parent_event->overflow_handler; context = parent_event->overflow_handler_context;#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING) if (parent_event->prog) { struct bpf_prog *prog = parent_event->prog;
bpf_prog_inc(prog); event->prog = prog; }#endif }
if (overflow_handler) { event->overflow_handler = overflow_handler; event->overflow_handler_context = context; } else if (is_write_backward(event)){ event->overflow_handler = perf_event_output_backward; event->overflow_handler_context = NULL; } else { event->overflow_handler = perf_event_output_forward; event->overflow_handler_context = NULL; }
perf_event__state_init(event);
pmu = NULL;
hwc = &event->hw; hwc->sample_period = attr->sample_period; if (is_event_in_freq_mode(event)) hwc->sample_period = 1; hwc->last_period = hwc->sample_period;
local64_set(&hwc->period_left, hwc->sample_period);
/* * We do not support PERF_SAMPLE_READ on inherited events unless * PERF_SAMPLE_TID is also selected, which allows inherited events to * collect per-thread samples. * See perf_output_read(). */ if (has_inherit_and_sample_read(attr) && !(attr->sample_type & PERF_SAMPLE_TID)) return ERR_PTR(-EINVAL);
if (!has_branch_stack(event)) event->attr.branch_sample_type = 0;
pmu = perf_init_event(event); if (IS_ERR(pmu)) return (void*)pmu;
/* * The PERF_ATTACH_TASK_DATA is set in the event_init()->hw_config(). * The attach should be right after the perf_init_event(). * Otherwise, the __free_event() would mistakenly detach the non-exist * perf_ctx_data because of the other errors between them. */ if (event->attach_state & PERF_ATTACH_TASK_DATA) { err = attach_perf_ctx_data(event); if (err) return ERR_PTR(err); }
/* * Disallow uncore-task events. Similarly, disallow uncore-cgroup * events (they don't make sense as the cgroup will be different * on other CPUs in the uncore mask). */ if (pmu->task_ctx_nr == perf_invalid_context && (task || cgroup_fd != -1)) return ERR_PTR(-EINVAL);
if (event->attr.aux_output && (!(pmu->capabilities & PERF_PMU_CAP_AUX_OUTPUT) || event->attr.aux_pause || event->attr.aux_resume)) return ERR_PTR(-EOPNOTSUPP);
if (event->attr.aux_pause && event->attr.aux_resume) return ERR_PTR(-EINVAL);
if (event->attr.aux_start_paused) { if (!(pmu->capabilities & PERF_PMU_CAP_AUX_PAUSE)) return ERR_PTR(-EOPNOTSUPP); event->hw.aux_paused = 1; }
if (cgroup_fd != -1) { err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader); if (err) return ERR_PTR(err); }
err = exclusive_event_init(event); if (err) return ERR_PTR(err);
if (has_addr_filter(event)) { event->addr_filter_ranges = kcalloc(pmu->nr_addr_filters, sizeof(struct perf_addr_filter_range), GFP_KERNEL); if (!event->addr_filter_ranges) return ERR_PTR(-ENOMEM);
/* * Clone the parent's vma offsets: they are valid until exec() * even if the mm is not shared with the parent. */ if (event->parent) { struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
raw_spin_lock_irq(&ifh->lock); memcpy(event->addr_filter_ranges, event->parent->addr_filter_ranges, pmu->nr_addr_filters * sizeof(struct perf_addr_filter_range)); raw_spin_unlock_irq(&ifh->lock); }
/* force hw sync on the address filters */ event->addr_filters_gen = 1; }
if (!event->parent) { if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { err = get_callchain_buffers(attr->sample_max_stack); if (err) return ERR_PTR(err); event->attach_state |= PERF_ATTACH_CALLCHAIN; } }
err = security_perf_event_alloc(event); if (err) return ERR_PTR(err);
err = mediated_pmu_account_event(event); if (err) return ERR_PTR(err);
/* symmetric to unaccount_event() in _free_event() */ account_event(event);
/* * Event creation should be under SRCU, see perf_pmu_unregister(). */ lockdep_assert_held(&pmus_srcu); scoped_guard (spinlock, &pmu->events_lock) list_add(&event->pmu_list, &pmu->events);
return_ptr(event);}
static int perf_copy_attr(struct perf_event_attr __user *uattr, struct perf_event_attr *attr){ u32 size; int ret;
/* Zero the full structure, so that a short copy will be nice. */ memset(attr, 0, sizeof(*attr));
ret = get_user(size, &uattr->size); if (ret) return ret;
/* ABI compatibility quirk: */ if (!size) size = PERF_ATTR_SIZE_VER0; if (size < PERF_ATTR_SIZE_VER0 || size > PAGE_SIZE) goto err_size;
ret = copy_struct_from_user(attr, sizeof(*attr), uattr, size); if (ret) { if (ret == -E2BIG) goto err_size; return ret; }
attr->size = size;
if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3) return -EINVAL;
if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) return -EINVAL;
if (attr->read_format & ~(PERF_FORMAT_MAX-1)) return -EINVAL;
if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) { u64 mask = attr->branch_sample_type;
/* only using defined bits */ if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1)) return -EINVAL;
/* at least one branch bit must be set */ if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL)) return -EINVAL;
/* propagate priv level, when not set for branch */ if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) {
/* exclude_kernel checked on syscall entry */ if (!attr->exclude_kernel) mask |= PERF_SAMPLE_BRANCH_KERNEL;
if (!attr->exclude_user) mask |= PERF_SAMPLE_BRANCH_USER;
if (!attr->exclude_hv) mask |= PERF_SAMPLE_BRANCH_HV; /* * adjust user setting (for HW filter setup) */ attr->branch_sample_type = mask; } /* privileged levels capture (kernel, hv): check permissions */ if (mask & PERF_SAMPLE_BRANCH_PERM_PLM) { ret = perf_allow_kernel(); if (ret) return ret; } }
if (attr->sample_type & PERF_SAMPLE_REGS_USER) { ret = perf_reg_validate(attr->sample_regs_user); if (ret) return ret; }
if (attr->sample_type & PERF_SAMPLE_STACK_USER) { if (!arch_perf_have_user_stack_dump()) return -ENOSYS;
/* * We have __u32 type for the size, but so far * we can only use __u16 as maximum due to the * __u16 sample size limit. */ if (attr->sample_stack_user >= USHRT_MAX) return -EINVAL; else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64))) return -EINVAL; }
if (!attr->sample_max_stack) attr->sample_max_stack = sysctl_perf_event_max_stack;
