Re: [PATCH] kcov: properly check if we are in an interrupt

Peter Zijlstra
2016-09-27T10:59:22Z

On Tue, Sep 27, 2016 at 09:50:41AM +0200, Dmitry Vyukov wrote:
> On Tue, Sep 27, 2016 at 9:34 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> > On Tue, Sep 27, 2016 at 08:21:32AM +0200, Dmitry Vyukov wrote:
> >>
> >> I suspect there is a bunch of places that use in_interrupt(), but mean
> >> the same as KCOV wants -- am I in interrupt? and not am I in interrupt
> >> context or in normal task context but inside local_bh_disable(). For
> >> example, why does fput handles closure asynchronously if the task
> >> called local_bh_disable?
> >
> > Agreed, but it would mean auditing all in_interrupt()/irq_count() users.
>
>
> I don't think this means auditing all users. We are not making things
> worse by introduction of a new predicate.
> It would be nice to look at some uses in core code, but the only place
> with observed harm is KCOV.
>
> Any naming suggestions? Other than really_in_interrupt or
> in_interrupt_and_not_in_bh_disabled?

Hence the suggestion to audit and fix instead of making a bigger mess :/