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Benjamin Tissoires e70f938a60 power: remove possible deadlock when unregistering power_supply
[ Upstream commit 3ffa6583e2 ]

If a device gets removed right after having registered a power_supply node,
we might enter in a deadlock between the remove call (that has a lock on
the parent device) and the deferred register work.

Allow the deferred register work to exit without taking the lock when
we are in the remove state.

Stack trace on a Ubuntu 16.04:

[16072.109121] INFO: task kworker/u16:2:1180 blocked for more than 120 seconds.
[16072.109127]       Not tainted 4.13.0-41-generic #46~16.04.1-Ubuntu
[16072.109129] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[16072.109132] kworker/u16:2   D    0  1180      2 0x80000000
[16072.109142] Workqueue: events_power_efficient power_supply_deferred_register_work
[16072.109144] Call Trace:
[16072.109152]  __schedule+0x3d6/0x8b0
[16072.109155]  schedule+0x36/0x80
[16072.109158]  schedule_preempt_disabled+0xe/0x10
[16072.109161]  __mutex_lock.isra.2+0x2ab/0x4e0
[16072.109166]  __mutex_lock_slowpath+0x13/0x20
[16072.109168]  ? __mutex_lock_slowpath+0x13/0x20
[16072.109171]  mutex_lock+0x2f/0x40
[16072.109174]  power_supply_deferred_register_work+0x2b/0x50
[16072.109179]  process_one_work+0x15b/0x410
[16072.109182]  worker_thread+0x4b/0x460
[16072.109186]  kthread+0x10c/0x140
[16072.109189]  ? process_one_work+0x410/0x410
[16072.109191]  ? kthread_create_on_node+0x70/0x70
[16072.109194]  ret_from_fork+0x35/0x40
[16072.109199] INFO: task test:2257 blocked for more than 120 seconds.
[16072.109202]       Not tainted 4.13.0-41-generic #46~16.04.1-Ubuntu
[16072.109204] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[16072.109206] test            D    0  2257   2256 0x00000004
[16072.109208] Call Trace:
[16072.109211]  __schedule+0x3d6/0x8b0
[16072.109215]  schedule+0x36/0x80
[16072.109218]  schedule_timeout+0x1f3/0x360
[16072.109221]  ? check_preempt_curr+0x5a/0xa0
[16072.109224]  ? ttwu_do_wakeup+0x1e/0x150
[16072.109227]  wait_for_completion+0xb4/0x140
[16072.109230]  ? wait_for_completion+0xb4/0x140
[16072.109233]  ? wake_up_q+0x70/0x70
[16072.109236]  flush_work+0x129/0x1e0
[16072.109240]  ? worker_detach_from_pool+0xb0/0xb0
[16072.109243]  __cancel_work_timer+0x10f/0x190
[16072.109247]  ? device_del+0x264/0x310
[16072.109250]  ? __wake_up+0x44/0x50
[16072.109253]  cancel_delayed_work_sync+0x13/0x20
[16072.109257]  power_supply_unregister+0x37/0xb0
[16072.109260]  devm_power_supply_release+0x11/0x20
[16072.109263]  release_nodes+0x110/0x200
[16072.109266]  devres_release_group+0x7c/0xb0
[16072.109274]  wacom_remove+0xc2/0x110 [wacom]
[16072.109279]  hid_device_remove+0x6e/0xd0 [hid]
[16072.109284]  device_release_driver_internal+0x158/0x210
[16072.109288]  device_release_driver+0x12/0x20
[16072.109291]  bus_remove_device+0xec/0x160
[16072.109293]  device_del+0x1de/0x310
[16072.109298]  hid_destroy_device+0x27/0x60 [hid]
[16072.109303]  usbhid_disconnect+0x51/0x70 [usbhid]
[16072.109308]  usb_unbind_interface+0x77/0x270
[16072.109311]  device_release_driver_internal+0x158/0x210
[16072.109315]  device_release_driver+0x12/0x20
[16072.109318]  usb_driver_release_interface+0x77/0x80
[16072.109321]  proc_ioctl+0x20f/0x250
[16072.109325]  usbdev_do_ioctl+0x57f/0x1140
[16072.109327]  ? __wake_up+0x44/0x50
[16072.109331]  usbdev_ioctl+0xe/0x20
[16072.109336]  do_vfs_ioctl+0xa4/0x600
[16072.109339]  ? vfs_write+0x15a/0x1b0
[16072.109343]  SyS_ioctl+0x79/0x90
[16072.109347]  entry_SYSCALL_64_fastpath+0x24/0xab
[16072.109349] RIP: 0033:0x7f20da807f47
[16072.109351] RSP: 002b:00007ffc422ae398 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[16072.109353] RAX: ffffffffffffffda RBX: 00000000010b8560 RCX: 00007f20da807f47
[16072.109355] RDX: 00007ffc422ae3a0 RSI: 00000000c0105512 RDI: 0000000000000009
[16072.109356] RBP: 0000000000000000 R08: 00007ffc422ae3e0 R09: 0000000000000010
[16072.109357] R10: 00000000000000a6 R11: 0000000000000246 R12: 0000000000000000
[16072.109359] R13: 00000000010b8560 R14: 00007ffc422ae2e0 R15: 0000000000000000

