Merge tag 'driver-core-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
"Here is the big set of driver core and debug printk changes for
6.1-rc1. Included in here is:

- dynamic debug updates for the core and the drm subsystem. The drm
changes have all been acked by the relevant maintainers

- kernfs fixes for syzbot reported problems

- kernfs refactors and updates for cgroup requirements

- magic number cleanups and removals from the kernel tree (they were
not being used and they really did not actually do anything)

- other tiny cleanups

All of these have been in linux-next for a while with no reported
issues"

* tag 'driver-core-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (74 commits)
docs: filesystems: sysfs: Make text and code for ->show() consistent
Documentation: NBD_REQUEST_MAGIC isn't a magic number
a.out: restore CMAGIC
device property: Add const qualifier to device_get_match_data() parameter
drm_print: add _ddebug descriptor to drm_*dbg prototypes
drm_print: prefer bare printk KERN_DEBUG on generic fn
drm_print: optimize drm_debug_enabled for jump-label
drm-print: add drm_dbg_driver to improve namespace symmetry
drm-print.h: include dyndbg header
drm_print: wrap drm_*_dbg in dyndbg descriptor factory macro
drm_print: interpose drm_*dbg with forwarding macros
drm: POC drm on dyndbg - use in core, 2 helpers, 3 drivers.
drm_print: condense enum drm_debug_category
debugfs: use DEFINE_SHOW_ATTRIBUTE to define debugfs_regset32_fops
driver core: use IS_ERR_OR_NULL() helper in device_create_groups_vargs()
Documentation: ENI155_MAGIC isn't a magic number
Documentation: NBD_REPLY_MAGIC isn't a magic number
nbd: remove define-only NBD_MAGIC, previously magic number
Documentation: FW_HEADER_MAGIC isn't a magic number
Documentation: EEPROM_MAGIC_VALUE isn't a magic number
...

Documentation/admin-guide/dynamic-debug-howto.rst

···
 Introduction
 ============
 
-This document describes how to use the dynamic debug (dyndbg) feature.
+Dynamic debug allows you to dynamically enable/disable kernel
+debug-print code to obtain additional kernel information.
 
-Dynamic debug is designed to allow you to dynamically enable/disable
-kernel code to obtain additional kernel information.  Currently, if
-``CONFIG_DYNAMIC_DEBUG`` is set, then all ``pr_debug()``/``dev_dbg()`` and
-``print_hex_dump_debug()``/``print_hex_dump_bytes()`` calls can be dynamically
-enabled per-callsite.
+If ``/proc/dynamic_debug/control`` exists, your kernel has dynamic
+debug.  You'll need root access (sudo su) to use this.
 
-If you do not want to enable dynamic debug globally (i.e. in some embedded
-system), you may set ``CONFIG_DYNAMIC_DEBUG_CORE`` as basic support of dynamic
-debug and add ``ccflags := -DDYNAMIC_DEBUG_MODULE`` into the Makefile of any
-modules which you'd like to dynamically debug later.
+Dynamic debug provides:
 
-If ``CONFIG_DYNAMIC_DEBUG`` is not set, ``print_hex_dump_debug()`` is just
-shortcut for ``print_hex_dump(KERN_DEBUG)``.
+ * a Catalog of all *prdbgs* in your kernel.
+   ``cat /proc/dynamic_debug/control`` to see them.
 
-For ``print_hex_dump_debug()``/``print_hex_dump_bytes()``, format string is
-its ``prefix_str`` argument, if it is constant string; or ``hexdump``
-in case ``prefix_str`` is built dynamically.
-
-Dynamic debug has even more useful features:
-
- * Simple query language allows turning on and off debugging
-   statements by matching any combination of 0 or 1 of:
+ * a Simple query/command language to alter *prdbgs* by selecting on
+   any combination of 0 or 1 of:
 
    - source filename
    - function name
    - line number (including ranges of line numbers)
    - module name
    - format string
-
- * Provides a debugfs control file: ``<debugfs>/dynamic_debug/control``
-   which can be read to display the complete list of known debug
-   statements, to help guide you
-
-Controlling dynamic debug Behaviour
-===================================
-
-The behaviour of ``pr_debug()``/``dev_dbg()`` are controlled via writing to a
-control file in the 'debugfs' filesystem. Thus, you must first mount
-the debugfs filesystem, in order to make use of this feature.
-Subsequently, we refer to the control file as:
-``<debugfs>/dynamic_debug/control``. For example, if you want to enable
-printing from source file ``svcsock.c``, line 1603 you simply do::
-
-  nullarbor:~ # echo 'file svcsock.c line 1603 +p' >
-				<debugfs>/dynamic_debug/control
-
-If you make a mistake with the syntax, the write will fail thus::
-
-  nullarbor:~ # echo 'file svcsock.c wtf 1 +p' >
-				<debugfs>/dynamic_debug/control
-  -bash: echo: write error: Invalid argument
-
-Note, for systems without 'debugfs' enabled, the control file can be
-found in ``/proc/dynamic_debug/control``.
+   - class name (as known/declared by each module)
 
 Viewing Dynamic Debug Behaviour
 ===============================
 
-You can view the currently configured behaviour of all the debug
-statements via::
+You can view the currently configured behaviour in the *prdbg* catalog::
 
-  nullarbor:~ # cat <debugfs>/dynamic_debug/control
+  :#> head -n7 /proc/dynamic_debug/control
   # filename:lineno [module]function flags format
-  net/sunrpc/svc_rdma.c:323 [svcxprt_rdma]svc_rdma_cleanup =_ "SVCRDMA Module Removed, deregister RPC RDMA transport\012"
-  net/sunrpc/svc_rdma.c:341 [svcxprt_rdma]svc_rdma_init =_ "\011max_inline       : %d\012"
-  net/sunrpc/svc_rdma.c:340 [svcxprt_rdma]svc_rdma_init =_ "\011sq_depth         : %d\012"
-  net/sunrpc/svc_rdma.c:338 [svcxprt_rdma]svc_rdma_init =_ "\011max_requests     : %d\012"
-  ...
+  init/main.c:1179 [main]initcall_blacklist =_ "blacklisting initcall %s\012
+  init/main.c:1218 [main]initcall_blacklisted =_ "initcall %s blacklisted\012"
+  init/main.c:1424 [main]run_init_process =_ "  with arguments:\012"
+  init/main.c:1426 [main]run_init_process =_ "    %s\012"
+  init/main.c:1427 [main]run_init_process =_ "  with environment:\012"
+  init/main.c:1429 [main]run_init_process =_ "    %s\012"
 
+The 3rd space-delimited column shows the current flags, preceded by
+a ``=`` for easy use with grep/cut. ``=p`` shows enabled callsites.
 
-You can also apply standard Unix text manipulation filters to this
-data, e.g.::
+Controlling dynamic debug Behaviour
+===================================
 
-  nullarbor:~ # grep -i rdma <debugfs>/dynamic_debug/control  | wc -l
-  62
+The behaviour of *prdbg* sites are controlled by writing
+query/commands to the control file.  Example::
 
-  nullarbor:~ # grep -i tcp <debugfs>/dynamic_debug/control | wc -l
-  42
+  # grease the interface
+  :#> alias ddcmd='echo $* > /proc/dynamic_debug/control'
 
-The third column shows the currently enabled flags for each debug
-statement callsite (see below for definitions of the flags).  The
-default value, with no flags enabled, is ``=_``.  So you can view all
-the debug statement callsites with any non-default flags::
+  :#> ddcmd '-p; module main func run* +p'
+  :#> grep =p /proc/dynamic_debug/control
+  init/main.c:1424 [main]run_init_process =p "  with arguments:\012"
+  init/main.c:1426 [main]run_init_process =p "    %s\012"
+  init/main.c:1427 [main]run_init_process =p "  with environment:\012"
+  init/main.c:1429 [main]run_init_process =p "    %s\012"
 
-  nullarbor:~ # awk '$3 != "=_"' <debugfs>/dynamic_debug/control
-  # filename:lineno [module]function flags format
-  net/sunrpc/svcsock.c:1603 [sunrpc]svc_send p "svc_process: st_sendto returned %d\012"
+Error messages go to console/syslog::
+
+  :#> ddcmd mode foo +p
+  dyndbg: unknown keyword "mode"
+  dyndbg: query parse failed
+  bash: echo: write error: Invalid argument
+
+If debugfs is also enabled and mounted, ``dynamic_debug/control`` is
+also under the mount-dir, typically ``/sys/kernel/debug/``.
 
 Command Language Reference
 ==========================
 
-At the lexical level, a command comprises a sequence of words separated
+At the basic lexical level, a command is a sequence of words separated
 by spaces or tabs.  So these are all equivalent::
 
-  nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
-				<debugfs>/dynamic_debug/control
-  nullarbor:~ # echo -n '  file   svcsock.c     line  1603 +p  ' >
-				<debugfs>/dynamic_debug/control
-  nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
-				<debugfs>/dynamic_debug/control
+  :#> ddcmd file svcsock.c line 1603 +p
+  :#> ddcmd "file svcsock.c line 1603 +p"
+  :#> ddcmd '  file   svcsock.c     line  1603 +p  '
 
 Command submissions are bounded by a write() system call.
 Multiple commands can be written together, separated by ``;`` or ``\n``::
 
-  ~# echo "func pnpacpi_get_resources +p; func pnp_assign_mem +p" \
-     > <debugfs>/dynamic_debug/control
+  :#> ddcmd "func pnpacpi_get_resources +p; func pnp_assign_mem +p"
+  :#> ddcmd <<"EOC"
+  func pnpacpi_get_resources +p
+  func pnp_assign_mem +p
+  EOC
+  :#> cat query-batch-file > /proc/dynamic_debug/control
 
-If your query set is big, you can batch them too::
+You can also use wildcards in each query term. The match rule supports
+``*`` (matches zero or more characters) and ``?`` (matches exactly one
+character). For example, you can match all usb drivers::
 
-  ~# cat query-batch-file > <debugfs>/dynamic_debug/control
+  :#> ddcmd file "drivers/usb/*" +p	# "" to suppress shell expansion
 
-Another way is to use wildcards. The match rule supports ``*`` (matches
-zero or more characters) and ``?`` (matches exactly one character). For
-example, you can match all usb drivers::
-
-  ~# echo "file drivers/usb/* +p" > <debugfs>/dynamic_debug/control
-
-At the syntactical level, a command comprises a sequence of match
-specifications, followed by a flags change specification::
+Syntactically, a command is pairs of keyword values, followed by a
+flags change or setting::
 
   command ::= match-spec* flags-spec
 
-The match-spec's are used to choose a subset of the known pr_debug()
-callsites to which to apply the flags-spec.  Think of them as a query
-with implicit ANDs between each pair.  Note that an empty list of
-match-specs will select all debug statement callsites.
+The match-spec's select *prdbgs* from the catalog, upon which to apply
+the flags-spec, all constraints are ANDed together.  An absent keyword
+is the same as keyword "*".
 
-A match specification comprises a keyword, which controls the
-attribute of the callsite to be compared, and a value to compare
-against.  Possible keywords are:::
+
+A match specification is a keyword, which selects the attribute of
+the callsite to be compared, and a value to compare against.  Possible
+keywords are:::
 
   match-spec ::= 'func' string |
 		 'file' string |
 		 'module' string |
 		 'format' string |
+		 'class' string |
 		 'line' line-range
 
   line-range ::= lineno |
···
 	format "nfsd: SETATTR"  // a neater way to match a format with whitespace
 	format 'nfsd: SETATTR'  // yet another way to match a format with whitespace
 
+class
+    The given class_name is validated against each module, which may
+    have declared a list of known class_names.  If the class_name is
+    found for a module, callsite & class matching and adjustment
+    proceeds.  Examples::
+
+	class DRM_UT_KMS	# a DRM.debug category
+	class JUNK		# silent non-match
+	// class TLD_*		# NOTICE: no wildcard in class names
+
 line
     The given line number or range of line numbers is compared
     against the line number of each ``pr_debug()`` callsite.  A single
···
 The flags are::
 
   p    enables the pr_debug() callsite.
-  f    Include the function name in the printed message
-  l    Include line number in the printed message
-  m    Include module name in the printed message
-  t    Include thread ID in messages not generated from interrupt context
-  _    No flags are set. (Or'd with others on input)
+  _    enables no flags.
 
-For ``print_hex_dump_debug()`` and ``print_hex_dump_bytes()``, only ``p`` flag
-have meaning, other flags ignored.
+  Decorator flags add to the message-prefix, in order:
+  t    Include thread ID, or <intr>
+  m    Include module name
+  f    Include the function name
+  l    Include line number
 
-For display, the flags are preceded by ``=``
-(mnemonic: what the flags are currently equal to).
+For ``print_hex_dump_debug()`` and ``print_hex_dump_bytes()``, only
+the ``p`` flag has meaning, other flags are ignored.
 
 Note the regexp ``^[-+=][flmpt_]+$`` matches a flags specification.
 To clear all flags at once, use ``=_`` or ``-flmpt``.
···
 enabled by ``-DDEBUG`` flag during compilation) can be disabled later via
 the debugfs interface if the debug messages are no longer needed::
 
-   echo "module module_name -p" > <debugfs>/dynamic_debug/control
+   echo "module module_name -p" > /proc/dynamic_debug/control
 
 Examples
 ========
···
 ::
 
   // enable the message at line 1603 of file svcsock.c
-  nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
-				<debugfs>/dynamic_debug/control
+  :#> ddcmd 'file svcsock.c line 1603 +p'
 
   // enable all the messages in file svcsock.c
-  nullarbor:~ # echo -n 'file svcsock.c +p' >
-				<debugfs>/dynamic_debug/control
+  :#> ddcmd 'file svcsock.c +p'
 
   // enable all the messages in the NFS server module
-  nullarbor:~ # echo -n 'module nfsd +p' >
-				<debugfs>/dynamic_debug/control
+  :#> ddcmd 'module nfsd +p'
 
   // enable all 12 messages in the function svc_process()
-  nullarbor:~ # echo -n 'func svc_process +p' >
-				<debugfs>/dynamic_debug/control
+  :#> ddcmd 'func svc_process +p'
 
   // disable all 12 messages in the function svc_process()
-  nullarbor:~ # echo -n 'func svc_process -p' >
-				<debugfs>/dynamic_debug/control
+  :#> ddcmd 'func svc_process -p'
 
   // enable messages for NFS calls READ, READLINK, READDIR and READDIR+.
-  nullarbor:~ # echo -n 'format "nfsd: READ" +p' >
-				<debugfs>/dynamic_debug/control
+  :#> ddcmd 'format "nfsd: READ" +p'
 
   // enable messages in files of which the paths include string "usb"
-  nullarbor:~ # echo -n 'file *usb* +p' > <debugfs>/dynamic_debug/control
+  :#> ddcmd 'file *usb* +p' > /proc/dynamic_debug/control
 
   // enable all messages
-  nullarbor:~ # echo -n '+p' > <debugfs>/dynamic_debug/control
+  :#> ddcmd '+p' > /proc/dynamic_debug/control
 
   // add module, function to all enabled messages
-  nullarbor:~ # echo -n '+mf' > <debugfs>/dynamic_debug/control
+  :#> ddcmd '+mf' > /proc/dynamic_debug/control
 
   // boot-args example, with newlines and comments for readability
   Kernel command line: ...
···
     dyndbg="file init/* +p #cmt ; func parse_one +p"
     // enable pr_debugs in 2 functions in a module loaded later
     pc87360.dyndbg="func pc87360_init_device +p; func pc87360_find +p"
+
+Kernel Configuration
+====================
+
+Dynamic Debug is enabled via kernel config items::
+
+  CONFIG_DYNAMIC_DEBUG=y	# build catalog, enables CORE
+  CONFIG_DYNAMIC_DEBUG_CORE=y	# enable mechanics only, skip catalog
+
+If you do not want to enable dynamic debug globally (i.e. in some embedded
+system), you may set ``CONFIG_DYNAMIC_DEBUG_CORE`` as basic support of dynamic
+debug and add ``ccflags := -DDYNAMIC_DEBUG_MODULE`` into the Makefile of any
+modules which you'd like to dynamically debug later.
+
+
+Kernel *prdbg* API
+==================
+
+The following functions are cataloged and controllable when dynamic
+debug is enabled::
+
+  pr_debug()
+  dev_dbg()
+  print_hex_dump_debug()
+  print_hex_dump_bytes()
+
+Otherwise, they are off by default; ``ccflags += -DDEBUG`` or
+``#define DEBUG`` in a source file will enable them appropriately.
+
+If ``CONFIG_DYNAMIC_DEBUG`` is not set, ``print_hex_dump_debug()`` is
+just a shortcut for ``print_hex_dump(KERN_DEBUG)``.
+
+For ``print_hex_dump_debug()``/``print_hex_dump_bytes()``, format string is
+its ``prefix_str`` argument, if it is constant string; or ``hexdump``
+in case ``prefix_str`` is built dynamically.

