Re: [PATCH v3 net-next] bpf: fix bpf_perf_event_read() helper

On 2015/10/23 8:10, Alexei Starovoitov wrote:

Fix safety checks for bpf_perf_event_read():
- only non-inherited events can be added to perf_event_array map
   (do this check statically at map insertion time)
- dynamically check that event is local and !pmu->count
Otherwise buggy bpf program can cause kernel splat.

Also fix error path after perf_event_attrs()
and remove redundant 'extern'.

Fixes: 35578d798400 ("bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Tested-by: Wang Nan <redacted>