linux/drivers/media
Takashi Iwai 2228d80dd0 [media] uvcvideo: Fix destruction order in uvc_delete()
We've got a bug report at disconnecting a Webcam, where the kernel
spews warnings like below:
  WARNING: CPU: 0 PID: 8385 at ../fs/sysfs/group.c:219 sysfs_remove_group+0x87/0x90()
  sysfs group c0b2350c not found for kobject 'event3'
  CPU: 0 PID: 8385 Comm: queue2:src Not tainted 3.16.2-1.gdcee397-default #1
  Hardware name: ASUSTeK Computer INC. A7N8X-E/A7N8X-E, BIOS ASUS A7N8X-E Deluxe ACPI BIOS Rev 1013  11/12/2004
    c08d0705 ddc75cbc c0718c5b ddc75ccc c024b654 c08c6d44 ddc75ce8 000020c1
    c08d0705 000000db c03d1ec7 c03d1ec7 00000009 00000000 c0b2350c d62c9064
    ddc75cd4 c024b6a3 00000009 ddc75ccc c08c6d44 ddc75ce8 ddc75cfc c03d1ec7
  Call Trace:
    [<c0205ba6>] try_stack_unwind+0x156/0x170
    [<c02046f3>] dump_trace+0x53/0x180
    [<c0205c06>] show_trace_log_lvl+0x46/0x50
    [<c0204871>] show_stack_log_lvl+0x51/0xe0
    [<c0205c67>] show_stack+0x27/0x50
    [<c0718c5b>] dump_stack+0x3e/0x4e
    [<c024b654>] warn_slowpath_common+0x84/0xa0
    [<c024b6a3>] warn_slowpath_fmt+0x33/0x40
    [<c03d1ec7>] sysfs_remove_group+0x87/0x90
    [<c05a2c54>] device_del+0x34/0x180
    [<c05e3989>] evdev_disconnect+0x19/0x50
    [<c05e06fa>] __input_unregister_device+0x9a/0x140
    [<c05e0845>] input_unregister_device+0x45/0x80
    [<f854b1d6>] uvc_delete+0x26/0x110 [uvcvideo]
    [<f84d66f8>] v4l2_device_release+0x98/0xc0 [videodev]
    [<c05a25bb>] device_release+0x2b/0x90
    [<c04ad8bf>] kobject_cleanup+0x6f/0x1a0
    [<f84d5453>] v4l2_release+0x43/0x70 [videodev]
    [<c0372f31>] __fput+0xb1/0x1b0
    [<c02650c1>] task_work_run+0x91/0xb0
    [<c024d845>] do_exit+0x265/0x910
    [<c024df64>] do_group_exit+0x34/0xa0
    [<c025a76f>] get_signal_to_deliver+0x17f/0x590
    [<c0201b6a>] do_signal+0x3a/0x960
    [<c02024f7>] do_notify_resume+0x67/0x90
    [<c071ebb5>] work_notifysig+0x30/0x3b
    [<b7739e60>] 0xb7739e5f
   ---[ end trace b1e56095a485b631 ]---

The cause is that uvc_status_cleanup() is called after usb_put_*() in
uvc_delete().  usb_put_*() removes the sysfs parent and eventually
removes the children recursively, so the later device_del() can't find
its sysfs.  The fix is simply rearrange the call orders in
uvc_delete() so that the child is removed before the parent.

Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=897736
Reported-and-tested-by: Martin Pluskal <mpluskal@suse.com>

Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2014-11-25 08:31:51 -02:00
..
common [media] v4l2-common: move v4l2_ctrl_check to cx2341x 2014-11-25 08:25:36 -02:00
dvb-core Merge tag 'v3.18-rc4' into patchwork 2014-11-11 08:37:35 -02:00
dvb-frontends [media] rtl2832: implement option to bypass slave demod TS 2014-11-21 16:03:39 -02:00
firewire [media] fix a warning on avr32 arch 2014-11-03 15:53:15 -02:00
i2c [media] i2c: Make use of media_bus_format enum 2014-11-14 17:52:48 -02:00
mmc [media] siano: get rid of CammelCase from smscoreapi.h 2013-03-21 10:03:16 -03:00
parport [media] pms: Fix a bad usage of the stack 2014-09-26 06:47:55 -03:00
pci [media] bttv/cx25821/cx88/ivtv: use sg_next instead of sg++ 2014-11-25 08:12:53 -02:00
platform [media] media: vivid: use vb2_ops_wait_prepare/finish helper 2014-11-25 08:12:30 -02:00
radio [media] si4713: add device tree support 2014-11-14 18:08:19 -02:00
rc Merge tag 'v3.18-rc4' into patchwork 2014-11-11 08:37:35 -02:00
tuners [media] r820t: add DVB-C config 2014-11-14 17:28:00 -02:00
usb [media] uvcvideo: Fix destruction order in uvc_delete() 2014-11-25 08:31:51 -02:00
v4l2-core [media] v4l2-common: move v4l2_ctrl_check to cx2341x 2014-11-25 08:25:36 -02:00
Kconfig [media] Kconfig: do not select SPI bus on sub-driver auto-select 2014-09-04 12:18:49 -03:00
Makefile [media] move i2c files into drivers/media/i2c 2012-09-06 18:42:54 -03:00
media-device.c [media] media: Use strlcpy instead of custom code 2014-09-21 20:27:08 -03:00
media-devnode.c [media] media-devnode: just return 0 instead of using a var 2014-09-03 17:59:28 -03:00
media-entity.c [media] media: Fix a compiler warning in media_entity_pipeline_start() 2014-11-03 19:09:13 -02:00