if (attr->sample_type & PERF_SAMPLE_REGS_INTR) ret = perf_reg_validate(attr->sample_regs_intr);
#ifndef CONFIG_CGROUP_PERF if (attr->sample_type & PERF_SAMPLE_CGROUP) return -EINVAL;#endif if ((attr->sample_type & PERF_SAMPLE_WEIGHT) && (attr->sample_type & PERF_SAMPLE_WEIGHT_STRUCT)) return -EINVAL;
if (!attr->inherit && attr->inherit_thread) return -EINVAL;
if (attr->remove_on_exec && attr->enable_on_exec) return -EINVAL;
if (attr->sigtrap && !attr->remove_on_exec) return -EINVAL;
out: return ret;
err_size: put_user(sizeof(*attr), &uattr->size); ret = -E2BIG; goto out;}
static void mutex_lock_double(struct mutex *a, struct mutex *b){ if (b < a) swap(a, b);
mutex_lock(a); mutex_lock_nested(b, SINGLE_DEPTH_NESTING);}
static intperf_event_set_output(struct perf_event *event, struct perf_event *output_event){ struct perf_buffer *rb = NULL; int ret = -EINVAL;
if (!output_event) { mutex_lock(&event->mmap_mutex); goto set; }
/* don't allow circular references */ if (event == output_event) goto out;
/* * Don't allow cross-cpu buffers */ if (output_event->cpu != event->cpu) goto out;
/* * If its not a per-cpu rb, it must be the same task. */ if (output_event->cpu == -1 && output_event->hw.target != event->hw.target) goto out;
/* * Mixing clocks in the same buffer is trouble you don't need. */ if (output_event->clock != event->clock) goto out;
/* * Either writing ring buffer from beginning or from end. * Mixing is not allowed. */ if (is_write_backward(output_event) != is_write_backward(event)) goto out;
/* * If both events generate aux data, they must be on the same PMU */ if (has_aux(event) && has_aux(output_event) && event->pmu != output_event->pmu) goto out;
/* * Hold both mmap_mutex to serialize against perf_mmap_close(). Since * output_event is already on rb->event_list, and the list iteration * restarts after every removal, it is guaranteed this new event is * observed *OR* if output_event is already removed, it's guaranteed we * observe !rb->mmap_count. */ mutex_lock_double(&event->mmap_mutex, &output_event->mmap_mutex);set: /* Can't redirect output if we've got an active mmap() */ if (refcount_read(&event->mmap_count)) goto unlock;
if (output_event) { if (output_event->state <= PERF_EVENT_STATE_REVOKED) goto unlock;
/* get the rb we want to redirect to */ rb = ring_buffer_get(output_event); if (!rb) goto unlock;
/* did we race against perf_mmap_close() */ if (!refcount_read(&rb->mmap_count)) { ring_buffer_put(rb); goto unlock; } }
ring_buffer_attach(event, rb);
ret = 0;unlock: mutex_unlock(&event->mmap_mutex); if (output_event) mutex_unlock(&output_event->mmap_mutex);
out: return ret;}
static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id){ bool nmi_safe = false;
switch (clk_id) { case CLOCK_MONOTONIC: event->clock = &ktime_get_mono_fast_ns; nmi_safe = true; break;
case CLOCK_MONOTONIC_RAW: event->clock = &ktime_get_raw_fast_ns; nmi_safe = true; break;
case CLOCK_REALTIME: event->clock = &ktime_get_real_ns; break;
case CLOCK_BOOTTIME: event->clock = &ktime_get_boottime_ns; break;
case CLOCK_TAI: event->clock = &ktime_get_clocktai_ns; break;
default: return -EINVAL; }
if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI)) return -EINVAL;
return 0;}
static boolperf_check_permission(struct perf_event_attr *attr, struct task_struct *task){ unsigned int ptrace_mode = PTRACE_MODE_READ_REALCREDS; bool is_capable = perfmon_capable();
if (attr->sigtrap) { /* * perf_event_attr::sigtrap sends signals to the other task. * Require the current task to also have CAP_KILL. */ rcu_read_lock(); is_capable &= ns_capable(__task_cred(task)->user_ns, CAP_KILL); rcu_read_unlock();
/* * If the required capabilities aren't available, checks for * ptrace permissions: upgrade to ATTACH, since sending signals * can effectively change the target task. */ ptrace_mode = PTRACE_MODE_ATTACH_REALCREDS; }
/* * Preserve ptrace permission check for backwards compatibility. The * ptrace check also includes checks that the current task and other * task have matching uids, and is therefore not done here explicitly. */ return is_capable || ptrace_may_access(task, ptrace_mode);}
/** * sys_perf_event_open - open a performance event, associate it to a task/cpu * * @attr_uptr: event_id type attributes for monitoring/sampling * @pid: target pid * @cpu: target cpu * @group_fd: group leader event fd * @flags: perf event open flags */SYSCALL_DEFINE5(perf_event_open, struct perf_event_attr __user *, attr_uptr, pid_t, pid, int, cpu, int, group_fd, unsigned long, flags){ struct perf_event *group_leader = NULL, *output_event = NULL; struct perf_event_pmu_context *pmu_ctx; struct perf_event *event, *sibling; struct perf_event_attr attr; struct perf_event_context *ctx; struct file *event_file = NULL; struct task_struct *task = NULL; struct pmu *pmu; int event_fd; int move_group = 0; int err; int f_flags = O_RDWR; int cgroup_fd = -1;
/* for future expandability... */ if (flags & ~PERF_FLAG_ALL) return -EINVAL;
err = perf_copy_attr(attr_uptr, &attr); if (err) return err;
/* Do we allow access to perf_event_open(2) ? */ err = security_perf_event_open(PERF_SECURITY_OPEN); if (err) return err;
if (!attr.exclude_kernel) { err = perf_allow_kernel(); if (err) return err; }
if (attr.namespaces) { if (!perfmon_capable()) return -EACCES; }
if (attr.freq) { if (attr.sample_freq > sysctl_perf_event_sample_rate) return -EINVAL; } else { if (attr.sample_period & (1ULL << 63)) return -EINVAL; }
/* Only privileged users can get physical addresses */ if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR)) { err = perf_allow_kernel(); if (err) return err; }
/* REGS_INTR can leak data, lockdown must prevent this */ if (attr.sample_type & PERF_SAMPLE_REGS_INTR) { err = security_locked_down(LOCKDOWN_PERF); if (err) return err; }
/* * In cgroup mode, the pid argument is used to pass the fd * opened to the cgroup directory in cgroupfs. The cpu argument * designates the cpu on which to monitor threads from that * cgroup. */ if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1)) return -EINVAL;
