Greetings, 0day kernel testing robot got the below dmesg and the first bad commit is https://github.com/0day-ci/linux/commits/Hans-Verkuil/mc-entity-c-use-WARN_ON-validate-link-pads/20200205-045118 commit c488a041dc93ca14925f0cc2092c45c7e31a84bb Author: Hans Verkuil AuthorDate: Tue Feb 4 19:13:13 2020 +0100 Commit: 0day robot CommitDate: Wed Feb 5 04:51:19 2020 +0800 mc-entity.c: use WARN_ON, validate link pads Use WARN_ON instead of BUG_ON. Add two new WARN_ONs to verify that the source pad is really a source and that the sink pad is really a sink. Signed-off-by: Hans Verkuil 1697d98124 media: staging/intel-ipu3: remove TODO item about acronyms c488a041dc mc-entity.c: use WARN_ON, validate link pads +----------------------------------------------------------------+------------+------------+ | | 1697d98124 | c488a041dc | +----------------------------------------------------------------+------------+------------+ | boot_successes | 35 | 0 | | boot_failures | 1 | 11 | | WARNING:at_lib/kobject.c:#kobject_put | 1 | | | EIP:kobject_put | 1 | | | WARNING:at_lib/refcount.c:#refcount_warn_saturate | 1 | | | EIP:refcount_warn_saturate | 1 | | | BUG:kernel_NULL_pointer_dereference,address | 1 | | | Oops:#[##] | 1 | | | EIP:__list_del_entry_valid | 1 | | | Kernel_panic-not_syncing:Fatal_exception | 1 | | | WARNING:at_drivers/media/mc/mc-entity.c:#media_create_pad_link | 0 | 11 | | EIP:media_create_pad_link | 0 | 11 | +----------------------------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot [ 8.927083] vivid-000: V4L2 metadata capture device registered as video2 [ 8.928030] vivid-000: V4L2 metadata output device registered as video3 [ 8.929014] vivid-000: V4L2 touch capture device registered as v4l-touch0 [ 8.930568] vim2m vim2m.0: Device registered as /dev/video4 [ 8.931315] ------------[ cut here ]------------ [ 8.931848] WARNING: CPU: 1 PID: 1 at drivers/media/mc/mc-entity.c:671 media_create_pad_link+0x72/0x124 [ 8.933076] Modules linked in: [ 8.933429] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G T 5.5.0-rc5-00209-gc488a041dc93ca #1 [ 8.934471] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 8.935408] EIP: media_create_pad_link+0x72/0x124 [ 8.935938] Code: 0b eb ea 8b 56 2c c1 e7 05 89 7d ec f6 44 3a 1c 02 75 04 0f 0b eb d6 c1 e0 05 89 45 e8 8b 43 2c 8b 4d e8 f6 44 08 1c 01 75 04 <0f> 0b eb bf 8d 46 30 e8 87 fc ff ff 89 45 f0 b8 f4 ff ff ff 83 7d [ 8.938080] EAX: f0d232e8 EBX: f0d23298 ECX: 00000020 EDX: f0d23208 [ 8.938780] ESI: f09be874 EDI: 00000000 EBP: b03dbdf8 ESP: b03dbde0 [ 8.938780] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010246 [ 8.938780] CR0: 80050033 CR2: ffffffff CR3: 027a7000 CR4: 00040690 [ 8.938780] Call Trace: [ 8.938780] v4l2_m2m_register_media_controller+0xb0/0x1a2 [ 8.938780] vim2m_probe+0x1d3/0x22e [ 8.938780] platform_drv_probe+0x41/0x7d [ 8.938780] really_probe+0x114/0x2c5 [ 8.938780] driver_probe_device+0xdd/0x118 [ 8.938780] device_driver_attach+0x36/0x49 [ 8.938780] __driver_attach+0x82/0x89 [ 8.938780] bus_for_each_dev+0x44/0x70 [ 8.938780] driver_attach+0x1c/0x21 [ 8.938780] ? device_driver_attach+0x49/0x49 [ 8.938780] bus_add_driver+0xc1/0x17c [ 8.938780] driver_register+0x8c/0xbe [ 8.938780] __platform_driver_register+0x35/0x39 [ 8.938780] ? vivid_init+0x73/0x73 [ 8.938780] vim2m_init+0x3c/0x73 [ 8.938780] ? vivid_init+0x73/0x73 [ 