diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2016-06-28 12:18:25 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-06-30 11:54:40 +0200 |
| commit | 6816a7ffce32e999601825ddfd887f36d3052932 (patch) | |
| tree | 99a35abec2ab665d9cd72ae8f143b544d5eef923 /kernel/trace | |
| parent | bpf, trace: fetch current cpu only once (diff) | |
| download | linux-6816a7ffce32e999601825ddfd887f36d3052932.tar.xz linux-6816a7ffce32e999601825ddfd887f36d3052932.zip | |
bpf, trace: add BPF_F_CURRENT_CPU flag for bpf_perf_event_read
Follow-up commit to 1e33759c788c ("bpf, trace: add BPF_F_CURRENT_CPU
flag for bpf_perf_event_output") to add the same functionality into
bpf_perf_event_read() helper. The split of index into flags and index
component is also safe here, since such large maps are rejected during
map allocation time.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 505f9e9cdb3b..19c5b4a5c3eb 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -188,13 +188,19 @@ const struct bpf_func_proto *bpf_get_trace_printk_proto(void) return &bpf_trace_printk_proto; } -static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, u64 r4, u64 r5) +static u64 bpf_perf_event_read(u64 r1, u64 flags, 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); + unsigned int cpu = smp_processor_id(); + u64 index = flags & BPF_F_INDEX_MASK; struct bpf_event_entry *ee; struct perf_event *event; + if (unlikely(flags & ~(BPF_F_INDEX_MASK))) + return -EINVAL; + if (index == BPF_F_CURRENT_CPU) + index = cpu; if (unlikely(index >= array->map.max_entries)) return -E2BIG; @@ -208,8 +214,7 @@ static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, u64 r4, u64 r5) return -EINVAL; /* make sure event is local and doesn't have pmu::count */ - if (event->oncpu != smp_processor_id() || - event->pmu->count) + if (unlikely(event->oncpu != cpu || event->pmu->count)) return -EINVAL; /* |