Following kernel crash noticed on Linux next-20240410 tag while running kunit testing on qemu-arm64 and qemu-x86_64.
Reported-by: Linux Kernel Functional Testing lkft@linaro.org
Crash log on qemu-arm64: ---------------- <3>[ 30.465716] BUG: KASAN: null-ptr-deref in _raw_spin_lock_irq (include/linux/instrumented.h:96 include/linux/atomic/atomic-instrumented.h:1301 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <3>[ 30.467097] Write of size 4 at addr 0000000000000008 by task swapper/0/1 <3>[ 30.468059] <3>[ 30.468393] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B N 6.9.0-rc3-next-20240410 #1 <3>[ 30.469209] Hardware name: linux,dummy-virt (DT) <3>[ 30.469645] Call trace: <3>[ 30.469919] dump_backtrace (arch/arm64/kernel/stacktrace.c:319) <3>[ 30.471622] show_stack (arch/arm64/kernel/stacktrace.c:326) <3>[ 30.472124] dump_stack_lvl (lib/dump_stack.c:117) <3>[ 30.472947] print_report (mm/kasan/report.c:493) <3>[ 30.473755] kasan_report (mm/kasan/report.c:603) <3>[ 30.474524] kasan_check_range (mm/kasan/generic.c:175 mm/kasan/generic.c:189) <3>[ 30.475094] __kasan_check_write (mm/kasan/shadow.c:38) <3>[ 30.475683] _raw_spin_lock_irq (include/linux/instrumented.h:96 include/linux/atomic/atomic-instrumented.h:1301 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <3>[ 30.476257] wait_for_completion_timeout (kernel/sched/completion.c:84 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:167) <3>[ 30.476909] kunit_try_catch_run (lib/kunit/try-catch.c:86) <3>[ 30.477628] kunit_run_case_catch_errors (lib/kunit/test.c:544) <3>[ 30.478311] kunit_run_tests (lib/kunit/test.c:635) <3>[ 30.478865] __kunit_test_suites_init (lib/kunit/test.c:729 (discriminator 1)) <3>[ 30.479482] kunit_run_all_tests (lib/kunit/executor.c:276 lib/kunit/executor.c:392) <3>[ 30.480079] kernel_init_freeable (init/main.c:1578) <3>[ 30.480747] kernel_init (init/main.c:1465) <3>[ 30.481474] ret_from_fork (arch/arm64/kernel/entry.S:861) <3>[ 30.482080] ================================================================== <1>[ 30.484503] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 <1>[ 30.485369] Mem abort info: <1>[ 30.485923] ESR = 0x000000009600006b <1>[ 30.486943] EC = 0x25: DABT (current EL), IL = 32 bits <1>[ 30.487540] SET = 0, FnV = 0 <1>[ 30.488007] EA = 0, S1PTW = 0 <1>[ 30.488509] FSC = 0x2b: level -1 translation fault <1>[ 30.489150] Data abort info: <1>[ 30.489610] ISV = 0, ISS = 0x0000006b, ISS2 = 0x00000000 <1>[ 30.490360] CM = 0, WnR = 1, TnD = 0, TagAccess = 0 <1>[ 30.491057] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 <1>[ 30.491822] [0000000000000008] user address but active_mm is swapper <0>[ 30.493008] Internal error: Oops: 000000009600006b [#1] PREEMPT SMP <4>[ 30.494105] Modules linked in: <4>[ 30.496244] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B N 6.9.0-rc3-next-20240410 #1 <4>[ 30.497171] Hardware name: linux,dummy-virt (DT) <4>[ 30.497905] pstate: 224000c9 (nzCv daIF +PAN -UAO +TCO -DIT -SSBS BTYPE=--) <4>[ 30.498895] pc : _raw_spin_lock_irq (arch/arm64/include/asm/atomic_lse.h:271 arch/arm64/include/asm/cmpxchg.h:120 arch/arm64/include/asm/cmpxchg.h:169 include/linux/atomic/atomic-arch-fallback.h:2055 include/linux/atomic/atomic-arch-fallback.h:2173 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <4>[ 30.499542] lr : _raw_spin_lock_irq (include/linux/atomic/atomic-arch-fallback.h:2172 (discriminator 1) include/linux/atomic/atomic-instrumented.h:1302 (discriminator 1) include/asm-generic/qspinlock.h:111 (discriminator 1) include/linux/spinlock.h:187 (discriminator 1) include/linux/spinlock_api_smp.h:120 (discriminator 1) kernel/locking/spinlock.c:170 (discriminator 1))
<trim>
<4>[ 30.511022] Call trace: <4>[ 30.511437] _raw_spin_lock_irq (arch/arm64/include/asm/atomic_lse.h:271 arch/arm64/include/asm/cmpxchg.h:120 arch/arm64/include/asm/cmpxchg.h:169 include/linux/atomic/atomic-arch-fallback.h:2055 include/linux/atomic/atomic-arch-fallback.h:2173 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <4>[ 30.512013] wait_for_completion_timeout (kernel/sched/completion.c:84 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:167) <4>[ 30.512627] kunit_try_catch_run (lib/kunit/try-catch.c:86) <4>[ 30.513188] kunit_run_case_catch_errors (lib/kunit/test.c:544) <4>[ 30.513801] kunit_run_tests (lib/kunit/test.c:635) <4>[ 30.514674] __kunit_test_suites_init (lib/kunit/test.c:729 (discriminator 1)) <4>[ 30.515259] kunit_run_all_tests (lib/kunit/executor.c:276 lib/kunit/executor.c:392) <4>[ 30.515831] kernel_init_freeable (init/main.c:1578) <4>[ 30.516384] kernel_init (init/main.c:1465) <4>[ 30.516900] ret_from_fork (arch/arm64/kernel/entry.S:861) <0>[ 30.518151] Code: 93407c02 d503201f 2a0003e1 52800022 (88e17e62) All code ======== 0: 93407c02 sxtw x2, w0 4: d503201f nop 8: 2a0003e1 mov w1, w0 c: 52800022 mov w2, #0x1 // #1 10:* 88e17e62 casa w1, w2, [x19] <-- trapping instruction
Code starting with the faulting instruction =========================================== 0: 88e17e62 casa w1, w2, [x19] <4>[ 30.519501] ---[ end trace 0000000000000000 ]--- <6>[ 30.520317] note: swapper/0[1] exited with irqs disabled <6>[ 30.521355] note: swapper/0[1] exited with preempt_count 1 <0>[ 30.523129] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b <2>[ 30.524397] SMP: stopping secondary CPUs <0>[ 30.525553] Kernel Offset: 0x25148d400000 from 0xffff800080000000 <0>[ 30.528341] PHYS_OFFSET: 0x40000000 <0>[ 30.529003] CPU features: 0x0,00000006,8f17bd7c,6766773f <0>[ 30.530313] Memory Limit: none <0>[ 30.531319] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---
Steps to reproduce: --- https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/2etdCz631GU...