8.938780] do_one_initcall+0xa2/0x1d3 [ 8.938780] ? trace_initcall_level+0x77/0x7b [ 8.938780] ? kernel_init_freeable+0x1a9/0x269 [ 8.938780] kernel_init_freeable+0x1c4/0x269 [ 8.938780] ? rest_init+0xdc/0xdc [ 8.938780] kernel_init+0xd/0xda [ 8.938780] ret_from_fork+0x1e/0x28 [ 8.938780] random: get_random_bytes called from init_oops_id+0x28/0x3f with crng_init=0 [ 8.938780] ---[ end trace db4e5087d0e8da6d ]--- [ 8.968305] vim2m vim2m.0: Failed to init mem2mem media controller # HH:MM RESULT GOOD BAD GOOD_BUT_DIRTY DIRTY_NOT_BAD git bisect start 1c77f50bd0619008004af8a9510697ffc9a14056 b3a987b0264d3ddbb24293ebff10eddfc472f653 -- git bisect good 66cdd670814f7f62b4ecbd5dbf831f5e7574ae88 # 07:30 G 10 0 1 1 Merge 'linux-review/Dan-Murphy/net-phy-dp83867-Add-speed-optimization-feature/20200205-045548' into devel-catchup-202002050542 git bisect good 55f7f760a632072e67f40f3a227110f18b51b10d # 07:58 G 10 0 0 0 Merge 'sound/for-next' into devel-catchup-202002050542 git bisect bad 61e24d7f5f2cdc1604fa5ccf93e8f0273fe81145 # 08:14 B 0 6 26 4 Merge 'linux-review/Hans-Verkuil/mc-entity-c-use-WARN_ON-validate-link-pads/20200205-045118' into devel-catchup-202002050542 git bisect good 1a6c0b36dd19c51cdd76895d009c5deba2286ebb # 09:06 G 11 0 1 1 media: v4l2-core: fix VIDIOC_DQEVENT for time64 ABI git bisect good 1ec4c6efe23154b4ab44c1a34dbc0eb121eb614a # 10:00 G 11 0 1 1 media: saa7146: Avoid using BUG_ON as an assertion git bisect good 402e77c4c7fdfbbd48f91160314c26fc39741d31 # 10:36 G 10 0 0 0 media: usb: dvb-usb-v2: anysee: convert to use i2c_new_client_device() git bisect good bae1155cf5798cc65fedeecfa82c2f48fa3ed18b # 10:58 G 10 0 1 1 media: staging: rkisp1: add output device for parameters git bisect good 1dd2e8f942574e2be18374ebb81751082d8d467c # 11:21 G 11 0 0 0 media: uvcvideo: Add a quirk to force GEO GC6500 Camera bits-per-pixel value git bisect good 0b09f98987568842422610f6622068c14e79b707 # 11:42 G 11 0 0 0 media: Revert "media: staging/intel-ipu3: make imgu use fixed running mode" git bisect good 1697d98124819aab09b86602978bd4f50e101e2d # 12:05 G 10 0 0 0 media: staging/intel-ipu3: remove TODO item about acronyms git bisect bad c488a041dc93ca14925f0cc2092c45c7e31a84bb # 12:24 B 0 1 17 0 mc-entity.c: use WARN_ON, validate link pads # first bad commit: [c488a041dc93ca14925f0cc2092c45c7e31a84bb] mc-entity.c: use WARN_ON, validate link pads git bisect good 1697d98124819aab09b86602978bd4f50e101e2d # 12:36 G 31 0 2 2 media: staging/intel-ipu3: remove TODO item about acronyms # extra tests with debug options git bisect good c488a041dc93ca14925f0cc2092c45c7e31a84bb # 13:25 G 10 0 5 8 mc-entity.c: use WARN_ON, validate link pads # extra tests on head commit of linux-review/Hans-Verkuil/mc-entity-c-use-WARN_ON-validate-link-pads/20200205-045118 git bisect bad c488a041dc93ca14925f0cc2092c45c7e31a84bb # 13:46 B 0 11 27 0 mc-entity.c: use WARN_ON, validate link pads # bad: [c488a041dc93ca14925f0cc2092c45c7e31a84bb] mc-entity.c: use WARN_ON, validate link pads # extra tests on revert first bad commit git bisect good 50f9a2ce1041b0b2ebe9da640c89c2f1dde201e9 # 14:41 G 10 0 0 0 Revert "mc-entity.c: use WARN_ON, validate link pads" # good: [50f9a2ce1041b0b2ebe9da640c89c2f1dde201e9] Revert "mc-entity.c: use WARN_ON, validate link pads" --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/hyperkitty/list/lkp(a)lists.01.org Intel Corporation