if (flags & PERF_FLAG_FD_CLOEXEC) f_flags |= O_CLOEXEC;
event_fd = get_unused_fd_flags(f_flags); if (event_fd < 0) return event_fd;
/* * Event creation should be under SRCU, see perf_pmu_unregister(). */ guard(srcu)(&pmus_srcu);
CLASS(fd, group)(group_fd); // group_fd == -1 => empty if (group_fd != -1) { if (!is_perf_file(group)) { err = -EBADF; goto err_fd; } group_leader = fd_file(group)->private_data; if (group_leader->state <= PERF_EVENT_STATE_REVOKED) { err = -ENODEV; goto err_fd; } if (flags & PERF_FLAG_FD_OUTPUT) output_event = group_leader; if (flags & PERF_FLAG_FD_NO_GROUP) group_leader = NULL; }
if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) { task = find_lively_task_by_vpid(pid); if (IS_ERR(task)) { err = PTR_ERR(task); goto err_fd; } }
if (task && group_leader && group_leader->attr.inherit != attr.inherit) { err = -EINVAL; goto err_task; }
if (flags & PERF_FLAG_PID_CGROUP) cgroup_fd = pid;
event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, NULL, NULL, cgroup_fd); if (IS_ERR(event)) { err = PTR_ERR(event); goto err_task; }
if (is_sampling_event(event)) { if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { err = -EOPNOTSUPP; goto err_alloc; } }
/* * Special case software events and allow them to be part of * any hardware group. */ pmu = event->pmu;
if (attr.use_clockid) { err = perf_event_set_clock(event, attr.clockid); if (err) goto err_alloc; }
if (pmu->task_ctx_nr == perf_sw_context) event->event_caps |= PERF_EV_CAP_SOFTWARE;
if (task) { err = down_read_interruptible(&task->signal->exec_update_lock); if (err) goto err_alloc;
/* * We must hold exec_update_lock across this and any potential * perf_install_in_context() call for this new event to * serialize against exec() altering our credentials (and the * perf_event_exit_task() that could imply). */ err = -EACCES; if (!perf_check_permission(&attr, task)) goto err_cred; }
/* * Get the target context (task or percpu): */ ctx = find_get_context(task, event); if (IS_ERR(ctx)) { err = PTR_ERR(ctx); goto err_cred; }
mutex_lock(&ctx->mutex);
if (ctx->task == TASK_TOMBSTONE) { err = -ESRCH; goto err_locked; }
if (!task) { /* * Check if the @cpu we're creating an event for is online. * * We use the perf_cpu_context::ctx::mutex to serialize against * the hotplug notifiers. See perf_event_{init,exit}_cpu(). */ struct perf_cpu_context *cpuctx = per_cpu_ptr(&perf_cpu_context, event->cpu);
if (!cpuctx->online) { err = -ENODEV; goto err_locked; } }
if (group_leader) { err = -EINVAL;
/* * Do not allow a recursive hierarchy (this new sibling * becoming part of another group-sibling): */ if (group_leader->group_leader != group_leader) goto err_locked;
/* All events in a group should have the same clock */ if (group_leader->clock != event->clock) goto err_locked;
/* * Make sure we're both events for the same CPU; * grouping events for different CPUs is broken; since * you can never concurrently schedule them anyhow. */ if (group_leader->cpu != event->cpu) goto err_locked;
/* * Make sure we're both on the same context; either task or cpu. */ if (group_leader->ctx != ctx) goto err_locked;
/* * Only a group leader can be exclusive or pinned */ if (attr.exclusive || attr.pinned) goto err_locked;
if (is_software_event(event) && !in_software_context(group_leader)) { /* * If the event is a sw event, but the group_leader * is on hw context. * * Allow the addition of software events to hw * groups, this is safe because software events * never fail to schedule. * * Note the comment that goes with struct * perf_event_pmu_context. */ pmu = group_leader->pmu_ctx->pmu; } else if (!is_software_event(event)) { if (is_software_event(group_leader) && (group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) { /* * In case the group is a pure software group, and we * try to add a hardware event, move the whole group to * the hardware context. */ move_group = 1; }
/* Don't allow group of multiple hw events from different pmus */ if (!in_software_context(group_leader) && group_leader->pmu_ctx->pmu != pmu) goto err_locked; } }
/* * Now that we're certain of the pmu; find the pmu_ctx. */ pmu_ctx = find_get_pmu_context(pmu, ctx, event); if (IS_ERR(pmu_ctx)) { err = PTR_ERR(pmu_ctx); goto err_locked; } event->pmu_ctx = pmu_ctx;
if (output_event) { err = perf_event_set_output(event, output_event); if (err) goto err_context; }
if (!perf_event_validate_size(event)) { err = -E2BIG; goto err_context; }
if (perf_need_aux_event(event) && !perf_get_aux_event(event, group_leader)) { err = -EINVAL; goto err_context; }
/* * Must be under the same ctx::mutex as perf_install_in_context(), * because we need to serialize with concurrent event creation. */ if (!exclusive_event_installable(event, ctx)) { err = -EBUSY; goto err_context; }
WARN_ON_ONCE(ctx->parent_ctx);
event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, f_flags); if (IS_ERR(event_file)) { err = PTR_ERR(event_file); event_file = NULL; goto err_context; }
/* * This is the point on no return; we cannot fail hereafter. This is * where we start modifying current state. */
if (move_group) { perf_remove_from_context(group_leader, 0); put_pmu_ctx(group_leader->pmu_ctx);
for_each_sibling_event(sibling, group_leader) { perf_remove_from_context(sibling, 0); put_pmu_ctx(sibling->pmu_ctx); }
/* * Install the group siblings before the group leader. * * Because a group leader will try and install the entire group * (through the sibling list, which is still in-tact), we can * end up with siblings installed in the wrong context. * * By installing siblings first we NO-OP because they're not * reachable through the group lists. */ for_each_sibling_event(sibling, group_leader) { sibling->pmu_ctx = pmu_ctx; get_pmu_ctx(pmu_ctx); perf_event__state_init(sibling); perf_install_in_context(ctx, sibling, sibling->cpu); }
/* * Removing from the context ends up with disabled * event. What we want here is event in the initial * startup state, ready to be add into new context. */ group_leader->pmu_ctx = pmu_ctx; get_pmu_ctx(pmu_ctx); perf_event__state_init(group_leader); perf_install_in_context(ctx, group_leader, group_leader->cpu); }