Links: - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20240410/tes... - https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/2etdCz631GU... - https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/2etdDjlx3eR...
-- Linaro LKFT https://lkft.linaro.org
On Wed, Apr 10, 2024 at 03:57:10PM +0530, Naresh Kamboju wrote:
Following kernel crash noticed on Linux next-20240410 tag while running kunit testing on qemu-arm64 and qemu-x86_64.
Reported-by: Linux Kernel Functional Testing lkft@linaro.org
Crash log on qemu-arm64:
<3>[ 30.465716] BUG: KASAN: null-ptr-deref in _raw_spin_lock_irq (include/linux/instrumented.h:96 include/linux/atomic/atomic-instrumented.h:1301 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <3>[ 30.467097] Write of size 4 at addr 0000000000000008 by task swapper/0/1 <3>[ 30.468059] <3>[ 30.468393] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B N 6.9.0-rc3-next-20240410 #1 <3>[ 30.469209] Hardware name: linux,dummy-virt (DT) <3>[ 30.469645] Call trace: <3>[ 30.469919] dump_backtrace (arch/arm64/kernel/stacktrace.c:319) <3>[ 30.471622] show_stack (arch/arm64/kernel/stacktrace.c:326) <3>[ 30.472124] dump_stack_lvl (lib/dump_stack.c:117) <3>[ 30.472947] print_report (mm/kasan/report.c:493) <3>[ 30.473755] kasan_report (mm/kasan/report.c:603) <3>[ 30.474524] kasan_check_range (mm/kasan/generic.c:175 mm/kasan/generic.c:189) <3>[ 30.475094] __kasan_check_write (mm/kasan/shadow.c:38) <3>[ 30.475683] _raw_spin_lock_irq (include/linux/instrumented.h:96 include/linux/atomic/atomic-instrumented.h:1301 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <3>[ 30.476257] wait_for_completion_timeout (kernel/sched/completion.c:84 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:167) <3>[ 30.476909] kunit_try_catch_run (lib/kunit/try-catch.c:86) <3>[ 30.477628] kunit_run_case_catch_errors (lib/kunit/test.c:544) <3>[ 30.478311] kunit_run_tests (lib/kunit/test.c:635) <3>[ 30.478865] __kunit_test_suites_init (lib/kunit/test.c:729 (discriminator 1)) <3>[ 30.479482] kunit_run_all_tests (lib/kunit/executor.c:276 lib/kunit/executor.c:392) <3>[ 30.480079] kernel_init_freeable (init/main.c:1578) <3>[ 30.480747] kernel_init (init/main.c:1465) <3>[ 30.481474] ret_from_fork (arch/arm64/kernel/entry.S:861) <3>[ 30.482080] ================================================================== <1>[ 30.484503] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 <1>[ 30.485369] Mem abort info: <1>[ 30.485923] ESR = 0x000000009600006b <1>[ 30.486943] EC = 0x25: DABT (current EL), IL = 32 bits <1>[ 30.487540] SET = 0, FnV = 0 <1>[ 30.488007] EA = 0, S1PTW = 0 <1>[ 30.488509] FSC = 0x2b: level -1 translation fault <1>[ 30.489150] Data abort info: <1>[ 30.489610] ISV = 0, ISS = 0x0000006b, ISS2 = 0x00000000 <1>[ 30.490360] CM = 0, WnR = 1, TnD = 0, TagAccess = 0 <1>[ 30.491057] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 <1>[ 30.491822] [0000000000000008] user address but active_mm is swapper <0>[ 30.493008] Internal error: Oops: 000000009600006b [#1] PREEMPT SMP <4>[ 30.494105] Modules linked in: <4>[ 30.496244] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B N 6.9.0-rc3-next-20240410 #1 <4>[ 30.497171] Hardware name: linux,dummy-virt (DT) <4>[ 30.497905] pstate: 224000c9 (nzCv daIF +PAN -UAO +TCO -DIT -SSBS BTYPE=--) <4>[ 30.498895] pc : _raw_spin_lock_irq (arch/arm64/include/asm/atomic_lse.h:271 arch/arm64/include/asm/cmpxchg.h:120 arch/arm64/include/asm/cmpxchg.h:169 include/linux/atomic/atomic-arch-fallback.h:2055 include/linux/atomic/atomic-arch-fallback.h:2173 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <4>[ 30.499542] lr : _raw_spin_lock_irq (include/linux/atomic/atomic-arch-fallback.h:2172 (discriminator 1) include/linux/atomic/atomic-instrumented.h:1302 (discriminator 1) include/asm-generic/qspinlock.h:111 (discriminator 1) include/linux/spinlock.h:187 (discriminator 1) include/linux/spinlock_api_smp.h:120 (discriminator 1) kernel/locking/spinlock.c:170 (discriminator 1))
<trim>
It's a shame that you have trimmed the register dump here.
<4>[ 30.511022] Call trace: <4>[ 30.511437] _raw_spin_lock_irq (arch/arm64/include/asm/atomic_lse.h:271 arch/arm64/include/asm/cmpxchg.h:120 arch/arm64/include/asm/cmpxchg.h:169 include/linux/atomic/atomic-arch-fallback.h:2055 include/linux/atomic/atomic-arch-fallback.h:2173 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <4>[ 30.512013] wait_for_completion_timeout (kernel/sched/completion.c:84 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:167) <4>[ 30.512627] kunit_try_catch_run (lib/kunit/try-catch.c:86) <4>[ 30.513188] kunit_run_case_catch_errors (lib/kunit/test.c:544) <4>[ 30.513801] kunit_run_tests (lib/kunit/test.c:635)
Ok, so 'task_struct->vfork_done' is NULL. Looks like this code was added recently, so adding Mickaël to cc.
