bisecting cause commit starting from cd8c917a56f20f48748dd43d9ae3caff51d5b987 building syzkaller on 0230ba3e7ee638765ace8e2c3b436e703017b46c testing commit cd8c917a56f20f48748dd43d9ae3caff51d5b987 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: ec9f7c82bad1c5619fb6e2fc944720a320c793378a914f0b3a3f9db3e4eadbd8 run #0: crashed: INFO: task hung in io_uring_cancel_generic run #1: crashed: INFO: task hung in io_uring_cancel_generic run #2: crashed: INFO: task hung in io_uring_cancel_generic run #3: crashed: INFO: task hung in io_uring_cancel_generic run #4: crashed: INFO: task hung in io_uring_cancel_generic run #5: crashed: INFO: task hung in io_uring_cancel_generic run #6: crashed: INFO: task hung in io_uring_cancel_generic run #7: crashed: INFO: task hung in io_uring_cancel_generic run #8: crashed: INFO: task hung in io_uring_cancel_generic run #9: crashed: INFO: task hung in io_uring_cancel_generic run #10: crashed: INFO: task hung in io_uring_cancel_generic run #11: crashed: INFO: task hung in io_uring_cancel_generic run #12: crashed: INFO: task hung in io_uring_cancel_generic run #13: crashed: INFO: task hung in io_uring_cancel_generic run #14: OK run #15: OK run #16: OK run #17: crashed: INFO: task hung in io_uring_cancel_generic run #18: OK run #19: OK testing release v5.15 testing commit 8bb7eca972ad531c9b149c0a51ab43a417385813 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: d9ca6cc1f68808c6961fd688fb3518bfe3e4364cb8fa55f582c934a8d643c6ec all runs: OK # git bisect start cd8c917a56f20f48748dd43d9ae3caff51d5b987 8bb7eca972ad531c9b149c0a51ab43a417385813 Bisecting: 7033 revisions left to test after this (roughly 13 steps) [ff0700f03609b9f0defacd4ce96d9519d721e0a2] Merge tag 'sound-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound testing commit ff0700f03609b9f0defacd4ce96d9519d721e0a2 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 861d11f64413b1907c8a3cbdfb2346af53561e8364b230b3d3b7c9d8d4667b32 all runs: crashed: INFO: task hung in io_uring_cancel_generic # git bisect bad ff0700f03609b9f0defacd4ce96d9519d721e0a2 Bisecting: 2697 revisions left to test after this (roughly 12 steps) [fc02cb2b37fe2cbf1d3334b9f0f0eab9431766c4] Merge tag 'net-next-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next testing commit fc02cb2b37fe2cbf1d3334b9f0f0eab9431766c4 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 2daaf58c7abefe8c753a24ab0cb1ab61c200030ff6465085786c2b251715f351 all runs: crashed: INFO: task hung in io_uring_cancel_generic # git bisect bad fc02cb2b37fe2cbf1d3334b9f0f0eab9431766c4 Bisecting: 2251 revisions left to test after this (roughly 11 steps) [b7b98f868987cd3e86c9bd9a6db048614933d7a0] Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next testing commit b7b98f868987cd3e86c9bd9a6db048614933d7a0 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 206de0cbbf007d3941cf4c49402a86e78f173985fc26e22b74bc73f1fc3985e0 all runs: OK # git bisect good b7b98f868987cd3e86c9bd9a6db048614933d7a0 Bisecting: 1127 revisions left to test after this (roughly 10 steps) [6e5772c8d9cf0a77ba4d6fd34fd4126fb66c9983] Merge tag 'x86_cc_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip testing commit 6e5772c8d9cf0a77ba4d6fd34fd4126fb66c9983 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 095cfc86839c6b7ad5b78d78dab6efc6562fc92264d8781d261091073ed047af all runs: crashed: INFO: task hung in io_uring_cancel_generic # git bisect bad 