Re: Alpha: rare random memory corruption/segfault in user space bisected

[Hillf Danton <hdanton@sina.com>]

On Sat, 7 May 2022 09:21:25 +1200 Michael Cree wrote:
> Alpha kernel has been exhibiting rare and random memory
> corruptions/segaults in user space since the 5.9.y kernel.  First seen
> on the Debian Ports build daemon when running 5.10.y kernel resulting
> in the occasional (one or two a day) build failures with gcc ICEs either
> due to self detected corrupt memory structures or segfaults.  Have been
> running 5.8.y kernel without such problems for over six months.
> 
> Tried bisecting last year but went off track with incorrect good/bad
> determinations due to rare nature of bug.  After trying a 5.16.y kernel
> early this year and seen the bug is still present retried the bisection
> and have got to:
> 
> aae466b0052e1888edd1d7f473d4310d64936196 is the first bad commit
> commit aae466b0052e1888edd1d7f473d4310d64936196
> Author: Joonsoo Kim <iamjoonsoo.kim@lge.com>
> Date:   Tue Aug 11 18:30:50 2020 -0700
> 
>     mm/swap: implement workingset detection for anonymous LRU
> 
> 
> Pretty confident this is the bad commit as the kernel built to the parent
> commit (3852f6768ede54...) has not failed in four days running. Always have
> seen the failure within one day of running in past.

See if the fix to the syzbot bisection [1] is not a cure to your issue.

[1] https://lore.kernel.org/lkml/000000000000625fa705dd1802e3@google.com/