Will
<4>[ 30.514674] __kunit_test_suites_init (lib/kunit/test.c:729 (discriminator 1)) <4>[ 30.515259] kunit_run_all_tests (lib/kunit/executor.c:276 lib/kunit/executor.c:392) <4>[ 30.515831] kernel_init_freeable (init/main.c:1578) <4>[ 30.516384] kernel_init (init/main.c:1465) <4>[ 30.516900] ret_from_fork (arch/arm64/kernel/entry.S:861) <0>[ 30.518151] Code: 93407c02 d503201f 2a0003e1 52800022 (88e17e62) All code ======== 0: 93407c02 sxtw x2, w0 4: d503201f nop 8: 2a0003e1 mov w1, w0 c: 52800022 mov w2, #0x1 // #1 10:* 88e17e62 casa w1, w2, [x19] <-- trapping instruction
Code starting with the faulting instruction
0: 88e17e62 casa w1, w2, [x19] <4>[ 30.519501] ---[ end trace 0000000000000000 ]--- <6>[ 30.520317] note: swapper/0[1] exited with irqs disabled <6>[ 30.521355] note: swapper/0[1] exited with preempt_count 1 <0>[ 30.523129] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b <2>[ 30.524397] SMP: stopping secondary CPUs <0>[ 30.525553] Kernel Offset: 0x25148d400000 from 0xffff800080000000 <0>[ 30.528341] PHYS_OFFSET: 0x40000000 <0>[ 30.529003] CPU features: 0x0,00000006,8f17bd7c,6766773f <0>[ 30.530313] Memory Limit: none <0>[ 30.531319] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---
Steps to reproduce:
https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/2etdCz631GU...
Links:
- https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20240410/tes...
- https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/2etdCz631GU...
- https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/2etdDjlx3eR...
-- Linaro LKFT https://lkft.linaro.org
On Wed, 10 Apr 2024 at 20:53, Will Deacon will@kernel.org wrote:
On Wed, Apr 10, 2024 at 03:57:10PM +0530, Naresh Kamboju wrote:
Following kernel crash noticed on Linux next-20240410 tag while running kunit testing on qemu-arm64 and qemu-x86_64.
Reported-by: Linux Kernel Functional Testing lkft@linaro.org
Crash log on qemu-arm64:
<3>[ 30.465716] BUG: KASAN: null-ptr-deref in _raw_spin_lock_irq (include/linux/instrumented.h:96 include/linux/atomic/atomic-instrumented.h:1301 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170)
It's a shame that you have trimmed the register dump here.
My apologies for that, the detailed crash log is attached and the links provided in the tail of this email.
<4>[ 30.511022] Call trace: <4>[ 30.511437] _raw_spin_lock_irq (arch/arm64/include/asm/atomic_lse.h:271 arch/arm64/include/asm/cmpxchg.h:120 arch/arm64/include/asm/cmpxchg.h:169 include/linux/atomic/atomic-arch-fallback.h:2055 include/linux/atomic/atomic-arch-fallback.h:2173 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <4>[ 30.512013] wait_for_completion_timeout (kernel/sched/completion.c:84 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:167) <4>[ 30.512627] kunit_try_catch_run (lib/kunit/try-catch.c:86) <4>[ 30.513188] kunit_run_case_catch_errors (lib/kunit/test.c:544) <4>[ 30.513801] kunit_run_tests (lib/kunit/test.c:635)
Ok, so 'task_struct->vfork_done' is NULL. Looks like this code was added recently, so adding Mickaël to cc.
Will
Thank you.
- Naresh
On Wed, 10 Apr 2024 at 22:44, Naresh Kamboju naresh.kamboju@linaro.org wrote:
On Wed, 10 Apr 2024 at 20:53, Will Deacon will@kernel.org wrote:
On Wed, Apr 10, 2024 at 03:57:10PM +0530, Naresh Kamboju wrote:
Following kernel crash noticed on Linux next-20240410 tag while running kunit testing on qemu-arm64 and qemu-x86_64.
Reported-by: Linux Kernel Functional Testing lkft@linaro.org
Crash log on qemu-arm64:
<3>[ 30.465716] BUG: KASAN: null-ptr-deref in _raw_spin_lock_irq (include/linux/instrumented.h:96 include/linux/atomic/atomic-instrumented.h:1301 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170)
It's a shame that you have trimmed the register dump here.
My apologies for that, the detailed crash log is attached and the links provided in the tail of this email.
<4>[ 30.511022] Call trace: <4>[ 30.511437] _raw_spin_lock_irq (arch/arm64/include/asm/atomic_lse.h:271 arch/arm64/include/asm/cmpxchg.h:120 arch/arm64/include/asm/cmpxchg.h:169 include/linux/atomic/atomic-arch-fallback.h:2055 include/linux/atomic/atomic-arch-fallback.h:2173 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <4>[ 30.512013] wait_for_completion_timeout (kernel/sched/completion.c:84 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:167) <4>[ 30.512627] kunit_try_catch_run (lib/kunit/try-catch.c:86) <4>[ 30.513188] kunit_run_case_catch_errors (lib/kunit/test.c:544) <4>[ 30.513801] kunit_run_tests (lib/kunit/test.c:635)
Ok, so 'task_struct->vfork_done' is NULL. Looks like this code was added recently, so adding Mickaël to cc.
Will
The decode stack trace dump file for arm64 has been attached.
- Naresh
On Wed, 10 Apr 2024 at 23:23, Will Deacon will@kernel.org wrote:
On Wed, Apr 10, 2024 at 03:57:10PM +0530, Naresh Kamboju wrote:
Following kernel crash noticed on Linux next-20240410 tag while running kunit testing on qemu-arm64 and qemu-x86_64.
