Ubuntu
v4l2loopback package

Call trace from __video_do_ioctl on focal

Bug #1878899 reported by Florian Hars on 2020-05-15

This bug affects 2 people

Affects		Status	Importance	Assigned to	Milestone
	v4l2loopback (Ubuntu)	Confirmed	Undecided	Unassigned

Bug Description

[92420.303133] ------------[ cut here ]------------
[92420.303141] WARNING: CPU: 2 PID: 259541 at drivers/media/v4l2-core/v4l2-ioctl.c:1069 v4l_querycap+0x8f/0xa0 [videodev]
[92420.303141] Modules linked in: btrfs xor zstd_compress raid6_pq ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs gspca_zc3xx joydev snd_seq_dummy iptable_mangle xt_CHECKSUM iptable_nat xt_MASQUERADE nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c xt_tcpudp bridge stp llc iptable_filter bpfilter v4l2loopback(OE) binfmt_misc nls_iso8859_1 uvcvideo gspca_vc032x gspca_main videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev snd_usb_audio snd_usbmidi_lib mc snd_seq_midi snd_seq_midi_event snd_rawmidi edac_mce_amd kvm_amd ccp snd_hda_codec_realtek snd_seq snd_hda_codec_generic ledtrig_audio snd_hda_codec_hdmi snd_hda_intel kvm snd_intel_dspcfg snd_hda_codec snd_hda_core snd_hwdep snd_seq_device snd_pcm input_leds serio_raw k10temp fam15h_power snd_timer snd soundcore mac_hid sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 uas usb_storage dm_crypt amdgpu amd_iommu_v2 gpu_sched hid_generic usbhid hid crct10dif_pclmul crc32_pclmul
[92420.303167] ghash_clmulni_intel radeon i2c_algo_bit ttm aesni_intel drm_kms_helper crypto_simd syscopyarea cryptd sysfillrect sysimgblt glue_helper fb_sys_fops ahci libahci i2c_piix4 drm r8169 realtek video
[92420.303174] CPU: 2 PID: 259541 Comm: teams Tainted: G W OE 5.4.0-29-lowlatency #33-Ubuntu
[92420.303175] Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./G1.Sniper A88X-CF, BIOS F7 01/08/2014
[92420.303182] RIP: 0010:v4l_querycap+0x8f/0xa0 [videodev]
[92420.303183] Code: 00 00 80 48 b9 00 00 20 00 00 00 20 00 48 0b 4b 54 21 d6 39 f2 75 13 48 89 4b 54 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b eb d0 <0f> 0b 48 89 4b 54 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 44 00 00
[92420.303184] RSP: 0018:ffffb4aa44dd7c78 EFLAGS: 00010202
[92420.303186] RAX: 0000000000000000 RBX: ffffb4aa44dd7d88 RCX: 8520800185208001
[92420.303187] RDX: 0000000085008003 RSI: 0000000085008001 RDI: 0000000000000000
[92420.303188] RBP: ffffb4aa44dd7ca0 R08: 0000000000000000 R09: 0000000000ffff0a
[92420.303188] R10: 0000000000000000 R11: 0000000000000000 R12: ffff994f4e421000
[92420.303189] R13: ffff994f4de6bf00 R14: ffff994f4c191940 R15: ffffffffc0f2e360
[92420.303191] FS: 00007f47f2ffd700(0000) GS:ffff994f5fb00000(0000) knlGS:0000000000000000
[92420.303192] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[92420.303193] CR2: 00007f482c0e1000 CR3: 00000003d0084000 CR4: 00000000000406e0
[92420.303194] Call Trace:
[92420.303201] __video_do_ioctl+0x1a7/0x410 [videodev]
[92420.303204] ? default_send_IPI_single+0x20/0x40
[92420.303206] ? resched_curr+0x62/0xe0
[92420.303213] video_usercopy+0x2ad/0x690 [videodev]
[92420.303220] ? v4l_s_fmt+0x670/0x670 [videodev]
[92420.303224] ? wake_up_q+0x40/0x70
[92420.303230] video_ioctl2+0x15/0x20 [videodev]
[92420.303237] v4l2_ioctl+0x4c/0x60 [videodev]
[92420.303238] do_vfs_ioctl+0x405/0x660
[92420.303240] ? __fget+0x77/0xa0
[92420.303242] ksys_ioctl+0x67/0x90
[92420.303244] __x64_sys_ioctl+0x1a/0x20
[92420.303246] do_syscall_64+0x57/0x190
[92420.303248] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[92420.303249] RIP: 0033:0x7f489773737b
[92420.303251] Code: 0f 1e fa 48 8b 05 15 3b 0d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e5 3a 0d 00 f7 d8 64 89 01 48
[92420.303252] RSP: 002b:00007f47f2ff77e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[92420.303254] RAX: ffffffffffffffda RBX: 00007f4824026900 RCX: 00007f489773737b
[92420.303255] RDX: 00007f47f2ff78b0 RSI: ffffffff80685600 RDI: 0000000000000046
[92420.303256] RBP: ffffffff80685600 R08: 0000000000000000 R09: 00005645ec03ee68
[92420.303257] R10: 0000000000000048 R11: 0000000000000246 R12: 0000000000000046
[92420.303258] R13: 00007f47f2ff78b0 R14: 0000000000000015 R15: 00007f485b666039
[92420.303260] ---[ end trace 6e9a5041142fdaab ]---