6e5772c8d9cf0a77ba4d6fd34fd4126fb66c9983 Bisecting: 564 revisions left to test after this (roughly 9 steps) [19901165d90fdca1e57c9baa0d5b4c63d15c476a] Merge tag 'for-5.16/inode-sync-2021-10-29' of git://git.kernel.dk/linux-block testing commit 19901165d90fdca1e57c9baa0d5b4c63d15c476a compiler: gcc (GCC) 10.2.1 20210217 ./include/linux/page-flags.h:806:29: error: macro "PAGEFLAG_FALSE" requires 2 arguments, but only 1 given ./include/linux/page-flags.h:807:32: error: macro "TESTSCFLAG_FALSE" requires 2 arguments, but only 1 given ./include/linux/page-flags.h:806:1: error: unknown type name 'PAGEFLAG_FALSE' ./include/linux/page-flags.h:807:18: error: expected ';' before 'static' # git bisect skip 19901165d90fdca1e57c9baa0d5b4c63d15c476a Bisecting: 564 revisions left to test after this (roughly 9 steps) [cf2197ca4b8c199d188593ca6800ea1827c42171] bcache: move uapi header bcache.h to bcache code directory testing commit cf2197ca4b8c199d188593ca6800ea1827c42171 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 487a97eb29d020c55cc2d7e241a580e0f03e2d34dcd133a8c82b732bfbbedc77 all runs: boot failed: general protection fault in blk_mq_free_request # git bisect skip cf2197ca4b8c199d188593ca6800ea1827c42171 Bisecting: 564 revisions left to test after this (roughly 9 steps) [3caee4634be68e755d2fb130962f1623661dbd5b] block: use bdev_get_queue() in bio.c testing commit 3caee4634be68e755d2fb130962f1623661dbd5b compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: b46593892b1c3db8d2e6444ab417d142ad291f546037f8e0dd07984f7ba63c7e all runs: OK # git bisect good 3caee4634be68e755d2fb130962f1623661dbd5b Bisecting: 539 revisions left to test after this (roughly 9 steps) [2cf3f8133bda2a0945cc4c70e681ecb25b52b913] btrfs: fix lzo_decompress_bio() kmap leakage testing commit 2cf3f8133bda2a0945cc4c70e681ecb25b52b913 compiler: gcc (GCC) 10.2.1 20210217 ./include/linux/page-flags.h:806:29: error: macro "PAGEFLAG_FALSE" requires 2 arguments, but only 1 given ./include/linux/page-flags.h:807:32: error: macro "TESTSCFLAG_FALSE" requires 2 arguments, but only 1 given ./include/linux/page-flags.h:806:1: error: unknown type name 'PAGEFLAG_FALSE' ./include/linux/page-flags.h:807:18: error: expected ';' before 'static' # git bisect skip 2cf3f8133bda2a0945cc4c70e681ecb25b52b913 Bisecting: 539 revisions left to test after this (roughly 9 steps) [582b01b6ab2714a0a4d554cea7f0d4efeaa2154d] x86/fpu: Remove old KVM FPU interface testing commit 582b01b6ab2714a0a4d554cea7f0d4efeaa2154d compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: c18b7008093be00b3f2ea050b11c2cd986ab913d67e1a32cc2fc1bede04418f8 all runs: OK # git bisect good 582b01b6ab2714a0a4d554cea7f0d4efeaa2154d Bisecting: 474 revisions left to test after this (roughly 9 steps) [cd3e8ea847eea97095aa01de3d12674d35fd0199] Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt testing commit cd3e8ea847eea97095aa01de3d12674d35fd0199 compiler: gcc (GCC) 10.2.1 20210217 ./include/linux/page-flags.h:806:29: error: macro "PAGEFLAG_FALSE" requires 2 arguments, but only 1 given ./include/linux/page-flags.h:807:32: error: macro "TESTSCFLAG_FALSE" requires 2 arguments, but only 1 given ./include/linux/page-flags.h:806:1: error: unknown type name 'PAGEFLAG_FALSE' ./include/linux/page-flags.h:807:18: error: expected ';' before 'static' # git bisect skip cd3e8ea847eea97095aa01de3d12674d35fd0199 Bisecting: 474 revisions left to test after this (roughly 9 steps) [9e6a6b1212100148c109675e003369e3e219dbd9] nvme: paring quiesce/unquiesce testing commit 9e6a6b1212100148c109675e003369e3e219dbd9 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 9ee14523361708a263bf7b438887007f0cb4ced5115c4933f647908ea5259447 all runs: OK # git bisect good 9e6a6b1212100148c109675e003369e3e219dbd9 Bisecting: 458 revisions left to test after this (roughly 9 steps) [67a135b80eb75b62d92a809b0246e70524f69b89] Merge tag 'erofs-for-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs testing commit 67a135b80eb75b62d92a809b0246e70524f69b89 compiler: gcc (GCC) 10.2.1 20210217 ./include/linux/page-flags.h:806:29: error: macro "PAGEFLAG_FALSE" requires 2 arguments, but only 1 given ./include/linux/page-flags.h:807:32: error: macro "TESTSCFLAG_FALSE" requires 2 arguments, but only 1 given ./include/linux/page-flags.h:806:1: error: unknown type name 'PAGEFLAG_FALSE' ./include/linux/page-flags.h:807:18: error: expected ';' before 'static' # git bisect skip 67a135b80eb75b62d92a809b0246e70524f69b89 Bisecting: 458 revisions left to test after this (roughly 9 steps) [f4f39fc5dc30d62625ad951b48dca2576f50768f] btrfs: remove btrfs_bio::logical member testing commit f4f39fc5dc30d62625ad951b48dca2576f50768f compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 5f26faf0248c9c6ba598d80122c518f8984e2ec9e7f993c8a71762fb974f04de run #0: crashed: INFO: task hung in io_uring_cancel_generic run #1: crashed: INFO: task hung in io_uring_cancel_generic run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK reproducer seems to be flaky # git bisect bad f4f39fc5dc30d62625ad951b48dca2576f50768f Bisecting: 57 revisions left to test after this (roughly 6 steps) [2adada886b26e998b5a624e72f0834ebfdc54cc7] btrfs: check for relocation inodes on zoned btrfs in should_nocow testing commit 2adada886b26e998b5a624e72f0834ebfdc54cc7 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: c29e651eb3db4db0cf1886cc38fc123988a38d3ba5f45edcd48c902c70e563a7 all runs: OK # git bisect good 2adada886b26e998b5a624e72f0834ebfdc54cc7 Bisecting: 28 revisions left to test after this (roughly 5 steps) [22c306fe0db7191df3d43938efd42423edf95f4d] btrfs: introduce alloc_compressed_bio() for compression testing commit 22c306fe0db7191df3d43938efd42423edf95f4d compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 8799f04f49b3a397453ecca2e29bb085189ebfeb2fc3bec7d8bb0fd159d9580e all runs: OK # git bisect good 22c306fe0db7191df3d43938efd42423edf95f4d Bisecting: 13 revisions left to test after this (roughly 4 steps) [0cf9b244e7db173bdb0cffed0253fea808f7f4e6] btrfs: subpage: only allow compression if the range is fully page aligned testing commit 0cf9b244e7db173bdb0cffed0253fea808f7f4e6 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 6e3b0f8ab1e9af75af2fc561d93c0a12e2e07c891c3fd419f1868a10a7b023c8 run #0: crashed: INFO: task hung in io_uring_cancel_generic run #1: OK run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK run #10: OK run #11: OK run #12: OK run #13: OK run #14: OK run #15: OK run #16: OK run #17: OK run #18: OK run #19: OK # git bisect bad 0cf9b244e7db173bdb0cffed0253fea808f7f4e6 Bisecting: 6 revisions left to test after this (roughly 3 steps) [741ec653ab58f5f263f2b6df38157997661c7a50] btrfs: subpage: make end_compressed_bio_writeback() compatible testing commit 741ec653ab58f5f263f2b6df38157997661c7a50 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 