Reported-by: Linux Kernel Functional Testing lkft@linaro.org
Crash log on qemu-arm64:
<3>[ 30.465716] BUG: KASAN: null-ptr-deref in _raw_spin_lock_irq (include/linux/instrumented.h:96 include/linux/atomic/atomic-instrumented.h:1301 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <3>[ 30.467097] Write of size 4 at addr 0000000000000008 by task swapper/0/1 <3>[ 30.468059] <3>[ 30.468393] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B N 6.9.0-rc3-next-20240410 #1 <3>[ 30.469209] Hardware name: linux,dummy-virt (DT) <3>[ 30.469645] Call trace: <3>[ 30.469919] dump_backtrace (arch/arm64/kernel/stacktrace.c:319) <3>[ 30.471622] show_stack (arch/arm64/kernel/stacktrace.c:326) <3>[ 30.472124] dump_stack_lvl (lib/dump_stack.c:117) <3>[ 30.472947] print_report (mm/kasan/report.c:493) <3>[ 30.473755] kasan_report (mm/kasan/report.c:603) <3>[ 30.474524] kasan_check_range (mm/kasan/generic.c:175 mm/kasan/generic.c:189) <3>[ 30.475094] __kasan_check_write (mm/kasan/shadow.c:38) <3>[ 30.475683] _raw_spin_lock_irq (include/linux/instrumented.h:96 include/linux/atomic/atomic-instrumented.h:1301 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <3>[ 30.476257] wait_for_completion_timeout (kernel/sched/completion.c:84 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:167) <3>[ 30.476909] kunit_try_catch_run (lib/kunit/try-catch.c:86) <3>[ 30.477628] kunit_run_case_catch_errors (lib/kunit/test.c:544) <3>[ 30.478311] kunit_run_tests (lib/kunit/test.c:635) <3>[ 30.478865] __kunit_test_suites_init (lib/kunit/test.c:729 (discriminator 1)) <3>[ 30.479482] kunit_run_all_tests (lib/kunit/executor.c:276 lib/kunit/executor.c:392) <3>[ 30.480079] kernel_init_freeable (init/main.c:1578) <3>[ 30.480747] kernel_init (init/main.c:1465) <3>[ 30.481474] ret_from_fork (arch/arm64/kernel/entry.S:861) <3>[ 30.482080] ================================================================== <1>[ 30.484503] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 <1>[ 30.485369] Mem abort info: <1>[ 30.485923] ESR = 0x000000009600006b <1>[ 30.486943] EC = 0x25: DABT (current EL), IL = 32 bits <1>[ 30.487540] SET = 0, FnV = 0 <1>[ 30.488007] EA = 0, S1PTW = 0 <1>[ 30.488509] FSC = 0x2b: level -1 translation fault <1>[ 30.489150] Data abort info: <1>[ 30.489610] ISV = 0, ISS = 0x0000006b, ISS2 = 0x00000000 <1>[ 30.490360] CM = 0, WnR = 1, TnD = 0, TagAccess = 0 <1>[ 30.491057] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 <1>[ 30.491822] [0000000000000008] user address but active_mm is swapper <0>[ 30.493008] Internal error: Oops: 000000009600006b [#1] PREEMPT SMP <4>[ 30.494105] Modules linked in: <4>[ 30.496244] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B N 6.9.0-rc3-next-20240410 #1 <4>[ 30.497171] Hardware name: linux,dummy-virt (DT) <4>[ 30.497905] pstate: 224000c9 (nzCv daIF +PAN -UAO +TCO -DIT -SSBS BTYPE=--) <4>[ 30.498895] pc : _raw_spin_lock_irq (arch/arm64/include/asm/atomic_lse.h:271 arch/arm64/include/asm/cmpxchg.h:120 arch/arm64/include/asm/cmpxchg.h:169 include/linux/atomic/atomic-arch-fallback.h:2055 include/linux/atomic/atomic-arch-fallback.h:2173 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <4>[ 30.499542] lr : _raw_spin_lock_irq (include/linux/atomic/atomic-arch-fallback.h:2172 (discriminator 1) include/linux/atomic/atomic-instrumented.h:1302 (discriminator 1) include/asm-generic/qspinlock.h:111 (discriminator 1) include/linux/spinlock.h:187 (discriminator 1) include/linux/spinlock_api_smp.h:120 (discriminator 1) kernel/locking/spinlock.c:170 (discriminator 1))
<trim>
It's a shame that you have trimmed the register dump here.
<4>[ 30.511022] Call trace: <4>[ 30.511437] _raw_spin_lock_irq (arch/arm64/include/asm/atomic_lse.h:271 arch/arm64/include/asm/cmpxchg.h:120 arch/arm64/include/asm/cmpxchg.h:169 include/linux/atomic/atomic-arch-fallback.h:2055 include/linux/atomic/atomic-arch-fallback.h:2173 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <4>[ 30.512013] wait_for_completion_timeout (kernel/sched/completion.c:84 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:167) <4>[ 30.512627] kunit_try_catch_run (lib/kunit/try-catch.c:86) <4>[ 30.513188] kunit_run_case_catch_errors (lib/kunit/test.c:544) <4>[ 30.513801] kunit_run_tests (lib/kunit/test.c:635)
Ok, so 'task_struct->vfork_done' is NULL. Looks like this code was added recently, so adding Mickaël to cc.
Thanks. This looks like a race condition where the KUnit test kthread can terminate before we wait on it.
Mickaël, does this seem like a correct fix to you? --- From: David Gow davidgow@google.com Date: Thu, 11 Apr 2024 12:07:47 +0800 Subject: [PATCH] kunit: Fix race condition in try-catch completion
KUnit's try-catch infrastructure now uses vfork_done, which is always set to a valid completion when a kthread is crated, but which is set to NULL once the thread terminates. This creates a race condition, where the kthread exits before we can wait on it.
Keep a copy of vfork_done, which is taken before we wake_up_process() and so valid, and wait on that instead.
Fixes: 4de2a8e4cca4 ("kunit: Handle test faults") Reported-by: Linux Kernel Functional Testing lkft@linaro.org Signed-off-by: David Gow davidgow@google.com --- lib/kunit/try-catch.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c index fa687278ccc9..fc6cd4d7e80f 100644 --- a/lib/kunit/try-catch.c +++ b/lib/kunit/try-catch.c @@ -63,6 +63,7 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) { struct kunit *test = try_catch->test; struct task_struct *task_struct; + struct completion *task_done; int exit_code, time_remaining;
try_catch->context = context; @@ -75,13 +76,14 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) return; } get_task_struct(task_struct); + task_done = task_struct->vfork_done; wake_up_process(task_struct); /* * As for a vfork(2), task_struct->vfork_done (pointing to the * underlying kthread->exited) can be used to wait for the end of a * kernel thread. */ - time_remaining = wait_for_completion_timeout(task_struct->vfork_done, + time_remaining = wait_for_completion_timeout(task_done, kunit_test_timeout()); if (time_remaining == 0) { try_catch->try_result = -ETIMEDOUT; --
On Thu, Apr 11, 2024 at 12:25:40PM +0800, David Gow wrote:
On Wed, 10 Apr 2024 at 23:23, Will Deacon will@kernel.org wrote:
On Wed, Apr 10, 2024 at 03:57:10PM +0530, Naresh Kamboju wrote:
Following kernel crash noticed on Linux next-20240410 tag while running kunit testing on qemu-arm64 and qemu-x86_64.
