Re: perf: bench/sched-messaging.c:73:13: error: 'dummy' may be used uninitialized

From: Anders Roxell
Date: Tue Jul 13 2021 - 11:32:33 EST


On Tue, 13 Jul 2021 at 17:18, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, Jul 13, 2021 at 08:40:28PM +0530, Naresh Kamboju wrote:
> > LKFT have noticed these warnings / errors when we have updated gcc version from
> > gcc-9 to gcc-11 on stable-rc linux-5.4.y branch. I have provided the steps to
> > reproduce in this email below.
> >
> > Following perf builds failed with gcc-11 with linux-5.4.y branch.
> > - build-arm-gcc-11-perf
> > - build-arm64-gcc-11-perf
> > - build-i386-gcc-11-perf
> > - build-x86-gcc-11-perf
> >
> > Build error log:
> > --------------------
>
> <snip>
>
> I imagine this is fixed in newer kernel versions, so if you could
> provide the git ids of the patches needed to fix this up in 5.4, that
> would be great!

You were correct, I did a bisect [1] and found
d493720581a6 ("perf bench: Fix 2 memory sanitizer warnings").

commit d2c73501a767514b6c85c7feff9457a165d51057 upstream.

Cherry picked it and I was able to build it on arm64 and x86.

Cheers,
Anders
[1] http://ix.io/3sS6