Re: [PATCH] ftrace: Remove possible deadlock between register_kprobe() and ftrace_run_update_code()

From: Jiri Kosina
Date: Fri Jun 28 2019 - 13:33:37 EST


On Thu, 27 Jun 2019, Josh Poimboeuf wrote:

> > How is that supposed to work?
> >
> > ftrace
> > prepare()
> > setrw()
> > setro()
> > patch <- FAIL
>
> /me dodges frozen shark
>
> You are right of course. My brain has apparently already shut off for
> the day.
>
> Maybe a comment or two would help though.

I'd actually prefer (perhaps in parallel to the comment) using the
__acquires() and __releases() anotations, so that sparse and friends don't
get confused by that either.

--
Jiri Kosina
SUSE Labs