Reported-by: Linux Kernel Functional Testing lkft@linaro.org
Crash log on qemu-arm64:
<3>[ 30.465716] BUG: KASAN: null-ptr-deref in _raw_spin_lock_irq (include/linux/instrumented.h:96 include/linux/atomic/atomic-instrumented.h:1301 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <3>[ 30.467097] Write of size 4 at addr 0000000000000008 by task swapper/0/1 <3>[ 30.468059] <3>[ 30.468393] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B N 6.9.0-rc3-next-20240410 #1 <3>[ 30.469209] Hardware name: linux,dummy-virt (DT) <3>[ 30.469645] Call trace: <3>[ 30.469919] dump_backtrace (arch/arm64/kernel/stacktrace.c:319) <3>[ 30.471622] show_stack (arch/arm64/kernel/stacktrace.c:326) <3>[ 30.472124] dump_stack_lvl (lib/dump_stack.c:117) <3>[ 30.472947] print_report (mm/kasan/report.c:493) <3>[ 30.473755] kasan_report (mm/kasan/report.c:603) <3>[ 30.474524] kasan_check_range (mm/kasan/generic.c:175 mm/kasan/generic.c:189) <3>[ 30.475094] __kasan_check_write (mm/kasan/shadow.c:38) <3>[ 30.475683] _raw_spin_lock_irq (include/linux/instrumented.h:96 include/linux/atomic/atomic-instrumented.h:1301 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <3>[ 30.476257] wait_for_completion_timeout (kernel/sched/completion.c:84 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:167) <3>[ 30.476909] kunit_try_catch_run (lib/kunit/try-catch.c:86) <3>[ 30.477628] kunit_run_case_catch_errors (lib/kunit/test.c:544) <3>[ 30.478311] kunit_run_tests (lib/kunit/test.c:635) <3>[ 30.478865] __kunit_test_suites_init (lib/kunit/test.c:729 (discriminator 1)) <3>[ 30.479482] kunit_run_all_tests (lib/kunit/executor.c:276 lib/kunit/executor.c:392) <3>[ 30.480079] kernel_init_freeable (init/main.c:1578) <3>[ 30.480747] kernel_init (init/main.c:1465) <3>[ 30.481474] ret_from_fork (arch/arm64/kernel/entry.S:861) <3>[ 30.482080] ================================================================== <1>[ 30.484503] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 <1>[ 30.485369] Mem abort info: <1>[ 30.485923] ESR = 0x000000009600006b <1>[ 30.486943] EC = 0x25: DABT (current EL), IL = 32 bits <1>[ 30.487540] SET = 0, FnV = 0 <1>[ 30.488007] EA = 0, S1PTW = 0 <1>[ 30.488509] FSC = 0x2b: level -1 translation fault <1>[ 30.489150] Data abort info: <1>[ 30.489610] ISV = 0, ISS = 0x0000006b, ISS2 = 0x00000000 <1>[ 30.490360] CM = 0, WnR = 1, TnD = 0, TagAccess = 0 <1>[ 30.491057] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 <1>[ 30.491822] [0000000000000008] user address but active_mm is swapper <0>[ 30.493008] Internal error: Oops: 000000009600006b [#1] PREEMPT SMP <4>[ 30.494105] Modules linked in: <4>[ 30.496244] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B N 6.9.0-rc3-next-20240410 #1 <4>[ 30.497171] Hardware name: linux,dummy-virt (DT) <4>[ 30.497905] pstate: 224000c9 (nzCv daIF +PAN -UAO +TCO -DIT -SSBS BTYPE=--) <4>[ 30.498895] pc : _raw_spin_lock_irq (arch/arm64/include/asm/atomic_lse.h:271 arch/arm64/include/asm/cmpxchg.h:120 arch/arm64/include/asm/cmpxchg.h:169 include/linux/atomic/atomic-arch-fallback.h:2055 include/linux/atomic/atomic-arch-fallback.h:2173 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <4>[ 30.499542] lr : _raw_spin_lock_irq (include/linux/atomic/atomic-arch-fallback.h:2172 (discriminator 1) include/linux/atomic/atomic-instrumented.h:1302 (discriminator 1) include/asm-generic/qspinlock.h:111 (discriminator 1) include/linux/spinlock.h:187 (discriminator 1) include/linux/spinlock_api_smp.h:120 (discriminator 1) kernel/locking/spinlock.c:170 (discriminator 1))
<trim>
It's a shame that you have trimmed the register dump here.
<4>[ 30.511022] Call trace: <4>[ 30.511437] _raw_spin_lock_irq (arch/arm64/include/asm/atomic_lse.h:271 arch/arm64/include/asm/cmpxchg.h:120 arch/arm64/include/asm/cmpxchg.h:169 include/linux/atomic/atomic-arch-fallback.h:2055 include/linux/atomic/atomic-arch-fallback.h:2173 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <4>[ 30.512013] wait_for_completion_timeout (kernel/sched/completion.c:84 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:167) <4>[ 30.512627] kunit_try_catch_run (lib/kunit/try-catch.c:86) <4>[ 30.513188] kunit_run_case_catch_errors (lib/kunit/test.c:544) <4>[ 30.513801] kunit_run_tests (lib/kunit/test.c:635)
Ok, so 'task_struct->vfork_done' is NULL. Looks like this code was added recently, so adding Mickaël to cc.
Thanks. This looks like a race condition where the KUnit test kthread can terminate before we wait on it.
Mickaël, does this seem like a correct fix to you?
From: David Gow davidgow@google.com Date: Thu, 11 Apr 2024 12:07:47 +0800 Subject: [PATCH] kunit: Fix race condition in try-catch completion
KUnit's try-catch infrastructure now uses vfork_done, which is always set to a valid completion when a kthread is crated, but which is set to
s/crated/created/
NULL once the thread terminates. This creates a race condition, where the kthread exits before we can wait on it.
Keep a copy of vfork_done, which is taken before we wake_up_process() and so valid, and wait on that instead.
Fixes: 4de2a8e4cca4 ("kunit: Handle test faults") Reported-by: Linux Kernel Functional Testing lkft@linaro.org Signed-off-by: David Gow davidgow@google.com
Minor suggestions, but it looks good. Thanks!
Acked-by: Mickaël Salaün mic@digikod.net
lib/kunit/try-catch.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c index fa687278ccc9..fc6cd4d7e80f 100644 --- a/lib/kunit/try-catch.c +++ b/lib/kunit/try-catch.c @@ -63,6 +63,7 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) { struct kunit *test = try_catch->test; struct task_struct *task_struct;
struct completion *task_done; int exit_code, time_remaining; try_catch->context = context;@@ -75,13 +76,14 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) return; } get_task_struct(task_struct);
task_done = task_struct->vfork_done; wake_up_process(task_struct);
/* * As for a vfork(2), task_struct->vfork_done (pointing to the * underlying kthread->exited) can be used to wait for the end of a * kernel thread.
"kernel thread. It is set to NULL when the thread ends."
*/
This block comment can now be moved up where task_done is set.
time_remaining = wait_for_completion_timeout(task_struct->vfork_done,
time_remaining = wait_for_completion_timeout(task_done, kunit_test_timeout()); if (time_remaining == 0) { try_catch->try_result = -ETIMEDOUT;--
On Thu, 11 Apr 2024 at 09:55, David Gow davidgow@google.com wrote:
On Wed, 10 Apr 2024 at 23:23, Will Deacon will@kernel.org wrote:
On Wed, Apr 10, 2024 at 03:57:10PM +0530, Naresh Kamboju wrote:
Following kernel crash noticed on Linux next-20240410 tag while running kunit testing on qemu-arm64 and qemu-x86_64.