Documentation/driver-api/driver-model/devres.rst

···
   devm_ioremap()
   devm_ioremap_uc()
   devm_ioremap_wc()
-  devm_ioremap_np()
   devm_ioremap_resource() : checks resource, requests memory region, ioremaps
   devm_ioremap_resource_wc()
   devm_platform_ioremap_resource() : calls devm_ioremap_resource() for platform device

Documentation/filesystems/sysfs.rst

···
     static ssize_t show_name(struct device *dev, struct device_attribute *attr,
 			    char *buf)
     {
-	    return scnprintf(buf, PAGE_SIZE, "%s\n", dev->name);
+	    return sysfs_emit(buf, "%s\n", dev->name);
     }
 
     static ssize_t store_name(struct device *dev, struct device_attribute *attr,

Documentation/process/magic-number.rst

···
 Magic Name            Number           Structure                File
 ===================== ================ ======================== ==========================================
 PG_MAGIC              'P'              pg_{read,write}_hdr      ``include/linux/pg.h``
-CMAGIC                0x0111           user                     ``include/linux/a.out.h``
-MKISS_DRIVER_MAGIC    0x04bf           mkiss_channel            ``drivers/net/mkiss.h``
 APM_BIOS_MAGIC        0x4101           apm_user                 ``arch/x86/kernel/apm_32.c``
-DB_MAGIC              0x4442           fc_info                  ``drivers/net/iph5526_novram.c``
-DL_MAGIC              0x444d           fc_info                  ``drivers/net/iph5526_novram.c``
 FASYNC_MAGIC          0x4601           fasync_struct            ``include/linux/fs.h``
-FF_MAGIC              0x4646           fc_info                  ``drivers/net/iph5526_novram.c``
-PTY_MAGIC             0x5001                                    ``drivers/char/pty.c``
-PPP_MAGIC             0x5002           ppp                      ``include/linux/if_pppvar.h``
-SSTATE_MAGIC          0x5302           serial_state             ``include/linux/serial.h``
 SLIP_MAGIC            0x5302           slip                     ``drivers/net/slip.h``
-STRIP_MAGIC           0x5303           strip                    ``drivers/net/strip.c``
-SIXPACK_MAGIC         0x5304           sixpack                  ``drivers/net/hamradio/6pack.h``
-AX25_MAGIC            0x5316           ax_disp                  ``drivers/net/mkiss.h``
 MGSLPC_MAGIC          0x5402           mgslpc_info              ``drivers/char/pcmcia/synclink_cs.c``
-USB_SERIAL_MAGIC      0x6702           usb_serial               ``drivers/usb/serial/usb-serial.h``
-FULL_DUPLEX_MAGIC     0x6969                                    ``drivers/net/ethernet/dec/tulip/de2104x.c``
-USB_BLUETOOTH_MAGIC   0x6d02           usb_bluetooth            ``drivers/usb/class/bluetty.c``
-RFCOMM_TTY_MAGIC      0x6d02                                    ``net/bluetooth/rfcomm/tty.c``
-USB_SERIAL_PORT_MAGIC 0x7301           usb_serial_port          ``drivers/usb/serial/usb-serial.h``
-CG_MAGIC              0x00090255       ufs_cylinder_group       ``include/linux/ufs_fs.h``
-LSEMAGIC              0x05091998       lse                      ``drivers/fc4/fc.c``
-RIEBL_MAGIC           0x09051990                                ``drivers/net/atarilance.c``
-NBD_REQUEST_MAGIC     0x12560953       nbd_request              ``include/linux/nbd.h``
-RED_MAGIC2            0x170fc2a5       (any)                    ``mm/slab.c``
 BAYCOM_MAGIC          0x19730510       baycom_state             ``drivers/net/baycom_epp.c``
-ISDN_X25IFACE_MAGIC   0x1e75a2b9       isdn_x25iface_proto_data ``drivers/isdn/isdn_x25iface.h``
-ECP_MAGIC             0x21504345       cdkecpsig                ``include/linux/cdk.h``
-LSOMAGIC              0x27091997       lso                      ``drivers/fc4/fc.c``
-LSMAGIC               0x2a3b4d2a       ls                       ``drivers/fc4/fc.c``
-WANPIPE_MAGIC         0x414C4453       sdla_{dump,exec}         ``include/linux/wanpipe.h``
-CS_CARD_MAGIC         0x43525553       cs_card                  ``sound/oss/cs46xx.c``
-LABELCL_MAGIC         0x4857434c       labelcl_info_s           ``include/asm/ia64/sn/labelcl.h``
-ISDN_ASYNC_MAGIC      0x49344C01       modem_info               ``include/linux/isdn.h``
-CTC_ASYNC_MAGIC       0x49344C01       ctc_tty_info             ``drivers/s390/net/ctctty.c``
-ISDN_NET_MAGIC        0x49344C02       isdn_net_local_s         ``drivers/isdn/i4l/isdn_net_lib.h``
-SAVEKMSG_MAGIC2       0x4B4D5347       savekmsg                 ``arch/*/amiga/config.c``
-CS_STATE_MAGIC        0x4c4f4749       cs_state                 ``sound/oss/cs46xx.c``
-SLAB_C_MAGIC          0x4f17a36d       kmem_cache               ``mm/slab.c``
-COW_MAGIC             0x4f4f4f4d       cow_header_v1            ``arch/um/drivers/ubd_user.c``
-I810_CARD_MAGIC       0x5072696E       i810_card                ``sound/oss/i810_audio.c``
-TRIDENT_CARD_MAGIC    0x5072696E       trident_card             ``sound/oss/trident.c``
-ROUTER_MAGIC          0x524d4157       wan_device               [in ``wanrouter.h`` pre 3.9]
-SAVEKMSG_MAGIC1       0x53415645       savekmsg                 ``arch/*/amiga/config.c``
-GDA_MAGIC             0x58464552       gda                      ``arch/mips/include/asm/sn/gda.h``
-RED_MAGIC1            0x5a2cf071       (any)                    ``mm/slab.c``
-EEPROM_MAGIC_VALUE    0x5ab478d2       lanai_dev                ``drivers/atm/lanai.c``
 HDLCDRV_MAGIC         0x5ac6e778       hdlcdrv_state            ``include/linux/hdlcdrv.h``
-PCXX_MAGIC            0x5c6df104       channel                  ``drivers/char/pcxx.h``
 KV_MAGIC              0x5f4b565f       kernel_vars_s            ``arch/mips/include/asm/sn/klkernvars.h``
-I810_STATE_MAGIC      0x63657373       i810_state               ``sound/oss/i810_audio.c``
-TRIDENT_STATE_MAGIC   0x63657373       trient_state             ``sound/oss/trident.c``
-M3_CARD_MAGIC         0x646e6f50       m3_card                  ``sound/oss/maestro3.c``
-FW_HEADER_MAGIC       0x65726F66       fw_header                ``drivers/atm/fore200e.h``
-SLOT_MAGIC            0x67267321       slot                     ``drivers/hotplug/cpqphp.h``
-SLOT_MAGIC            0x67267322       slot                     ``drivers/hotplug/acpiphp.h``
-LO_MAGIC              0x68797548       nbd_device               ``include/linux/nbd.h``
-M3_STATE_MAGIC        0x734d724d       m3_state                 ``sound/oss/maestro3.c``
-VMALLOC_MAGIC         0x87654320       snd_alloc_track          ``sound/core/memory.c``
-KMALLOC_MAGIC         0x87654321       snd_alloc_track          ``sound/core/memory.c``
-PWC_MAGIC             0x89DC10AB       pwc_device               ``drivers/usb/media/pwc.h``
-NBD_REPLY_MAGIC       0x96744668       nbd_reply                ``include/linux/nbd.h``
-ENI155_MAGIC          0xa54b872d       midway_eprom	        ``drivers/atm/eni.h``
 CODA_MAGIC            0xC0DAC0DA       coda_file_info           ``fs/coda/coda_fs_i.h``
 YAM_MAGIC             0xF10A7654       yam_port                 ``drivers/net/hamradio/yam.c``
 CCB_MAGIC             0xf2691ad2       ccb                      ``drivers/scsi/ncr53c8xx.c``
 QUEUE_MAGIC_FREE      0xf7e1c9a3       queue_entry              ``drivers/scsi/arm/queue.c``
 QUEUE_MAGIC_USED      0xf7e1cc33       queue_entry              ``drivers/scsi/arm/queue.c``
-HTB_CMAGIC            0xFEFAFEF1       htb_class                ``net/sched/sch_htb.c``
 NMI_MAGIC             0x48414d4d455201 nmi_s                    ``arch/mips/include/asm/sn/nmi.h``
 ===================== ================ ======================== ==========================================
-
-Note that there are also defined special per-driver magic numbers in sound
-memory management. See ``include/sound/sndmagic.h`` for complete list of them. Many
-OSS sound drivers have their magic numbers constructed from the soundcard PCI
-ID - these are not listed here as well.
-
-HFS is another larger user of magic numbers - you can find them in
-``fs/hfs/hfs.h``.

Documentation/translations/it_IT/process/magic-number.rst

···
 Nome magico           Numero           Struttura                File
 ===================== ================ ======================== ==========================================
 PG_MAGIC              'P'              pg_{read,write}_hdr      ``include/linux/pg.h``
-CMAGIC                0x0111           user                     ``include/linux/a.out.h``
-MKISS_DRIVER_MAGIC    0x04bf           mkiss_channel            ``drivers/net/mkiss.h``
 APM_BIOS_MAGIC        0x4101           apm_user                 ``arch/x86/kernel/apm_32.c``
-DB_MAGIC              0x4442           fc_info                  ``drivers/net/iph5526_novram.c``
-DL_MAGIC              0x444d           fc_info                  ``drivers/net/iph5526_novram.c``
 FASYNC_MAGIC          0x4601           fasync_struct            ``include/linux/fs.h``
-FF_MAGIC              0x4646           fc_info                  ``drivers/net/iph5526_novram.c``
-PTY_MAGIC             0x5001                                    ``drivers/char/pty.c``
-PPP_MAGIC             0x5002           ppp                      ``include/linux/if_pppvar.h``
-SSTATE_MAGIC          0x5302           serial_state             ``include/linux/serial.h``
 SLIP_MAGIC            0x5302           slip                     ``drivers/net/slip.h``
-STRIP_MAGIC           0x5303           strip                    ``drivers/net/strip.c``
-SIXPACK_MAGIC         0x5304           sixpack                  ``drivers/net/hamradio/6pack.h``
-AX25_MAGIC            0x5316           ax_disp                  ``drivers/net/mkiss.h``
 MGSLPC_MAGIC          0x5402           mgslpc_info              ``drivers/char/pcmcia/synclink_cs.c``
-USB_SERIAL_MAGIC      0x6702           usb_serial               ``drivers/usb/serial/usb-serial.h``
-FULL_DUPLEX_MAGIC     0x6969                                    ``drivers/net/ethernet/dec/tulip/de2104x.c``
-USB_BLUETOOTH_MAGIC   0x6d02           usb_bluetooth            ``drivers/usb/class/bluetty.c``
-RFCOMM_TTY_MAGIC      0x6d02                                    ``net/bluetooth/rfcomm/tty.c``
-USB_SERIAL_PORT_MAGIC 0x7301           usb_serial_port          ``drivers/usb/serial/usb-serial.h``
-CG_MAGIC              0x00090255       ufs_cylinder_group       ``include/linux/ufs_fs.h``
-LSEMAGIC              0x05091998       lse                      ``drivers/fc4/fc.c``
-RIEBL_MAGIC           0x09051990                                ``drivers/net/atarilance.c``
-NBD_REQUEST_MAGIC     0x12560953       nbd_request              ``include/linux/nbd.h``
-RED_MAGIC2            0x170fc2a5       (any)                    ``mm/slab.c``
 BAYCOM_MAGIC          0x19730510       baycom_state             ``drivers/net/baycom_epp.c``
-ISDN_X25IFACE_MAGIC   0x1e75a2b9       isdn_x25iface_proto_data ``drivers/isdn/isdn_x25iface.h``
-ECP_MAGIC             0x21504345       cdkecpsig                ``include/linux/cdk.h``
-LSOMAGIC              0x27091997       lso                      ``drivers/fc4/fc.c``
-LSMAGIC               0x2a3b4d2a       ls                       ``drivers/fc4/fc.c``
-WANPIPE_MAGIC         0x414C4453       sdla_{dump,exec}         ``include/linux/wanpipe.h``
-CS_CARD_MAGIC         0x43525553       cs_card                  ``sound/oss/cs46xx.c``
-LABELCL_MAGIC         0x4857434c       labelcl_info_s           ``include/asm/ia64/sn/labelcl.h``
-ISDN_ASYNC_MAGIC      0x49344C01       modem_info               ``include/linux/isdn.h``
-CTC_ASYNC_MAGIC       0x49344C01       ctc_tty_info             ``drivers/s390/net/ctctty.c``
-ISDN_NET_MAGIC        0x49344C02       isdn_net_local_s         ``drivers/isdn/i4l/isdn_net_lib.h``
-SAVEKMSG_MAGIC2       0x4B4D5347       savekmsg                 ``arch/*/amiga/config.c``
-CS_STATE_MAGIC        0x4c4f4749       cs_state                 ``sound/oss/cs46xx.c``
-SLAB_C_MAGIC          0x4f17a36d       kmem_cache               ``mm/slab.c``
-COW_MAGIC             0x4f4f4f4d       cow_header_v1            ``arch/um/drivers/ubd_user.c``
-I810_CARD_MAGIC       0x5072696E       i810_card                ``sound/oss/i810_audio.c``
-TRIDENT_CARD_MAGIC    0x5072696E       trident_card             ``sound/oss/trident.c``
-ROUTER_MAGIC          0x524d4157       wan_device               [in ``wanrouter.h`` pre 3.9]
-SAVEKMSG_MAGIC1       0x53415645       savekmsg                 ``arch/*/amiga/config.c``
-GDA_MAGIC             0x58464552       gda                      ``arch/mips/include/asm/sn/gda.h``
-RED_MAGIC1            0x5a2cf071       (any)                    ``mm/slab.c``
-EEPROM_MAGIC_VALUE    0x5ab478d2       lanai_dev                ``drivers/atm/lanai.c``
 HDLCDRV_MAGIC         0x5ac6e778       hdlcdrv_state            ``include/linux/hdlcdrv.h``
-PCXX_MAGIC            0x5c6df104       channel                  ``drivers/char/pcxx.h``
 KV_MAGIC              0x5f4b565f       kernel_vars_s            ``arch/mips/include/asm/sn/klkernvars.h``
-I810_STATE_MAGIC      0x63657373       i810_state               ``sound/oss/i810_audio.c``
-TRIDENT_STATE_MAGIC   0x63657373       trient_state             ``sound/oss/trident.c``
-M3_CARD_MAGIC         0x646e6f50       m3_card                  ``sound/oss/maestro3.c``
-FW_HEADER_MAGIC       0x65726F66       fw_header                ``drivers/atm/fore200e.h``
-SLOT_MAGIC            0x67267321       slot                     ``drivers/hotplug/cpqphp.h``
-SLOT_MAGIC            0x67267322       slot                     ``drivers/hotplug/acpiphp.h``
-LO_MAGIC              0x68797548       nbd_device               ``include/linux/nbd.h``
-M3_STATE_MAGIC        0x734d724d       m3_state                 ``sound/oss/maestro3.c``
-VMALLOC_MAGIC         0x87654320       snd_alloc_track          ``sound/core/memory.c``
-KMALLOC_MAGIC         0x87654321       snd_alloc_track          ``sound/core/memory.c``
-PWC_MAGIC             0x89DC10AB       pwc_device               ``drivers/usb/media/pwc.h``
-NBD_REPLY_MAGIC       0x96744668       nbd_reply                ``include/linux/nbd.h``
-ENI155_MAGIC          0xa54b872d       midway_eprom	        ``drivers/atm/eni.h``
 CODA_MAGIC            0xC0DAC0DA       coda_file_info           ``fs/coda/coda_fs_i.h``
 YAM_MAGIC             0xF10A7654       yam_port                 ``drivers/net/hamradio/yam.c``
 CCB_MAGIC             0xf2691ad2       ccb                      ``drivers/scsi/ncr53c8xx.c``
 QUEUE_MAGIC_FREE      0xf7e1c9a3       queue_entry              ``drivers/scsi/arm/queue.c``
 QUEUE_MAGIC_USED      0xf7e1cc33       queue_entry              ``drivers/scsi/arm/queue.c``
-HTB_CMAGIC            0xFEFAFEF1       htb_class                ``net/sched/sch_htb.c``
 NMI_MAGIC             0x48414d4d455201 nmi_s                    ``arch/mips/include/asm/sn/nmi.h``
 ===================== ================ ======================== ==========================================
-
-Da notare che ci sono anche dei numeri magici specifici per driver nel
-*sound memory management*. Consultate ``include/sound/sndmagic.h`` per una
-lista completa.  Molti driver audio OSS hanno i loro numeri magici costruiti a
-partire dall'identificativo PCI della scheda audio - nemmeno questi sono
-elencati in questo file.
-
-Il file-system HFS è un altro grande utilizzatore di numeri magici - potete
-trovarli qui ``fs/hfs/hfs.h``.

