Re: KCSAN: data-race in tick_nohz_stop_tick / tick_sched_timer

From: Dmitry Vyukov
Date: Wed Jan 12 2022 - 02:39:42 EST


On Wed, 12 Jan 2022 at 02:39, Hao Sun <sunhao.th@xxxxxxxxx> wrote:
>
> Dmitry Vyukov <dvyukov@xxxxxxxxxx> 于2022年1月12日周三 01:18写道:
> >
> > On Tue, 11 Jan 2022 at 17:56, Kaia Yadira
> > <hypericumperforatum4444@xxxxxxxxx> wrote:
> > >
> > > I'm sorry. They are similar but I can't tell if they are the same bug,
> > > so I report them individually.
> >
> > +CC list back
> >
> > I did not mean that you report similar bugs. I meant that you and
> > kvartet seem to be following the same process. There are several
> > complaints about the quality of reports. So I am wondering what you
> > are doing/why/what's your goal.
> >
> > Hao Sun, you are CCed on all emails, maybe you can shed some light on this?
>
> Hi Dmitry,
>
> I'm on holiday and ignored these emails.
> kvartet is an acquaintance of mine, I have no idea who Kaia is.
> I have little knowledge of their actions. They may be new to the
> kernel community and may not understand the rules in reporting bugs
>
> Maybe we should add some `WARNING` in Syzkaller docs, e.g.,
> `how_to_report_bug.md`, to tell people to polish their reports before
> sending them out.

Hi Hao,

Thanks for the info.

We've already extended how_to_report_bug.md with some warning:
https://github.com/google/syzkaller/commit/ca0f51ac4a404a5378464e91c42eca8c1e78e21a
But it does not mention KCSAN/KMSAN yet, as these reports come in later.

> Or maybe we should just suppress all the `task-hung` and `kcsan`
> reports in Syzkaller by default, enable them manually if the user
> knows what they are doing.

This is a good idea.
We will need to figure out details, and this will require some coding.