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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