/* * Precalculate sample_data sizes; do while holding ctx::mutex such * that we're serialized against further additions and before * perf_install_in_context() which is the point the event is active and * can use these values. */ perf_event__header_size(event); perf_event__id_header_size(event);
event->owner = current;
perf_install_in_context(ctx, event, event->cpu); perf_unpin_context(ctx);
mutex_unlock(&ctx->mutex);
if (task) { up_read(&task->signal->exec_update_lock); put_task_struct(task); }
mutex_lock(¤t->perf_event_mutex); list_add_tail(&event->owner_entry, ¤t->perf_event_list); mutex_unlock(¤t->perf_event_mutex);
/* * File reference in group guarantees that group_leader has been * kept alive until we place the new event on the sibling_list. * This ensures destruction of the group leader will find * the pointer to itself in perf_group_detach(). */ fd_install(event_fd, event_file); return event_fd;
err_context: put_pmu_ctx(event->pmu_ctx); event->pmu_ctx = NULL; /* _free_event() */err_locked: mutex_unlock(&ctx->mutex); perf_unpin_context(ctx); put_ctx(ctx);err_cred: if (task) up_read(&task->signal->exec_update_lock);err_alloc: put_event(event);err_task: if (task) put_task_struct(task);err_fd: put_unused_fd(event_fd); return err;}
/** * perf_event_create_kernel_counter * * @attr: attributes of the counter to create * @cpu: cpu in which the counter is bound * @task: task to profile (NULL for percpu) * @overflow_handler: callback to trigger when we hit the event * @context: context data could be used in overflow_handler callback */struct perf_event *perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, struct task_struct *task, perf_overflow_handler_t overflow_handler, void *context){ struct perf_event_pmu_context *pmu_ctx; struct perf_event_context *ctx; struct perf_event *event; struct pmu *pmu; int err;
/* * Grouping is not supported for kernel events, neither is 'AUX', * make sure the caller's intentions are adjusted. */ if (attr->aux_output || attr->aux_action) return ERR_PTR(-EINVAL);
/* * Event creation should be under SRCU, see perf_pmu_unregister(). */ guard(srcu)(&pmus_srcu);
event = perf_event_alloc(attr, cpu, task, NULL, NULL, overflow_handler, context, -1); if (IS_ERR(event)) { err = PTR_ERR(event); goto err; }
/* Mark owner so we could distinguish it from user events. */ event->owner = TASK_TOMBSTONE; pmu = event->pmu;
if (pmu->task_ctx_nr == perf_sw_context) event->event_caps |= PERF_EV_CAP_SOFTWARE;
/* * Get the target context (task or percpu): */ ctx = find_get_context(task, event); if (IS_ERR(ctx)) { err = PTR_ERR(ctx); goto err_alloc; }
WARN_ON_ONCE(ctx->parent_ctx); mutex_lock(&ctx->mutex); if (ctx->task == TASK_TOMBSTONE) { err = -ESRCH; goto err_unlock; }
pmu_ctx = find_get_pmu_context(pmu, ctx, event); if (IS_ERR(pmu_ctx)) { err = PTR_ERR(pmu_ctx); goto err_unlock; } event->pmu_ctx = pmu_ctx;
if (!task) { /* * Check if the @cpu we're creating an event for is online. * * We use the perf_cpu_context::ctx::mutex to serialize against * the hotplug notifiers. See perf_event_{init,exit}_cpu(). */ struct perf_cpu_context *cpuctx = container_of(ctx, struct perf_cpu_context, ctx); if (!cpuctx->online) { err = -ENODEV; goto err_pmu_ctx; } }
if (!exclusive_event_installable(event, ctx)) { err = -EBUSY; goto err_pmu_ctx; }
perf_install_in_context(ctx, event, event->cpu); perf_unpin_context(ctx); mutex_unlock(&ctx->mutex);
return event;
err_pmu_ctx: put_pmu_ctx(pmu_ctx); event->pmu_ctx = NULL; /* _free_event() */err_unlock: mutex_unlock(&ctx->mutex); perf_unpin_context(ctx); put_ctx(ctx);err_alloc: put_event(event);err: return ERR_PTR(err);}EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
static void __perf_pmu_remove(struct perf_event_context *ctx, int cpu, struct pmu *pmu, struct perf_event_groups *groups, struct list_head *events){ struct perf_event *event, *sibling;
perf_event_groups_for_cpu_pmu(event, groups, cpu, pmu) { perf_remove_from_context(event, 0); put_pmu_ctx(event->pmu_ctx); list_add(&event->migrate_entry, events);
for_each_sibling_event(sibling, event) { perf_remove_from_context(sibling, 0); put_pmu_ctx(sibling->pmu_ctx); list_add(&sibling->migrate_entry, events); } }}
static void __perf_pmu_install_event(struct pmu *pmu, struct perf_event_context *ctx, int cpu, struct perf_event *event){ struct perf_event_pmu_context *epc; struct perf_event_context *old_ctx = event->ctx;
get_ctx(ctx); /* normally find_get_context() */
event->cpu = cpu; epc = find_get_pmu_context(pmu, ctx, event); event->pmu_ctx = epc;
if (event->state >= PERF_EVENT_STATE_OFF) event->state = PERF_EVENT_STATE_INACTIVE; perf_install_in_context(ctx, event, cpu);
/* * Now that event->ctx is updated and visible, put the old ctx. */ put_ctx(old_ctx);}
static void __perf_pmu_install(struct perf_event_context *ctx, int cpu, struct pmu *pmu, struct list_head *events){ struct perf_event *event, *tmp;
/* * Re-instate events in 2 passes. * * Skip over group leaders and only install siblings on this first * pass, siblings will not get enabled without a leader, however a * leader will enable its siblings, even if those are still on the old * context. */ list_for_each_entry_safe(event, tmp, events, migrate_entry) { if (event->group_leader == event) continue;
list_del(&event->migrate_entry); __perf_pmu_install_event(pmu, ctx, cpu, event); }
/* * Once all the siblings are setup properly, install the group leaders * to make it go. */ list_for_each_entry_safe(event, tmp, events, migrate_entry) { list_del(&event->migrate_entry); __perf_pmu_install_event(pmu, ctx, cpu, event); }}
void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu){ struct perf_event_context *src_ctx, *dst_ctx; LIST_HEAD(events);
/* * Since per-cpu context is persistent, no need to grab an extra * reference. */ src_ctx = &per_cpu_ptr(&perf_cpu_context, src_cpu)->ctx; dst_ctx = &per_cpu_ptr(&perf_cpu_context, dst_cpu)->ctx;
