Re: [Syzkaller & bisect] There is "__perf_event_overflow" WARNING in v6.1-rc5 kernel in guest

From: Peter Zijlstra
Date: Wed Nov 16 2022 - 09:40:42 EST


On Wed, Nov 16, 2022 at 11:39:53AM +0800, Pengfei Xu wrote:
> Hi Peter and perf expert,
>
> Greeting!
>
> Platform: TGL-H
>
> There is "__perf_event_overflow" WARNING issue in v6.1-rc5 kernel in
> guest in double check test.
>
> Found first bad commit is ca6c21327c6af02b7eec31ce4b9a740a18c6c13f
> "perf: Fix missing SIGTRAPs"
>
> And revert this commit on top of v6.1-rc5, this issue could not be reproduced.
>
> Guest kconfig, reproduce code from syzkaller, and bisect info are in attached.
>
> And more detailed info is in link:
> https://github.com/xupengfe/syzkaller_logs/tree/main/221114_134736___perf_event_overflow
>
> If it's helpful and in time, please add the Reported-by tag from me.

Does this help?

https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=perf/urgent&id=bb88f9695460bec25aa30ba9072595025cf6c8af