Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
code
Clone this repository
https://tangled.org/tjh.dev/kernel
git@gordian.tjh.dev:tjh.dev/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Pull char/misc driver fixes from Greg KH:
"Here are some small char and misc driver fixes for reported issues for
5.3-rc7
Also included in here is the documentation for how we are handling
hardware issues under embargo that everyone has finally agreed on, as
well as a MAINTAINERS update for the suckers who agreed to handle the
LICENSES/ files.
All of these have been in linux-next last week with no reported
issues"
* tag 'char-misc-5.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
fsi: scom: Don't abort operations for minor errors
vmw_balloon: Fix offline page marking with compaction
VMCI: Release resource if the work is already queued
Documentation/process: Embargoed hardware security issues
lkdtm/bugs: fix build error in lkdtm_EXHAUST_STACK
mei: me: add Tiger Lake point LP device ID
intel_th: pci: Add Tiger Lake support
intel_th: pci: Add support for another Lewisburg PCH
stm class: Fix a double free of stm_source_device
MAINTAINERS: add entry for LICENSES and SPDX stuff
fpga: altera-ps-spi: Fix getting of optional confd gpio
Pull USB fixes from Greg KH:
"Here are some small USB fixes that have been in linux-next this past
week for 5.3-rc7
They fix the usual xhci, syzbot reports, and other small issues that
have come up last week.
All have been in linux-next with no reported issues"
* tag 'usb-5.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
USB: cdc-wdm: fix race between write and disconnect due to flag abuse
usb: host: xhci: rcar: Fix typo in compatible string matching
usb: host: xhci-tegra: Set DMA mask correctly
USB: storage: ums-realtek: Whitelist auto-delink support
USB: storage: ums-realtek: Update module parameter description for auto_delink_en
usb: host: ohci: fix a race condition between shutdown and irq
usb: hcd: use managed device resources
typec: tcpm: fix a typo in the comparison of pdo_max_voltage
usb-storage: Add new JMS567 revision to unusual_devs
usb: chipidea: udc: don't do hardware access if gadget has stopped
usbtmc: more sanity checking for packet size
usb: udc: lpc32xx: silence fall-through warning
The scom driver currently fails out of operations if certain system
errors are flagged in the status register; system checkstop, special
attention, or recoverable error. These errors won't impact the ability
of the scom engine to perform operations, so the driver should continue
under these conditions.
Also, don't do a PIB reset for these conditions, since it won't help.
Fixes: 6b293258cded ("fsi: scom: Major overhaul")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20190827041249.13381-1-jk@ozlabs.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull networking fixes from David Miller:
1) Fix some length checks during OGM processing in batman-adv, from
Sven Eckelmann.
2) Fix regression that caused netfilter conntrack sysctls to not be
per-netns any more. From Florian Westphal.
3) Use after free in netpoll, from Feng Sun.
4) Guard destruction of pfifo_fast per-cpu qdisc stats with
qdisc_is_percpu_stats(), from Davide Caratti. Similar bug is fixed
in pfifo_fast_enqueue().
5) Fix memory leak in mld_del_delrec(), from Eric Dumazet.
6) Handle neigh events on internal ports correctly in nfp, from John
Hurley.
7) Clear SKB timestamp in NF flow table code so that it does not
confuse fq scheduler. From Florian Westphal.
8) taprio destroy can crash if it is invoked in a failure path of
taprio_init(), because the list head isn't setup properly yet and
the list del is unconditional. Perform the list add earlier to
address this. From Vladimir Oltean.
9) Make sure to reapply vlan filters on device up, in aquantia driver.
From Dmitry Bogdanov.
