Re: general protection fault in perf_misc_flags

From: Borislav Petkov
Date: Sun Sep 27 2020 - 10:58:02 EST


On Sat, Sep 19, 2020 at 01:32:14AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 92ab97ad Merge tag 'sh-for-5.9-part2' of git://git.libc.or..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1069669b900000
> kernel config: https://syzkaller.appspot.com/x/.config?x=cd992d74d6c7e62
> dashboard link: https://syzkaller.appspot.com/bug?extid=ce179bc99e64377c24bc
> compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)

All below is AFAICT:

This compiler you're using is not some official release but some random
commit before the v10 release:

$ git show c2443155a0fb245c8f17f2c1c72b6ea391e86e81
Author: Hans Wennborg <hans@xxxxxxxxxxxx>
Date: Sat Nov 30 14:20:11 2019 +0100

Revert 651f07908a1 "[AArch64] Don't combine callee-save and local stack adjustment when optimizing for size"
...

$ git describe c2443155a0fb245c8f17f2c1c72b6ea391e86e81
llvmorg-10-init-10900-gc2443155a0fb

The v10 release is:

$ git show llvmorg-10.0.0
tag llvmorg-10.0.0
Tagger: Hans Wennborg <hans@xxxxxxxxxxxx>
Date: Tue Mar 24 12:58:58 2020 +0100

Tag 10.0.0

and v10 has reached v10.0.1 in the meantime:

$ git log --oneline c2443155a0fb245c8f17f2c1c72b6ea391e86e81~1..llvmorg-10.0.1 | wc -l
7051

so can you please update your compiler and see if you can still
reproduce with 10.0.1 so that we don't waste time chasing a bug which
has been likely already fixed in one of those >7K commits.

Thx.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette