Re: [Cocci] Coccinelle rule for CVE-2019-18683

[Julia Lawall]

> >> kthread_stop@stop_p(...)
> >> ...
> >> mutex_lock@lock_p(E)
> >>
> >> @script:python@
> >> stop_p << race.stop_p;
> >> unlock_p << race.unlock_p;
> >> lock_p << race.lock_p;
> >> E << race.E;
> >> @@
> >>
> >> coccilib.report.print_report(unlock_p[0], 'mutex_unlock(' + E + ') here')
> >> coccilib.report.print_report(stop_p[0], 'kthread_stop here')
> >> coccilib.report.print_report(lock_p[0], 'mutex_lock(' + E + ') here\n')
>
> ...
>
> > Based on Jann's suggestion, it seem like it could be interesting to find
> > these locking pauses, and then collect functions that are used in locks
> > and in lock pauses.  If a function is mostly used with locks held, then
> > using it in a lock pause could be a sign of a bug.  I will see if it turns
> > up anything interesting.
>
> Do you mean collecting the behaviour that happens between unlocking and locking
> and then analysing it somehow?

Yes.  I have tried doing what I described, but I'm not sure that the
results are very reliable at the moment.

julia