10) sgiseeq driver releases DMA memory using free_page() instead of
dma_free_attrs(). From Christophe JAILLET.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (58 commits)
net: seeq: Fix the function used to release some memory in an error handling path
enetc: Add missing call to 'pci_free_irq_vectors()' in probe and remove functions
net: bcmgenet: use ethtool_op_get_ts_info()
tc-testing: don't hardcode 'ip' in nsPlugin.py
net: dsa: microchip: add KSZ8563 compatibility string
dt-bindings: net: dsa: document additional Microchip KSZ8563 switch
net: aquantia: fix out of memory condition on rx side
net: aquantia: linkstate irq should be oneshot
net: aquantia: reapply vlan filters on up
net: aquantia: fix limit of vlan filters
net: aquantia: fix removal of vlan 0
net/sched: cbs: Set default link speed to 10 Mbps in cbs_set_port_rate
taprio: Set default link speed to 10 Mbps in taprio_set_picos_per_byte
taprio: Fix kernel panic in taprio_destroy
net: dsa: microchip: fill regmap_config name
rxrpc: Fix lack of conn cleanup when local endpoint is cleaned up [ver #2]
net: stmmac: dwmac-rk: Don't fail if phy regulator is absent
amd-xgbe: Fix error path in xgbe_mod_init()
netfilter: nft_meta_bridge: Fix get NFT_META_BRI_IIFVPROTO in network byteorder
mac80211: Correctly set noencrypt for PAE frames
...
In case of a disconnect an ongoing flush() has to be made fail.
Nevertheless we cannot be sure that any pending URB has already
finished, so although they will never succeed, they still must
not be touched.
The clean solution for this is to check for WDM_IN_USE
and WDM_DISCONNECTED in flush(). There is no point in ever
clearing WDM_IN_USE, as no further writes make sense.
The issue is as old as the driver.
Fixes: afba937e540c9 ("USB: CDC WDM driver")
Reported-by: syzbot+d232cca6ec42c2edb3fc@syzkaller.appspotmail.com
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190827103436.21143-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The compaction code already marks pages as offline when it enqueues
pages in the ballooned page list, and removes the mapping when the pages
are removed from the list. VMware balloon also updates the flags,
instead of letting the balloon-compaction logic handle it, which causes
the assertion VM_BUG_ON_PAGE(!PageOffline(page)) to fire, when
__ClearPageOffline is called the second time. This causes the following
crash.
[ 487.104520] kernel BUG at include/linux/page-flags.h:749!
[ 487.106364] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
[ 487.107681] CPU: 7 PID: 1106 Comm: kworker/7:3 Not tainted 5.3.0-rc5balloon #227
[ 487.109196] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 12/12/2018
[ 487.111452] Workqueue: events_freezable vmballoon_work [vmw_balloon]
[ 487.112779] RIP: 0010:vmballoon_release_page_list+0xaa/0x100 [vmw_balloon]
[ 487.114200] Code: fe 48 c1 e7 06 4c 01 c7 8b 47 30 41 89 c1 41 81 e1 00 01 00 f0 41 81 f9 00 00 00 f0 74 d3 48 c7 c6 08 a1 a1 c0 e8 06 0d e7 ea <0f> 0b 44 89 f6 4c 89 c7 e8 49 9c e9 ea 49 8d 75 08 49 8b 45 08 4d
[ 487.118033] RSP: 0018:ffffb82f012bbc98 EFLAGS: 00010246
[ 487.119135] RAX: 0000000000000037 RBX: 0000000000000001 RCX: 0000000000000006
[ 487.120601] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9a85b6bd7620
[ 487.122071] RBP: ffffb82f012bbcc0 R08: 0000000000000001 R09: 0000000000000000
[ 487.123536] R10: 0000000000000000 R11: 0000000000000000 R12: ffffb82f012bbd00
[ 487.125002] R13: ffffe97f4598d9c0 R14: 0000000000000000 R15: ffffb82f012bbd34
[ 487.126463] FS: 0000000000000000(0000) GS:ffff9a85b6bc0000(0000) knlGS:0000000000000000
[ 487.128110] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 487.129316] CR2: 00007ffe6e413ea0 CR3: 0000000230b18001 CR4: 00000000003606e0
[ 487.130812] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 487.132283] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 487.133749] Call Trace:
[ 487.134333] vmballoon_deflate+0x22c/0x390 [vmw_balloon]
[ 487.135468] vmballoon_work+0x6e7/0x913 [vmw_balloon]
[ 487.136711] ? process_one_work+0x21a/0x5e0
[ 487.138581] process_one_work+0x298/0x5e0
[ 487.139926] ? vmballoon_migratepage+0x310/0x310 [vmw_balloon]
[ 487.141610] ? process_one_work+0x298/0x5e0
[ 487.143053] worker_thread+0x41/0x400
[ 487.144389] kthread+0x12b/0x150
[ 487.145582] ? process_one_work+0x5e0/0x5e0
[ 487.146937] ? kthread_create_on_node+0x60/0x60
[ 487.148637] ret_from_fork+0x3a/0x50
Fix it by updating the PageOffline indication only when a 2MB page is
enqueued and dequeued. The 4KB pages will be handled correctly by the
balloon compaction logic.