Documentation/translations/zh_CN/process/magic-number.rst

···
 魔术数名              数字             结构                     文件
 ===================== ================ ======================== ==========================================
 PG_MAGIC              'P'              pg_{read,write}_hdr      ``include/linux/pg.h``
-CMAGIC                0x0111           user                     ``include/linux/a.out.h``
-MKISS_DRIVER_MAGIC    0x04bf           mkiss_channel            ``drivers/net/mkiss.h``
 APM_BIOS_MAGIC        0x4101           apm_user                 ``arch/x86/kernel/apm_32.c``
-DB_MAGIC              0x4442           fc_info                  ``drivers/net/iph5526_novram.c``
-DL_MAGIC              0x444d           fc_info                  ``drivers/net/iph5526_novram.c``
 FASYNC_MAGIC          0x4601           fasync_struct            ``include/linux/fs.h``
-FF_MAGIC              0x4646           fc_info                  ``drivers/net/iph5526_novram.c``
-PTY_MAGIC             0x5001                                    ``drivers/char/pty.c``
-PPP_MAGIC             0x5002           ppp                      ``include/linux/if_pppvar.h``
-SSTATE_MAGIC          0x5302           serial_state             ``include/linux/serial.h``
 SLIP_MAGIC            0x5302           slip                     ``drivers/net/slip.h``
-STRIP_MAGIC           0x5303           strip                    ``drivers/net/strip.c``
-SIXPACK_MAGIC         0x5304           sixpack                  ``drivers/net/hamradio/6pack.h``
-AX25_MAGIC            0x5316           ax_disp                  ``drivers/net/mkiss.h``
 MGSLPC_MAGIC          0x5402           mgslpc_info              ``drivers/char/pcmcia/synclink_cs.c``
-USB_SERIAL_MAGIC      0x6702           usb_serial               ``drivers/usb/serial/usb-serial.h``
-FULL_DUPLEX_MAGIC     0x6969                                    ``drivers/net/ethernet/dec/tulip/de2104x.c``
-USB_BLUETOOTH_MAGIC   0x6d02           usb_bluetooth            ``drivers/usb/class/bluetty.c``
-RFCOMM_TTY_MAGIC      0x6d02                                    ``net/bluetooth/rfcomm/tty.c``
-USB_SERIAL_PORT_MAGIC 0x7301           usb_serial_port          ``drivers/usb/serial/usb-serial.h``
-CG_MAGIC              0x00090255       ufs_cylinder_group       ``include/linux/ufs_fs.h``
-LSEMAGIC              0x05091998       lse                      ``drivers/fc4/fc.c``
-GDTIOCTL_MAGIC        0x06030f07       gdth_iowr_str            ``drivers/scsi/gdth_ioctl.h``
-RIEBL_MAGIC           0x09051990                                ``drivers/net/atarilance.c``
-NBD_REQUEST_MAGIC     0x12560953       nbd_request              ``include/linux/nbd.h``
-RED_MAGIC2            0x170fc2a5       (any)                    ``mm/slab.c``
 BAYCOM_MAGIC          0x19730510       baycom_state             ``drivers/net/baycom_epp.c``
-ISDN_X25IFACE_MAGIC   0x1e75a2b9       isdn_x25iface_proto_data ``drivers/isdn/isdn_x25iface.h``
-ECP_MAGIC             0x21504345       cdkecpsig                ``include/linux/cdk.h``
-LSOMAGIC              0x27091997       lso                      ``drivers/fc4/fc.c``
-LSMAGIC               0x2a3b4d2a       ls                       ``drivers/fc4/fc.c``
-WANPIPE_MAGIC         0x414C4453       sdla_{dump,exec}         ``include/linux/wanpipe.h``
-CS_CARD_MAGIC         0x43525553       cs_card                  ``sound/oss/cs46xx.c``
-LABELCL_MAGIC         0x4857434c       labelcl_info_s           ``include/asm/ia64/sn/labelcl.h``
-ISDN_ASYNC_MAGIC      0x49344C01       modem_info               ``include/linux/isdn.h``
-CTC_ASYNC_MAGIC       0x49344C01       ctc_tty_info             ``drivers/s390/net/ctctty.c``
-ISDN_NET_MAGIC        0x49344C02       isdn_net_local_s         ``drivers/isdn/i4l/isdn_net_lib.h``
-SAVEKMSG_MAGIC2       0x4B4D5347       savekmsg                 ``arch/*/amiga/config.c``
-CS_STATE_MAGIC        0x4c4f4749       cs_state                 ``sound/oss/cs46xx.c``
-SLAB_C_MAGIC          0x4f17a36d       kmem_cache               ``mm/slab.c``
-COW_MAGIC             0x4f4f4f4d       cow_header_v1            ``arch/um/drivers/ubd_user.c``
-I810_CARD_MAGIC       0x5072696E       i810_card                ``sound/oss/i810_audio.c``
-TRIDENT_CARD_MAGIC    0x5072696E       trident_card             ``sound/oss/trident.c``
-ROUTER_MAGIC          0x524d4157       wan_device               [in ``wanrouter.h`` pre 3.9]
-SAVEKMSG_MAGIC1       0x53415645       savekmsg                 ``arch/*/amiga/config.c``
-GDA_MAGIC             0x58464552       gda                      ``arch/mips/include/asm/sn/gda.h``
-RED_MAGIC1            0x5a2cf071       (any)                    ``mm/slab.c``
-EEPROM_MAGIC_VALUE    0x5ab478d2       lanai_dev                ``drivers/atm/lanai.c``
 HDLCDRV_MAGIC         0x5ac6e778       hdlcdrv_state            ``include/linux/hdlcdrv.h``
-PCXX_MAGIC            0x5c6df104       channel                  ``drivers/char/pcxx.h``
 KV_MAGIC              0x5f4b565f       kernel_vars_s            ``arch/mips/include/asm/sn/klkernvars.h``
-I810_STATE_MAGIC      0x63657373       i810_state               ``sound/oss/i810_audio.c``
-TRIDENT_STATE_MAGIC   0x63657373       trient_state             ``sound/oss/trident.c``
-M3_CARD_MAGIC         0x646e6f50       m3_card                  ``sound/oss/maestro3.c``
-FW_HEADER_MAGIC       0x65726F66       fw_header                ``drivers/atm/fore200e.h``
-SLOT_MAGIC            0x67267321       slot                     ``drivers/hotplug/cpqphp.h``
-SLOT_MAGIC            0x67267322       slot                     ``drivers/hotplug/acpiphp.h``
-LO_MAGIC              0x68797548       nbd_device               ``include/linux/nbd.h``
-M3_STATE_MAGIC        0x734d724d       m3_state                 ``sound/oss/maestro3.c``
-VMALLOC_MAGIC         0x87654320       snd_alloc_track          ``sound/core/memory.c``
-KMALLOC_MAGIC         0x87654321       snd_alloc_track          ``sound/core/memory.c``
-PWC_MAGIC             0x89DC10AB       pwc_device               ``drivers/usb/media/pwc.h``
-NBD_REPLY_MAGIC       0x96744668       nbd_reply                ``include/linux/nbd.h``
-ENI155_MAGIC          0xa54b872d       midway_eprom	        ``drivers/atm/eni.h``
 CODA_MAGIC            0xC0DAC0DA       coda_file_info           ``fs/coda/coda_fs_i.h``
-DPMEM_MAGIC           0xc0ffee11       gdt_pci_sram             ``drivers/scsi/gdth.h``
 YAM_MAGIC             0xF10A7654       yam_port                 ``drivers/net/hamradio/yam.c``
 CCB_MAGIC             0xf2691ad2       ccb                      ``drivers/scsi/ncr53c8xx.c``
 QUEUE_MAGIC_FREE      0xf7e1c9a3       queue_entry              ``drivers/scsi/arm/queue.c``
 QUEUE_MAGIC_USED      0xf7e1cc33       queue_entry              ``drivers/scsi/arm/queue.c``
-HTB_CMAGIC            0xFEFAFEF1       htb_class                ``net/sched/sch_htb.c``
 NMI_MAGIC             0x48414d4d455201 nmi_s                    ``arch/mips/include/asm/sn/nmi.h``
 ===================== ================ ======================== ==========================================
-
-
-请注意，在声音记忆管理中仍然有一些特殊的为每个驱动定义的魔术值。查看include/sound/sndmagic.h来获取他们完整的列表信息。很多OSS声音驱动拥有自己从声卡PCI ID构建的魔术值-他们也没有被列在这里。
-
-IrDA子系统也使用了大量的自己的魔术值，查看include/net/irda/irda.h来获取他们完整的信息。
-
-HFS是另外一个比较大的使用魔术值的文件系统-你可以在fs/hfs/hfs.h中找到他们。

Documentation/translations/zh_TW/process/magic-number.rst

···
 魔術數名              數字             結構                     文件
 ===================== ================ ======================== ==========================================
 PG_MAGIC              'P'              pg_{read,write}_hdr      ``include/linux/pg.h``
-CMAGIC                0x0111           user                     ``include/linux/a.out.h``
-MKISS_DRIVER_MAGIC    0x04bf           mkiss_channel            ``drivers/net/mkiss.h``
 APM_BIOS_MAGIC        0x4101           apm_user                 ``arch/x86/kernel/apm_32.c``
-DB_MAGIC              0x4442           fc_info                  ``drivers/net/iph5526_novram.c``
-DL_MAGIC              0x444d           fc_info                  ``drivers/net/iph5526_novram.c``
 FASYNC_MAGIC          0x4601           fasync_struct            ``include/linux/fs.h``
-FF_MAGIC              0x4646           fc_info                  ``drivers/net/iph5526_novram.c``
-PTY_MAGIC             0x5001                                    ``drivers/char/pty.c``
-PPP_MAGIC             0x5002           ppp                      ``include/linux/if_pppvar.h``
-SSTATE_MAGIC          0x5302           serial_state             ``include/linux/serial.h``
 SLIP_MAGIC            0x5302           slip                     ``drivers/net/slip.h``
-STRIP_MAGIC           0x5303           strip                    ``drivers/net/strip.c``
-SIXPACK_MAGIC         0x5304           sixpack                  ``drivers/net/hamradio/6pack.h``
-AX25_MAGIC            0x5316           ax_disp                  ``drivers/net/mkiss.h``
 MGSLPC_MAGIC          0x5402           mgslpc_info              ``drivers/char/pcmcia/synclink_cs.c``
-USB_SERIAL_MAGIC      0x6702           usb_serial               ``drivers/usb/serial/usb-serial.h``
-FULL_DUPLEX_MAGIC     0x6969                                    ``drivers/net/ethernet/dec/tulip/de2104x.c``
-USB_BLUETOOTH_MAGIC   0x6d02           usb_bluetooth            ``drivers/usb/class/bluetty.c``
-RFCOMM_TTY_MAGIC      0x6d02                                    ``net/bluetooth/rfcomm/tty.c``
-USB_SERIAL_PORT_MAGIC 0x7301           usb_serial_port          ``drivers/usb/serial/usb-serial.h``
-CG_MAGIC              0x00090255       ufs_cylinder_group       ``include/linux/ufs_fs.h``
-LSEMAGIC              0x05091998       lse                      ``drivers/fc4/fc.c``
-GDTIOCTL_MAGIC        0x06030f07       gdth_iowr_str            ``drivers/scsi/gdth_ioctl.h``
-RIEBL_MAGIC           0x09051990                                ``drivers/net/atarilance.c``
-NBD_REQUEST_MAGIC     0x12560953       nbd_request              ``include/linux/nbd.h``
-RED_MAGIC2            0x170fc2a5       (any)                    ``mm/slab.c``
 BAYCOM_MAGIC          0x19730510       baycom_state             ``drivers/net/baycom_epp.c``
-ISDN_X25IFACE_MAGIC   0x1e75a2b9       isdn_x25iface_proto_data ``drivers/isdn/isdn_x25iface.h``
-ECP_MAGIC             0x21504345       cdkecpsig                ``include/linux/cdk.h``
-LSOMAGIC              0x27091997       lso                      ``drivers/fc4/fc.c``
-LSMAGIC               0x2a3b4d2a       ls                       ``drivers/fc4/fc.c``
-WANPIPE_MAGIC         0x414C4453       sdla_{dump,exec}         ``include/linux/wanpipe.h``
-CS_CARD_MAGIC         0x43525553       cs_card                  ``sound/oss/cs46xx.c``
-LABELCL_MAGIC         0x4857434c       labelcl_info_s           ``include/asm/ia64/sn/labelcl.h``
-ISDN_ASYNC_MAGIC      0x49344C01       modem_info               ``include/linux/isdn.h``
-CTC_ASYNC_MAGIC       0x49344C01       ctc_tty_info             ``drivers/s390/net/ctctty.c``
-ISDN_NET_MAGIC        0x49344C02       isdn_net_local_s         ``drivers/isdn/i4l/isdn_net_lib.h``
-SAVEKMSG_MAGIC2       0x4B4D5347       savekmsg                 ``arch/*/amiga/config.c``
-CS_STATE_MAGIC        0x4c4f4749       cs_state                 ``sound/oss/cs46xx.c``
-SLAB_C_MAGIC          0x4f17a36d       kmem_cache               ``mm/slab.c``
-COW_MAGIC             0x4f4f4f4d       cow_header_v1            ``arch/um/drivers/ubd_user.c``
-I810_CARD_MAGIC       0x5072696E       i810_card                ``sound/oss/i810_audio.c``
-TRIDENT_CARD_MAGIC    0x5072696E       trident_card             ``sound/oss/trident.c``
-ROUTER_MAGIC          0x524d4157       wan_device               [in ``wanrouter.h`` pre 3.9]
-SAVEKMSG_MAGIC1       0x53415645       savekmsg                 ``arch/*/amiga/config.c``
-GDA_MAGIC             0x58464552       gda                      ``arch/mips/include/asm/sn/gda.h``
-RED_MAGIC1            0x5a2cf071       (any)                    ``mm/slab.c``
-EEPROM_MAGIC_VALUE    0x5ab478d2       lanai_dev                ``drivers/atm/lanai.c``
 HDLCDRV_MAGIC         0x5ac6e778       hdlcdrv_state            ``include/linux/hdlcdrv.h``
-PCXX_MAGIC            0x5c6df104       channel                  ``drivers/char/pcxx.h``
 KV_MAGIC              0x5f4b565f       kernel_vars_s            ``arch/mips/include/asm/sn/klkernvars.h``
-I810_STATE_MAGIC      0x63657373       i810_state               ``sound/oss/i810_audio.c``
-TRIDENT_STATE_MAGIC   0x63657373       trient_state             ``sound/oss/trident.c``
-M3_CARD_MAGIC         0x646e6f50       m3_card                  ``sound/oss/maestro3.c``
-FW_HEADER_MAGIC       0x65726F66       fw_header                ``drivers/atm/fore200e.h``
-SLOT_MAGIC            0x67267321       slot                     ``drivers/hotplug/cpqphp.h``
-SLOT_MAGIC            0x67267322       slot                     ``drivers/hotplug/acpiphp.h``
-LO_MAGIC              0x68797548       nbd_device               ``include/linux/nbd.h``
-M3_STATE_MAGIC        0x734d724d       m3_state                 ``sound/oss/maestro3.c``
-VMALLOC_MAGIC         0x87654320       snd_alloc_track          ``sound/core/memory.c``
-KMALLOC_MAGIC         0x87654321       snd_alloc_track          ``sound/core/memory.c``
-PWC_MAGIC             0x89DC10AB       pwc_device               ``drivers/usb/media/pwc.h``
-NBD_REPLY_MAGIC       0x96744668       nbd_reply                ``include/linux/nbd.h``
-ENI155_MAGIC          0xa54b872d       midway_eprom	        ``drivers/atm/eni.h``
 CODA_MAGIC            0xC0DAC0DA       coda_file_info           ``fs/coda/coda_fs_i.h``
-DPMEM_MAGIC           0xc0ffee11       gdt_pci_sram             ``drivers/scsi/gdth.h``
 YAM_MAGIC             0xF10A7654       yam_port                 ``drivers/net/hamradio/yam.c``
 CCB_MAGIC             0xf2691ad2       ccb                      ``drivers/scsi/ncr53c8xx.c``
 QUEUE_MAGIC_FREE      0xf7e1c9a3       queue_entry              ``drivers/scsi/arm/queue.c``
 QUEUE_MAGIC_USED      0xf7e1cc33       queue_entry              ``drivers/scsi/arm/queue.c``
-HTB_CMAGIC            0xFEFAFEF1       htb_class                ``net/sched/sch_htb.c``
 NMI_MAGIC             0x48414d4d455201 nmi_s                    ``arch/mips/include/asm/sn/nmi.h``
 ===================== ================ ======================== ==========================================
-
-
-請注意，在聲音記憶管理中仍然有一些特殊的爲每個驅動定義的魔術值。查看include/sound/sndmagic.h來獲取他們完整的列表信息。很多OSS聲音驅動擁有自己從音效卡PCI ID構建的魔術值-他們也沒有被列在這裡。
-
-IrDA子系統也使用了大量的自己的魔術值，查看include/net/irda/irda.h來獲取他們完整的信息。
-
-HFS是另外一個比較大的使用魔術值的文件系統-你可以在fs/hfs/hfs.h中找到他們。
-

MAINTAINERS

···
 S:	Maintained
 F:	include/linux/dynamic_debug.h
 F:	lib/dynamic_debug.c
+M:	Jim Cromie <[e-mail]>
+F:	lib/test_dynamic_debug.c
 
 DYNAMIC INTERRUPT MODERATION
 M:	Tal Gilboa <[e-mail]>

arch/mips/include/asm/sn/gda.h

···
 
 #include <asm/sn/addrs.h>
 
-#define GDA_MAGIC	0x58464552
-
 /*
  * GDA Version History
  *

drivers/base/base.h

···
 				 const struct attribute_group **groups);
 void device_driver_detach(struct device *dev);
 
-extern char *make_class_name(const char *name, struct kobject *kobj);
-
 extern int devres_release_all(struct device *dev);
 extern void device_block_probing(void);
 extern void device_unblock_probing(void);

drivers/base/class.c

···
  */
 void class_destroy(struct class *cls)
 {
-	if ((cls == NULL) || (IS_ERR(cls)))
+	if (IS_ERR_OR_NULL(cls))
 		return;
 
 	class_unregister(cls);

drivers/base/core.c

···
 	rc = kobject_synth_uevent(&dev->kobj, buf, count);
 
 	if (rc) {
-		dev_err(dev, "uevent: failed to send synthetic uevent\n");
+		dev_err(dev, "uevent: failed to send synthetic uevent: %d\n", rc);
 		return rc;
 	}
 
···
 	struct device *dev = NULL;
 	int retval = -ENODEV;
 
