Bug 689675

Summary:	segfault in kernel thread on monitor unplug
Product:	[Fedora] Fedora	Reporter:	Bernie Innocenti <bernie+fedora>
Component:	kernel	Assignee:	Kernel Maintainer List <kernel-maint>
Status:	CLOSED RAWHIDE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	14	CC:	gansalmon, itamar, jonathan, kernel-maint, madhu.chinakonda
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-08-29 15:34:36 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Bernie Innocenti 2011-03-22 05:17:55 UTC

Upon unplugging the VGA connector on a Lenovo X201, occasionally I get this oops:

general protection fault: 0000 [#1] SMP 
last sysfs file: /sys/devices/pci0000:00/0000:00:1a.0/usb1/idVendor
CPU 0 
Modules linked in: pl2303 hidp fuse usb_storage rfcomm sco bnep l2cap vboxnetadp vboxnetflt vboxdrv coretemp ipv6 cpufreq_ondemand acpi_cpufreq freq_table mperf kvm_intel kvm uinput qcserial usb_wwan arc4 i2400m_usb i2400m ecb wimax snd_hda_codec_intelhdmi btusb bluetooth usbserial snd_hda_codec_conexant iwlagn snd_hda_intel snd_hda_codec snd_hwdep snd_seq iwlcore snd_seq_device snd_pcm mac80211 thinkpad_acpi cfg80211 snd_timer e1000e snd snd_page_alloc joydev iTCO_wdt i2c_i801 wmi iTCO_vendor_support rfkill microcode soundcore i915 drm_kms_helper drm i2c_algo_bit i2c_core video output [last unloaded: scsi_wait_scan]
Pid: 2080, comm: kslowd002 Not tainted 2.6.35.11-83.fc14.x86_64 #1 3249CTO/3249CTO
RIP: 0010:[<ffffffff812266a0>]  [<ffffffff812266a0>] list_del+0x10/0x8b
RSP: 0018:ffff88012d9cfc90  EFLAGS: 00010286
RAX: dead000000200200 RBX: ffff88008d8b09c8 RCX: ffff880130648000
RDX: 0000000000000000 RSI: ffff88012d9cfff8 RDI: ffff88008d8b09c8
RBP: ffff88012d9cfca0 R08: ffff88012d9cfb5c R09: ffffffff8100aae0
R10: ffff8801ad9cf98f R11: 0000000000000000 R12: ffff88012fd27800
R13: ffff88012fd25000 R14: ffffffffa009ea10 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff880002000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007f2168285018 CR3: 0000000132253000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process kslowd002 (pid: 2080, threadinfo ffff88012d9ce000, task ffff880130648000)
Stack:
 ffff88012fd27800 ffff88008d8b09c0 ffff88012d9cfcf0 ffffffffa0035425
<0> 0000000000000000 0000000000000001 ffff88012fd27800 ffff88012fd27800
<0> 0000000000000000 ffff88012fd27a68 ffffffffa009ea10 0000000000000438
Call Trace:
 [<ffffffffa0035425>] drm_mode_connector_update_edid_property+0x3f/0xf3 [drm]
 [<ffffffffa0067c40>] drm_helper_probe_single_connector_modes+0x110/0x29d [drm_kms_helper]
 [<ffffffffa00654e5>] drm_fb_helper_probe_connector_modes+0x47/0x5f [drm_kms_helper]
 [<ffffffffa0066756>] drm_fb_helper_hotplug_event+0xac/0xc9 [drm_kms_helper]
 [<ffffffffa0094888>] intel_fb_output_poll_changed+0x1c/0x20 [i915]	
 [<ffffffffa006757b>] output_poll_execute+0xf2/0x12e [drm_kms_helper]
 [<ffffffff810c9f1b>] slow_work_execute+0x1a2/0x2cc
 [<ffffffff810ca3c5>] slow_work_thread+0x173/0x2a4
 [<ffffffff81066633>] ? autoremove_wake_function+0x0/0x39
 [<ffffffff81469fcf>] ? _raw_spin_unlock_irqrestore+0x17/0x19
 [<ffffffff810ca252>] ? slow_work_thread+0x0/0x2a4
 [<ffffffff81066199>] kthread+0x7f/0x87
 [<ffffffff8100aae4>] kernel_thread_helper+0x4/0x10
 [<ffffffff8106611a>] ? kthread+0x0/0x87
 [<ffffffff8100aae0>] ? kernel_thread_helper+0x0/0x10
Code: 00 00 00 74 05 e8 8b 74 e2 ff 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f c9 c3 90 90 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 8b 47 08 <4c> 8b 00 49 39 f8 74 1d 48 89 f9 48 c7 c2 fb 18 7b 81 be 30 00 
RIP  [<ffffffff812266a0>] list_del+0x10/0x8b
 RSP <ffff88012d9cfc90>

Comment 1 Bernie Innocenti 2011-03-22 05:19:12 UTC

Probably related to #680828

Comment 2 Bernie Innocenti 2011-04-25 02:56:56 UTC

Update: I can no longer reproduce this bug after disabling Sync to VBlank in Compiz and upgrading to kernel-2.6.39-0.rc3.git2.0.fc16.x86_64.

I'm not sure which of these things fixed it, though.

Comment 3 Bernie Innocenti 2011-04-25 02:58:21 UTC

However, I'm still getting a black screen on monitor unplug. This bug can be easily worked around by switching to another virtual console and then back to X.

Comment 4 Josh Boyer 2011-08-29 15:34:36 UTC

Bernie, it seems you've moved on to f16.  I'm going to close out this specific oops bug for now.  Please open a new bug for any issues you hit on f16.

Comment 5 Bernie Innocenti 2011-08-29 19:14:34 UTC

This bug seems to have been fixed upstream, but it's not clear in which kernel version:

  https://bugs.freedesktop.org/show_bug.cgi?id=34787