Messages in this thread | | | From | Dmitry Vyukov <> | Date | Wed, 13 Apr 2016 18:27:13 +0200 | Subject | Re: [PATCH] kcov: Don't trace the code coverage code |
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On Wed, Apr 13, 2016 at 6:22 PM, James Morse <james.morse@arm.com> wrote: > Kcov causes the compiler to add a call to __sanitizer_cov_trace_pc() in > every basic block. Ftrace patches in a call to _mcount() to each function > it has annotated. > > Letting these mechanisms annotate each other is a bad thing. Break the > loop by adding 'notrace' to __sanitizer_cov_trace_pc() so that ftrace > won't try to patch this code. > > Signed-off-by: James Morse <james.morse@arm.com> > --- > This patch lets arm64 with KCOV and STACK_TRACER boot. > > kernel/kcov.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/kcov.c b/kernel/kcov.c > index 3efbee0834a8..78bed7125515 100644 > --- a/kernel/kcov.c > +++ b/kernel/kcov.c > @@ -43,7 +43,7 @@ struct kcov { > * Entry point from instrumented code. > * This is called once per basic-block/edge. > */ > -void __sanitizer_cov_trace_pc(void) > +void notrace __sanitizer_cov_trace_pc(void) > { > struct task_struct *t; > enum kcov_mode mode; > -- > 2.8.0.rc3
Thanks!
Acked-by: Dmitry Vyukov <dvyukov@google.com>
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