Reported-by: Linux Kernel Functional Testing lkft@linaro.org
<trim>
Ok, so 'task_struct->vfork_done' is NULL. Looks like this code was added recently, so adding Mickaël to cc.
Thanks. This looks like a race condition where the KUnit test kthread can terminate before we wait on it.
Mickaël, does this seem like a correct fix to you?
From: David Gow davidgow@google.com Date: Thu, 11 Apr 2024 12:07:47 +0800 Subject: [PATCH] kunit: Fix race condition in try-catch completion
KUnit's try-catch infrastructure now uses vfork_done, which is always set to a valid completion when a kthread is crated, but which is set to NULL once the thread terminates. This creates a race condition, where the kthread exits before we can wait on it.
Keep a copy of vfork_done, which is taken before we wake_up_process() and so valid, and wait on that instead.
Fixes: 4de2a8e4cca4 ("kunit: Handle test faults") Reported-by: Linux Kernel Functional Testing lkft@linaro.org Signed-off-by: David Gow davidgow@google.com
This patch tested on top of Linux next and reported issues fixed.
Tested-by: Linux Kernel Functional Testing lkft@linaro.org
lib/kunit/try-catch.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c index fa687278ccc9..fc6cd4d7e80f 100644 --- a/lib/kunit/try-catch.c +++ b/lib/kunit/try-catch.c @@ -63,6 +63,7 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) { struct kunit *test = try_catch->test; struct task_struct *task_struct;
struct completion *task_done; int exit_code, time_remaining; try_catch->context = context;@@ -75,13 +76,14 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) return; } get_task_struct(task_struct);
task_done = task_struct->vfork_done; wake_up_process(task_struct); /* * As for a vfork(2), task_struct->vfork_done (pointing to the * underlying kthread->exited) can be used to wait for the end of a * kernel thread. */
time_remaining = wait_for_completion_timeout(task_struct->vfork_done,
time_remaining = wait_for_completion_timeout(task_done, kunit_test_timeout()); if (time_remaining == 0) { try_catch->try_result = -ETIMEDOUT;--
-- Linaro LKFT https://lkft.linaro.org
On Thu, 11 Apr 2024 at 20:12, Naresh Kamboju naresh.kamboju@linaro.org wrote:
On Thu, 11 Apr 2024 at 09:55, David Gow davidgow@google.com wrote:
On Wed, 10 Apr 2024 at 23:23, Will Deacon will@kernel.org wrote:
On Wed, Apr 10, 2024 at 03:57:10PM +0530, Naresh Kamboju wrote:
Following kernel crash noticed on Linux next-20240410 tag while running kunit testing on qemu-arm64 and qemu-x86_64.
Reported-by: Linux Kernel Functional Testing lkft@linaro.org
<trim>
Ok, so 'task_struct->vfork_done' is NULL. Looks like this code was added recently, so adding Mickaël to cc.
Thanks. This looks like a race condition where the KUnit test kthread can terminate before we wait on it.
Mickaël, does this seem like a correct fix to you?
From: David Gow davidgow@google.com Date: Thu, 11 Apr 2024 12:07:47 +0800 Subject: [PATCH] kunit: Fix race condition in try-catch completion
KUnit's try-catch infrastructure now uses vfork_done, which is always set to a valid completion when a kthread is crated, but which is set to NULL once the thread terminates. This creates a race condition, where the kthread exits before we can wait on it.
Keep a copy of vfork_done, which is taken before we wake_up_process() and so valid, and wait on that instead.
Fixes: 4de2a8e4cca4 ("kunit: Handle test faults") Reported-by: Linux Kernel Functional Testing lkft@linaro.org Signed-off-by: David Gow davidgow@google.com
This patch tested on top of Linux next and reported issues fixed.
Tested-by: Linux Kernel Functional Testing lkft@linaro.org
lib/kunit/try-catch.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c index fa687278ccc9..fc6cd4d7e80f 100644 --- a/lib/kunit/try-catch.c +++ b/lib/kunit/try-catch.c @@ -63,6 +63,7 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) { struct kunit *test = try_catch->test; struct task_struct *task_struct;
struct completion *task_done; int exit_code, time_remaining; try_catch->context = context;@@ -75,13 +76,14 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) return; } get_task_struct(task_struct);
task_done = task_struct->vfork_done; wake_up_process(task_struct); /* * As for a vfork(2), task_struct->vfork_done (pointing to the * underlying kthread->exited) can be used to wait for the end of a * kernel thread. */
time_remaining = wait_for_completion_timeout(task_struct->vfork_done,
time_remaining = wait_for_completion_timeout(task_done, kunit_test_timeout()); if (time_remaining == 0) { try_catch->try_result = -ETIMEDOUT;--
I use to notice kernel panic while running kunit tests now I have noticed this
Unable to handle kernel paging request at virtual address KASAN: null-ptr-deref in range pc : kunit_test_null_dereference (lib/kunit/kunit-test.c:119) lr : kunit_generic_run_threadfn_adapter (lib/kunit/try-catch.c:31)
The kunit tests run to completion and the system is stable. Kernel did not panic.