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: linux-image-lowlatency 5.4.0.29.34
ProcVersionSignature: Ubuntu 5.4.0-29.33-lowlatency 5.4.30
Uname: Linux 5.4.0-29-lowlatency x86_64
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Fri May 15 12:52:50 2020
HibernationDevice: RESUME=UUID=2ac5f511-9e86-402d-b41b-405dabdb7861
InstallationDate: Installed on 2014-04-14 (2222 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Beta amd64 (20140326)
IwConfig:
lo no wireless extensions.

eth0 no wireless extensions.

lxcbr0 no wireless extensions.
MachineType: Gigabyte Technology Co., Ltd. To be filled by O.E.M.
ProcEnviron:
TERM=screen-256color-bce
PATH=(custom, no user)
XDG_RUNTIME_DIR=<set>
LANG=de_DE.UTF-8
SHELL=/bin/bash
ProcFB: 0 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.4.0-29-lowlatency root=/dev/mapper/ubuntu--vg-root ro quiet splash
RelatedPackageVersions:
linux-restricted-modules-5.4.0-29-lowlatency N/A
linux-backports-modules-5.4.0-29-lowlatency N/A
linux-firmware 1.187
RfKill:

SourcePackage: linux
UpgradeStatus: Upgraded to focal on 2020-05-08 (6 days ago)
dmi.bios.date: 01/08/2014
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: F7
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: G1.Sniper A88X-CF
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF7:bd01/08/2014:svnGigabyteTechnologyCo.,Ltd.:pnTobefilledbyO.E.M.:pvrTobefilledbyO.E.M.:rvnGigabyteTechnologyCo.,Ltd.:rnG1.SniperA88X-CF:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: To be filled by O.E.M.
dmi.product.sku: To be filled by O.E.M.
dmi.product.version: To be filled by O.E.M.
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

Tags:

Revision history for this message

Florian Hars (hars) wrote on 2020-05-15:

AlsaInfo.txt Edit (134.9 KiB, text/plain; charset="utf-8")
AudioDevicesInUse.txt Edit (398 bytes, text/plain; charset="utf-8")
CRDA.txt Edit (454 bytes, text/plain; charset="utf-8")
CurrentDmesg.txt Edit (250.2 KiB, text/plain; charset="utf-8")
Dependencies.txt Edit (2.6 KiB, text/plain; charset="utf-8")
Lspci.txt Edit (14.3 KiB, text/plain; charset="utf-8")
Lspci-vt.txt Edit (2.3 KiB, text/plain; charset="utf-8")
Lsusb.txt Edit (1.1 KiB, text/plain; charset="utf-8")
Lsusb-t.txt Edit (1.7 KiB, text/plain; charset="utf-8")
Lsusb-v.txt Edit (139.9 KiB, text/plain; charset="utf-8")
ProcCpuinfo.txt Edit (5.0 KiB, text/plain; charset="utf-8")
ProcCpuinfoMinimal.txt Edit (1.2 KiB, text/plain; charset="utf-8")
ProcInterrupts.txt Edit (3.6 KiB, text/plain; charset="utf-8")
ProcModules.txt Edit (6.3 KiB, text/plain; charset="utf-8")
PulseList.txt Edit (31.1 KiB, text/plain; charset="utf-8")
UdevDb.txt Edit (207.2 KiB, text/plain; charset="utf-8")
WifiSyslog.txt Edit (97.5 KiB, text/plain; charset="utf-8")

Revision history for this message

Ubuntu Kernel Bot (ubuntu-kernel-bot) wrote on 2020-05-15: Status changed to Confirmed

This change was made by a bot.

Changed in linux (Ubuntu):
status:	New → Confirmed

Revision history for this message

Kai-Heng Feng (kaihengfeng) wrote on 2020-05-20: Re: Call trace from __video_do_ioctl

Which camera was in use?

Changed in linux (Ubuntu):
status:	Confirmed → Incomplete

Revision history for this message

Florian Hars (hars) wrote on 2020-05-22:

Bus 008 Device 015: ID 046d:08af Logitech, Inc. QuickCam Easy/Cool
Bus 008 Device 013: ID 046d:0892 Logitech, Inc. OrbiCam

Both used by OBS Studio, which then sent its output to a v4l2loobback device, module parameters:

/sbin/modprobe v4l2loopback devices=1 video_nr=10 card_label="OBS Cam" exclusive_caps=1

Revision history for this message

Kai-Heng Feng (kaihengfeng) wrote on 2020-05-22:

Can you please try linux-generic kernel instead of linux-lowlatency?

Revision history for this message

Florian Hars (hars) wrote on 2020-05-28:

Download full text (16.3 KiB)

Same, happens on loading the v4l2loopback module:

[ 1039.168432] v4l2loopback driver version 0.12.3 loaded
[ 1039.172977] ------------[ cut here ]------------
[ 1039.172994] WARNING: CPU: 3 PID: 8520 at drivers/media/v4l2-core/v4l2-ioctl.c:1064 v4l_querycap+0x8b/0xa0 [videodev]
[ 1039.172995] Modules linked in: v4l2loopback(OE) snd_seq_dummy iptable_mangle xt_CHECKSUM iptable_nat xt_MASQUERADE nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c xt_tcpudp bridge stp llc iptable_filter bpfilter binfmt_misc nls_iso8859_1 snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_hda_codec_hdmi edac_mce_amd snd_hda_intel snd_intel_dspcfg kvm_amd snd_hda_codec ccp snd_hda_core snd_usb_audio kvm snd_usbmidi_lib snd_hwdep serio_raw snd_pcm fam15h_power k10temp snd_seq_midi snd_seq_midi_event snd_rawmidi gspca_zc3xx gspca_vc032x uvcvideo gspca_main snd_seq input_leds videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common joydev videodev snd_seq_device mc cdc_acm snd_timer snd soundcore mac_hid sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 dm_crypt amdgpu amd_iommu_v2 gpu_sched uas usb_storage hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel radeon i2c_algo_bit ttm aesni_intel crypto_simd drm_kms_helper
[ 1039.173027]  cryptd syscopyarea glue_helper sysfillrect sysimgblt fb_sys_fops i2c_piix4 ahci drm libahci r8169 realtek video [last unloaded: v4l2loopback]
[ 1039.173035] CPU: 3 PID: 8520 Comm: v4l_id Tainted: G        W  OE     5.4.0-29-generic #33-Ubuntu
[ 1039.173036] Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./G1.Sniper A88X-CF, BIOS F7 01/08/2014
[ 1039.173042] RIP: 0010:v4l_querycap+0x8b/0xa0 [videodev]
[ 1039.173044] Code: 54 81 ca 00 00 00 80 48 b9 00 00 20 00 00 00 20 00 48 0b 4b 54 21 d6 39 f2 75 13 48 89 4b 54 5b 41 5c 41 5d 41 5e 41 5f 5d c3 <0f> 0b eb d0 0f 0b 48 89 4b 54 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f
[ 1039.173045] RSP: 0018:ffffbc64429c3c70 EFLAGS: 00010297
[ 1039.173047] RAX: 0000000000000000 RBX: ffffbc64429c3d88 RCX: 0000000000000001
[ 1039.173048] RDX: 0000000085008003 RSI: 0000000000000000 RDI: 0000000000000000
[ 1039.173048] RBP: ffffbc64429c3c98 R08: 0000000000000000 R09: 0000000000ffff0a
[ 1039.173049] R10: 0000000000000000 R11: 0000000000000000 R12: ffff92f309255000
[ 1039.173050] R13: ffff92f317d7e200 R14: ffff92f234abe6a0 R15: ffffffffc0fd8380
[ 1039.173052] FS:  00007fc41b97e580(0000) GS:ffff92f31fb80000(0000) knlGS:0000000000000000
[ 1039.173053] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1039.173053] CR2: 00007fc41b830cc0 CR3: 00000007a7e00000 CR4: 00000000000406e0
[ 1039.173054] Call Trace:
[ 1039.173064]  __video_do_ioctl+0x1a7/0x410 [videodev]
[ 1039.173070]  video_usercopy+0x2b5/0x670 [videodev]
[ 1039.173076]  ? v4l_s_fmt+0x670/0x670 [videodev]
[ 1039.173082]  video_ioctl2+0x15/0x20 [videodev]
[ 1039.173087]  v4l2_ioctl+0x4c/0x60 [videodev]
[ 1039.173091]  do_vfs_ioctl+0x407/0x670
[ 1039.173095]  ? __secure_computing+0x42/0xe0
[ 1039.173096]  ksys_ioctl+0x67/0x90
[ 1039.173098]  __x64_sys_ioctl+0x1a/0x20
[ 1039.173100]  do_syscall_64+0x57/0x190
[ 1039.173103]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1039.173105] RIP: 0033:0x7fc41b83737b
[ 1039.173107] Code: 0f 1e fa 48 8b 05 15 3b 0d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e5 3a 0d 00 f7 d8 64 89 01 48
[ 1039.173108] RSP: 002b:00007ffd63439488 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 1039.173109] RAX: ffffffffffffffda RBX: 00007ffd63439608 RCX: 00007fc41b83737b
[ 1039.173110] RDX: 00007ffd63439490 RSI: 0000000080685600 RDI: 0000000000000003
[ 1039.173110] RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
[ 1039.173111] R10: 0000000000000000 R11: 0000000000000246 R12: 000055a68fffa440
[ 1039.173112] R13: 00007ffd63439600 R14: 0000000000000000 R15: 0000000000000000
[ 1039.173114] ---[ end trace d94124d807433b7d ]---