Reported-and-tested-by: Richard Hughes <rhughes@redhat.com>
Tested-by: Aaron Skomra <Aaron.Skomra@wacom.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Fixes: 7f1a57fdd6 ("power_supply: Fix possible NULL pointer dereference on early uevent")
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-03 17:00:47 -07:00
arch s390/mm: correct allocate_pgste proc_handler callback 2018-10-03 17:00:47 -07:00
block blk-mq: avoid to synchronize rcu inside blk_cleanup_queue() 2018-09-26 08:38:13 +02:00
certs Replace magic for trusting the secondary keyring with #define 2018-09-09 19:55:54 +02:00
crypto crypto: skcipher - Fix -Wstringop-truncation warnings 2018-10-03 17:00:45 -07:00
Documentation inet: frags: break the 2GB limit for frags storage 2018-09-19 22:43:46 +02:00
drivers power: remove possible deadlock when unregistering power_supply 2018-10-03 17:00:47 -07:00
firmware License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs ext4: show test_dummy_encryption mount option in /proc/mounts 2018-09-29 03:06:06 -07:00
include power: remove possible deadlock when unregistering power_supply 2018-10-03 17:00:47 -07:00
init init: rename and re-order boot_cpu_state_init() 2018-08-15 18:12:48 +02:00
ipc ipc/sem.c: prevent queue.status tearing in semop 2018-09-05 09:26:30 +02:00
kernel tick/nohz: Prevent bogus softirq pending warning 2018-09-29 03:06:07 -07:00
lib rhashtable: add schedule points 2018-09-19 22:43:45 +02:00
mm mm: shmem.c: Correctly annotate new inodes for lockdep 2018-09-29 03:06:04 -07:00
net 6lowpan: iphc: reset mac_header after decompress to fix panic 2018-10-03 17:00:47 -07:00
samples samples/bpf: Check the error of write() and read() 2018-08-24 13:09:12 +02:00
scripts kbuild: add .DELETE_ON_ERROR special target 2018-09-26 08:37:59 +02:00
security Revert "uapi/linux/keyctl.h: don't use C++ reserved keyword as a struct member name" 2018-09-29 03:06:04 -07:00
sound ALSA: oxfw: fix memory leak of private data 2018-09-29 03:06:03 -07:00
tools selftest: timers: Tweak raw_skew to SKIP when ADJ_OFFSET/other clock adjustments are in progress 2018-09-26 08:38:13 +02:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt KVM: arm/arm64: Fix vgic init race 2018-09-26 08:38:04 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: rpm-pkg: keep spec file until make mrproper 2018-02-13 10:19:46 +01:00
.mailmap .mailmap: Add Maciej W. Rozycki's Imagination e-mail address 2017-11-10 12:16:15 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS dt-bindings: Document mti,mips-cpc binding 2018-03-15 10:54:35 +01:00
Makefile Linux 4.14.73 2018-09-29 03:06:07 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.