kunit test log: ------ <6>[ 76.784878] # Subtest: kunit_fault <6>[ 76.785527] # module: kunit_test <6>[ 76.785785] 1..1 <1>[ 76.794318] Unable to handle kernel paging request at virtual address dfff800000000000 <1>[ 76.796137] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] <1>[ 76.796970] Mem abort info: <1>[ 76.797685] ESR = 0x0000000096000005 <1>[ 76.798868] EC = 0x25: DABT (current EL), IL = 32 bits <1>[ 76.800355] SET = 0, FnV = 0 <1>[ 76.800893] EA = 0, S1PTW = 0 <1>[ 76.801715] FSC = 0x05: level 1 translation fault <1>[ 76.802654] Data abort info: <1>[ 76.803713] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 <1>[ 76.804362] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 <1>[ 76.805278] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 <1>[ 76.806302] [dfff800000000000] address between user and kernel address ranges <0>[ 76.808597] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP <4>[ 76.809876] Modules linked in: <4>[ 76.812055] CPU: 1 PID: 567 Comm: kunit_try_catch Tainted: G B N 6.9.0-rc3-next-20240410 #1 <4>[ 76.812987] Hardware name: linux,dummy-virt (DT) <4>[ 76.814123] pstate: 12400009 (nzcV daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) <4>[ 76.814947] pc : kunit_test_null_dereference (lib/kunit/kunit-test.c:119) <4>[ 76.815862] lr : kunit_generic_run_threadfn_adapter (lib/kunit/try-catch.c:31) <4>[ 76.816765] sp : ffff800083137dc0 <4>[ 76.817473] x29: ffff800083137e20 x28: 0000000000000000 x27: 0000000000000000 <4>[ 76.818684] x26: 0000000000000000 x25: 0000000000000000 x24: fff00000c1b30c00 <4>[ 76.819798] x23: ffffa76fb372e348 x22: ffffa76fb3736550 x21: fff00000c1b30c08 <4>[ 76.820900] x20: 1ffff00010626fb8 x19: ffff8000800879f0 x18: 0000000000000068 <4>[ 76.822008] x17: 0000000000000000 x16: fff00000da132180 x15: ffffa76fb36f3b04 <4>[ 76.823125] x14: ffffa76fb2e3cc28 x13: 1ffe0000181547e4 x12: fffd80001832511a <4>[ 76.824229] x11: 1ffe000018325119 x10: fffd800018325119 x9 : ffffa76fb372e3d0 <4>[ 76.825409] x8 : ffff800083137cb8 x7 : 0000000000000000 x6 : 0000000041b58ab3 <4>[ 76.826532] x5 : ffff700010626fb8 x4 : 00000000f1f1f1f1 x3 : 0000000000000003 <4>[ 76.827653] x2 : dfff800000000000 x1 : fff00000c1928000 x0 : ffff8000800879f0 <4>[ 76.828829] Call trace: <4>[ 76.829410] kunit_test_null_dereference (lib/kunit/kunit-test.c:119) <4>[ 76.830294] kunit_generic_run_threadfn_adapter (lib/kunit/try-catch.c:31) <4>[ 76.831168] kthread (kernel/kthread.c:389) <4>[ 76.831870] ret_from_fork (arch/arm64/kernel/entry.S:861) <0>[ 76.833252] Code: b90004a3 d5384101 52800063 aa0003f3 (39c00042) All code ======== 0: b90004a3 str w3, [x5, #4] 4: d5384101 mrs x1, sp_el0 8: 52800063 mov w3, #0x3 // #3 c: aa0003f3 mov x19, x0 10:* 39c00042 ldrsb w2, [x2] <-- trapping instruction
Code starting with the faulting instruction =========================================== 0: 39c00042 ldrsb w2, [x2] <4>[ 76.834489] ---[ end trace 0000000000000000 ]---
Links: - https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/2exQ84OHGOd... -- Linaro LKFT https://lkft.linaro.org
On Thu, Apr 11, 2024 at 08:20:55PM +0530, Naresh Kamboju wrote:
I use to notice kernel panic while running kunit tests now I have noticed this
Unable to handle kernel paging request at virtual address KASAN: null-ptr-deref in range pc : kunit_test_null_dereference (lib/kunit/kunit-test.c:119) lr : kunit_generic_run_threadfn_adapter (lib/kunit/try-catch.c:31)
The kunit tests run to completion and the system is stable. Kernel did not panic.
[ Snip ]
<0>[ 76.808597] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP <4>[ 76.809876] Modules linked in: <4>[ 76.812055] CPU: 1 PID: 567 Comm: kunit_try_catch Tainted: G B N 6.9.0-rc3-next-20240410 #1 <4>[ 76.812987] Hardware name: linux,dummy-virt (DT) <4>[ 76.814123] pstate: 12400009 (nzcV daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) <4>[ 76.814947] pc : kunit_test_null_dereference (lib/kunit/kunit-test.c:119)
^^^^^^^^^^^^^^^^^^^^^^^^^^^ This is a new intentional NULL dereferencer that was added yesterday.
Maybe these should have a big printk, "Intentional NULL dereference coming up!\n".
regards, dan carpenter
On Thu, Apr 11, 2024 at 06:00:25PM +0300, Dan Carpenter wrote:
On Thu, Apr 11, 2024 at 08:20:55PM +0530, Naresh Kamboju wrote:
I use to notice kernel panic while running kunit tests now I have noticed this
Unable to handle kernel paging request at virtual address KASAN: null-ptr-deref in range pc : kunit_test_null_dereference (lib/kunit/kunit-test.c:119) lr : kunit_generic_run_threadfn_adapter (lib/kunit/try-catch.c:31)
The kunit tests run to completion and the system is stable. Kernel did not panic.
[ Snip ]
<0>[ 76.808597] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP <4>[ 76.809876] Modules linked in: <4>[ 76.812055] CPU: 1 PID: 567 Comm: kunit_try_catch Tainted: G B N 6.9.0-rc3-next-20240410 #1 <4>[ 76.812987] Hardware name: linux,dummy-virt (DT) <4>[ 76.814123] pstate: 12400009 (nzcV daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) <4>[ 76.814947] pc : kunit_test_null_dereference (lib/kunit/kunit-test.c:119)
^^^^^^^^^^^^^^^^^^^^^^^^^^^This is a new intentional NULL dereferencer that was added yesterday.
Maybe these should have a big printk, "Intentional NULL dereference coming up!\n".
Can the backtrace be suppressed, similar to the warnings suppression I am working on ?
Thanks, Guenter
On Thu, 11 Apr 2024 at 23:05, Guenter Roeck linux@roeck-us.net wrote:
On Thu, Apr 11, 2024 at 06:00:25PM +0300, Dan Carpenter wrote:
On Thu, Apr 11, 2024 at 08:20:55PM +0530, Naresh Kamboju wrote:
I use to notice kernel panic while running kunit tests now I have noticed this
Unable to handle kernel paging request at virtual address KASAN: null-ptr-deref in range pc : kunit_test_null_dereference (lib/kunit/kunit-test.c:119) lr : kunit_generic_run_threadfn_adapter (lib/kunit/try-catch.c:31)
The kunit tests run to completion and the system is stable. Kernel did not panic.
[ Snip ]
<0>[ 76.808597] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP <4>[ 76.809876] Modules linked in: <4>[ 76.812055] CPU: 1 PID: 567 Comm: kunit_try_catch Tainted: G B N 6.9.0-rc3-next-20240410 #1 <4>[ 76.812987] Hardware name: linux,dummy-virt (DT) <4>[ 76.814123] pstate: 12400009 (nzcV daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) <4>[ 76.814947] pc : kunit_test_null_dereference (lib/kunit/kunit-test.c:119)
^^^^^^^^^^^^^^^^^^^^^^^^^^^This is a new intentional NULL dereferencer that was added yesterday.
Maybe these should have a big printk, "Intentional NULL dereference coming up!\n".
Can the backtrace be suppressed, similar to the warnings suppression I am working on ?