/* * See perf_event_ctx_lock() for comments on the details * of swizzling perf_event::ctx. */ mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex);
__perf_pmu_remove(src_ctx, src_cpu, pmu, &src_ctx->pinned_groups, &events); __perf_pmu_remove(src_ctx, src_cpu, pmu, &src_ctx->flexible_groups, &events);
if (!list_empty(&events)) { /* * Wait for the events to quiesce before re-instating them. */ synchronize_rcu();
__perf_pmu_install(dst_ctx, dst_cpu, pmu, &events); }
mutex_unlock(&dst_ctx->mutex); mutex_unlock(&src_ctx->mutex);}EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
static void sync_child_event(struct perf_event *child_event, struct task_struct *task){ struct perf_event *parent_event = child_event->parent; u64 child_val;
if (child_event->attr.inherit_stat) { if (task && task != TASK_TOMBSTONE) perf_event_read_event(child_event, task); }
child_val = perf_event_count(child_event, false);
/* * Add back the child's count to the parent's count: */ atomic64_add(child_val, &parent_event->child_count); atomic64_add(child_event->total_time_enabled, &parent_event->child_total_time_enabled); atomic64_add(child_event->total_time_running, &parent_event->child_total_time_running);}
static voidperf_event_exit_event(struct perf_event *event, struct perf_event_context *ctx, struct task_struct *task, unsigned long detach_flags){ struct perf_event *parent_event = event->parent; unsigned int attach_state;
detach_flags |= DETACH_EXIT;
if (parent_event) { /* * Do not destroy the 'original' grouping; because of the * context switch optimization the original events could've * ended up in a random child task. * * If we were to destroy the original group, all group related * operations would cease to function properly after this * random child dies. * * Do destroy all inherited groups, we don't care about those * and being thorough is better. */ detach_flags |= DETACH_GROUP | DETACH_CHILD; mutex_lock(&parent_event->child_mutex); /* PERF_ATTACH_ITRACE might be set concurrently */ attach_state = READ_ONCE(event->attach_state);
if (attach_state & PERF_ATTACH_CHILD) sync_child_event(event, task); }
if (detach_flags & DETACH_REVOKE) detach_flags |= DETACH_GROUP;
perf_remove_from_context(event, detach_flags); /* * Child events can be freed. */ if (parent_event) { mutex_unlock(&parent_event->child_mutex);
/* * Match the refcount initialization. Make sure it doesn't happen * twice if pmu_detach_event() calls it on an already exited task. */ if (attach_state & PERF_ATTACH_CHILD) { /* * Kick perf_poll() for is_event_hup(); */ perf_event_wakeup(parent_event); /* * pmu_detach_event() will have an extra refcount. * perf_pending_task() might have one too. */ put_event(event); }
return; }
/* * Parent events are governed by their filedesc, retain them. */ perf_event_wakeup(event);}
static void perf_event_exit_task_context(struct task_struct *task, bool exit){ struct perf_event_context *ctx, *clone_ctx = NULL; struct perf_event *child_event, *next;
ctx = perf_pin_task_context(task); if (!ctx) return;
/* * In order to reduce the amount of tricky in ctx tear-down, we hold * ctx::mutex over the entire thing. This serializes against almost * everything that wants to access the ctx. * * The exception is sys_perf_event_open() / * perf_event_create_kernel_count() which does find_get_context() * without ctx::mutex (it cannot because of the move_group double mutex * lock thing). See the comments in perf_install_in_context(). */ mutex_lock(&ctx->mutex);
/* * In a single ctx::lock section, de-schedule the events and detach the * context from the task such that we cannot ever get it scheduled back * in. */ raw_spin_lock_irq(&ctx->lock); if (exit) task_ctx_sched_out(ctx, NULL, EVENT_ALL);
/* * Now that the context is inactive, destroy the task <-> ctx relation * and mark the context dead. */ RCU_INIT_POINTER(task->perf_event_ctxp, NULL); put_ctx(ctx); /* cannot be last */ WRITE_ONCE(ctx->task, TASK_TOMBSTONE); put_task_struct(task); /* cannot be last */
clone_ctx = unclone_ctx(ctx); raw_spin_unlock_irq(&ctx->lock);
if (clone_ctx) put_ctx(clone_ctx);
/* * Report the task dead after unscheduling the events so that we * won't get any samples after PERF_RECORD_EXIT. We can however still * get a few PERF_RECORD_READ events. */ if (exit) perf_event_task(task, ctx, 0);
list_for_each_entry_safe(child_event, next, &ctx->event_list, event_entry) perf_event_exit_event(child_event, ctx, exit ? task : NULL, 0);
mutex_unlock(&ctx->mutex);
if (!exit) { /* * perf_event_release_kernel() could still have a reference on * this context. In that case we must wait for these events to * have been freed (in particular all their references to this * task must've been dropped). * * Without this copy_process() will unconditionally free this * task (irrespective of its reference count) and * _free_event()'s put_task_struct(event->hw.target) will be a * use-after-free. * * Wait for all events to drop their context reference. */ wait_var_event(&ctx->refcount, refcount_read(&ctx->refcount) == 1); } put_ctx(ctx);}
/* * When a task exits, feed back event values to parent events. * * Can be called with exec_update_lock held when called from * setup_new_exec(). */void perf_event_exit_task(struct task_struct *task){ struct perf_event *event, *tmp;
WARN_ON_ONCE(task != current);
mutex_lock(&task->perf_event_mutex); list_for_each_entry_safe(event, tmp, &task->perf_event_list, owner_entry) { list_del_init(&event->owner_entry);
/* * Ensure the list deletion is visible before we clear * the owner, closes a race against perf_release() where * we need to serialize on the owner->perf_event_mutex. */ smp_store_release(&event->owner, NULL); } mutex_unlock(&task->perf_event_mutex);
perf_event_exit_task_context(task, true);
/* * The perf_event_exit_task_context calls perf_event_task * with task's task_ctx, which generates EXIT events for * task contexts and sets task->perf_event_ctxp[] to NULL. * At this point we need to send EXIT events to cpu contexts. */ perf_event_task(task, NULL, 0);
