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

From: Dmitry Vyukov
Date: Tue Sep 27 2016 - 03:51:15 EST


On Tue, Sep 27, 2016 at 9:34 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> 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?