Messages in this thread | | | Date | Mon, 3 Aug 2015 11:34:37 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v3 2/3] bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter |
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On Thu, Jul 23, 2015 at 09:42:41AM +0000, Kaixu Xia wrote: > +static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, u64 r4, u64 r5) > +{ > + struct bpf_map *map = (struct bpf_map *) (unsigned long) r1; > + struct bpf_array *array = container_of(map, struct bpf_array, map); > + struct perf_event *event; > + > + if (index >= array->map.max_entries) > + return -E2BIG; > + > + event = array->events[index]; > + if (!event) > + return -EBADF; > + > + if (event->state != PERF_EVENT_STATE_ACTIVE) > + return -ENOENT; > + > + if (event->oncpu != raw_smp_processor_id() && > + event->ctx->task != current) > + return -EINVAL; > + > + if (event->attr.inherit) > + return -EINVAL; > + > + __perf_event_read(event); > + > + return perf_event_count(event); > +}
Please no poking of event internal state outside of perf code.
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