[ 1039.173126] ------------[ cut here ]------------
[ 1039.173132] WARNING: CPU: 3 PID: 8520 at drivers/media/v4l2-core/v4l2-ioctl.c:1069 v4l_querycap+0x8f/0xa0 [videodev]
[ 1039.173132] Modules linked in: v4l2loopback(OE) snd_seq_dummy iptable_mangle xt_CHECKSUM iptable_nat xt_MASQUERADE nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c xt_tcpudp bridge stp llc iptable_filter bpfilter binfmt_misc nls_iso8859_1 snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_hda_codec_hdmi edac_mce_amd snd_hda_intel snd_intel_dspcfg kvm_amd snd_hda_codec ccp snd_hda_core snd_usb_audio kvm snd_usbmidi_lib snd_hwdep serio_raw snd_pcm fam15h_power k10temp snd_seq_midi snd_seq_midi_event snd_rawmidi gspca_zc3xx gspca_vc032x uvcvideo gspca_main snd_seq input_leds videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common joydev videodev snd_seq_device mc cdc_acm snd_timer snd soundcore mac_hid sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 dm_crypt amdgpu amd_iommu_v2 gpu_sched uas usb_storage hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel radeon i2c_algo_bit ttm aesni_intel crypto_simd drm_kms_helper
[ 1039.173153]  cryptd syscopyarea glue_helper sysfillrect sysimgblt fb_sys_fops i2c_piix4 ahci drm libahci r8169 realtek video [last unloaded: v4l2loopback]
[ 1039.173158] CPU: 3 PID: 8520 Comm: v4l_id Tainted: G        W  OE     5.4.0-29-generic #33-Ubuntu
[ 1039.173158] Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./G1.Sniper A88X-CF, BIOS F7 01/08/2014
[ 1039.173164] RIP: 0010:v4l_querycap+0x8f/0xa0 [videodev]
[ 1039.173165] Code: 00 00 80 48 b9 00 00 20 00 00 00 20 00 48 0b 4b 54 21 d6 39 f2 75 13 48 89 4b 54 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b eb d0 <0f> 0b 48 89 4b 54 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 44 00 00
[ 1039.173166] RSP: 0018:ffffbc64429c3c70 EFLAGS: 00010202
[ 1039.173167] RAX: 0000000000000000 RBX: ffffbc64429c3d88 RCX: 8520800285208002
[ 1039.173168] RDX: 0000000085008003 RSI: 0000000085008002 RDI: 0000000000000000
[ 1039.173169] RBP: ffffbc64429c3c98 R08: 0000000000000000 R09: 0000000000ffff0a
[ 1039.173170] R10: 0000000000000000 R11: 0000000000000000 R12: ffff92f309255000
[ 1039.173171] R13: ffff92f317d7e200 R14: ffff92f234abe6a0 R15: ffffffffc0fd8380
[ 1039.173172] FS:  00007fc41b97e580(0000) GS:ffff92f31fb80000(0000) knlGS:0000000000000000
[ 1039.173173] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1039.173174] CR2: 00007fc41b830cc0 CR3: 00000007a7e00000 CR4: 00000000000406e0
[ 1039.173175] Call Trace:
[ 1039.173180]  __video_do_ioctl+0x1a7/0x410 [videodev]
[ 1039.173186]  video_usercopy+0x2b5/0x670 [videodev]
[ 1039.173192]  ? v4l_s_fmt+0x670/0x670 [videodev]
[ 1039.173198]  video_ioctl2+0x15/0x20 [videodev]
[ 1039.173202]  v4l2_ioctl+0x4c/0x60 [videodev]
[ 1039.173204]  do_vfs_ioctl+0x407/0x670
[ 1039.173207]  ? __secure_computing+0x42/0xe0
[ 1039.173208]  ksys_ioctl+0x67/0x90
[ 1039.173210]  __x64_sys_ioctl+0x1a/0x20
[ 1039.173211]  do_syscall_64+0x57/0x190
[ 1039.173213]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1039.173214] RIP: 0033:0x7fc41b83737b
[ 1039.173216] Code: 0f 1e fa 48 8b 05 15 3b 0d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e5 3a 0d 00 f7 d8 64 89 01 48
[ 1039.173217] RSP: 002b:00007ffd63439488 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 1039.173218] RAX: ffffffffffffffda RBX: 00007ffd63439608 RCX: 00007fc41b83737b
[ 1039.173219] RDX: 00007ffd63439490 RSI: 0000000080685600 RDI: 0000000000000003
[ 1039.173219] RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
[ 1039.173220] R10: 0000000000000000 R11: 0000000000000246 R12: 000055a68fffa440
[ 1039.173221] R13: 00007ffd63439600 R14: 0000000000000000 R15: 0000000000000000
[ 1039.173222] ---[ end trace d94124d807433b7e ]---