-	if (class == NULL || IS_ERR(class))
+	if (IS_ERR_OR_NULL(class))
 		goto error;
 
 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);

drivers/base/dd.c

···
 	if (strlen(buf) >= ASYNC_DRV_NAMES_MAX_LEN)
 		pr_warn("Too long list of driver names for 'driver_async_probe'!\n");
 
-	strlcpy(async_probe_drv_names, buf, ASYNC_DRV_NAMES_MAX_LEN);
+	strscpy(async_probe_drv_names, buf, ASYNC_DRV_NAMES_MAX_LEN);
 	async_probe_default = parse_option_str(async_probe_drv_names, "*");
 
 	return 1;

drivers/base/devcoredump.c

···
 	struct device devcd_dev;
 	void *data;
 	size_t datalen;
+	/*
+	 * Here, mutex is required to serialize the calls to del_wk work between
+	 * user/kernel space which happens when devcd is added with device_add()
+	 * and that sends uevent to user space. User space reads the uevents,
+	 * and calls to devcd_data_write() which try to modify the work which is
+	 * not even initialized/queued from devcoredump.
+	 *
+	 *
+	 *
+	 *        cpu0(X)                                 cpu1(Y)
+	 *
+	 *        dev_coredump() uevent sent to user space
+	 *        device_add()  ======================> user space process Y reads the
+	 *                                              uevents writes to devcd fd
+	 *                                              which results into writes to
+	 *
+	 *                                             devcd_data_write()
+	 *                                               mod_delayed_work()
+	 *                                                 try_to_grab_pending()
+	 *                                                   del_timer()
+	 *                                                     debug_assert_init()
+	 *       INIT_DELAYED_WORK()
+	 *       schedule_delayed_work()
+	 *
+	 *
+	 * Also, mutex alone would not be enough to avoid scheduling of
+	 * del_wk work after it get flush from a call to devcd_free()
+	 * mentioned as below.
+	 *
+	 *	disabled_store()
+	 *        devcd_free()
+	 *          mutex_lock()             devcd_data_write()
+	 *          flush_delayed_work()
+	 *          mutex_unlock()
+	 *                                   mutex_lock()
+	 *                                   mod_delayed_work()
+	 *                                   mutex_unlock()
+	 * So, delete_work flag is required.
+	 */
+	struct mutex mutex;
+	bool delete_work;
 	struct module *owner;
 	ssize_t (*read)(char *buffer, loff_t offset, size_t count,
 			void *data, size_t datalen);
···
 	struct device *dev = kobj_to_dev(kobj);
 	struct devcd_entry *devcd = dev_to_devcd(dev);
 
-	mod_delayed_work(system_wq, &devcd->del_wk, 0);
+	mutex_lock(&devcd->mutex);
+	if (!devcd->delete_work) {
+		devcd->delete_work = true;
+		mod_delayed_work(system_wq, &devcd->del_wk, 0);
+	}
+	mutex_unlock(&devcd->mutex);
 
 	return count;
 }
···
 {
 	struct devcd_entry *devcd = dev_to_devcd(dev);
 
+	mutex_lock(&devcd->mutex);
+	if (!devcd->delete_work)
+		devcd->delete_work = true;
+
 	flush_delayed_work(&devcd->del_wk);
+	mutex_unlock(&devcd->mutex);
 	return 0;
 }
 
···
 {
 	return sysfs_emit(buf, "%d\n", devcd_disabled);
 }
+
+/*
+ *
+ *	disabled_store()                                	worker()
+ *	 class_for_each_device(&devcd_class,
+ *		NULL, NULL, devcd_free)
+ *         ...
+ *         ...
+ *	   while ((dev = class_dev_iter_next(&iter))
+ *                                                             devcd_del()
+ *                                                               device_del()
+ *                                                                 put_device() <- last reference
+ *             error = fn(dev, data)                           devcd_dev_release()
+ *             devcd_free(dev, data)                           kfree(devcd)
+ *             mutex_lock(&devcd->mutex);
+ *
+ *
+ * In the above diagram, It looks like disabled_store() would be racing with parallely
+ * running devcd_del() and result in memory abort while acquiring devcd->mutex which
+ * is called after kfree of devcd memory  after dropping its last reference with
+ * put_device(). However, this will not happens as fn(dev, data) runs
+ * with its own reference to device via klist_node so it is not its last reference.
+ * so, above situation would not occur.
+ */
 
 static ssize_t disabled_store(struct class *class, struct class_attribute *attr,
 			      const char *buf, size_t count)
···
 	devcd->read = read;
 	devcd->free = free;
 	devcd->failing_dev = get_device(dev);
+	devcd->delete_work = false;
 
+	mutex_init(&devcd->mutex);
 	device_initialize(&devcd->devcd_dev);
 
 	dev_set_name(&devcd->devcd_dev, "devcd%d",
 		     atomic_inc_return(&devcd_count));
 	devcd->devcd_dev.class = &devcd_class;
 
+	mutex_lock(&devcd->mutex);
 	if (device_add(&devcd->devcd_dev))
 		goto put_device;
 
···
 
 	INIT_DELAYED_WORK(&devcd->del_wk, devcd_del);
 	schedule_delayed_work(&devcd->del_wk, DEVCD_TIMEOUT);
-
+	mutex_unlock(&devcd->mutex);
 	return;
  put_device:
 	put_device(&devcd->devcd_dev);
+	mutex_unlock(&devcd->mutex);
  put_module:
 	module_put(owner);
  free:

drivers/base/devres.c

···
 	if (unlikely(!dr))
 		return NULL;
 
-	memset(dr, 0, offsetof(struct devres, data));
+	/* No need to clear memory twice */
+	if (!(gfp & __GFP_ZERO))
+		memset(dr, 0, offsetof(struct devres, data));
 
 	INIT_LIST_HEAD(&dr->node.entry);
 	dr->node.release = release;

drivers/base/property.c

···
 #include <linux/property.h>
 #include <linux/phy.h>
 
-struct fwnode_handle *dev_fwnode(struct device *dev)
+struct fwnode_handle *dev_fwnode(const struct device *dev)
 {
 	return IS_ENABLED(CONFIG_OF) && dev->of_node ?
 		of_fwnode_handle(dev->of_node) : dev->fwnode;
···
 }
 EXPORT_SYMBOL(fwnode_graph_parse_endpoint);
 
-const void *device_get_match_data(struct device *dev)
+const void *device_get_match_data(const struct device *dev)
 {
 	return fwnode_call_ptr_op(dev_fwnode(dev), device_get_match_data, dev);
 }

drivers/block/nbd.c

···
 
 #define nbd_name(nbd) ((nbd)->disk->disk_name)
 
-#define NBD_MAGIC 0x68797548
-
 #define NBD_DEF_BLKSIZE_BITS 10
 
 static unsigned int nbds_max = 16;

drivers/gpu/drm/Kconfig

···
 
 	  If in doubt, say "N".
 
+config DRM_USE_DYNAMIC_DEBUG
+	bool "use dynamic debug to implement drm.debug"
+	default y
+	depends on DRM
+	depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
+	depends on JUMP_LABEL
+	help
+	  Use dynamic-debug to avoid drm_debug_enabled() runtime overheads.
+	  Due to callsite counts in DRM drivers (~4k in amdgpu) and 56
+	  bytes per callsite, the .data costs can be substantial, and
+	  are therefore configurable.
+
 config DRM_KUNIT_TEST
 	tristate "KUnit tests for DRM" if !KUNIT_ALL_TESTS
 	depends on DRM && KUNIT

drivers/gpu/drm/Makefile

···
 # Makefile for the drm device driver.  This driver provides support for the
 # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
 
+CFLAGS-$(CONFIG_DRM_USE_DYNAMIC_DEBUG)	+= -DDYNAMIC_DEBUG_MODULE
+
 drm-y       :=	drm_aperture.o drm_auth.o drm_cache.o \
 		drm_file.o drm_gem.o drm_ioctl.o \
 		drm_drv.o \

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

···
 #include <linux/mmu_notifier.h>
 #include <linux/suspend.h>
 #include <linux/cc_platform.h>
+#include <linux/fb.h>
+#include <linux/dynamic_debug.h>
 
 #include "amdgpu.h"
 #include "amdgpu_irq.h"
···
 int amdgpu_vcnfw_log;
 
 static void amdgpu_drv_delayed_reset_work_handler(struct work_struct *work);
+
+DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
+			"DRM_UT_CORE",
+			"DRM_UT_DRIVER",
+			"DRM_UT_KMS",
+			"DRM_UT_PRIME",
+			"DRM_UT_ATOMIC",
+			"DRM_UT_VBL",
+			"DRM_UT_STATE",
+			"DRM_UT_LEASE",
+			"DRM_UT_DP",
+			"DRM_UT_DRMRES");
 
 struct amdgpu_mgpu_info mgpu_info = {
 	.mutex = __MUTEX_INITIALIZER(mgpu_info.mutex),

drivers/gpu/drm/display/drm_dp_helper.c

···
 #include <linux/sched.h>
 #include <linux/seq_file.h>
 #include <linux/string_helpers.h>
+#include <linux/dynamic_debug.h>
 
 #include <drm/display/drm_dp_helper.h>
 #include <drm/display/drm_dp_mst_helper.h>
···
 #include <drm/drm_panel.h>
 
 #include "drm_dp_helper_internal.h"
+
+DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
+			"DRM_UT_CORE",
+			"DRM_UT_DRIVER",
+			"DRM_UT_KMS",
+			"DRM_UT_PRIME",
+			"DRM_UT_ATOMIC",
+			"DRM_UT_VBL",
+			"DRM_UT_STATE",
+			"DRM_UT_LEASE",
+			"DRM_UT_DP",
+			"DRM_UT_DRMRES");
 
 struct dp_aux_backlight {
 	struct backlight_device *base;

drivers/gpu/drm/drm_crtc_helper.c

···
 #include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/moduleparam.h>
+#include <linux/dynamic_debug.h>
 
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
···
 #include <drm/drm_vblank.h>
 
 #include "drm_crtc_helper_internal.h"
+
+DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
+			"DRM_UT_CORE",
+			"DRM_UT_DRIVER",
+			"DRM_UT_KMS",
+			"DRM_UT_PRIME",
+			"DRM_UT_ATOMIC",
+			"DRM_UT_VBL",
+			"DRM_UT_STATE",
+			"DRM_UT_LEASE",
+			"DRM_UT_DP",
+			"DRM_UT_DRMRES");
 
 /**
  * DOC: overview

drivers/gpu/drm/drm_print.c

···
  * Rob Clark <[e-mail]>
  */
 
-#define DEBUG /* for pr_debug() */
-
 #include <linux/stdarg.h>
 
 #include <linux/io.h>
 #include <linux/moduleparam.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
+#include <linux/dynamic_debug.h>
 
 #include <drm/drm.h>
 #include <drm/drm_drv.h>
···
  * __drm_debug: Enable debug output.
  * Bitmask of DRM_UT_x. See include/drm/drm_print.h for details.
  */
-unsigned int __drm_debug;
+unsigned long __drm_debug;
 EXPORT_SYMBOL(__drm_debug);
 
 MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug category.\n"
···
 "\t\tBit 5 (0x20)  will enable VBL messages (vblank code)\n"
 "\t\tBit 7 (0x80)  will enable LEASE messages (leasing code)\n"
 "\t\tBit 8 (0x100) will enable DP messages (displayport code)");
-module_param_named(debug, __drm_debug, int, 0600);
+
+#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
+module_param_named(debug, __drm_debug, ulong, 0600);
+#else
+/* classnames must match vals of enum drm_debug_category */
+DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
+			"DRM_UT_CORE",
+			"DRM_UT_DRIVER",
+			"DRM_UT_KMS",
+			"DRM_UT_PRIME",
+			"DRM_UT_ATOMIC",
+			"DRM_UT_VBL",
+			"DRM_UT_STATE",
+			"DRM_UT_LEASE",
+			"DRM_UT_DP",
+			"DRM_UT_DRMRES");
+
+static struct ddebug_class_param drm_debug_bitmap = {
+	.bits = &__drm_debug,
+	.flags = "p",
+	.map = &drm_debug_classes,
+};
+module_param_cb(debug, &param_ops_dyndbg_classes, &drm_debug_bitmap, 0600);
+#endif
 
 void __drm_puts_coredump(struct drm_printer *p, const char *str)
 {
···
 
 void __drm_printfn_debug(struct drm_printer *p, struct va_format *vaf)
 {
-	pr_debug("%s %pV", p->prefix, vaf);
+	/* pr_debug callsite decorations are unhelpful here */
+	printk(KERN_DEBUG "%s %pV", p->prefix, vaf);
 }
 EXPORT_SYMBOL(__drm_printfn_debug);
 
···
 }
 EXPORT_SYMBOL(drm_dev_printk);
 
-void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
-		 const char *format, ...)
+void __drm_dev_dbg(struct _ddebug *desc, const struct device *dev,
+		   enum drm_debug_category category, const char *format, ...)
 {
 	struct va_format vaf;
 	va_list args;
 
-	if (!drm_debug_enabled(category))
+	if (!__drm_debug_enabled(category))
 		return;
 
+	/* we know we are printing for either syslog, tracefs, or both */
 	va_start(args, format);
 	vaf.fmt = format;
 	vaf.va = &args;
···
 
 	va_end(args);
 }
-EXPORT_SYMBOL(drm_dev_dbg);
+EXPORT_SYMBOL(__drm_dev_dbg);
 
-void __drm_dbg(enum drm_debug_category category, const char *format, ...)
+void ___drm_dbg(struct _ddebug *desc, enum drm_debug_category category, const char *format, ...)
 {
 	struct va_format vaf;
 	va_list args;
 
-	if (!drm_debug_enabled(category))
+	if (!__drm_debug_enabled(category))
 		return;
 
 	va_start(args, format);
···
 
 	va_end(args);
 }
-EXPORT_SYMBOL(__drm_dbg);
+EXPORT_SYMBOL(___drm_dbg);
 
 void __drm_err(const char *format, ...)
 {

drivers/gpu/drm/i915/i915_params.c

···
 #include "i915_params.h"
 #include "i915_drv.h"
 
+DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
+			"DRM_UT_CORE",
+			"DRM_UT_DRIVER",
+			"DRM_UT_KMS",
+			"DRM_UT_PRIME",
+			"DRM_UT_ATOMIC",
+			"DRM_UT_VBL",
+			"DRM_UT_STATE",
+			"DRM_UT_LEASE",
+			"DRM_UT_DP",
+			"DRM_UT_DRMRES");
+
 #define i915_param_named(name, T, perm, desc) \
 	module_param_named(name, i915_modparams.name, T, perm); \
 	MODULE_PARM_DESC(name, desc)

drivers/gpu/drm/nouveau/nouveau_drm.c

···
 #include <linux/pm_runtime.h>
 #include <linux/vga_switcheroo.h>
 #include <linux/mmu_notifier.h>
+#include <linux/dynamic_debug.h>
 
 #include <drm/drm_aperture.h>
 #include <drm/drm_crtc_helper.h>
···
 #include "nouveau_platform.h"
 #include "nouveau_svm.h"
 #include "nouveau_dmem.h"
+
+DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
+			"DRM_UT_CORE",
+			"DRM_UT_DRIVER",
+			"DRM_UT_KMS",
+			"DRM_UT_PRIME",
+			"DRM_UT_ATOMIC",
+			"DRM_UT_VBL",
+			"DRM_UT_STATE",
+			"DRM_UT_LEASE",
+			"DRM_UT_DP",
+			"DRM_UT_DRMRES");
 
 MODULE_PARM_DESC(config, "option string to pass to driver core");
 static char *nouveau_config;

fs/debugfs/file.c

···
 }
 EXPORT_SYMBOL_GPL(debugfs_print_regs32);
 
-static int debugfs_show_regset32(struct seq_file *s, void *data)
+static int debugfs_regset32_show(struct seq_file *s, void *data)
 {
 	struct debugfs_regset32 *regset = s->private;
 
···
 	return 0;
 }
 
-static int debugfs_open_regset32(struct inode *inode, struct file *file)
-{
-	return single_open(file, debugfs_show_regset32, inode->i_private);
-}
-
-static const struct file_operations fops_regset32 = {
-	.open =		debugfs_open_regset32,
-	.read =		seq_read,
-	.llseek =	seq_lseek,
-	.release =	single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(debugfs_regset32);
 
 /**
  * debugfs_create_regset32 - create a debugfs file that returns register values
···
 			     struct dentry *parent,
 			     struct debugfs_regset32 *regset)
 {
-	debugfs_create_file(name, mode, parent, regset, &fops_regset32);
+	debugfs_create_file(name, mode, parent, regset, &debugfs_regset32_fops);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_regset32);
 

fs/debugfs/inode.c

···
 	kuid_t uid;
 	kgid_t gid;
 	umode_t mode;
+	/* Opt_* bitfield. */
+	unsigned int opts;
 };
 
 enum {
···
 	kgid_t gid;
 	char *p;
 
+	opts->opts = 0;
 	opts->mode = DEBUGFS_DEFAULT_MODE;
 
 	while ((p = strsep(&data, ",")) != NULL) {
···
 		 * but traditionally debugfs has ignored all mount options
 		 */
 		}
+
+		opts->opts |= BIT(token);
 	}
 
 	return 0;
 }
 
-static int debugfs_apply_options(struct super_block *sb)
+static void _debugfs_apply_options(struct super_block *sb, bool remount)
 {
 	struct debugfs_fs_info *fsi = sb->s_fs_info;
 	struct inode *inode = d_inode(sb->s_root);
 	struct debugfs_mount_opts *opts = &fsi->mount_opts;
 
