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-rw-r--r--kernel/trace/bpf_trace.c22
1 files changed, 8 insertions, 14 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 460a031..08eb072 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -234,7 +234,8 @@ BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
unsigned int cpu = smp_processor_id();
u64 index = flags & BPF_F_INDEX_MASK;
struct bpf_event_entry *ee;
- struct perf_event *event;
+ u64 value = 0;
+ int err;
if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
return -EINVAL;
@@ -247,21 +248,14 @@ BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
if (!ee)
return -ENOENT;
- event = ee->event;
- if (unlikely(event->attr.type != PERF_TYPE_HARDWARE &&
- event->attr.type != PERF_TYPE_RAW))
- return -EINVAL;
-
- /* make sure event is local and doesn't have pmu::count */
- if (unlikely(event->oncpu != cpu || event->pmu->count))
- return -EINVAL;
-
+ err = perf_event_read_local(ee->event, &value);
/*
- * we don't know if the function is run successfully by the
- * return value. It can be judged in other places, such as
- * eBPF programs.
+ * this api is ugly since we miss [-22..-2] range of valid
+ * counter values, but that's uapi
*/
- return perf_event_read_local(event);
+ if (err)
+ return err;
+ return value;
}
static const struct bpf_func_proto bpf_perf_event_read_proto = {
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