I get more or less the same traces again if I then start the v4l2sink in OBS Studio:

[ 1534.189944] ------------[ cut here ]------------
[ 1534.189983] WARNING: CPU: 1 PID: 9882 at drivers/media/v4l2-core/v4l2-ioctl.c:1064 v4l_querycap+0x8b/0xa0 [videodev]
[ 1534.189984] Modules linked in: v4l2loopback(OE) snd_seq_dummy iptable_mangle xt_CHECKSUM iptable_nat xt_MASQUERADE nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c xt_tcpudp bridge stp llc iptable_filter bpfilter binfmt_misc nls_iso8859_1 snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_hda_codec_hdmi edac_mce_amd snd_hda_intel snd_intel_dspcfg kvm_amd snd_hda_codec ccp snd_hda_core snd_usb_audio kvm snd_usbmidi_lib snd_hwdep serio_raw snd_pcm fam15h_power k10temp snd_seq_midi snd_seq_midi_event snd_rawmidi gspca_zc3xx gspca_vc032x uvcvideo gspca_main snd_seq input_leds videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common joydev videodev snd_seq_device mc cdc_acm snd_timer snd soundcore mac_hid sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 dm_crypt amdgpu amd_iommu_v2 gpu_sched uas usb_storage hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel radeon i2c_algo_bit ttm aesni_intel crypto_simd drm_kms_helper
[ 1534.190019]  cryptd syscopyarea glue_helper sysfillrect sysimgblt fb_sys_fops i2c_piix4 ahci drm libahci r8169 realtek video [last unloaded: v4l2loopback]
[ 1534.190030] CPU: 1 PID: 9882 Comm: obs Tainted: G        W  OE     5.4.0-29-generic #33-Ubuntu
[ 1534.190031] Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./G1.Sniper A88X-CF, BIOS F7 01/08/2014
[ 1534.190037] RIP: 0010:v4l_querycap+0x8b/0xa0 [videodev]
[ 1534.190039] Code: 54 81 ca 00 00 00 80 48 b9 00 00 20 00 00 00 20 00 48 0b 4b 54 21 d6 39 f2 75 13 48 89 4b 54 5b 41 5c 41 5d 41 5e 41 5f 5d c3 <0f> 0b eb d0 0f 0b 48 89 4b 54 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f
[ 1534.190040] RSP: 0018:ffffbc6442973c70 EFLAGS: 00010293
[ 1534.190041] RAX: 0000000000000000 RBX: ffffbc6442973d88 RCX: 0000000000000000
[ 1534.190042] RDX: 0000000085008003 RSI: 0000000000000000 RDI: 0000000000000000
[ 1534.190043] RBP: ffffbc6442973c98 R08: 0000000000000000 R09: 0000000000ffff0a
[ 1534.190043] R10: 0000000000000000 R11: 0000000000000000 R12: ffff92f309255000
[ 1534.190044] R13: ffff92f314284600 R14: ffff92f315fc96a0 R15: ffffffffc0fd8380
[ 1534.190045] FS:  00007f518ceedf00(0000) GS:ffff92f31fa80000(0000) knlGS:0000000000000000
[ 1534.190046] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1534.190047] CR2: 00007f5aae1a2000 CR3: 000000077def6000 CR4: 00000000000406e0
[ 1534.190048] Call Trace:
[ 1534.190057]  __video_do_ioctl+0x1a7/0x410 [videodev]
[ 1534.190062]  video_usercopy+0x2b5/0x670 [videodev]
[ 1534.190067]  ? v4l_s_fmt+0x670/0x670 [videodev]
[ 1534.190072]  video_ioctl2+0x15/0x20 [videodev]
[ 1534.190076]  v4l2_ioctl+0x4c/0x60 [videodev]
[ 1534.190080]  do_vfs_ioctl+0x407/0x670
[ 1534.190084]  ? putname+0x4a/0x50
[ 1534.190085]  ksys_ioctl+0x67/0x90
[ 1534.190086]  __x64_sys_ioctl+0x1a/0x20
[ 1534.190090]  do_syscall_64+0x57/0x190
[ 1534.190093]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1534.190095] RIP: 0033:0x7f518d02737b
[ 1534.190096] Code: 0f 1e fa 48 8b 05 15 3b 0d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e5 3a 0d 00 f7 d8 64 89 01 48
[ 1534.190097] RSP: 002b:00007ffce69e4028 EFLAGS: 00000206 ORIG_RAX: 0000000000000010
[ 1534.190098] RAX: ffffffffffffffda RBX: 000055ba74163e80 RCX: 00007f518d02737b
[ 1534.190098] RDX: 00007ffce69e4090 RSI: 0000000080685600 RDI: 0000000000000027
[ 1534.190099] RBP: 00007ffce69e41e0 R08: 000000000000ffff R09: 000000000000003f
[ 1534.190100] R10: 00007f518d077020 R11: 0000000000000206 R12: 0000000000000029
[ 1534.190100] R13: 00007f5125354044 R14: 00007ffce69e4490 R15: 00007f518d9cfe68