-	inode->i_mode &= ~S_IALLUGO;
-	inode->i_mode |= opts->mode;
+	/*
+	 * On remount, only reset mode/uid/gid if they were provided as mount
+	 * options.
+	 */
 
-	inode->i_uid = opts->uid;
-	inode->i_gid = opts->gid;
+	if (!remount || opts->opts & BIT(Opt_mode)) {
+		inode->i_mode &= ~S_IALLUGO;
+		inode->i_mode |= opts->mode;
+	}
 
-	return 0;
+	if (!remount || opts->opts & BIT(Opt_uid))
+		inode->i_uid = opts->uid;
+
+	if (!remount || opts->opts & BIT(Opt_gid))
+		inode->i_gid = opts->gid;
+}
+
+static void debugfs_apply_options(struct super_block *sb)
+{
+	_debugfs_apply_options(sb, false);
+}
+
+static void debugfs_apply_options_remount(struct super_block *sb)
+{
+	_debugfs_apply_options(sb, true);
 }
 
 static int debugfs_remount(struct super_block *sb, int *flags, char *data)
···
 	if (err)
 		goto fail;
 
-	debugfs_apply_options(sb);
+	debugfs_apply_options_remount(sb);
 
 fail:
 	return err;

fs/kernfs/dir.c

···
 	lockdep_assert_held_write(&root->kernfs_rwsem);
 	WARN_ON_ONCE(kernfs_active(kn));
 
+	/*
+	 * Skip draining if already fully drained. This avoids draining and its
+	 * lockdep annotations for nodes which have never been activated
+	 * allowing embedding kernfs_remove() in create error paths without
+	 * worrying about draining.
+	 */
+	if (atomic_read(&kn->active) == KN_DEACTIVATED_BIAS &&
+	    !kernfs_should_drain_open_files(kn))
+		return;
+
 	up_write(&root->kernfs_rwsem);
 
 	if (kernfs_lockdep(kn)) {
···
 			lock_contended(&kn->dep_map, _RET_IP_);
 	}
 
-	/* but everyone should wait for draining */
 	wait_event(root->deactivate_waitq,
 		   atomic_read(&kn->active) == KN_DEACTIVATED_BIAS);
 
···
 		rwsem_release(&kn->dep_map, _RET_IP_);
 	}
 
-	kernfs_drain_open_files(kn);
+	if (kernfs_should_drain_open_files(kn))
+		kernfs_drain_open_files(kn);
 
 	down_write(&root->kernfs_rwsem);
 }
···
 			goto err_unlock;
 	}
 
-	/*
-	 * ACTIVATED is protected with kernfs_mutex but it was clear when
-	 * @kn was added to idr and we just wanna see it set.  No need to
-	 * grab kernfs_mutex.
-	 */
-	if (unlikely(!(kn->flags & KERNFS_ACTIVATED) ||
-		     !atomic_inc_not_zero(&kn->count)))
+	if (unlikely(!kernfs_active(kn) || !atomic_inc_not_zero(&kn->count)))
 		goto err_unlock;
 
 	spin_unlock(&kernfs_idr_lock);
···
 		goto out_unlock;
 
 	ret = -ENOENT;
-	if (parent->flags & KERNFS_EMPTY_DIR)
-		goto out_unlock;
-
-	if ((parent->flags & KERNFS_ACTIVATED) && !kernfs_active(parent))
+	if (parent->flags & (KERNFS_REMOVING | KERNFS_EMPTY_DIR))
 		goto out_unlock;
 
 	kn->hash = kernfs_name_hash(kn->name, kn->ns);
···
 	return pos->parent;
 }
 
+static void kernfs_activate_one(struct kernfs_node *kn)
+{
+	lockdep_assert_held_write(&kernfs_root(kn)->kernfs_rwsem);
+
+	kn->flags |= KERNFS_ACTIVATED;
+
+	if (kernfs_active(kn) || (kn->flags & (KERNFS_HIDDEN | KERNFS_REMOVING)))
+		return;
+
+	WARN_ON_ONCE(kn->parent && RB_EMPTY_NODE(&kn->rb));
+	WARN_ON_ONCE(atomic_read(&kn->active) != KN_DEACTIVATED_BIAS);
+
+	atomic_sub(KN_DEACTIVATED_BIAS, &kn->active);
+}
+
 /**
  * kernfs_activate - activate a node which started deactivated
  * @kn: kernfs_node whose subtree is to be activated
···
 	down_write(&root->kernfs_rwsem);
 
 	pos = NULL;
-	while ((pos = kernfs_next_descendant_post(pos, kn))) {
-		if (pos->flags & KERNFS_ACTIVATED)
-			continue;
+	while ((pos = kernfs_next_descendant_post(pos, kn)))
+		kernfs_activate_one(pos);
 
-		WARN_ON_ONCE(pos->parent && RB_EMPTY_NODE(&pos->rb));
-		WARN_ON_ONCE(atomic_read(&pos->active) != KN_DEACTIVATED_BIAS);
+	up_write(&root->kernfs_rwsem);
+}
 
-		atomic_sub(KN_DEACTIVATED_BIAS, &pos->active);
-		pos->flags |= KERNFS_ACTIVATED;
+/**
+ * kernfs_show - show or hide a node
+ * @kn: kernfs_node to show or hide
+ * @show: whether to show or hide
+ *
+ * If @show is %false, @kn is marked hidden and deactivated. A hidden node is
+ * ignored in future activaitons. If %true, the mark is removed and activation
+ * state is restored. This function won't implicitly activate a new node in a
+ * %KERNFS_ROOT_CREATE_DEACTIVATED root which hasn't been activated yet.
+ *
+ * To avoid recursion complexities, directories aren't supported for now.
+ */
+void kernfs_show(struct kernfs_node *kn, bool show)
+{
+	struct kernfs_root *root = kernfs_root(kn);
+
+	if (WARN_ON_ONCE(kernfs_type(kn) == KERNFS_DIR))
+		return;
+
+	down_write(&root->kernfs_rwsem);
+
+	if (show) {
+		kn->flags &= ~KERNFS_HIDDEN;
+		if (kn->flags & KERNFS_ACTIVATED)
+			kernfs_activate_one(kn);
+	} else {
+		kn->flags |= KERNFS_HIDDEN;
+		if (kernfs_active(kn))
+			atomic_add(KN_DEACTIVATED_BIAS, &kn->active);
+		kernfs_drain(kn);
 	}
 
 	up_write(&root->kernfs_rwsem);
···
 
 	pr_debug("kernfs %s: removing\n", kn->name);
 
-	/* prevent any new usage under @kn by deactivating all nodes */
+	/* prevent new usage by marking all nodes removing and deactivating */
 	pos = NULL;
-	while ((pos = kernfs_next_descendant_post(pos, kn)))
+	while ((pos = kernfs_next_descendant_post(pos, kn))) {
+		pos->flags |= KERNFS_REMOVING;
 		if (kernfs_active(pos))
 			atomic_add(KN_DEACTIVATED_BIAS, &pos->active);
+	}
 
 	/* deactivate and unlink the subtree node-by-node */
 	do {
 		pos = kernfs_leftmost_descendant(kn);
 
 		/*
-		 * kernfs_drain() drops kernfs_rwsem temporarily and @pos's
+		 * kernfs_drain() may drop kernfs_rwsem temporarily and @pos's
 		 * base ref could have been put by someone else by the time
 		 * the function returns.  Make sure it doesn't go away
 		 * underneath us.
 		 */
 		kernfs_get(pos);
 
-		/*
-		 * Drain iff @kn was activated.  This avoids draining and
-		 * its lockdep annotations for nodes which have never been
-		 * activated and allows embedding kernfs_remove() in create
-		 * error paths without worrying about draining.
-		 */
-		if (kn->flags & KERNFS_ACTIVATED)
-			kernfs_drain(pos);
-		else
-			WARN_ON_ONCE(atomic_read(&kn->active) != KN_DEACTIVATED_BIAS);
+		kernfs_drain(pos);
 
 		/*
 		 * kernfs_unlink_sibling() succeeds once per node.  Use it
···
 	down_write(&root->kernfs_rwsem);
 
 	kn = kernfs_find_ns(parent, name, ns);
-	if (kn)
+	if (kn) {
+		kernfs_get(kn);
 		__kernfs_remove(kn);
+		kernfs_put(kn);
+	}
 
 	up_write(&root->kernfs_rwsem);
 

fs/kernfs/file.c

···
 	atomic_t		event;
 	wait_queue_head_t	poll;
 	struct list_head	files; /* goes through kernfs_open_file.list */
+	unsigned int		nr_mmapped;
+	unsigned int		nr_to_release;
 };
 
 /*
···
 }
 
 /**
- * kernfs_deref_open_node - Get kernfs_open_node corresponding to @kn.
- *
- * @of: associated kernfs_open_file instance.
- * @kn: target kernfs_node.
- *
- * Fetch and return ->attr.open of @kn if @of->list is non empty.
- * If @of->list is not empty we can safely assume that @of is on
- * @kn->attr.open->files list and this guarantees that @kn->attr.open
- * will not vanish i.e. dereferencing outside RCU read-side critical
- * section is safe here.
- *
- * The caller needs to make sure that @of->list is not empty.
+ * of_on - Return the kernfs_open_node of the specified kernfs_open_file
+ * @of: taret kernfs_open_file
  */
-static struct kernfs_open_node *
-kernfs_deref_open_node(struct kernfs_open_file *of, struct kernfs_node *kn)
+static struct kernfs_open_node *of_on(struct kernfs_open_file *of)
 {
-	struct kernfs_open_node *on;
-
-	on = rcu_dereference_check(kn->attr.open, !list_empty(&of->list));
-
-	return on;
+	return rcu_dereference_protected(of->kn->attr.open,
+					 !list_empty(&of->list));
 }
 
 /**
- * kernfs_deref_open_node_protected - Get kernfs_open_node corresponding to @kn
+ * kernfs_deref_open_node_locked - Get kernfs_open_node corresponding to @kn
  *
  * @kn: target kernfs_node.
  *
···
  * The caller needs to make sure that kernfs_open_file_mutex is held.
  */
 static struct kernfs_open_node *
-kernfs_deref_open_node_protected(struct kernfs_node *kn)
+kernfs_deref_open_node_locked(struct kernfs_node *kn)
 {
 	return rcu_dereference_protected(kn->attr.open,
 				lockdep_is_held(kernfs_open_file_mutex_ptr(kn)));
···
 static int kernfs_seq_show(struct seq_file *sf, void *v)
 {
 	struct kernfs_open_file *of = sf->private;
-	struct kernfs_open_node *on = kernfs_deref_open_node(of, of->kn);
 
-	if (!on)
-		return -EINVAL;
-
-	of->event = atomic_read(&on->event);
+	of->event = atomic_read(&of_on(of)->event);
 
 	return of->kn->attr.ops->seq_show(sf, v);
 }
···
 	struct kernfs_open_file *of = kernfs_of(iocb->ki_filp);
 	ssize_t len = min_t(size_t, iov_iter_count(iter), PAGE_SIZE);
 	const struct kernfs_ops *ops;
-	struct kernfs_open_node *on;
 	char *buf;
 
 	buf = of->prealloc_buf;
···
 		goto out_free;
 	}
 
-	on = kernfs_deref_open_node(of, of->kn);
-	if (!on) {
-		len = -EINVAL;
-		mutex_unlock(&of->mutex);
-		goto out_free;
-	}
-
-	of->event = atomic_read(&on->event);
+	of->event = atomic_read(&of_on(of)->event);
 
 	ops = kernfs_ops(of->kn);
 	if (ops->read)
···
 
 	rc = 0;
 	of->mmapped = true;
+	of_on(of)->nr_mmapped++;
 	of->vm_ops = vma->vm_ops;
 	vma->vm_ops = &kernfs_vm_ops;
 out_put:
···
 static int kernfs_get_open_node(struct kernfs_node *kn,
 				struct kernfs_open_file *of)
 {
-	struct kernfs_open_node *on, *new_on = NULL;
-	struct mutex *mutex = NULL;
+	struct kernfs_open_node *on;
+	struct mutex *mutex;
 
 	mutex = kernfs_open_file_mutex_lock(kn);
-	on = kernfs_deref_open_node_protected(kn);
+	on = kernfs_deref_open_node_locked(kn);
 
-	if (on) {
-		list_add_tail(&of->list, &on->files);
-		mutex_unlock(mutex);
-		return 0;
-	} else {
+	if (!on) {
 		/* not there, initialize a new one */
-		new_on = kmalloc(sizeof(*new_on), GFP_KERNEL);
-		if (!new_on) {
+		on = kzalloc(sizeof(*on), GFP_KERNEL);
+		if (!on) {
 			mutex_unlock(mutex);
 			return -ENOMEM;
 		}
-		atomic_set(&new_on->event, 1);
-		init_waitqueue_head(&new_on->poll);
-		INIT_LIST_HEAD(&new_on->files);
-		list_add_tail(&of->list, &new_on->files);
-		rcu_assign_pointer(kn->attr.open, new_on);
+		atomic_set(&on->event, 1);
+		init_waitqueue_head(&on->poll);
+		INIT_LIST_HEAD(&on->files);
+		rcu_assign_pointer(kn->attr.open, on);
 	}
-	mutex_unlock(mutex);
 
+	list_add_tail(&of->list, &on->files);
+	if (kn->flags & KERNFS_HAS_RELEASE)
+		on->nr_to_release++;
+
+	mutex_unlock(mutex);
 	return 0;
 }
 
···
  *
  *	@kn: target kernfs_node
  *	@of: associated kernfs_open_file
+ *	@open_failed: ->open() failed, cancel ->release()
  *
  *	Unlink @of from list of @kn's associated open files. If list of
  *	associated open files becomes empty, disassociate and free
···
  *	None.
  */
 static void kernfs_unlink_open_file(struct kernfs_node *kn,
-				 struct kernfs_open_file *of)
+				    struct kernfs_open_file *of,
+				    bool open_failed)
 {
 	struct kernfs_open_node *on;
-	struct mutex *mutex = NULL;
+	struct mutex *mutex;
 
 	mutex = kernfs_open_file_mutex_lock(kn);
 
-	on = kernfs_deref_open_node_protected(kn);
+	on = kernfs_deref_open_node_locked(kn);
 	if (!on) {
 		mutex_unlock(mutex);
 		return;
 	}
 
-	if (of)
+	if (of) {
+		if (kn->flags & KERNFS_HAS_RELEASE) {
+			WARN_ON_ONCE(of->released == open_failed);
+			if (open_failed)
+				on->nr_to_release--;
+		}
+		if (of->mmapped)
+			on->nr_mmapped--;
 		list_del(&of->list);
+	}
 
 	if (list_empty(&on->files)) {
 		rcu_assign_pointer(kn->attr.open, NULL);
···
 	return 0;
 
 err_put_node:
-	kernfs_unlink_open_file(kn, of);
+	kernfs_unlink_open_file(kn, of, true);
 err_seq_release:
 	seq_release(inode, file);
 err_free:
···
 		 */
 		kn->attr.ops->release(of);
 		of->released = true;
+		of_on(of)->nr_to_release--;
 	}
 }
 
···
 {
 	struct kernfs_node *kn = inode->i_private;
 	struct kernfs_open_file *of = kernfs_of(filp);
-	struct mutex *mutex = NULL;
 
 	if (kn->flags & KERNFS_HAS_RELEASE) {
+		struct mutex *mutex;
+
 		mutex = kernfs_open_file_mutex_lock(kn);
 		kernfs_release_file(kn, of);
 		mutex_unlock(mutex);
 	}
 
-	kernfs_unlink_open_file(kn, of);
+	kernfs_unlink_open_file(kn, of, false);
 	seq_release(inode, filp);
 	kfree(of->prealloc_buf);
 	kfree(of);
···
 	return 0;
 }
 
+bool kernfs_should_drain_open_files(struct kernfs_node *kn)
+{
+	struct kernfs_open_node *on;
+	bool ret;
+
+	/*
+	 * @kn being deactivated guarantees that @kn->attr.open can't change
+	 * beneath us making the lockless test below safe.
+	 */
+	WARN_ON_ONCE(atomic_read(&kn->active) != KN_DEACTIVATED_BIAS);
+
+	rcu_read_lock();
+	on = rcu_dereference(kn->attr.open);
+	ret = on && (on->nr_mmapped || on->nr_to_release);
+	rcu_read_unlock();
+
+	return ret;
+}
+
 void kernfs_drain_open_files(struct kernfs_node *kn)
 {
 	struct kernfs_open_node *on;
 	struct kernfs_open_file *of;
-	struct mutex *mutex = NULL;
-
-	if (!(kn->flags & (KERNFS_HAS_MMAP | KERNFS_HAS_RELEASE)))
-		return;
-
-	/*
-	 * lockless opportunistic check is safe below because no one is adding to
-	 * ->attr.open at this point of time. This check allows early bail out
-	 * if ->attr.open is already NULL. kernfs_unlink_open_file makes
-	 * ->attr.open NULL only while holding kernfs_open_file_mutex so below
-	 * check under kernfs_open_file_mutex_ptr(kn) will ensure bailing out if
-	 * ->attr.open became NULL while waiting for the mutex.
-	 */
-	if (!rcu_access_pointer(kn->attr.open))
-		return;
+	struct mutex *mutex;
 
 	mutex = kernfs_open_file_mutex_lock(kn);
-	on = kernfs_deref_open_node_protected(kn);
+	on = kernfs_deref_open_node_locked(kn);
 	if (!on) {
 		mutex_unlock(mutex);
 		return;
···
 	list_for_each_entry(of, &on->files, list) {
 		struct inode *inode = file_inode(of->file);
 