3a2997a21ebcc122354c88d07a2144b2d186e90106daef7b636951e359450d26 run #0: crashed: INFO: task hung in io_uring_cancel_generic run #1: crashed: INFO: task hung in io_uring_cancel_generic run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK run #10: OK run #11: OK run #12: OK run #13: OK run #14: OK run #15: OK run #16: OK run #17: OK run #18: OK run #19: OK # git bisect bad 741ec653ab58f5f263f2b6df38157997661c7a50 Bisecting: 3 revisions left to test after this (roughly 2 steps) [b4ccace878f47fd5008de41d45ec42f38d0e8c7d] btrfs: refactor submit_compressed_extents() testing commit b4ccace878f47fd5008de41d45ec42f38d0e8c7d compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 92512a743f3cf6c6003066ecace929b8540305b3364affd17764d95287661d49 all runs: OK # git bisect good b4ccace878f47fd5008de41d45ec42f38d0e8c7d Bisecting: 1 revision left to test after this (roughly 1 step) [4c162778d63eb8822492f715dbe06970d242b4fd] btrfs: subpage: make compress_file_range() compatible testing commit 4c162778d63eb8822492f715dbe06970d242b4fd compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: c5d9d34096dcb5600f8aab915e48de59b875346d2643128c578beff4c357ad30 all runs: OK # git bisect good 4c162778d63eb8822492f715dbe06970d242b4fd Bisecting: 0 revisions left to test after this (roughly 0 steps) [bbbff01a47bfe1b7733c5ccac6a78ff6d7a8954f] btrfs: subpage: make btrfs_submit_compressed_write() compatible testing commit bbbff01a47bfe1b7733c5ccac6a78ff6d7a8954f compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 71be79fe31df8b9e68b9648d7f4b1cd6f5bca6451024e3afe6c770ee32e7bede all runs: OK # git bisect good bbbff01a47bfe1b7733c5ccac6a78ff6d7a8954f 741ec653ab58f5f263f2b6df38157997661c7a50 is the first bad commit commit 741ec653ab58f5f263f2b6df38157997661c7a50 Author: Qu Wenruo Date: Mon Sep 27 15:22:01 2021 +0800 btrfs: subpage: make end_compressed_bio_writeback() compatible In end_compressed_writeback() we just clear the full page writeback. For subpage case, if there are two delalloc ranges in the same page, the 2nd range will trigger a BUG_ON() as the page writeback is already cleared by previous range. Fix it by using btrfs_page_clamp_clear_writeback() helper. Signed-off-by: Qu Wenruo Signed-off-by: David Sterba fs/btrfs/compression.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) culprit signature: 3a2997a21ebcc122354c88d07a2144b2d186e90106daef7b636951e359450d26 parent signature: 71be79fe31df8b9e68b9648d7f4b1cd6f5bca6451024e3afe6c770ee32e7bede Reproducer flagged being flaky revisions tested: 18, total time: 5h13m24.503439818s (build: 1h56m15.356340314s, test: 3h15m17.74234306s) first bad commit: 741ec653ab58f5f263f2b6df38157997661c7a50 btrfs: subpage: make end_compressed_bio_writeback() compatible recipients (to): ["clm@fb.com" "dsterba@suse.com" "dsterba@suse.com" "josef@toxicpanda.com" "linux-btrfs@vger.kernel.org" "wqu@suse.com"] recipients (cc): ["linux-kernel@vger.kernel.org"] crash: INFO: task hung in io_uring_cancel_generic INFO: task syz-executor.0:17528 blocked for more than 143 seconds. Not tainted 5.15.