Fixes: 83a8afa72e9c ("vmw_balloon: Compaction support")
Cc: David Hildenbrand <david@redhat.com>
Reported-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Link: https://lore.kernel.org/r/20190820160121.452-1-namit@vmware.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull x86 fixes from Thomas Gleixner:
"A set of fixes for x86:
- Fix the bogus detection of 32bit user mode for uretprobes which
caused corruption of the user return address resulting in
application crashes. In the uprobes handler in_ia32_syscall() is
obviously always returning false on a 64bit kernel. Use
user_64bit_mode() instead which works correctly.
- Prevent large page splitting when ftrace flips RW/RO on the kernel
text which caused iTLB performance issues. Ftrace wants to be
converted to text_poke() which avoids the problem, but for now
allow large page preservation in the static protections check when
the change request spawns a full large page.
- Prevent arch_dynirq_lower_bound() from returning 0 when the IOAPIC
is configured via device tree. In the device tree case the GSI 1:1
mapping is meaningless therefore the lower bound which protects the
GSI range on ACPI machines is irrelevant. Return the lower bound
which the core hands to the function instead of blindly returning 0
which causes the core to allocate the invalid virtual interupt
number 0 which in turn prevents all drivers from allocating and
requesting an interrupt.
- Remove the bogus initialization of LDR and DFR in the 32bit bigsmp
APIC driver. That uses physical destination mode where LDR/DFR are
ignored, but the initialization and the missing clear of LDR caused
the APIC to be left in a inconsistent state on kexec/reboot.
- Clear LDR when clearing the APIC registers so the APIC is in a well
defined state.
- Initialize variables proper in the find_trampoline_placement()
code.
- Silence GCC( build warning for the real mode part of the build"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm/cpa: Prevent large page split when ftrace flips RW on kernel text
x86/build: Add -Wnoaddress-of-packed-member to REALMODE_CFLAGS, to silence GCC9 build warning
x86/boot/compressed/64: Fix missing initialization in find_trampoline_placement()
x86/apic: Include the LDR when clearing out APIC registers
x86/apic: Do not initialize LDR and DFR for bigsmp
uprobes/x86: Fix detection of 32-bit user mode
x86/apic: Fix arch_dynirq_lower_bound() bug for DT enabled machines
In commit 99cd149efe82 ("sgiseeq: replace use of dma_cache_wback_inv"),
a call to 'get_zeroed_page()' has been turned into a call to
'dma_alloc_coherent()'. Only the remove function has been updated to turn
the corresponding 'free_page()' into 'dma_free_attrs()'.
The error hndling path of the probe function has not been updated.
Fix it now.
Rename the corresponding label to something more in line.
Fixes: 99cd149efe82 ("sgiseeq: replace use of dma_cache_wback_inv")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
It's spelled "renesas", not "renensas".
Due to this typo, RZ/G1M and RZ/G1N were not covered by the check.
Fixes: 2dc240a3308b ("usb: host: xhci: rcar: retire use of xhci_plat_type_is()")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20190827125112.12192-1-geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Francois reported that VMware balloon gets stuck after a balloon reset,
when the VMCI doorbell is removed. A similar error can occur when the
balloon driver is removed with the following splat:
[ 1088.622000] INFO: task modprobe:3565 blocked for more than 120 seconds.
[ 1088.622035] Tainted: G W 5.2.0 #4
[ 1088.622087] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1088.622205] modprobe D 0 3565 1450 0x00000000
[ 1088.622210] Call Trace:
[ 1088.622246] __schedule+0x2a8/0x690
[ 1088.622248] schedule+0x2d/0x90
[ 1088.622250] schedule_timeout+0x1d3/0x2f0
[ 1088.622252] wait_for_completion+0xba/0x140
[ 1088.622320] ? wake_up_q+0x80/0x80
[ 1088.622370] vmci_resource_remove+0xb9/0xc0 [vmw_vmci]
[ 1088.622373] vmci_doorbell_destroy+0x9e/0xd0 [vmw_vmci]
[ 1088.622379] vmballoon_vmci_cleanup+0x6e/0xf0 [vmw_balloon]
[ 1088.622381] vmballoon_exit+0x18/0xcc8 [vmw_balloon]
[ 1088.622394] __x64_sys_delete_module+0x146/0x280
[ 1088.622408] do_syscall_64+0x5a/0x130
[ 1088.622410] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1088.622415] RIP: 0033:0x7f54f62791b7
[ 1088.622421] Code: Bad RIP value.