-		if (kn->flags & KERNFS_HAS_MMAP)
+		if (of->mmapped) {
 			unmap_mapping_range(inode->i_mapping, 0, 0, 1);
+			of->mmapped = false;
+			on->nr_mmapped--;
+		}
 
 		if (kn->flags & KERNFS_HAS_RELEASE)
 			kernfs_release_file(kn, of);
 	}
 
+	WARN_ON_ONCE(on->nr_mmapped || on->nr_to_release);
 	mutex_unlock(mutex);
 }
 
···
  */
 __poll_t kernfs_generic_poll(struct kernfs_open_file *of, poll_table *wait)
 {
-	struct kernfs_node *kn = kernfs_dentry_node(of->file->f_path.dentry);
-	struct kernfs_open_node *on = kernfs_deref_open_node(of, kn);
-
-	if (!on)
-		return EPOLLERR;
+	struct kernfs_open_node *on = of_on(of);
 
 	poll_wait(of->file, &on->poll, wait);
 

fs/kernfs/kernfs-internal.h

···
  */
 extern const struct file_operations kernfs_file_fops;
 
+bool kernfs_should_drain_open_files(struct kernfs_node *kn);
 void kernfs_drain_open_files(struct kernfs_node *kn);
 
 /*

include/asm-generic/vmlinux.lds.h

···
 	*(__tracepoints)						\
 	/* implement dynamic printk debug */				\
 	. = ALIGN(8);							\
+	__start___dyndbg_classes = .;					\
+	KEEP(*(__dyndbg_classes))					\
+	__stop___dyndbg_classes = .;					\
 	__start___dyndbg = .;						\
 	KEEP(*(__dyndbg))						\
 	__stop___dyndbg = .;						\

include/drm/drm_print.h

···
 #include <linux/seq_file.h>
 #include <linux/device.h>
 #include <linux/debugfs.h>
+#include <linux/dynamic_debug.h>
 
 #include <drm/drm.h>
 
 /* Do *not* use outside of drm_print.[ch]! */
-extern unsigned int __drm_debug;
+extern unsigned long __drm_debug;
 
 /**
  * DOC: print
···
  *
  */
 enum drm_debug_category {
+	/* These names must match those in DYNAMIC_DEBUG_CLASSBITS */
 	/**
 	 * @DRM_UT_CORE: Used in the generic drm code: drm_ioctl.c, drm_mm.c,
 	 * drm_memory.c, ...
 	 */
-	DRM_UT_CORE		= 0x01,
+	DRM_UT_CORE,
 	/**
 	 * @DRM_UT_DRIVER: Used in the vendor specific part of the driver: i915,
 	 * radeon, ... macro.
 	 */
-	DRM_UT_DRIVER		= 0x02,
+	DRM_UT_DRIVER,
 	/**
 	 * @DRM_UT_KMS: Used in the modesetting code.
 	 */
-	DRM_UT_KMS		= 0x04,
+	DRM_UT_KMS,
 	/**
 	 * @DRM_UT_PRIME: Used in the prime code.
 	 */
-	DRM_UT_PRIME		= 0x08,
+	DRM_UT_PRIME,
 	/**
 	 * @DRM_UT_ATOMIC: Used in the atomic code.
 	 */
-	DRM_UT_ATOMIC		= 0x10,
+	DRM_UT_ATOMIC,
 	/**
 	 * @DRM_UT_VBL: Used for verbose debug message in the vblank code.
 	 */
-	DRM_UT_VBL		= 0x20,
+	DRM_UT_VBL,
 	/**
 	 * @DRM_UT_STATE: Used for verbose atomic state debugging.
 	 */
-	DRM_UT_STATE		= 0x40,
+	DRM_UT_STATE,
 	/**
 	 * @DRM_UT_LEASE: Used in the lease code.
 	 */
-	DRM_UT_LEASE		= 0x80,
+	DRM_UT_LEASE,
 	/**
 	 * @DRM_UT_DP: Used in the DP code.
 	 */
-	DRM_UT_DP		= 0x100,
+	DRM_UT_DP,
 	/**
 	 * @DRM_UT_DRMRES: Used in the drm managed resources code.
 	 */
-	DRM_UT_DRMRES		= 0x200,
+	DRM_UT_DRMRES
 };
 
-static inline bool drm_debug_enabled(enum drm_debug_category category)
+static inline bool drm_debug_enabled_raw(enum drm_debug_category category)
 {
-	return unlikely(__drm_debug & category);
+	return unlikely(__drm_debug & BIT(category));
 }
+
+#define drm_debug_enabled_instrumented(category)			\
+	({								\
+		pr_debug("todo: is this frequent enough to optimize ?\n"); \
+		drm_debug_enabled_raw(category);			\
+	})
+
+#if defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
+/*
+ * the drm.debug API uses dyndbg, so each drm_*dbg macro/callsite gets
+ * a descriptor, and only enabled callsites are reachable.  They use
+ * the private macro to avoid re-testing the enable-bit.
+ */
+#define __drm_debug_enabled(category)	true
+#define drm_debug_enabled(category)	drm_debug_enabled_instrumented(category)
+#else
+#define __drm_debug_enabled(category)	drm_debug_enabled_raw(category)
+#define drm_debug_enabled(category)	drm_debug_enabled_raw(category)
+#endif
 
 /*
  * struct device based logging
···
 __printf(3, 4)
 void drm_dev_printk(const struct device *dev, const char *level,
 		    const char *format, ...);
-__printf(3, 4)
-void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
-		 const char *format, ...);
+struct _ddebug;
+__printf(4, 5)
+void __drm_dev_dbg(struct _ddebug *desc, const struct device *dev,
+		   enum drm_debug_category category, const char *format, ...);
 
 /**
  * DRM_DEV_ERROR() - Error output.
···
 		DRM_DEV_INFO(dev, fmt, ##__VA_ARGS__);			\
 	}								\
 })
+
+#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
+#define drm_dev_dbg(dev, cat, fmt, ...)				\
+	__drm_dev_dbg(NULL, dev, cat, fmt, ##__VA_ARGS__)
+#else
+#define drm_dev_dbg(dev, cat, fmt, ...)				\
+	_dynamic_func_call_cls(cat, fmt, __drm_dev_dbg,		\
+			       dev, cat, fmt, ##__VA_ARGS__)
+#endif
 
 /**
  * DRM_DEV_DEBUG() - Debug output for generic drm code
···
 
 #define drm_dbg_core(drm, fmt, ...)					\
 	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_CORE, fmt, ##__VA_ARGS__)
-#define drm_dbg(drm, fmt, ...)						\
+#define drm_dbg_driver(drm, fmt, ...)						\
 	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DRIVER, fmt, ##__VA_ARGS__)
 #define drm_dbg_kms(drm, fmt, ...)					\
 	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_KMS, fmt, ##__VA_ARGS__)
···
 #define drm_dbg_drmres(drm, fmt, ...)					\
 	drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DRMRES, fmt, ##__VA_ARGS__)
 
+#define drm_dbg(drm, fmt, ...)	drm_dbg_driver(drm, fmt, ##__VA_ARGS__)
 
 /*
  * printk based logging
···
  * Prefer drm_device based logging over device or prink based logging.
  */
 
-__printf(2, 3)
-void __drm_dbg(enum drm_debug_category category, const char *format, ...);
+__printf(3, 4)
+void ___drm_dbg(struct _ddebug *desc, enum drm_debug_category category, const char *format, ...);
 __printf(1, 2)
 void __drm_err(const char *format, ...);
+
+#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
+#define __drm_dbg(fmt, ...)		___drm_dbg(NULL, fmt, ##__VA_ARGS__)
+#else
+#define __drm_dbg(cat, fmt, ...)					\
+	_dynamic_func_call_cls(cat, fmt, ___drm_dbg,			\
+			       cat, fmt, ##__VA_ARGS__)
+#endif
 
 /* Macros to make printk easier */
 

include/linux/cgroup.h

···
 int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
 int cgroup_rm_cftypes(struct cftype *cfts);
 void cgroup_file_notify(struct cgroup_file *cfile);
+void cgroup_file_show(struct cgroup_file *cfile, bool show);
 
 int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen);
 int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry);

include/linux/dynamic_debug.h

···
 #include <linux/jump_label.h>
 #endif
 
+#include <linux/build_bug.h>
+
 /*
  * An instance of this structure is created in a special
  * ELF section at every dynamic debug callsite.  At runtime,
···
 	const char *filename;
 	const char *format;
 	unsigned int lineno:18;
+#define CLS_BITS 6
+	unsigned int class_id:CLS_BITS;
+#define _DPRINTK_CLASS_DFLT		((1 << CLS_BITS) - 1)
 	/*
 	 * The flags field controls the behaviour at the callsite.
 	 * The bits here are changed dynamically when the user
···
 #endif
 } __attribute__((aligned(8)));
 
+enum class_map_type {
+	DD_CLASS_TYPE_DISJOINT_BITS,
+	/**
+	 * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, one per bit.
+	 * expecting hex input. Built for drm.debug, basis for other types.
+	 */
+	DD_CLASS_TYPE_LEVEL_NUM,
+	/**
+	 * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0-N.
+	 * N turns on just bits N-1 .. 0, so N=0 turns all bits off.
+	 */
+	DD_CLASS_TYPE_DISJOINT_NAMES,
+	/**
+	 * DD_CLASS_TYPE_DISJOINT_NAMES: input is a CSV of [+-]CLASS_NAMES,
+	 * classes are independent, like _DISJOINT_BITS.
+	 */
+	DD_CLASS_TYPE_LEVEL_NAMES,
+	/**
+	 * DD_CLASS_TYPE_LEVEL_NAMES: input is a CSV of [+-]CLASS_NAMES,
+	 * intended for names like: INFO,DEBUG,TRACE, with a module prefix
+	 * avoid EMERG,ALERT,CRIT,ERR,WARNING: they're not debug
+	 */
+};
 
+struct ddebug_class_map {
+	struct list_head link;
+	struct module *mod;
+	const char *mod_name;	/* needed for builtins */
+	const char **class_names;
+	const int length;
+	const int base;		/* index of 1st .class_id, allows split/shared space */
+	enum class_map_type map_type;
+};
+
+/**
+ * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
+ * @_var:   a struct ddebug_class_map, passed to module_param_cb
+ * @_type:  enum class_map_type, chooses bits/verbose, numeric/symbolic
+ * @_base:  offset of 1st class-name. splits .class_id space
+ * @classes: class-names used to control class'd prdbgs
+ */
+#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...)		\
+	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
+	static struct ddebug_class_map __aligned(8) __used		\
+		__section("__dyndbg_classes") _var = {			\
+		.mod = THIS_MODULE,					\
+		.mod_name = KBUILD_MODNAME,				\
+		.base = _base,						\
+		.map_type = _maptype,					\
+		.length = NUM_TYPE_ARGS(char*, __VA_ARGS__),		\
+		.class_names = _var##_classnames,			\
+	}
+#define NUM_TYPE_ARGS(eltype, ...)				\
+        (sizeof((eltype[]){__VA_ARGS__}) / sizeof(eltype))
+
+/* encapsulate linker provided built-in (or module) dyndbg data */
+struct _ddebug_info {
+	struct _ddebug *descs;
+	struct ddebug_class_map *classes;
+	unsigned int num_descs;
+	unsigned int num_classes;
+};
+
+struct ddebug_class_param {
+	union {
+		unsigned long *bits;
+		unsigned int *lvl;
+	};
+	char flags[8];
+	const struct ddebug_class_map *map;
+};
 
 #if defined(CONFIG_DYNAMIC_DEBUG_CORE)
 
-/* exported for module authors to exercise >control */
-int dynamic_debug_exec_queries(const char *query, const char *modname);
+int ddebug_add_module(struct _ddebug_info *dyndbg, const char *modname);
 
-int ddebug_add_module(struct _ddebug *tab, unsigned int n,
-				const char *modname);
 extern int ddebug_remove_module(const char *mod_name);
 extern __printf(2, 3)
 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
···
 			 const struct ib_device *ibdev,
 			 const char *fmt, ...);
 
-#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)		\
+#define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt)	\
 	static struct _ddebug  __aligned(8)			\
 	__section("__dyndbg") name = {				\
 		.modname = KBUILD_MODNAME,			\
···
 		.format = (fmt),				\
 		.lineno = __LINE__,				\
 		.flags = _DPRINTK_FLAGS_DEFAULT,		\
+		.class_id = cls,				\
 		_DPRINTK_KEY_INIT				\
-	}
+	};							\
+	BUILD_BUG_ON_MSG(cls > _DPRINTK_CLASS_DFLT,		\
+			 "classid value overflow")
+
+#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)		\
+	DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, _DPRINTK_CLASS_DFLT, fmt)
 
 #ifdef CONFIG_JUMP_LABEL
 
···
 
 #endif /* CONFIG_JUMP_LABEL */
 
-#define __dynamic_func_call(id, fmt, func, ...) do {	\
-	DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt);		\
-	if (DYNAMIC_DEBUG_BRANCH(id))			\
-		func(&id, ##__VA_ARGS__);		\
-} while (0)
-
-#define __dynamic_func_call_no_desc(id, fmt, func, ...) do {	\
-	DEFINE_DYNAMIC_DEBUG_METADATA(id, fmt);			\
+/*
+ * Factory macros: ($prefix)dynamic_func_call($suffix)
+ *
+ * Lower layer (with __ prefix) gets the callsite metadata, and wraps
+ * the func inside a debug-branch/static-key construct.  Upper layer
+ * (with _ prefix) does the UNIQUE_ID once, so that lower can ref the
+ * name/label multiple times, and tie the elements together.
+ * Multiple flavors:
+ * (|_cls):	adds in _DPRINT_CLASS_DFLT as needed
+ * (|_no_desc):	former gets callsite descriptor as 1st arg (for prdbgs)
+ */
+#define __dynamic_func_call_cls(id, cls, fmt, func, ...) do {	\
+	DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt);	\
 	if (DYNAMIC_DEBUG_BRANCH(id))				\
-		func(__VA_ARGS__);				\
+		func(&id, ##__VA_ARGS__);			\
 } while (0)
+#define __dynamic_func_call(id, fmt, func, ...)				\
+	__dynamic_func_call_cls(id, _DPRINTK_CLASS_DFLT, fmt,		\
+				func, ##__VA_ARGS__)
+
+#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) do {	\
+	DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt);		\
+	if (DYNAMIC_DEBUG_BRANCH(id))					\
+		func(__VA_ARGS__);					\
+} while (0)
+#define __dynamic_func_call_no_desc(id, fmt, func, ...)			\
+	__dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT,	\
+					fmt, func, ##__VA_ARGS__)
 
 /*
  * "Factory macro" for generating a call to func, guarded by a
···
  * the varargs. Note that fmt is repeated in invocations of this
  * macro.
  */
+#define _dynamic_func_call_cls(cls, fmt, func, ...)			\
+	__dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__)
 #define _dynamic_func_call(fmt, func, ...)				\
-	__dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
+	_dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__)
+
 /*
  * A variant that does the same, except that the descriptor is not
  * passed as the first argument to the function; it is only called
  * with precisely the macro's varargs.
  */
-#define _dynamic_func_call_no_desc(fmt, func, ...)	\
-	__dynamic_func_call_no_desc(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
+#define _dynamic_func_call_cls_no_desc(cls, fmt, func, ...)		\
+	__dynamic_func_call_cls_no_desc(__UNIQUE_ID(ddebug), cls, fmt,	\
+					func, ##__VA_ARGS__)
+#define _dynamic_func_call_no_desc(fmt, func, ...)			\
+	_dynamic_func_call_cls_no_desc(_DPRINTK_CLASS_DFLT, fmt,	\
+				       func, ##__VA_ARGS__)
+
+#define dynamic_pr_debug_cls(cls, fmt, ...)				\
+	_dynamic_func_call_cls(cls, fmt, __dynamic_pr_debug,		\
+			   pr_fmt(fmt), ##__VA_ARGS__)
 
 #define dynamic_pr_debug(fmt, ...)				\
-	_dynamic_func_call(fmt,	__dynamic_pr_debug,		\
+	_dynamic_func_call(fmt, __dynamic_pr_debug,		\
 			   pr_fmt(fmt), ##__VA_ARGS__)
 
 #define dynamic_dev_dbg(dev, fmt, ...)				\
-	_dynamic_func_call(fmt,__dynamic_dev_dbg, 		\
+	_dynamic_func_call(fmt, __dynamic_dev_dbg, 		\
 			   dev, fmt, ##__VA_ARGS__)
 
 #define dynamic_netdev_dbg(dev, fmt, ...)			\
···
 				   KERN_DEBUG, prefix_str, prefix_type,	\
 				   rowsize, groupsize, buf, len, ascii)
 
+struct kernel_param;
+int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp);
+int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp);
+
+/* for test only, generally expect drm.debug style macro wrappers */
+#define __pr_debug_cls(cls, fmt, ...) do {			\
+	BUILD_BUG_ON_MSG(!__builtin_constant_p(cls),		\
+			 "expecting constant class int/enum");	\
+	dynamic_pr_debug_cls(cls, fmt, ##__VA_ARGS__);		\
+	} while (0)
+
 #else /* !CONFIG_DYNAMIC_DEBUG_CORE */
 
 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/printk.h>
 
-static inline int ddebug_add_module(struct _ddebug *tab, unsigned int n,
-				    const char *modname)
+static inline int ddebug_add_module(struct _ddebug_info *dinfo, const char *modname)
 {
 	return 0;
 }
···
 static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
 						const char *modname)
 {
-	if (strstr(param, "dyndbg")) {
+	if (!strcmp(param, "dyndbg")) {
 		/* avoid pr_warn(), which wants pr_fmt() fully defined */
 		printk(KERN_WARNING "dyndbg param is supported only in "
 			"CONFIG_DYNAMIC_DEBUG builds\n");
···
 				rowsize, groupsize, buf, len, ascii);	\
 	} while (0)
 