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:29072 pid:17528 ppid: 6949 flags:0x00024004 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb04/0x5920 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 io_uring_cancel_generic+0x4e8/0x650 fs/io_uring.c:9799 io_uring_files_cancel include/linux/io_uring.h:16 [inline] do_exit+0x1dc/0x24b0 kernel/exit.c:780 do_group_exit+0xe7/0x290 kernel/exit.c:922 get_signal+0x3b2/0x1ce0 kernel/signal.c:2855 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fad1a281af9 RSP: 002b:00007fad199f7218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fad1a394f68 RCX: 00007fad1a281af9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fad1a394f68 RBP: 00007fad1a394f60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fad1a394f6c R13: 00007ffff0b6a51f R14: 00007fad199f7300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8ab75d40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 3 locks held by kworker/u4:2/148: #0: ffff8880b9f31a98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:474 #1: ffff8880b9f1f9c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x16a/0x480 kernel/sched/psi.c:871 #2: ffff888078184858 (key#16){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] #2: ffff888078184858 (key#16){+...}-{2:2}, at: batadv_nc_purge_paths+0xc0/0x2d0 net/batman-adv/network-coding.c:444 1 lock held by in:imklog/6169: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x57/0x7d lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x30/0xc0 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x11a/0x160 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0x88c/0xbf0 kernel/hung_task.c:295 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 9148 Comm: kworker/u4:7 Not tainted 5.15.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: phy11 ieee80211_iface_work RIP: 0010:lock_is_held_type+0xfd/0x140 kernel/locking/lockdep.c:5673 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 9e b7 96 77 83 f8 01 75 29 9c 58 f6 c4 02 75 3d 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 45 31 ed eb b9 0f 0b 48 RSP: 0018:ffffc9000d2efbc8 EFLAGS: 00000282 RAX: 0000000000000046 RBX: 0000000000000002 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff88cb3d40 RDI: ffffffff891fdca0 RBP: ffffffff8ab75c80 R08: 0000000000000000 R09: ffff8880b9f32a4b R10: ffffed10173e6549 R11: 0000000000000000 R12: ffff888072c8e2c0 R13: 0000000000000000 R14: 00000000ffffffff R15: ffff888072c8ed08 FS: 0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f305e186020 CR3: 000000000a88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_kfree include/trace/events/kmem.h:118 [inline] kfree+0x1b0/0x2c0 mm/slab.c:3789 skb_free_head net/core/skbuff.c:654 [inline] skb_release_data+0x500/0x640 net/core/skbuff.c:676 skb_release_all net/core/skbuff.c:741 [inline] __kfree_skb net/core/skbuff.c:755 [inline] kfree_skb net/core/skbuff.c:773 [inline] kfree_skb+0xe0/0x2c0 net/core/skbuff.c:767 ieee80211_iface_work+0x2a6/0x970 net/mac80211/iface.c:1495 process_one_work+0x87f/0x1450 kernel/workqueue.c:2297 worker_thread+0x598/0x1040 kernel/workqueue.c:2444 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: b8 ff ff ff ff mov $0xffffffff,%eax 7: 65 0f c1 05 9e b7 96 xadd %eax,%gs:0x7796b79e(%rip) # 0x7796b7ad e: 77 f: 83 f8 01 cmp $0x1,%eax 12: 75 29 jne 0x3d 14: 9c pushfq 15: 58 pop %rax 16: f6 c4 02 test $0x2,%ah 19: 75 3d jne 0x58 1b: 48 f7 04 24 00 02 00 testq $0x200,(%rsp) 22: 00 23: 74 01 je 0x26 25: fb sti 26: 48 83 c4 08 add $0x8,%rsp * 2a: 44 89 e8 mov %r13d,%eax <-- trapping instruction 2d: 5b pop %rbx 2e: 5d pop %rbp 2f: 41 5c pop %r12 31: 41 5d pop %r13 33: 41 5e pop %r14 35: 41 5f pop %r15 37: c3 retq 38: 45 31 ed xor %r13d,%r13d 3b: eb b9 jmp 0xfffffff6 3d: 0f 0b ud2 3f: 48 rex.W