/* * Detach the perf_ctx_data for the system-wide event. * * Done without holding global_ctx_data_rwsem; typically * attach_global_ctx_data() will skip over this task, but otherwise * attach_task_ctx_data() will observe PF_EXITING. */ detach_task_ctx_data(task);}
/* * Free a context as created by inheritance by perf_event_init_task() below, * used by fork() in case of fail. * * Even though the task has never lived, the context and events have been * exposed through the child_list, so we must take care tearing it all down. */void perf_event_free_task(struct task_struct *task){ perf_event_exit_task_context(task, false);}
void perf_event_delayed_put(struct task_struct *task){ WARN_ON_ONCE(task->perf_event_ctxp);}
struct file *perf_event_get(unsigned int fd){ struct file *file = fget(fd); if (!file) return ERR_PTR(-EBADF);
if (file->f_op != &perf_fops) { fput(file); return ERR_PTR(-EBADF); }
return file;}
const struct perf_event *perf_get_event(struct file *file){ if (file->f_op != &perf_fops) return ERR_PTR(-EINVAL);
return file->private_data;}
const struct perf_event_attr *perf_event_attrs(struct perf_event *event){ if (!event) return ERR_PTR(-EINVAL);
return &event->attr;}
int perf_allow_kernel(void){ if (sysctl_perf_event_paranoid > 1 && !perfmon_capable()) return -EACCES;
return security_perf_event_open(PERF_SECURITY_KERNEL);}EXPORT_SYMBOL_GPL(perf_allow_kernel);
/* * Inherit an event from parent task to child task. * * Returns: * - valid pointer on success * - NULL for orphaned events * - IS_ERR() on error */static struct perf_event *inherit_event(struct perf_event *parent_event, struct task_struct *parent, struct perf_event_context *parent_ctx, struct task_struct *child, struct perf_event *group_leader, struct perf_event_context *child_ctx){ enum perf_event_state parent_state = parent_event->state; struct perf_event_pmu_context *pmu_ctx; struct perf_event *child_event; unsigned long flags;
/* * Instead of creating recursive hierarchies of events, * we link inherited events back to the original parent, * which has a filp for sure, which we use as the reference * count: */ if (parent_event->parent) parent_event = parent_event->parent;
if (parent_event->state <= PERF_EVENT_STATE_REVOKED) return NULL;
/* * Event creation should be under SRCU, see perf_pmu_unregister(). */ guard(srcu)(&pmus_srcu);
child_event = perf_event_alloc(&parent_event->attr, parent_event->cpu, child, group_leader, parent_event, NULL, NULL, -1); if (IS_ERR(child_event)) return child_event;
get_ctx(child_ctx); child_event->ctx = child_ctx;
pmu_ctx = find_get_pmu_context(parent_event->pmu_ctx->pmu, child_ctx, child_event); if (IS_ERR(pmu_ctx)) { free_event(child_event); return ERR_CAST(pmu_ctx); } child_event->pmu_ctx = pmu_ctx;
/* * is_orphaned_event() and list_add_tail(&parent_event->child_list) * must be under the same lock in order to serialize against * perf_event_release_kernel(), such that either we must observe * is_orphaned_event() or they will observe us on the child_list. */ mutex_lock(&parent_event->child_mutex); if (is_orphaned_event(parent_event) || !atomic_long_inc_not_zero(&parent_event->refcount)) { mutex_unlock(&parent_event->child_mutex); free_event(child_event); return NULL; }
/* * Make the child state follow the state of the parent event, * not its attr.disabled bit. We hold the parent's mutex, * so we won't race with perf_event_{en, dis}able_family. */ if (parent_state >= PERF_EVENT_STATE_INACTIVE) child_event->state = PERF_EVENT_STATE_INACTIVE; else child_event->state = PERF_EVENT_STATE_OFF;
if (parent_event->attr.freq) { u64 sample_period = parent_event->hw.sample_period; struct hw_perf_event *hwc = &child_event->hw;
hwc->sample_period = sample_period; hwc->last_period = sample_period;
local64_set(&hwc->period_left, sample_period); }
child_event->overflow_handler = parent_event->overflow_handler; child_event->overflow_handler_context = parent_event->overflow_handler_context;
/* * Precalculate sample_data sizes */ perf_event__header_size(child_event); perf_event__id_header_size(child_event);
/* * Link it up in the child's context: */ raw_spin_lock_irqsave(&child_ctx->lock, flags); add_event_to_ctx(child_event, child_ctx); child_event->attach_state |= PERF_ATTACH_CHILD; raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
/* * Link this into the parent event's child list */ list_add_tail(&child_event->child_list, &parent_event->child_list); mutex_unlock(&parent_event->child_mutex);
return child_event;}
/* * Inherits an event group. * * This will quietly suppress orphaned events; !inherit_event() is not an error. * This matches with perf_event_release_kernel() removing all child events. * * Returns: * - 0 on success * - <0 on error */static int inherit_group(struct perf_event *parent_event, struct task_struct *parent, struct perf_event_context *parent_ctx, struct task_struct *child, struct perf_event_context *child_ctx){ struct perf_event *leader; struct perf_event *sub; struct perf_event *child_ctr;
leader = inherit_event(parent_event, parent, parent_ctx, child, NULL, child_ctx); if (IS_ERR(leader)) return PTR_ERR(leader); /* * @leader can be NULL here because of is_orphaned_event(). In this * case inherit_event() will create individual events, similar to what * perf_group_detach() would do anyway. */ for_each_sibling_event(sub, parent_event) { child_ctr = inherit_event(sub, parent, parent_ctx, child, leader, child_ctx); if (IS_ERR(child_ctr)) return PTR_ERR(child_ctr);
if (sub->aux_event == parent_event && child_ctr && !perf_get_aux_event(child_ctr, leader)) return -EINVAL; } if (leader) leader->group_generation = parent_event->group_generation; return 0;}
/* * Creates the child task context and tries to inherit the event-group. * * Clears @inherited_all on !attr.inherited or error. Note that we'll leave * inherited_all set when we 'fail' to inherit an orphaned event; this is * consistent with perf_event_release_kernel() removing all child events. * * Returns: * - 0 on success * - <0 on error */static intinherit_task_group(struct perf_event *event, struct task_struct *parent, struct perf_event_context *parent_ctx, struct task_struct *child, u64 clone_flags, int *inherited_all){ struct perf_event_context *child_ctx; int ret;