-static inline int dynamic_debug_exec_queries(const char *query, const char *modname)
-{
-	pr_warn("kernel not built with CONFIG_DYNAMIC_DEBUG_CORE\n");
-	return 0;
-}
+struct kernel_param;
+static inline int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
+{ return 0; }
+static inline int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
+{ return 0; }
 
 #endif /* !CONFIG_DYNAMIC_DEBUG_CORE */
+
+extern const struct kernel_param_ops param_ops_dyndbg_classes;
 
 #endif

include/linux/io.h

···
 				   resource_size_t size);
 void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
 				   resource_size_t size);
-void __iomem *devm_ioremap_np(struct device *dev, resource_size_t offset,
-				   resource_size_t size);
 void devm_iounmap(struct device *dev, void __iomem *addr);
 int check_signature(const volatile void __iomem *io_addr,
 			const unsigned char *signature, int length);

include/linux/kernfs.h

···
 	KERNFS_HAS_SEQ_SHOW	= 0x0040,
 	KERNFS_HAS_MMAP		= 0x0080,
 	KERNFS_LOCKDEP		= 0x0100,
+	KERNFS_HIDDEN		= 0x0200,
 	KERNFS_SUICIDAL		= 0x0400,
 	KERNFS_SUICIDED		= 0x0800,
 	KERNFS_EMPTY_DIR	= 0x1000,
 	KERNFS_HAS_RELEASE	= 0x2000,
+	KERNFS_REMOVING		= 0x4000,
 };
 
 /* @flags for kernfs_create_root() */
···
 				       const char *name,
 				       struct kernfs_node *target);
 void kernfs_activate(struct kernfs_node *kn);
+void kernfs_show(struct kernfs_node *kn, bool show);
 void kernfs_remove(struct kernfs_node *kn);
 void kernfs_break_active_protection(struct kernfs_node *kn);
 void kernfs_unbreak_active_protection(struct kernfs_node *kn);

include/linux/property.h

···
 	DEV_DMA_COHERENT,
 };
 
-struct fwnode_handle *dev_fwnode(struct device *dev);
+struct fwnode_handle *dev_fwnode(const struct device *dev);
 
 bool device_property_present(struct device *dev, const char *propname);
 int device_property_read_u8_array(struct device *dev, const char *propname,
···
 
 enum dev_dma_attr device_get_dma_attr(struct device *dev);
 
-const void *device_get_match_data(struct device *dev);
+const void *device_get_match_data(const struct device *dev);
 
 int device_get_phy_mode(struct device *dev);
 int fwnode_get_phy_mode(struct fwnode_handle *fwnode);

kernel/cgroup/cgroup.c

···
 }
 
 /**
+ * cgroup_file_show - show or hide a hidden cgroup file
+ * @cfile: target cgroup_file obtained by setting cftype->file_offset
+ * @show: whether to show or hide
+ */
+void cgroup_file_show(struct cgroup_file *cfile, bool show)
+{
+	struct kernfs_node *kn;
+
+	spin_lock_irq(&cgroup_file_kn_lock);
+	kn = cfile->kn;
+	kernfs_get(kn);
+	spin_unlock_irq(&cgroup_file_kn_lock);
+
+	if (kn)
+		kernfs_show(kn, show);
+
+	kernfs_put(kn);
+}
+
+/**
  * css_next_child - find the next child of a given css
  * @pos: the current position (%NULL to initiate traversal)
  * @parent: css whose children to walk

kernel/module/internal.h

···
 extern const s32 __start___kcrctab[];
 extern const s32 __start___kcrctab_gpl[];
 
+#include <linux/dynamic_debug.h>
 struct load_info {
 	const char *name;
 	/* pointer to module in temporary copy, freed at end of load_module() */
···
 	Elf_Shdr *sechdrs;
 	char *secstrings, *strtab;
 	unsigned long symoffs, stroffs, init_typeoffs, core_typeoffs;
-	struct _ddebug *debug;
-	unsigned int num_debug;
+	struct _ddebug_info dyndbg;
 	bool sig_ok;
 #ifdef CONFIG_KALLSYMS
 	unsigned long mod_kallsyms_init_off;

kernel/module/main.c

···
 	}
 }
 
-static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
+static void dynamic_debug_setup(struct module *mod, struct _ddebug_info *dyndbg)
 {
-	if (!debug)
+	if (!dyndbg->num_descs)
 		return;
-	ddebug_add_module(debug, num, mod->name);
+	ddebug_add_module(dyndbg, mod->name);
 }
 
-static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
+static void dynamic_debug_remove(struct module *mod, struct _ddebug_info *dyndbg)
 {
-	if (debug)
+	if (dyndbg->num_descs)
 		ddebug_remove_module(mod->name);
 }
 
···
 	if (section_addr(info, "__obsparm"))
 		pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
 
-	info->debug = section_objs(info, "__dyndbg",
-				   sizeof(*info->debug), &info->num_debug);
+	info->dyndbg.descs = section_objs(info, "__dyndbg",
+					sizeof(*info->dyndbg.descs), &info->dyndbg.num_descs);
+	info->dyndbg.classes = section_objs(info, "__dyndbg_classes",
+					sizeof(*info->dyndbg.classes), &info->dyndbg.num_classes);
 
 	return 0;
 }
···
 	}
 
 	init_build_id(mod, info);
-	dynamic_debug_setup(mod, info->debug, info->num_debug);
+	dynamic_debug_setup(mod, &info->dyndbg);
 
 	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
 	ftrace_module_init(mod);
···
 
  ddebug_cleanup:
 	ftrace_release_mod(mod);
-	dynamic_debug_remove(mod, info->debug);
+	dynamic_debug_remove(mod, &info->dyndbg);
 	synchronize_rcu();
 	kfree(mod->args);
  free_arch_cleanup:

lib/Kconfig.debug

···
 
 	  If unsure, say N.
 
+config TEST_DYNAMIC_DEBUG
+	tristate "Test DYNAMIC_DEBUG"
+	depends on DYNAMIC_DEBUG
+	help
+	  This module registers a tracer callback to count enabled
+	  pr_debugs in a 'do_debugging' function, then alters their
+	  enablements, calls the function, and compares counts.
+
+	  If unsure, say N.
+
 config TEST_KMOD
 	tristate "kmod stress tester"
 	depends on m

lib/Makefile

···
 obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
 obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
 obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
+obj-$(CONFIG_TEST_DYNAMIC_DEBUG) += test_dynamic_debug.o
 obj-$(CONFIG_TEST_PRINTF) += test_printf.o
 obj-$(CONFIG_TEST_SCANF) += test_scanf.o
 obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o

lib/devres.c

···
 EXPORT_SYMBOL(devm_ioremap_wc);
 
 /**
- * devm_ioremap_np - Managed ioremap_np()
- * @dev: Generic device to remap IO address for
- * @offset: Resource address to map
- * @size: Size of map
- *
- * Managed ioremap_np().  Map is automatically unmapped on driver detach.
- */
-void __iomem *devm_ioremap_np(struct device *dev, resource_size_t offset,
-			      resource_size_t size)
-{
-	return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_NP);
-}
-EXPORT_SYMBOL(devm_ioremap_np);
-
-/**
  * devm_iounmap - Managed iounmap()
  * @dev: Generic device to unmap for
  * @addr: Address to unmap

lib/dynamic_debug.c

···
 
 extern struct _ddebug __start___dyndbg[];
 extern struct _ddebug __stop___dyndbg[];
+extern struct ddebug_class_map __start___dyndbg_classes[];
+extern struct ddebug_class_map __stop___dyndbg_classes[];
 
 struct ddebug_table {
-	struct list_head link;
+	struct list_head link, maps;
 	const char *mod_name;
 	unsigned int num_ddebugs;
 	struct _ddebug *ddebugs;
···
 	const char *module;
 	const char *function;
 	const char *format;
+	const char *class_string;
 	unsigned int first_lineno, last_lineno;
 };
 
 struct ddebug_iter {
 	struct ddebug_table *table;
-	unsigned int idx;
+	int idx;
 };
 
 struct flag_settings {
···
 			fmtlen--;
 	}
 
-	v3pr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u\n",
-		 msg,
-		 query->function ?: "",
-		 query->filename ?: "",
-		 query->module ?: "",
-		 fmtlen, query->format ?: "",
-		 query->first_lineno, query->last_lineno);
+	v3pr_info("%s: func=\"%s\" file=\"%s\" module=\"%s\" format=\"%.*s\" lineno=%u-%u class=%s\n",
+		  msg,
+		  query->function ?: "",
+		  query->filename ?: "",
+		  query->module ?: "",
+		  fmtlen, query->format ?: "",
+		  query->first_lineno, query->last_lineno, query->class_string);
 }
 
+static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
+							  const char *class_string, int *class_id)
+{
+	struct ddebug_class_map *map;
+	int idx;
+
+	list_for_each_entry(map, &dt->maps, link) {
+		idx = match_string(map->class_names, map->length, class_string);
+		if (idx >= 0) {
+			*class_id = idx + map->base;
+			return map;
+		}
+	}
+	*class_id = -ENOENT;
+	return NULL;
+}
+
+#define __outvar /* filled by callee */
 /*
  * Search the tables for _ddebug's which match the given `query' and
  * apply the `flags' and `mask' to them.  Returns number of matching
···
 	struct ddebug_table *dt;
 	unsigned int newflags;
 	unsigned int nfound = 0;
-	struct flagsbuf fbuf;
+	struct flagsbuf fbuf, nbuf;
+	struct ddebug_class_map *map = NULL;
+	int __outvar valid_class;
 
 	/* search for matching ddebugs */
 	mutex_lock(&ddebug_lock);
···
 		    !match_wildcard(query->module, dt->mod_name))
 			continue;
 
+		if (query->class_string) {
+			map = ddebug_find_valid_class(dt, query->class_string, &valid_class);
+			if (!map)
+				continue;
+		} else {
+			/* constrain query, do not touch class'd callsites */
+			valid_class = _DPRINTK_CLASS_DFLT;
+		}
+
 		for (i = 0; i < dt->num_ddebugs; i++) {
 			struct _ddebug *dp = &dt->ddebugs[i];
+
+			/* match site against query-class */
+			if (dp->class_id != valid_class)
+				continue;
 
 			/* match against the source filename */
 			if (query->filename &&
···
 				continue;
 #ifdef CONFIG_JUMP_LABEL
 			if (dp->flags & _DPRINTK_FLAGS_PRINT) {
-				if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT))
+				if (!(newflags & _DPRINTK_FLAGS_PRINT))
 					static_branch_disable(&dp->key.dd_key_true);
-			} else if (modifiers->flags & _DPRINTK_FLAGS_PRINT)
+			} else if (newflags & _DPRINTK_FLAGS_PRINT) {
 				static_branch_enable(&dp->key.dd_key_true);
+			}
 #endif
+			v4pr_info("changed %s:%d [%s]%s %s => %s\n",
+				  trim_prefix(dp->filename), dp->lineno,
+				  dt->mod_name, dp->function,
+				  ddebug_describe_flags(dp->flags, &fbuf),
+				  ddebug_describe_flags(newflags, &nbuf));
 			dp->flags = newflags;
-			v4pr_info("changed %s:%d [%s]%s =%s\n",
-				 trim_prefix(dp->filename), dp->lineno,
-				 dt->mod_name, dp->function,
-				 ddebug_describe_flags(dp->flags, &fbuf));
 		}
 	}
 	mutex_unlock(&ddebug_lock);
···
 		return -EINVAL;
 	}
 
-	if (modname)
-		/* support $modname.dyndbg=<multiple queries> */
-		query->module = modname;
-
 	for (i = 0; i < nwords; i += 2) {
 		char *keyword = words[i];
 		char *arg = words[i+1];
···
 		} else if (!strcmp(keyword, "line")) {
 			if (parse_linerange(query, arg))
 				return -EINVAL;
+		} else if (!strcmp(keyword, "class")) {
+			rc = check_set(&query->class_string, arg, "class");
 		} else {
 			pr_err("unknown keyword \"%s\"\n", keyword);
 			return -EINVAL;
···
 		if (rc)
 			return rc;
 	}
+	if (!query->module && modname)
+		/*
+		 * support $modname.dyndbg=<multiple queries>, when
+		 * not given in the query itself
+		 */
+		query->module = modname;
+
 	vpr_info_dq(query, "parsed");
 	return 0;
 }
···
 	return nfound;
 }
 
-/**
- * dynamic_debug_exec_queries - select and change dynamic-debug prints
- * @query: query-string described in admin-guide/dynamic-debug-howto
- * @modname: string containing module name, usually &module.mod_name
- *
- * This uses the >/proc/dynamic_debug/control reader, allowing module
- * authors to modify their dynamic-debug callsites. The modname is
- * canonically struct module.mod_name, but can also be null or a
- * module-wildcard, for example: "drm*".
- */
-int dynamic_debug_exec_queries(const char *query, const char *modname)
+/* apply a new bitmap to the sys-knob's current bit-state */
+static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
+				     unsigned long *new_bits, unsigned long *old_bits)
 {
-	int rc;
-	char *qry; /* writable copy of query */
+#define QUERY_SIZE 128
+	char query[QUERY_SIZE];
+	const struct ddebug_class_map *map = dcp->map;
+	int matches = 0;
+	int bi, ct;
 
-	if (!query) {
-		pr_err("non-null query/command string expected\n");
+	v2pr_info("apply: 0x%lx to: 0x%lx\n", *new_bits, *old_bits);
+
+	for (bi = 0; bi < map->length; bi++) {
+		if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
+			continue;
+
+		snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
+			 test_bit(bi, new_bits) ? '+' : '-', dcp->flags);
+
+		ct = ddebug_exec_queries(query, NULL);
+		matches += ct;
+
+		v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
+			  ct, map->class_names[bi], *new_bits);
+	}
+	return matches;
+}
+
+/* stub to later conditionally add "$module." prefix where not already done */
+#define KP_NAME(kp)	kp->name
+
+#define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
+
+/* accept comma-separated-list of [+-] classnames */
+static int param_set_dyndbg_classnames(const char *instr, const struct kernel_param *kp)
+{
+	const struct ddebug_class_param *dcp = kp->arg;
+	const struct ddebug_class_map *map = dcp->map;
+	unsigned long curr_bits, old_bits;
+	char *cl_str, *p, *tmp;
+	int cls_id, totct = 0;
+	bool wanted;
+
+	cl_str = tmp = kstrdup(instr, GFP_KERNEL);
+	p = strchr(cl_str, '\n');
+	if (p)
+		*p = '\0';
+
+	/* start with previously set state-bits, then modify */
+	curr_bits = old_bits = *dcp->bits;
+	vpr_info("\"%s\" > %s:0x%lx\n", cl_str, KP_NAME(kp), curr_bits);
+
+	for (; cl_str; cl_str = p) {
+		p = strchr(cl_str, ',');
+		if (p)
+			*p++ = '\0';
+
+		if (*cl_str == '-') {
+			wanted = false;
+			cl_str++;
+		} else {
+			wanted = true;
+			if (*cl_str == '+')
+				cl_str++;
+		}
+		cls_id = match_string(map->class_names, map->length, cl_str);
+		if (cls_id < 0) {
+			pr_err("%s unknown to %s\n", cl_str, KP_NAME(kp));
+			continue;
+		}
+
+		/* have one or more valid class_ids of one *_NAMES type */
+		switch (map->map_type) {
+		case DD_CLASS_TYPE_DISJOINT_NAMES:
+			/* the +/- pertains to a single bit */
+			if (test_bit(cls_id, &curr_bits) == wanted) {
+				v3pr_info("no change on %s\n", cl_str);
+				continue;
+			}
+			curr_bits ^= BIT(cls_id);
+			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits);
+			*dcp->bits = curr_bits;
+			v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
+				  map->class_names[cls_id]);
+			break;
+		case DD_CLASS_TYPE_LEVEL_NAMES:
+			/* cls_id = N in 0..max. wanted +/- determines N or N-1 */
+			old_bits = CLASSMAP_BITMASK(*dcp->lvl);
+			curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
+
+			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits);
+			*dcp->lvl = (cls_id + (wanted ? 1 : 0));
+			v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
+				  map->class_names[cls_id], old_bits, curr_bits);
+			break;
+		default:
+			pr_err("illegal map-type value %d\n", map->map_type);
+		}
+	}
+	kfree(tmp);
+	vpr_info("total matches: %d\n", totct);
+	return 0;
+}
+
+/**
+ * param_set_dyndbg_classes - class FOO >control
+ * @instr: string echo>d to sysfs, input depends on map_type
+ * @kp:    kp->arg has state: bits/lvl, map, map_type
+ *
+ * Enable/disable prdbgs by their class, as given in the arguments to
+ * DECLARE_DYNDBG_CLASSMAP.  For LEVEL map-types, enforce relative
+ * levels by bitpos.
+ *
+ * Returns: 0 or <0 if error.
+ */
+int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
+{
+	const struct ddebug_class_param *dcp = kp->arg;
+	const struct ddebug_class_map *map = dcp->map;
+	unsigned long inrep, new_bits, old_bits;
+	int rc, totct = 0;
+
+	switch (map->map_type) {
+
+	case DD_CLASS_TYPE_DISJOINT_NAMES:
+	case DD_CLASS_TYPE_LEVEL_NAMES:
+		/* handle [+-]classnames list separately, we are done here */
+		return param_set_dyndbg_classnames(instr, kp);
+
+	case DD_CLASS_TYPE_DISJOINT_BITS:
+	case DD_CLASS_TYPE_LEVEL_NUM:
+		/* numeric input, accept and fall-thru */
+		rc = kstrtoul(instr, 0, &inrep);
+		if (rc) {
+			pr_err("expecting numeric input: %s > %s\n", instr, KP_NAME(kp));
+			return -EINVAL;
+		}
+		break;
+	default:
+		pr_err("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
 		return -EINVAL;
 	}
-	qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL);
-	if (!qry)
-		return -ENOMEM;
 