[ 1534.190102] ---[ end trace d94124d807433b83 ]---
[ 1534.190135] ------------[ cut here ]------------
[ 1534.190140] WARNING: CPU: 1 PID: 9882 at drivers/media/v4l2-core/v4l2-ioctl.c:1069 v4l_querycap+0x8f/0xa0 [videodev]
[ 1534.190141] Modules linked in: v4l2loopback(OE) snd_seq_dummy iptable_mangle xt_CHECKSUM iptable_nat xt_MASQUERADE nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c xt_tcpudp bridge stp llc iptable_filter bpfilter binfmt_misc nls_iso8859_1 snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_hda_codec_hdmi edac_mce_amd snd_hda_intel snd_intel_dspcfg kvm_amd snd_hda_codec ccp snd_hda_core snd_usb_audio kvm snd_usbmidi_lib snd_hwdep serio_raw snd_pcm fam15h_power k10temp snd_seq_midi snd_seq_midi_event snd_rawmidi gspca_zc3xx gspca_vc032x uvcvideo gspca_main snd_seq input_leds videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common joydev videodev snd_seq_device mc cdc_acm snd_timer snd soundcore mac_hid sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 dm_crypt amdgpu amd_iommu_v2 gpu_sched uas usb_storage hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel radeon i2c_algo_bit ttm aesni_intel crypto_simd drm_kms_helper
[ 1534.190157]  cryptd syscopyarea glue_helper sysfillrect sysimgblt fb_sys_fops i2c_piix4 ahci drm libahci r8169 realtek video [last unloaded: v4l2loopback]
[ 1534.190161] CPU: 1 PID: 9882 Comm: obs Tainted: G        W  OE     5.4.0-29-generic #33-Ubuntu
[ 1534.190161] Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./G1.Sniper A88X-CF, BIOS F7 01/08/2014
[ 1534.190166] RIP: 0010:v4l_querycap+0x8f/0xa0 [videodev]
[ 1534.190167] Code: 00 00 80 48 b9 00 00 20 00 00 00 20 00 48 0b 4b 54 21 d6 39 f2 75 13 48 89 4b 54 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b eb d0 <0f> 0b 48 89 4b 54 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 44 00 00
[ 1534.190168] RSP: 0018:ffffbc6442973c70 EFLAGS: 00010206
[ 1534.190169] RAX: 0000000000000000 RBX: ffffbc6442973d88 RCX: 8520800085208000
[ 1534.190169] RDX: 0000000085008003 RSI: 0000000085008000 RDI: 0000000000000000
[ 1534.190170] RBP: ffffbc6442973c98 R08: 0000000000000000 R09: 0000000000ffff0a
[ 1534.190170] R10: 0000000000000000 R11: 0000000000000000 R12: ffff92f309255000
[ 1534.190171] R13: ffff92f314284600 R14: ffff92f315fc96a0 R15: ffffffffc0fd8380
[ 1534.190172] FS:  00007f518ceedf00(0000) GS:ffff92f31fa80000(0000) knlGS:0000000000000000
[ 1534.190173] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1534.190174] CR2: 00007f5aae1a2000 CR3: 000000077def6000 CR4: 00000000000406e0
[ 1534.190174] Call Trace:
[ 1534.190179]  __video_do_ioctl+0x1a7/0x410 [videodev]
[ 1534.190184]  video_usercopy+0x2b5/0x670 [videodev]
[ 1534.190188]  ? v4l_s_fmt+0x670/0x670 [videodev]
[ 1534.190193]  video_ioctl2+0x15/0x20 [videodev]
[ 1534.190197]  v4l2_ioctl+0x4c/0x60 [videodev]
[ 1534.190198]  do_vfs_ioctl+0x407/0x670
[ 1534.190200]  ? putname+0x4a/0x50
[ 1534.190201]  ksys_ioctl+0x67/0x90
[ 1534.190202]  __x64_sys_ioctl+0x1a/0x20
[ 1534.190204]  do_syscall_64+0x57/0x190
[ 1534.190205]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1534.190206] RIP: 0033:0x7f518d02737b
[ 1534.190207] Code: 0f 1e fa 48 8b 05 15 3b 0d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e5 3a 0d 00 f7 d8 64 89 01 48
[ 1534.190208] RSP: 002b:00007ffce69e4028 EFLAGS: 00000206 ORIG_RAX: 0000000000000010
[ 1534.190209] RAX: ffffffffffffffda RBX: 000055ba74163e80 RCX: 00007f518d02737b
[ 1534.190209] RDX: 00007ffce69e4090 RSI: 0000000080685600 RDI: 0000000000000027
[ 1534.190210] RBP: 00007ffce69e41e0 R08: 000000000000ffff R09: 000000000000003f
[ 1534.190210] R10: 00007f518d077020 R11: 0000000000000206 R12: 0000000000000029
[ 1534.190211] R13: 00007f5125354044 R14: 00007ffce69e4490 R15: 00007f518d9cfe68
[ 1534.190212] ---[ end trace d94124d807433b84 ]---

