Benjamin Tissoires 3ffa6583e2 power: remove possible deadlock when unregistering power_supply ... 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>		2018-07-06 16:03:21 +02:00
..
acpi	Additional ACPI updates for 4.18-rc1	2018-06-13 07:32:10 -07:00
asm-generic	int-ll64.h: define u{8,16,32,64} and s{8,16,32,64} based on uapi header	2018-06-07 17:34:38 -07:00
clocksource
crypto	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2018-06-05 15:51:21 -07:00
drm	drm for v4.18-rc1	2018-06-06 08:16:33 -07:00
dt-bindings	ARM: SoC driver updates	2018-06-11 18:15:22 -07:00
keys	docs: Fix some broken references	2018-06-15 18:10:01 -03:00
kvm
linux	power: remove possible deadlock when unregistering power_supply	2018-07-06 16:03:21 +02:00
math-emu
media	media: v4l2-core: push taking ioctl mutex down to ioctl handler	2018-05-28 16:31:44 -04:00
memory
misc	ocxl: Expose the thread_id needed for wait on POWER9	2018-06-03 20:40:32 +10:00
net	sctp: define sctp_packet_gso_append to build GSO frames	2018-06-14 10:25:53 -07:00
pcmcia
ras
rdma	Convert infiniband uverbs to struct_size	2018-06-12 16:19:22 -07:00
scsi	SCSI misc on 20180610	2018-06-10 13:01:12 -07:00
soc	ARM: SoC: late updates	2018-06-11 18:19:45 -07:00
sound	sound updates for 4.18	2018-06-06 09:08:38 -07:00
target
trace	NFS client updates for Linux 4.18	2018-06-12 10:09:03 -07:00
uapi	Solve a series of broken links for files under Documentation:	2018-06-17 05:25:18 +09:00
video	fbdev changes for v4.18:	2018-06-17 05:00:24 +09:00
xen	docs: Fix some broken references	2018-06-15 18:10:01 -03:00