On Fri, 23 Sep 2016 16:51:13 +0200 Andrey Konovalov <andreyk...@google.com> wrote:
> in_interrupt() returns a nonzero value when we are either in an > interrupt or have bh disabled via local_bh_disable(). Since we are > interested in only ignoring coverage from actual interrupts, do a > proper check of whether we are really in an interrupt. > > Signed-off-by: Andrey Konovalov <andreyk...@google.com> > --- > It would look totally better to reuse in_irq(), in_serving_softirq() and > in_nmi() instead of checking flags manually, but that leads to slower > generated code (three separate tests for each of the flags). Would it be > better to add another macro to preempt.h that would check if we're actually > in interrupt and use it? Yes please. Is there anywhere else where such a macro can be used? > --- a/kernel/kcov.c > +++ b/kernel/kcov.c > @@ -54,7 +54,8 @@ void notrace __sanitizer_cov_trace_pc(void) > * We are interested in code coverage as a function of a syscall inputs, > * so we ignore code executed in interrupts. > */ > - if (!t || in_interrupt()) > + if (!t || (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_OFFSET > + | NMI_MASK))) Or include a prominent and very apologetic comment here explaining why it is open-coded. But I do agree that not open-coding it is better.