if (!event->attr.inherit || (event->attr.inherit_thread && !(clone_flags & CLONE_THREAD)) || /* Do not inherit if sigtrap and signal handlers were cleared. */ (event->attr.sigtrap && (clone_flags & CLONE_CLEAR_SIGHAND))) { *inherited_all = 0; return 0; }
child_ctx = child->perf_event_ctxp; if (!child_ctx) { /* * This is executed from the parent task context, so * inherit events that have been marked for cloning. * First allocate and initialize a context for the * child. */ child_ctx = alloc_perf_context(child); if (!child_ctx) return -ENOMEM;
child->perf_event_ctxp = child_ctx; }
ret = inherit_group(event, parent, parent_ctx, child, child_ctx); if (ret) *inherited_all = 0;
return ret;}
/* * Initialize the perf_event context in task_struct */static int perf_event_init_context(struct task_struct *child, u64 clone_flags){ struct perf_event_context *child_ctx, *parent_ctx; struct perf_event_context *cloned_ctx; struct perf_event *event; struct task_struct *parent = current; int inherited_all = 1; unsigned long flags; int ret = 0;
if (likely(!parent->perf_event_ctxp)) return 0;
/* * If the parent's context is a clone, pin it so it won't get * swapped under us. */ parent_ctx = perf_pin_task_context(parent); if (!parent_ctx) return 0;
/* * No need to check if parent_ctx != NULL here; since we saw * it non-NULL earlier, the only reason for it to become NULL * is if we exit, and since we're currently in the middle of * a fork we can't be exiting at the same time. */
/* * Lock the parent list. No need to lock the child - not PID * hashed yet and not running, so nobody can access it. */ mutex_lock(&parent_ctx->mutex);
/* * We dont have to disable NMIs - we are only looking at * the list, not manipulating it: */ perf_event_groups_for_each(event, &parent_ctx->pinned_groups) { ret = inherit_task_group(event, parent, parent_ctx, child, clone_flags, &inherited_all); if (ret) goto out_unlock; }
/* * We can't hold ctx->lock when iterating the ->flexible_group list due * to allocations, but we need to prevent rotation because * rotate_ctx() will change the list from interrupt context. */ raw_spin_lock_irqsave(&parent_ctx->lock, flags); parent_ctx->rotate_disable = 1; raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
perf_event_groups_for_each(event, &parent_ctx->flexible_groups) { ret = inherit_task_group(event, parent, parent_ctx, child, clone_flags, &inherited_all); if (ret) goto out_unlock; }
raw_spin_lock_irqsave(&parent_ctx->lock, flags); parent_ctx->rotate_disable = 0;
child_ctx = child->perf_event_ctxp;
if (child_ctx && inherited_all) { /* * Mark the child context as a clone of the parent * context, or of whatever the parent is a clone of. * * Note that if the parent is a clone, the holding of * parent_ctx->lock avoids it from being uncloned. */ cloned_ctx = parent_ctx->parent_ctx; if (cloned_ctx) { child_ctx->parent_ctx = cloned_ctx; child_ctx->parent_gen = parent_ctx->parent_gen; } else { child_ctx->parent_ctx = parent_ctx; child_ctx->parent_gen = parent_ctx->generation; } get_ctx(child_ctx->parent_ctx); }
raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);out_unlock: mutex_unlock(&parent_ctx->mutex);
perf_unpin_context(parent_ctx); put_ctx(parent_ctx);
return ret;}
/* * Initialize the perf_event context in task_struct */int perf_event_init_task(struct task_struct *child, u64 clone_flags){ int ret;
memset(child->perf_recursion, 0, sizeof(child->perf_recursion)); child->perf_event_ctxp = NULL; mutex_init(&child->perf_event_mutex); INIT_LIST_HEAD(&child->perf_event_list); child->perf_ctx_data = NULL;
ret = perf_event_init_context(child, clone_flags); if (ret) { perf_event_free_task(child); return ret; }
return 0;}
static void __init perf_event_init_all_cpus(void){ struct swevent_htable *swhash; struct perf_cpu_context *cpuctx; int cpu;
zalloc_cpumask_var(&perf_online_mask, GFP_KERNEL); zalloc_cpumask_var(&perf_online_core_mask, GFP_KERNEL); zalloc_cpumask_var(&perf_online_die_mask, GFP_KERNEL); zalloc_cpumask_var(&perf_online_cluster_mask, GFP_KERNEL); zalloc_cpumask_var(&perf_online_pkg_mask, GFP_KERNEL); zalloc_cpumask_var(&perf_online_sys_mask, GFP_KERNEL);
for_each_possible_cpu(cpu) { swhash = &per_cpu(swevent_htable, cpu); mutex_init(&swhash->hlist_mutex);
INIT_LIST_HEAD(&per_cpu(pmu_sb_events.list, cpu)); raw_spin_lock_init(&per_cpu(pmu_sb_events.lock, cpu));
INIT_LIST_HEAD(&per_cpu(sched_cb_list, cpu));
cpuctx = per_cpu_ptr(&perf_cpu_context, cpu); __perf_event_init_context(&cpuctx->ctx); lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex); lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock); cpuctx->online = cpumask_test_cpu(cpu, perf_online_mask); cpuctx->heap_size = ARRAY_SIZE(cpuctx->heap_default); cpuctx->heap = cpuctx->heap_default; }}
static void perf_swevent_init_cpu(unsigned int cpu){ struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
mutex_lock(&swhash->hlist_mutex); if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) { struct swevent_hlist *hlist;
hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu)); WARN_ON(!hlist); rcu_assign_pointer(swhash->swevent_hlist, hlist); } mutex_unlock(&swhash->hlist_mutex);}
#if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_COREstatic void __perf_event_exit_context(void *__info){ struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context); struct perf_event_context *ctx = __info; struct perf_event *event;
raw_spin_lock(&ctx->lock); ctx_sched_out(ctx, NULL, EVENT_TIME); list_for_each_entry(event, &ctx->event_list, event_entry) __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP); raw_spin_unlock(&ctx->lock);}
static void perf_event_clear_cpumask(unsigned int cpu){ int target[PERF_PMU_MAX_SCOPE]; unsigned int scope; struct pmu *pmu;
cpumask_clear_cpu(cpu, perf_online_mask);
for (scope = PERF_PMU_SCOPE_NONE + 1; scope < PERF_PMU_MAX_SCOPE; scope++) { const struct cpumask *cpumask = perf_scope_cpu_topology_cpumask(scope, cpu); struct cpumask *pmu_cpumask = perf_scope_cpumask(scope);