I'd like to do that going forward. Of course, this isn't a warning, so it doesn't work as-is (and it'd be harder to pass things like the function name through), but it seems like a worthwhile feature to have going forward. We did have some similar stuff for trapping KASAN errors as a part of the KASAN tests a while ago: that's also something to look at.
I have been playing with the warning suppression with the fortify test, and that seems to be working well.
Cheers, -- David
On Thu, 11 Apr 2024 at 12:25, David Gow davidgow@google.com wrote:
On Wed, 10 Apr 2024 at 23:23, Will Deacon will@kernel.org wrote:
On Wed, Apr 10, 2024 at 03:57:10PM +0530, Naresh Kamboju wrote:
Following kernel crash noticed on Linux next-20240410 tag while running kunit testing on qemu-arm64 and qemu-x86_64.
Reported-by: Linux Kernel Functional Testing lkft@linaro.org
Crash log on qemu-arm64:
<3>[ 30.465716] BUG: KASAN: null-ptr-deref in _raw_spin_lock_irq (include/linux/instrumented.h:96 include/linux/atomic/atomic-instrumented.h:1301 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <3>[ 30.467097] Write of size 4 at addr 0000000000000008 by task swapper/0/1 <3>[ 30.468059] <3>[ 30.468393] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B N 6.9.0-rc3-next-20240410 #1 <3>[ 30.469209] Hardware name: linux,dummy-virt (DT) <3>[ 30.469645] Call trace: <3>[ 30.469919] dump_backtrace (arch/arm64/kernel/stacktrace.c:319) <3>[ 30.471622] show_stack (arch/arm64/kernel/stacktrace.c:326) <3>[ 30.472124] dump_stack_lvl (lib/dump_stack.c:117) <3>[ 30.472947] print_report (mm/kasan/report.c:493) <3>[ 30.473755] kasan_report (mm/kasan/report.c:603) <3>[ 30.474524] kasan_check_range (mm/kasan/generic.c:175 mm/kasan/generic.c:189) <3>[ 30.475094] __kasan_check_write (mm/kasan/shadow.c:38) <3>[ 30.475683] _raw_spin_lock_irq (include/linux/instrumented.h:96 include/linux/atomic/atomic-instrumented.h:1301 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <3>[ 30.476257] wait_for_completion_timeout (kernel/sched/completion.c:84 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:167) <3>[ 30.476909] kunit_try_catch_run (lib/kunit/try-catch.c:86) <3>[ 30.477628] kunit_run_case_catch_errors (lib/kunit/test.c:544) <3>[ 30.478311] kunit_run_tests (lib/kunit/test.c:635) <3>[ 30.478865] __kunit_test_suites_init (lib/kunit/test.c:729 (discriminator 1)) <3>[ 30.479482] kunit_run_all_tests (lib/kunit/executor.c:276 lib/kunit/executor.c:392) <3>[ 30.480079] kernel_init_freeable (init/main.c:1578) <3>[ 30.480747] kernel_init (init/main.c:1465) <3>[ 30.481474] ret_from_fork (arch/arm64/kernel/entry.S:861) <3>[ 30.482080] ================================================================== <1>[ 30.484503] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 <1>[ 30.485369] Mem abort info: <1>[ 30.485923] ESR = 0x000000009600006b <1>[ 30.486943] EC = 0x25: DABT (current EL), IL = 32 bits <1>[ 30.487540] SET = 0, FnV = 0 <1>[ 30.488007] EA = 0, S1PTW = 0 <1>[ 30.488509] FSC = 0x2b: level -1 translation fault <1>[ 30.489150] Data abort info: <1>[ 30.489610] ISV = 0, ISS = 0x0000006b, ISS2 = 0x00000000 <1>[ 30.490360] CM = 0, WnR = 1, TnD = 0, TagAccess = 0 <1>[ 30.491057] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 <1>[ 30.491822] [0000000000000008] user address but active_mm is swapper <0>[ 30.493008] Internal error: Oops: 000000009600006b [#1] PREEMPT SMP <4>[ 30.494105] Modules linked in: <4>[ 30.496244] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B N 6.9.0-rc3-next-20240410 #1 <4>[ 30.497171] Hardware name: linux,dummy-virt (DT) <4>[ 30.497905] pstate: 224000c9 (nzCv daIF +PAN -UAO +TCO -DIT -SSBS BTYPE=--) <4>[ 30.498895] pc : _raw_spin_lock_irq (arch/arm64/include/asm/atomic_lse.h:271 arch/arm64/include/asm/cmpxchg.h:120 arch/arm64/include/asm/cmpxchg.h:169 include/linux/atomic/atomic-arch-fallback.h:2055 include/linux/atomic/atomic-arch-fallback.h:2173 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <4>[ 30.499542] lr : _raw_spin_lock_irq (include/linux/atomic/atomic-arch-fallback.h:2172 (discriminator 1) include/linux/atomic/atomic-instrumented.h:1302 (discriminator 1) include/asm-generic/qspinlock.h:111 (discriminator 1) include/linux/spinlock.h:187 (discriminator 1) include/linux/spinlock_api_smp.h:120 (discriminator 1) kernel/locking/spinlock.c:170 (discriminator 1))
<trim>
It's a shame that you have trimmed the register dump here.
<4>[ 30.511022] Call trace: <4>[ 30.511437] _raw_spin_lock_irq (arch/arm64/include/asm/atomic_lse.h:271 arch/arm64/include/asm/cmpxchg.h:120 arch/arm64/include/asm/cmpxchg.h:169 include/linux/atomic/atomic-arch-fallback.h:2055 include/linux/atomic/atomic-arch-fallback.h:2173 include/linux/atomic/atomic-instrumented.h:1302 include/asm-generic/qspinlock.h:111 include/linux/spinlock.h:187 include/linux/spinlock_api_smp.h:120 kernel/locking/spinlock.c:170) <4>[ 30.512013] wait_for_completion_timeout (kernel/sched/completion.c:84 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:167) <4>[ 30.512627] kunit_try_catch_run (lib/kunit/try-catch.c:86) <4>[ 30.513188] kunit_run_case_catch_errors (lib/kunit/test.c:544) <4>[ 30.513801] kunit_run_tests (lib/kunit/test.c:635)
Ok, so 'task_struct->vfork_done' is NULL. Looks like this code was added recently, so adding Mickaël to cc.
Thanks. This looks like a race condition where the KUnit test kthread can terminate before we wait on it.
Mickaël, does this seem like a correct fix to you?
<snip>
Thanks, everyone. I've sent this out here: https://lore.kernel.org/linux-kselftest/20240412025903.489470-1-davidgow@goo...
-- David
-
Dan Carpenter -
David Gow -
Guenter Roeck -
Mickaël Salaün -
Naresh Kamboju -
Will Deacon