On Thu, Oct 22, 2015 at 05:10:14PM -0700, Alexei Starovoitov wrote: > +++ b/kernel/trace/bpf_trace.c > @@ -199,6 +199,11 @@ static u64 bpf_perf_event_read(u64 r1, u64 index, u64 > r3, u64 r4, u64 r5) > if (!event) > return -ENOENT; > > + /* make sure event is local and doesn't have pmu::count */ > + if (event->oncpu != smp_processor_id() || > + event->pmu->count) > + return -EINVAL; > + > /* > * we don't know if the function is run successfully by the > * return value. It can be judged in other places, such as
I might want to go turn that into a helper function to keep !perf code from poking around in the event itself, but its ok for now I suppose. > @@ -207,7 +212,7 @@ static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, > u64 r4, u64 r5) > return perf_event_read_local(event); > } So the bpf_perf_event_read() returns the count value, does this not also mean that returning -EINVAL here is also 'wrong'? I mean, sure an actual count value that high is unlikely, but its still a broken interface. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