-	rc = ddebug_exec_queries(qry, modname);
-	kfree(qry);
-	return rc;
+	/* only _BITS,_NUM (numeric) map-types get here */
+	switch (map->map_type) {
+	case DD_CLASS_TYPE_DISJOINT_BITS:
+		/* expect bits. mask and warn if too many */
+		if (inrep & ~CLASSMAP_BITMASK(map->length)) {
+			pr_warn("%s: input: 0x%lx exceeds mask: 0x%lx, masking\n",
+				KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
+			inrep &= CLASSMAP_BITMASK(map->length);
+		}
+		v2pr_info("bits:%lx > %s\n", inrep, KP_NAME(kp));
+		totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits);
+		*dcp->bits = inrep;
+		break;
+	case DD_CLASS_TYPE_LEVEL_NUM:
+		/* input is bitpos, of highest verbosity to be enabled */
+		if (inrep > map->length) {
+			pr_warn("%s: level:%ld exceeds max:%d, clamping\n",
+				KP_NAME(kp), inrep, map->length);
+			inrep = map->length;
+		}
+		old_bits = CLASSMAP_BITMASK(*dcp->lvl);
+		new_bits = CLASSMAP_BITMASK(inrep);
+		v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
+		totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits);
+		*dcp->lvl = inrep;
+		break;
+	default:
+		pr_warn("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
+	}
+	vpr_info("%s: total matches: %d\n", KP_NAME(kp), totct);
+	return 0;
 }
-EXPORT_SYMBOL_GPL(dynamic_debug_exec_queries);
+EXPORT_SYMBOL(param_set_dyndbg_classes);
+
+/**
+ * param_get_dyndbg_classes - classes reader
+ * @buffer: string description of controlled bits -> classes
+ * @kp:     kp->arg has state: bits, map
+ *
+ * Reads last written state, underlying prdbg state may have been
+ * altered by direct >control.  Displays 0x for DISJOINT, 0-N for
+ * LEVEL Returns: #chars written or <0 on error
+ */
+int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
+{
+	const struct ddebug_class_param *dcp = kp->arg;
+	const struct ddebug_class_map *map = dcp->map;
+
+	switch (map->map_type) {
+
+	case DD_CLASS_TYPE_DISJOINT_NAMES:
+	case DD_CLASS_TYPE_DISJOINT_BITS:
+		return scnprintf(buffer, PAGE_SIZE, "0x%lx\n", *dcp->bits);
+
+	case DD_CLASS_TYPE_LEVEL_NAMES:
+	case DD_CLASS_TYPE_LEVEL_NUM:
+		return scnprintf(buffer, PAGE_SIZE, "%d\n", *dcp->lvl);
+	default:
+		return -1;
+	}
+}
+EXPORT_SYMBOL(param_get_dyndbg_classes);
+
+const struct kernel_param_ops param_ops_dyndbg_classes = {
+	.set = param_set_dyndbg_classes,
+	.get = param_get_dyndbg_classes,
+};
+EXPORT_SYMBOL(param_ops_dyndbg_classes);
 
 #define PREFIX_SIZE 64
 
···
 {
 	if (list_empty(&ddebug_tables)) {
 		iter->table = NULL;
-		iter->idx = 0;
 		return NULL;
 	}
 	iter->table = list_entry(ddebug_tables.next,
 				 struct ddebug_table, link);
-	iter->idx = 0;
-	return &iter->table->ddebugs[iter->idx];
+	iter->idx = iter->table->num_ddebugs;
+	return &iter->table->ddebugs[--iter->idx];
 }
 
 /*
···
 {
 	if (iter->table == NULL)
 		return NULL;
-	if (++iter->idx == iter->table->num_ddebugs) {
+	if (--iter->idx < 0) {
 		/* iterate to next table */
-		iter->idx = 0;
 		if (list_is_last(&iter->table->link, &ddebug_tables)) {
 			iter->table = NULL;
 			return NULL;
 		}
 		iter->table = list_entry(iter->table->link.next,
 					 struct ddebug_table, link);
+		iter->idx = iter->table->num_ddebugs;
+		--iter->idx;
 	}
 	return &iter->table->ddebugs[iter->idx];
 }
···
 	return dp;
 }
 
+#define class_in_range(class_id, map)					\
+	(class_id >= map->base && class_id < map->base + map->length)
+
+static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
+{
+	struct ddebug_class_map *map;
+
+	list_for_each_entry(map, &iter->table->maps, link)
+		if (class_in_range(dp->class_id, map))
+			return map->class_names[dp->class_id - map->base];
+
+	return NULL;
+}
+
 /*
  * Seq_ops show method.  Called several times within a read()
  * call from userspace, with ddebug_lock held.  Formats the
···
 	struct ddebug_iter *iter = m->private;
 	struct _ddebug *dp = p;
 	struct flagsbuf flags;
+	char const *class;
 
 	if (p == SEQ_START_TOKEN) {
 		seq_puts(m,
···
 		   trim_prefix(dp->filename), dp->lineno,
 		   iter->table->mod_name, dp->function,
 		   ddebug_describe_flags(dp->flags, &flags));
-	seq_escape(m, dp->format, "\t\r\n\"");
-	seq_puts(m, "\"\n");
+	seq_escape_str(m, dp->format, ESCAPE_SPACE, "\t\r\n\"");
+	seq_puts(m, "\"");
+
+	if (dp->class_id != _DPRINTK_CLASS_DFLT) {
+		class = ddebug_class_name(iter, dp);
+		if (class)
+			seq_printf(m, " class:%s", class);
+		else
+			seq_printf(m, " class unknown, _id:%d", dp->class_id);
+	}
+	seq_puts(m, "\n");
 
 	return 0;
 }
···
 	.proc_write = ddebug_proc_write
 };
 
+static void ddebug_attach_module_classes(struct ddebug_table *dt,
+					 struct ddebug_class_map *classes,
+					 int num_classes)
+{
+	struct ddebug_class_map *cm;
+	int i, j, ct = 0;
+
+	for (cm = classes, i = 0; i < num_classes; i++, cm++) {
+
+		if (!strcmp(cm->mod_name, dt->mod_name)) {
+
+			v2pr_info("class[%d]: module:%s base:%d len:%d ty:%d\n", i,
+				  cm->mod_name, cm->base, cm->length, cm->map_type);
+
+			for (j = 0; j < cm->length; j++)
+				v3pr_info(" %d: %d %s\n", j + cm->base, j,
+					  cm->class_names[j]);
+
+			list_add(&cm->link, &dt->maps);
+			ct++;
+		}
+	}
+	if (ct)
+		vpr_info("module:%s attached %d classes\n", dt->mod_name, ct);
+}
+
 /*
  * Allocate a new ddebug_table for the given module
  * and add it to the global list.
  */
-int ddebug_add_module(struct _ddebug *tab, unsigned int n,
-			     const char *name)
+static int __ddebug_add_module(struct _ddebug_info *di, unsigned int base,
+			       const char *modname)
 {
 	struct ddebug_table *dt;
 
+	v3pr_info("add-module: %s.%d sites\n", modname, di->num_descs);
+	if (!di->num_descs) {
+		v3pr_info(" skip %s\n", modname);
+		return 0;
+	}
+
 	dt = kzalloc(sizeof(*dt), GFP_KERNEL);
 	if (dt == NULL) {
-		pr_err("error adding module: %s\n", name);
+		pr_err("error adding module: %s\n", modname);
 		return -ENOMEM;
 	}
 	/*
···
 	 * member of struct module, which lives at least as long as
 	 * this struct ddebug_table.
 	 */
-	dt->mod_name = name;
-	dt->num_ddebugs = n;
-	dt->ddebugs = tab;
+	dt->mod_name = modname;
+	dt->ddebugs = di->descs;
+	dt->num_ddebugs = di->num_descs;
+
+	INIT_LIST_HEAD(&dt->link);
+	INIT_LIST_HEAD(&dt->maps);
+
+	if (di->classes && di->num_classes)
+		ddebug_attach_module_classes(dt, di->classes, di->num_classes);
 
 	mutex_lock(&ddebug_lock);
-	list_add(&dt->link, &ddebug_tables);
+	list_add_tail(&dt->link, &ddebug_tables);
 	mutex_unlock(&ddebug_lock);
 
-	vpr_info("%3u debug prints in module %s\n", n, dt->mod_name);
+	vpr_info("%3u debug prints in module %s\n", di->num_descs, modname);
 	return 0;
+}
+
+int ddebug_add_module(struct _ddebug_info *di, const char *modname)
+{
+	return __ddebug_add_module(di, 0, modname);
 }
 
 /* helper for ddebug_dyndbg_(boot|module)_param_cb */
···
 
 static int __init dynamic_debug_init(void)
 {
-	struct _ddebug *iter, *iter_start;
-	const char *modname = NULL;
+	struct _ddebug *iter, *iter_mod_start;
+	int ret, i, mod_sites, mod_ct;
+	const char *modname;
 	char *cmdline;
-	int ret = 0;
-	int n = 0, entries = 0, modct = 0;
+
+	struct _ddebug_info di = {
+		.descs = __start___dyndbg,
+		.classes = __start___dyndbg_classes,
+		.num_descs = __stop___dyndbg - __start___dyndbg,
+		.num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
+	};
 
 	if (&__start___dyndbg == &__stop___dyndbg) {
 		if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
···
 		ddebug_init_success = 1;
 		return 0;
 	}
-	iter = __start___dyndbg;
+
+	iter = iter_mod_start = __start___dyndbg;
 	modname = iter->modname;
-	iter_start = iter;
-	for (; iter < __stop___dyndbg; iter++) {
-		entries++;
+	i = mod_sites = mod_ct = 0;
+
+	for (; iter < __stop___dyndbg; iter++, i++, mod_sites++) {
+
 		if (strcmp(modname, iter->modname)) {
-			modct++;
-			ret = ddebug_add_module(iter_start, n, modname);
+			mod_ct++;
+			di.num_descs = mod_sites;
+			di.descs = iter_mod_start;
+			ret = __ddebug_add_module(&di, i - mod_sites, modname);
 			if (ret)
 				goto out_err;
-			n = 0;
+
+			mod_sites = 0;
 			modname = iter->modname;
-			iter_start = iter;
+			iter_mod_start = iter;
 		}
-		n++;
 	}
-	ret = ddebug_add_module(iter_start, n, modname);
+	di.num_descs = mod_sites;
+	di.descs = iter_mod_start;
+	ret = __ddebug_add_module(&di, i - mod_sites, modname);
 	if (ret)
 		goto out_err;
 
 	ddebug_init_success = 1;
 	vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg section\n",
-		 entries, modct, (int)((modct * sizeof(struct ddebug_table)) >> 10),
-		 (int)((entries * sizeof(struct _ddebug)) >> 10));
+		 i, mod_ct, (int)((mod_ct * sizeof(struct ddebug_table)) >> 10),
+		 (int)((i * sizeof(struct _ddebug)) >> 10));
+
+	if (di.num_classes)
+		v2pr_info("  %d builtin ddebug class-maps\n", di.num_classes);
 
 	/* now that ddebug tables are loaded, process all boot args
 	 * again to find and activate queries given in dyndbg params.

lib/test_dynamic_debug.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Kernel module for testing dynamic_debug
+ *
+ * Authors:
+ *      Jim Cromie	<[e-mail]>
+ */
+
+#define pr_fmt(fmt) "test_dd: " fmt
+
+#include <linux/module.h>
+
+/* run tests by reading or writing sysfs node: do_prints */
+
+static void do_prints(void); /* device under test */
+static int param_set_do_prints(const char *instr, const struct kernel_param *kp)
+{
+	do_prints();
+	return 0;
+}
+static int param_get_do_prints(char *buffer, const struct kernel_param *kp)
+{
+	do_prints();
+	return scnprintf(buffer, PAGE_SIZE, "did do_prints\n");
+}
+static const struct kernel_param_ops param_ops_do_prints = {
+	.set = param_set_do_prints,
+	.get = param_get_do_prints,
+};
+module_param_cb(do_prints, &param_ops_do_prints, NULL, 0600);
+
+/*
+ * Using the CLASSMAP api:
+ * - classmaps must have corresponding enum
+ * - enum symbols must match/correlate with class-name strings in the map.
+ * - base must equal enum's 1st value
+ * - multiple maps must set their base to share the 0-30 class_id space !!
+ *   (build-bug-on tips welcome)
+ * Additionally, here:
+ * - tie together sysname, mapname, bitsname, flagsname
+ */
+#define DD_SYS_WRAP(_model, _flags)					\
+	static unsigned long bits_##_model;				\
+	static struct ddebug_class_param _flags##_model = {		\
+		.bits = &bits_##_model,					\
+		.flags = #_flags,					\
+		.map = &map_##_model,					\
+	};								\
+	module_param_cb(_flags##_##_model, &param_ops_dyndbg_classes, &_flags##_model, 0600)
+
+/* numeric input, independent bits */
+enum cat_disjoint_bits {
+	D2_CORE = 0,
+	D2_DRIVER,
+	D2_KMS,
+	D2_PRIME,
+	D2_ATOMIC,
+	D2_VBL,
+	D2_STATE,
+	D2_LEASE,
+	D2_DP,
+	D2_DRMRES };
+DECLARE_DYNDBG_CLASSMAP(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS, 0,
+			"D2_CORE",
+			"D2_DRIVER",
+			"D2_KMS",
+			"D2_PRIME",
+			"D2_ATOMIC",
+			"D2_VBL",
+			"D2_STATE",
+			"D2_LEASE",
+			"D2_DP",
+			"D2_DRMRES");
+DD_SYS_WRAP(disjoint_bits, p);
+DD_SYS_WRAP(disjoint_bits, T);
+
+/* symbolic input, independent bits */
+enum cat_disjoint_names { LOW = 11, MID, HI };
+DECLARE_DYNDBG_CLASSMAP(map_disjoint_names, DD_CLASS_TYPE_DISJOINT_NAMES, 10,
+			"LOW", "MID", "HI");
+DD_SYS_WRAP(disjoint_names, p);
+DD_SYS_WRAP(disjoint_names, T);
+
+/* numeric verbosity, V2 > V1 related */
+enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 };
+DECLARE_DYNDBG_CLASSMAP(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, 14,
+		       "V0", "V1", "V2", "V3", "V4", "V5", "V6", "V7");
+DD_SYS_WRAP(level_num, p);
+DD_SYS_WRAP(level_num, T);
+
+/* symbolic verbosity */
+enum cat_level_names { L0 = 22, L1, L2, L3, L4, L5, L6, L7 };
+DECLARE_DYNDBG_CLASSMAP(map_level_names, DD_CLASS_TYPE_LEVEL_NAMES, 22,
+			"L0", "L1", "L2", "L3", "L4", "L5", "L6", "L7");
+DD_SYS_WRAP(level_names, p);
+DD_SYS_WRAP(level_names, T);
+
+/* stand-in for all pr_debug etc */
+#define prdbg(SYM) __pr_debug_cls(SYM, #SYM " msg\n")
+
+static void do_cats(void)
+{
+	pr_debug("doing categories\n");
+
+	prdbg(LOW);
+	prdbg(MID);
+	prdbg(HI);
+
+	prdbg(D2_CORE);
+	prdbg(D2_DRIVER);
+	prdbg(D2_KMS);
+	prdbg(D2_PRIME);
+	prdbg(D2_ATOMIC);
+	prdbg(D2_VBL);
+	prdbg(D2_STATE);
+	prdbg(D2_LEASE);
+	prdbg(D2_DP);
+	prdbg(D2_DRMRES);
+}
+
+static void do_levels(void)
+{
+	pr_debug("doing levels\n");
+
+	prdbg(V1);
+	prdbg(V2);
+	prdbg(V3);
+	prdbg(V4);
+	prdbg(V5);
+	prdbg(V6);
+	prdbg(V7);
+
+	prdbg(L1);
+	prdbg(L2);
+	prdbg(L3);
+	prdbg(L4);
+	prdbg(L5);
+	prdbg(L6);
+	prdbg(L7);
+}
+
+static void do_prints(void)
+{
+	do_cats();
+	do_levels();
+}
+
+static int __init test_dynamic_debug_init(void)
+{
+	pr_debug("init start\n");
+	do_prints();
+	pr_debug("init done\n");
+	return 0;
+}
+
+static void __exit test_dynamic_debug_exit(void)
+{
+	pr_debug("exited\n");
+}
+
+module_init(test_dynamic_debug_init);
+module_exit(test_dynamic_debug_exit);
+
+MODULE_AUTHOR("Jim Cromie <[e-mail]>");
+MODULE_LICENSE("GPL");

net/bluetooth/rfcomm/tty.c

···
 #include <net/bluetooth/hci_core.h>
 #include <net/bluetooth/rfcomm.h>
 
-#define RFCOMM_TTY_MAGIC 0x6d02		/* magic number for rfcomm struct */
 #define RFCOMM_TTY_PORTS RFCOMM_MAX_DEV	/* whole lotta rfcomm devices */
 #define RFCOMM_TTY_MAJOR 216		/* device node major id of the usb/bluetooth.c driver */
 #define RFCOMM_TTY_MINOR 0