Re: [syzbot] WARNING in __perf_install_in_context

From: Dmitry Vyukov
Date: Mon May 17 2021 - 12:38:24 EST


On Mon, May 17, 2021 at 2:46 PM Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
>
> On Mon, May 17, 2021 at 1:28 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> >
> > On Mon, May 17, 2021 at 03:56:22AM -0700, syzbot wrote:
> > > Hello,
> > >
> > > syzbot found the following issue on:
> > >
> > > HEAD commit: 18a3c5f7 Merge tag 'for_linus' of git://git.kernel.org/pub..
> > > git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=1662c153d00000
> > > kernel config: https://syzkaller.appspot.com/x/.config?x=b8ac1fe5995f69d7
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=0fb24f56fa707081e4f2
> > > userspace arch: riscv64
> > >
> > > Unfortunately, I don't have any reproducer for this issue yet.
> > >
> > > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > > Reported-by: syzbot+0fb24f56fa707081e4f2@xxxxxxxxxxxxxxxxxxxxxxxxx
> > >
> > > ------------[ cut here ]------------
> > > WARNING: CPU: 1 PID: 8643 at kernel/events/core.c:2781 __perf_install_in_context+0x1c0/0x47c kernel/events/core.c:2781
> > > Modules linked in:
> > > CPU: 1 PID: 8643 Comm: syz-executor.0 Not tainted 5.12.0-rc8-syzkaller-00011-g18a3c5f7abfd #0
> > > Hardware name: riscv-virtio,qemu (DT)
> >
> > How serious should I take this thing? ARM64 and x86_64 don't show these
> > errors.
>
> +riscv mainters for this question
> Is perf on riscv considered stable?

Another perf/riscv64 warning just come in:
https://syzkaller.appspot.com/bug?extid=30189c98403be62bc05a