bisecting cause commit starting from 6d028043b55e54f48fbdf62ea8ce11a4ad830cac building syzkaller on 14544a569e7d56e60cba4c0451613bad8e1d18e0 testing commit 6d028043b55e54f48fbdf62ea8ce11a4ad830cac with gcc (GCC) 8.1.0 all runs: crashed: possible deadlock in __mmu_notifier_invalidate_range_end testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.1.0 all runs: OK # git bisect start 6d028043b55e54f48fbdf62ea8ce11a4ad830cac v5.2 Bisecting: 12603 revisions left to test after this (roughly 14 steps) [af6af87d7e4ff67324425daa699b9cda32e3161d] Merge tag 'armsoc-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc testing commit af6af87d7e4ff67324425daa699b9cda32e3161d with gcc (GCC) 8.1.0 all runs: OK # git bisect good af6af87d7e4ff67324425daa699b9cda32e3161d Bisecting: 6011 revisions left to test after this (roughly 13 steps) [05f4b611dfe75def9a5e21d4c162a94083b0dafb] Merge remote-tracking branch 'net-next/master' testing commit 05f4b611dfe75def9a5e21d4c162a94083b0dafb with gcc (GCC) 8.1.0 all runs: OK # git bisect good 05f4b611dfe75def9a5e21d4c162a94083b0dafb Bisecting: 3044 revisions left to test after this (roughly 12 steps) [99fa4cdf9cc24249e2fb8e0b0caf296a179c2cfb] Merge remote-tracking branch 'input/next' testing commit 99fa4cdf9cc24249e2fb8e0b0caf296a179c2cfb with gcc (GCC) 8.1.0 all runs: OK # git bisect good 99fa4cdf9cc24249e2fb8e0b0caf296a179c2cfb Bisecting: 1525 revisions left to test after this (roughly 11 steps) [6933f8bdee12723b5ec3fa9af55f8523a3c92298] Merge remote-tracking branch 'phy-next/next' testing commit 6933f8bdee12723b5ec3fa9af55f8523a3c92298 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 6933f8bdee12723b5ec3fa9af55f8523a3c92298 Bisecting: 709 revisions left to test after this (roughly 10 steps) [ecda3e90e6357b15f3189ce00938ea5a20850b76] Merge remote-tracking branch 'scsi/for-next' testing commit ecda3e90e6357b15f3189ce00938ea5a20850b76 with gcc (GCC) 8.1.0 all runs: OK # git bisect good ecda3e90e6357b15f3189ce00938ea5a20850b76 Bisecting: 354 revisions left to test after this (roughly 9 steps) [4cb65f973115d07578f5b8f4492da7d8295effe2] Merge remote-tracking branch 'rtc/rtc-next' testing commit 4cb65f973115d07578f5b8f4492da7d8295effe2 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 4cb65f973115d07578f5b8f4492da7d8295effe2 Bisecting: 177 revisions left to test after this (roughly 8 steps) [f3bf5fa4097e06b9cabb193599a012680380e52e] kernel/elfcore.c: include proper prototypes testing commit f3bf5fa4097e06b9cabb193599a012680380e52e with gcc (GCC) 8.1.0 all runs: OK # git bisect good f3bf5fa4097e06b9cabb193599a012680380e52e Bisecting: 78 revisions left to test after this (roughly 7 steps) [e58b341134ca751d9c12bacded12a8b4dd51368d] Merge remote-tracking branch 'hmm/hmm' testing commit e58b341134ca751d9c12bacded12a8b4dd51368d with gcc (GCC) 8.1.0 all runs: crashed: possible deadlock in __mmu_notifier_invalidate_range_end # git bisect bad e58b341134ca751d9c12bacded12a8b4dd51368d Bisecting: 49 revisions left to test after this (roughly 6 steps) [47f725ee7b5f5cae1f83512961bcf8b41a7a5794] RDMA/odp: remove ib_ucontext from ib_umem testing commit 47f725ee7b5f5cae1f83512961bcf8b41a7a5794 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 47f725ee7b5f5cae1f83512961bcf8b41a7a5794 Bisecting: 25 revisions left to test after this (roughly 5 steps) [f9016e8058fdcd4aadc9932e045891a7b3bc8c8f] Merge remote-tracking branch 'nvmem/for-next' testing commit f9016e8058fdcd4aadc9932e045891a7b3bc8c8f with gcc (GCC) 8.1.0 run #0: OK run #1: OK run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: boot failed: WARNING: workqueue cpumask: online intersect > possible intersect run #9: OK # git bisect good f9016e8058fdcd4aadc9932e045891a7b3bc8c8f Bisecting: 11 revisions left to test after this (roughly 4 steps) [2f6e2a06b51e0dd9767bf37c3542ee3b5e4611d4] Merge remote-tracking branch 'pidfd/for-next' testing commit 2f6e2a06b51e0dd9767bf37c3542ee3b5e4611d4 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 2f6e2a06b51e0dd9767bf37c3542ee3b5e4611d4 Bisecting: 5 revisions left to test after this (roughly 3 steps) [d2b219ed03d45a9799e4ba780c209edf9c510d3b] mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end testing commit d2b219ed03d45a9799e4ba780c209edf9c510d3b with gcc (GCC) 8.1.0 all runs: OK # git bisect good d2b219ed03d45a9799e4ba780c209edf9c510d3b Bisecting: 2 revisions left to test after this (roughly 2 steps) [4e10e8c36663a011f77d39c937aaa473fad90de3] mm: split out a new pagewalk.h header from mm.h testing commit 4e10e8c36663a011f77d39c937aaa473fad90de3 