[ 1088.622421] RSP: 002b:00007fff2a949008 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[ 1088.622426] RAX: ffffffffffffffda RBX: 000055dff8b55d00 RCX: 00007f54f62791b7
[ 1088.622426] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055dff8b55d68
[ 1088.622427] RBP: 000055dff8b55d00 R08: 00007fff2a947fb1 R09: 0000000000000000
[ 1088.622427] R10: 00007f54f62f5cc0 R11: 0000000000000206 R12: 000055dff8b55d68
[ 1088.622428] R13: 0000000000000001 R14: 000055dff8b55d68 R15: 00007fff2a94a3f0
The cause for the bug is that when the "delayed" doorbell is invoked, it
takes a reference on the doorbell entry and schedules work that is
supposed to run the appropriate code and drop the doorbell entry
reference. The code ignores the fact that if the work is already queued,
it will not be scheduled to run one more time. As a result one of the
references would not be dropped. When the code waits for the reference
to get to zero, during balloon reset or module removal, it gets stuck.
Fix it. Drop the reference if schedule_work() indicates that the work is
already queued.
Note that this bug got more apparent (or apparent at all) due to
commit ce664331b248 ("vmw_balloon: VMCI_DOORBELL_SET does not check status").
Fixes: 83e2ec765be03 ("VMCI: doorbell implementation.")
Reported-by: Francois Rigault <rigault.francois@gmail.com>
Cc: Jorgen Hansen <jhansen@vmware.com>
Cc: Adit Ranadive <aditr@vmware.com>
Cc: Alexios Zavras <alexios.zavras@intel.com>
Cc: Vishnu DASA <vdasa@vmware.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nadav Amit <namit@vmware.com>
Reviewed-by: Vishnu Dasa <vdasa@vmware.com>
Link: https://lore.kernel.org/r/20190820202638.49003-1-namit@vmware.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull perf fixes from Thomas Gleixner:
"Two fixes for perf x86 hardware implementations:
- Restrict the period on Nehalem machines to prevent perf from
hogging the CPU
- Prevent the AMD IBS driver from overwriting the hardwre controlled
and pre-seeded reserved bits (0-6) in the count register which
caused a sample bias for dispatched micro-ops"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/amd/ibs: Fix sample bias for dispatched micro-ops
perf/x86/intel: Restrict period on Nehalem
ftrace does not use text_poke() for enabling trace functionality. It uses
its own mechanism and flips the whole kernel text to RW and back to RO.
The CPA rework removed a loop based check of 4k pages which tried to
preserve a large page by checking each 4k page whether the change would
actually cover all pages in the large page.
This resulted in endless loops for nothing as in testing it turned out that
it actually never preserved anything. Of course testing missed to include
ftrace, which is the one and only case which benefitted from the 4k loop.
As a consequence enabling function tracing or ftrace based kprobes results
in a full 4k split of the kernel text, which affects iTLB performance.
The kernel RO protection is the only valid case where this can actually
preserve large pages.
All other static protections (RO data, data NX, PCI, BIOS) are truly
static. So a conflict with those protections which results in a split
should only ever happen when a change of memory next to a protected region
is attempted. But these conflicts are rightfully splitting the large page
to preserve the protected regions. In fact a change to the protected
regions itself is a bug and is warned about.
Add an exception for the static protection check for kernel text RO when
the to be changed region spawns a full large page which allows to preserve
the large mappings. This also prevents the syslog to be spammed about CPA
violations when ftrace is used.
The exception needs to be removed once ftrace switched over to text_poke()
which avoids the whole issue.
Fixes: 585948f4f695 ("x86/mm/cpa: Avoid the 4k pages check completely")
Reported-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Song Liu <songliubraving@fb.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908282355340.1938@nanos.tec.linutronix.de
Call to 'pci_free_irq_vectors()' are missing both in the error handling
path of the probe function, and in the remove function.
Add them.
Fixes: 19971f5ea0ab ("enetc: add PTP clock driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>