Re: [LTP] selftests: core: unshare_test: WARNING: at mm/util.c:671 __kvmalloc_node_noprof

[Sasha Levin <sashal@kernel.org>]

On Wed, Dec 11, 2024 at 11:09:46AM +0530, Naresh Kamboju wrote:
>[Gentle Reminder]
>
>On Mon, 26 Aug 2024 at 18:50, Naresh Kamboju <naresh.kamboju@linaro.org> wrote:
>>
>> The following kernel warning is noticed on all arch and all devices while
>> running selftests: core: unshare_test on Linux next-20240823 and next-20240826.
>>
>> First seen on next-20240823.
>>   Good: next-20240822
>>   BAD:  next-20240823 and next-20240826
>
>This is an open issue from August.
>The reported kernel warning is still seen on linux next and mainline
>while running selftests: core: unshare_test.

I attempted a bisection of the range provided above, and that has landed
on: 611fbeb44a77 ("selftests:core: test coverage for dup_fd() failure
handling in unshare_fd()"), so the underlying issue was probably there
for much longer.

Al, any thoughts on what could trigger this? I'm assuming you had
something in mind when you added the above test?

>Linux version: 6.13.0-rc2-next-20241210
>> Crash log:
>> --------
>> # selftests: core: unshare_test
>> <4>[   61.084149] ------------[ cut here ]------------
>> <4>[ 61.085175] WARNING: CPU: 0 PID: 477 at mm/util.c:671
>> __kvmalloc_node_noprof (mm/util.c:671 (discriminator 1))
>> <4>[   61.088958] Modules linked in: crct10dif_ce sm3_ce sm3 sha3_ce
>> sha512_ce sha512_arm64 drm fuse backlight dm_mod ip_tables x_tables
>> <4>[   61.093141] CPU: 0 UID: 0 PID: 477 Comm: unshare_test Not
>> tainted 6.11.0-rc5-next-20240826 #1
>> <4>[   61.094558] Hardware name: linux,dummy-virt (DT)
>> <4>[   61.096763] pstate: 23400009 (nzCv daif +PAN -UAO +TCO +DIT
>> -SSBS BTYPE=--)
>> <4>[ 61.097841] pc : __kvmalloc_node_noprof (mm/util.c:671 (discriminator 1))
>> <4>[ 61.099701] lr : __kvmalloc_node_noprof (mm/util.c:661)
>> <4>[   61.100448] sp : ffff800080abbce0
>> <4>[   61.100819] x29: ffff800080abbcf0 x28: fff0000004549280 x27:
>> 0000000000000000
>> <4>[   61.101744] x26: 0000000000000000 x25: 0000000000000000 x24:
>> fff0000003615e40
>> <4>[   61.102512] x23: fff0000003615ec0 x22: bfafa45863b285c8 x21:
>> 0000000200002000
>> <4>[   61.103232] x20: 00000000ffffffff x19: 0000000000400cc0 x18:
>> 0000000000000000
>> <4>[   61.104053] x17: 0000000000000000 x16: 0000000000000000 x15:
>> 0000000000000000
>> <4>[   61.104927] x14: 0000000000000000 x13: 0000000000000000 x12:
>> 0000000000000000
>> <4>[   61.105752] x11: 0000000000000000 x10: 0000000000000000 x9 :
>> 0000000000000000
>> <4>[   61.106606] x8 : 0000000000000001 x7 : 0000000000000001 x6 :
>> 0000000000000005
>> <4>[   61.107377] x5 : 0000000000000000 x4 : fff0000004549280 x3 :
>> 0000000000000000
>> <4>[   61.108207] x2 : 0000000000000000 x1 : 000000007fffffff x0 :
>> 0000000000000000
>> <4>[   61.109262] Call trace:
>> <4>[ 61.109619] __kvmalloc_node_noprof (mm/util.c:671 (discriminator 1))
>> <4>[ 61.110248] alloc_fdtable (fs/file.c:133)
>> <4>[ 61.110751] expand_files
>> (include/linux/atomic/atomic-arch-fallback.h:457
>> include/linux/atomic/atomic-instrumented.h:33 fs/file.c:177
>> fs/file.c:238)
>> <4>[ 61.111171] ksys_dup3 (fs/file.c:1337)
>> <4>[ 61.111596] __arm64_sys_dup3 (fs/file.c:1355)
>> <4>[ 61.112006] invoke_syscall (arch/arm64/include/asm/current.h:19
>> arch/arm64/kernel/syscall.c:54)
>> <4>[ 61.112480] el0_svc_common.constprop.0
>> (include/linux/thread_info.h:127 (discriminator 2)
>> arch/arm64/kernel/syscall.c:140 (discriminator 2))
>> <4>[ 61.112955] do_el0_svc (arch/arm64/kernel/syscall.c:152)
>> <4>[ 61.113384] el0_svc (arch/arm64/include/asm/irqflags.h:55
>> arch/arm64/include/asm/irqflags.h:76
>> arch/arm64/kernel/entry-common.c:165
>> arch/arm64/kernel/entry-common.c:178
>> arch/arm64/kernel/entry-common.c:713)
>> <4>[ 61.113742] el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:731)
>> <4>[ 61.115181] el0t_64_sync (arch/arm64/kernel/entry.S:598)
>> <4>[   61.115709] ---[ end trace 0000000000000000 ]---
>>
>>
>> Crash Log links,
>> --------
>>  - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20240826/testrun/24953436/suite/log-parser-test/test/check-kernel-exception-warning-cpu-pid-at-mmutilc-__kvmalloc_node_noprof/log
>>
>> Crash failed comparison:
>> ----------
>>  - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20240826/testrun/24953436/suite/log-parser-test/test/check-kernel-exception-warning-cpu-pid-at-mmutilc-__kvmalloc_node_noprof/history/
>>
>> metadata:
>> ----
>>   git describe: next-20240823 and next-20240826
>>   git repo: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next
>>   git sha: c79c85875f1af04040fe4492ed94ce37ad729c4d
>>
>> Please let me know if you need more information.
>>
>
>Kernel warning log:
>-----------------
> - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20241210/testrun/26261199/suite/kselftest-core/test/core_unshare_test/log
>
>> --
>> Linaro LKFT
>> https://lkft.linaro.org
>
>-- 
>Mailing list info: https://lists.linux.it/listinfo/ltp

-- 
Thanks,
Sasha