target[scope] = -1; if (WARN_ON_ONCE(!pmu_cpumask || !cpumask)) continue;
if (!cpumask_test_and_clear_cpu(cpu, pmu_cpumask)) continue; target[scope] = cpumask_any_but(cpumask, cpu); if (target[scope] < nr_cpu_ids) cpumask_set_cpu(target[scope], pmu_cpumask); }
/* migrate */ list_for_each_entry(pmu, &pmus, entry) { if (pmu->scope == PERF_PMU_SCOPE_NONE || WARN_ON_ONCE(pmu->scope >= PERF_PMU_MAX_SCOPE)) continue;
if (target[pmu->scope] >= 0 && target[pmu->scope] < nr_cpu_ids) perf_pmu_migrate_context(pmu, cpu, target[pmu->scope]); }}
static void perf_event_exit_cpu_context(int cpu){ struct perf_cpu_context *cpuctx; struct perf_event_context *ctx;
// XXX simplify cpuctx->online mutex_lock(&pmus_lock); /* * Clear the cpumasks, and migrate to other CPUs if possible. * Must be invoked before the __perf_event_exit_context. */ perf_event_clear_cpumask(cpu); cpuctx = per_cpu_ptr(&perf_cpu_context, cpu); ctx = &cpuctx->ctx;
mutex_lock(&ctx->mutex); if (ctx->nr_events) smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1); cpuctx->online = 0; mutex_unlock(&ctx->mutex); mutex_unlock(&pmus_lock);}#else
static void perf_event_exit_cpu_context(int cpu) { }
#endif
static void perf_event_setup_cpumask(unsigned int cpu){ struct cpumask *pmu_cpumask; unsigned int scope;
/* * Early boot stage, the cpumask hasn't been set yet. * The perf_online_<domain>_masks includes the first CPU of each domain. * Always unconditionally set the boot CPU for the perf_online_<domain>_masks. */ if (cpumask_empty(perf_online_mask)) { for (scope = PERF_PMU_SCOPE_NONE + 1; scope < PERF_PMU_MAX_SCOPE; scope++) { pmu_cpumask = perf_scope_cpumask(scope); if (WARN_ON_ONCE(!pmu_cpumask)) continue; cpumask_set_cpu(cpu, pmu_cpumask); } goto end; }
for (scope = PERF_PMU_SCOPE_NONE + 1; scope < PERF_PMU_MAX_SCOPE; scope++) { const struct cpumask *cpumask = perf_scope_cpu_topology_cpumask(scope, cpu);
pmu_cpumask = perf_scope_cpumask(scope);
if (WARN_ON_ONCE(!pmu_cpumask || !cpumask)) continue;
if (!cpumask_empty(cpumask) && cpumask_any_and(pmu_cpumask, cpumask) >= nr_cpu_ids) cpumask_set_cpu(cpu, pmu_cpumask); }end: cpumask_set_cpu(cpu, perf_online_mask);}
int perf_event_init_cpu(unsigned int cpu){ struct perf_cpu_context *cpuctx; struct perf_event_context *ctx;
perf_swevent_init_cpu(cpu);
mutex_lock(&pmus_lock); perf_event_setup_cpumask(cpu); cpuctx = per_cpu_ptr(&perf_cpu_context, cpu); ctx = &cpuctx->ctx;
mutex_lock(&ctx->mutex); cpuctx->online = 1; mutex_unlock(&ctx->mutex); mutex_unlock(&pmus_lock);
return 0;}
int perf_event_exit_cpu(unsigned int cpu){ perf_event_exit_cpu_context(cpu); return 0;}
static intperf_reboot(struct notifier_block *notifier, unsigned long val, void *v){ int cpu;
for_each_online_cpu(cpu) perf_event_exit_cpu(cpu);
return NOTIFY_OK;}
/* * Run the perf reboot notifier at the very last possible moment so that * the generic watchdog code runs as long as possible. */static struct notifier_block perf_reboot_notifier = { .notifier_call = perf_reboot, .priority = INT_MIN,};
void __init perf_event_init(void){ int ret;
idr_init(&pmu_idr);
unwind_deferred_init(&perf_unwind_work, perf_unwind_deferred_callback);
perf_event_init_all_cpus(); init_srcu_struct(&pmus_srcu); perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE); perf_pmu_register(&perf_cpu_clock, "cpu_clock", -1); perf_pmu_register(&perf_task_clock, "task_clock", -1); perf_tp_register(); perf_event_init_cpu(smp_processor_id()); register_reboot_notifier(&perf_reboot_notifier);
ret = init_hw_breakpoint(); WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
perf_event_cache = KMEM_CACHE(perf_event, SLAB_PANIC);
/* * Build time assertion that we keep the data_head at the intended * location. IOW, validation we got the __reserved[] size right. */ BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head)) != 1024);}
ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, char *page){ struct perf_pmu_events_attr *pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
if (pmu_attr->event_str) return sprintf(page, "%s\n", pmu_attr->event_str);
return 0;}EXPORT_SYMBOL_GPL(perf_event_sysfs_show);
static int __init perf_event_sysfs_init(void){ struct pmu *pmu; int ret;
mutex_lock(&pmus_lock);
ret = bus_register(&pmu_bus); if (ret) goto unlock;
list_for_each_entry(pmu, &pmus, entry) { if (pmu->dev) continue;
ret = pmu_dev_alloc(pmu); WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); } pmu_bus_running = 1; ret = 0;
unlock: mutex_unlock(&pmus_lock);
return ret;}device_initcall(perf_event_sysfs_init);
#ifdef CONFIG_CGROUP_PERFstatic struct cgroup_subsys_state *perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css){ struct perf_cgroup *jc;
jc = kzalloc_obj(*jc); if (!jc) return ERR_PTR(-ENOMEM);
jc->info = alloc_percpu(struct perf_cgroup_info); if (!jc->info) { kfree(jc); return ERR_PTR(-ENOMEM); }
return &jc->css;}
static void perf_cgroup_css_free(struct cgroup_subsys_state *css){ struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css);
free_percpu(jc->info); kfree(jc);}
static int perf_cgroup_css_online(struct cgroup_subsys_state *css){ perf_event_cgroup(css->cgroup); return 0;}
static int __perf_cgroup_move(void *info){ struct task_struct *task = info;
preempt_disable(); perf_cgroup_switch(task); preempt_enable();
return 0;}
static void perf_cgroup_attach(struct cgroup_taskset *tset){ struct task_struct *task; struct cgroup_subsys_state *css;
cgroup_taskset_for_each(task, css, tset) task_function_call(task, __perf_cgroup_move, task);}
struct cgroup_subsys perf_event_cgrp_subsys = { .css_alloc = perf_cgroup_css_alloc, .css_free = perf_cgroup_css_free, .css_online = perf_cgroup_css_online, .attach = perf_cgroup_attach, /* * Implicitly enable on dfl hierarchy so that perf events can * always be filtered by cgroup2 path as long as perf_event * controller is not mounted on a legacy hierarchy. */ .implicit_on_dfl = true, .threaded = true,};#endif /* CONFIG_CGROUP_PERF */
DEFINE_STATIC_CALL_RET0(perf_snapshot_branch_stack, perf_snapshot_branch_stack_t);