Maybe the culprit is one of these:

$ LANG=C dpkg -l v4l2loopback-*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                 Version      Architecture Description
+++-====================-============-============-==========================================================
ii  v4l2loopback-dkms    0.12.3-1     all          Source for the v4l2loopback driver (DKMS)
un  v4l2loopback-modules <none>       <none>       (no description available)
ii  v4l2loopback-utils   0.12.3-1     all          Commandline utilities for the for the v4l2-loopback module

And no, I cannot test with the most recent 5.4.0-31 kernel as the boot partition created six years ago is too small to update a kernel if two current kernels (-generic and -lowlatency) are already installed. Even with compression = xz. And I'll retire the system later today, I'll report back if the issue persists on ryzen based systems.

Revision history for this message

Florian Hars (hars) wrote on 2020-05-28:

Argh, why did Firefox keep the contents of comment #6 in the edit box? Ignore comment #7, the relevant part is

And I have since retired the AMD A10 system, same behaviour on

[ 6442.968740] CPU: 0 PID: 45180 Comm: v4l_id Tainted: G W OE 5.4.0-33-generic #37-Ubuntu
[ 6442.968741] Hardware name: System manufacturer System Product Name/PRIME X570-PRO, BIOS 0604 07/02/2019

Revision history for this message

Kai-Heng Feng (kaihengfeng) wrote on 2020-05-29:

Ok, it's a bug in v4l2loopback:
https://github.com/umlaeute/v4l2loopback/commit/10b1c7e6bda4255fdfaa187ce2b3be13433416d2

Changed in linux (Ubuntu):
status:	Incomplete → Invalid

Tiago Stürmer Daitx (tdaitx) on 2020-09-30

Changed in v4l2loopback (Ubuntu):
status:	New → Confirmed
no longer affects:	linux (Ubuntu)
summary:	- Call trace from __video_do_ioctl + Call trace from __video_do_ioctl on focal

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Ubuntuv4l2loopback package

Call trace from __video_do_ioctl on focal

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v4l2loopback package