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 4e10e8c36663a011f77d39c937aaa473fad90de3 Bisecting: 0 revisions left to test after this (roughly 1 step) [5b8f3df6239c3a9b625ab4bdc69c54d4768a4f06] pagewalk: use lockdep_assert_held for locking validation testing commit 5b8f3df6239c3a9b625ab4bdc69c54d4768a4f06 with gcc (GCC) 8.1.0 all runs: OK # git bisect good 5b8f3df6239c3a9b625ab4bdc69c54d4768a4f06 e58b341134ca751d9c12bacded12a8b4dd51368d is the first bad commit revisions tested: 16, total time: 4h30m35.616412487s (build: 1h33m39.526463854s, test: 2h50m13.608432173s) first bad commit: e58b341134ca751d9c12bacded12a8b4dd51368d Merge remote-tracking branch 'hmm/hmm' cc: ["airlied@linux.ie" "akpm@linux-foundation.org" "bhelgaas@google.com" "bskeggs@redhat.com" "dan.j.williams@intel.com" "daniel@ffwll.ch" "dri-devel@lists.freedesktop.org" "jglisse@redhat.com" "linux-kernel@vger.kernel.org" "logang@deltatee.com" "nouveau@lists.freedesktop.org" "sfr@canb.auug.org.au"] crash: possible deadlock in __mmu_notifier_invalidate_range_end ============================================ WARNING: possible recursive locking detected 5.3.0-rc6+ #0 Not tainted -------------------------------------------- oom_reaper/1065 is trying to acquire lock: ffffffff88645bc0 (mmu_notifier_invalidate_range_start){+.+.}, at: __mmu_notifier_invalidate_range_end+0x0/0x300 mm/mmu_notifier.c:169 but task is already holding lock: ffffffff88645bc0 (mmu_notifier_invalidate_range_start){+.+.}, at: __oom_reap_task_mm+0x1b6/0x3d0 mm/oom_kill.c:543 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(mmu_notifier_invalidate_range_start); lock(mmu_notifier_invalidate_range_start); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by oom_reaper/1065: #0: ffff888090ff02d0 (&mm->mmap_sem#2){++++}, at: oom_reap_task_mm mm/oom_kill.c:571 [inline] #0: ffff888090ff02d0 (&mm->mmap_sem#2){++++}, at: oom_reap_task mm/oom_kill.c:614 [inline] #0: ffff888090ff02d0 (&mm->mmap_sem#2){++++}, at: oom_reaper+0x297/0xd00 mm/oom_kill.c:652 #1: ffffffff88645bc0 (mmu_notifier_invalidate_range_start){+.+.}, at: __oom_reap_task_mm+0x1b6/0x3d0 mm/oom_kill.c:543 stack backtrace: CPU: 1 PID: 1065 Comm: oom_reaper Not tainted 5.3.0-rc6+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x113/0x167 lib/dump_stack.c:113 print_deadlock_bug kernel/locking/lockdep.c:2371 [inline] check_deadlock kernel/locking/lockdep.c:2412 [inline] validate_chain kernel/locking/lockdep.c:2955 [inline] __lock_acquire.cold.66+0x15d/0x398 kernel/locking/lockdep.c:3955 lock_acquire+0x194/0x410 kernel/locking/lockdep.c:4487 __mmu_notifier_invalidate_range_end+0x37/0x300 mm/mmu_notifier.c:193 mmu_notifier_invalidate_range_end include/linux/mmu_notifier.h:375 [inline] __oom_reap_task_mm+0x2b4/0x3d0 mm/oom_kill.c:553 oom_reap_task_mm mm/oom_kill.c:590 [inline] oom_reap_task mm/oom_kill.c:614 [inline] oom_reaper+0x20f/0xd00 mm/oom_kill.c:652 kthread+0x331/0x3f0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 oom_reaper: reaped process 7867 (syz-executor.1), now anon-rss:18232kB, file-rss:19516kB, shmem-rss:0kB oom_reaper: reaped process 7891 (syz-executor.5), now anon-rss:18232kB, file-rss:19516kB, shmem-rss:0kB oom_reaper: reaped process 7894 (syz-executor.2), now anon-rss:18232kB, file-rss:19516kB, shmem-rss:0kB oom_reaper: reaped process 7898 (syz-executor.4), now anon-rss:18352kB, file-rss:19516kB, shmem-rss:0kB oom_reaper: reaped process 7906 (syz-executor.3), now anon-rss:18200kB, file-rss:18552kB, shmem-rss:0kB oom_reaper: reaped process 7856 (syz-executor.1), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB oom_reaper: reaped process 7850 (syz-executor.5), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB oom_reaper: reaped process 7887 (syz-executor.2), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB oom_reaper: reaped process 7802 (syz-executor.2), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB oom_reaper: reaped process 7943 (syz-executor.1), now anon-rss:17868kB, file-rss:19516kB, shmem-rss:0kB oom_reaper: reaped process 7947 (syz-executor.5), now anon-rss:18324kB, file-rss:18552kB, shmem-rss:0kB oom_reaper: reaped process 7959 (syz-executor.0), now anon-rss:18172kB, file-rss:19512kB, shmem-rss:0kB oom_reaper: reaped process 7764 (syz-executor.0), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB oom_reaper: reaped process 7834 (syz-executor.4), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB oom_reaper: reaped process 7969 (syz-executor.3), now anon-rss:18208kB, file-rss:18552kB, shmem-rss:0kB