bpf: add a test case for helper bpf_perf_event_read_value
The bpf sample program tracex6 is enhanced to use the new
helper to read enabled/running time as well.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/samples/bpf/tracex6_kern.c b/samples/bpf/tracex6_kern.c
index e7d1803..46c557a 100644
--- a/samples/bpf/tracex6_kern.c
+++ b/samples/bpf/tracex6_kern.c
@@ -15,6 +15,12 @@ struct bpf_map_def SEC("maps") values = {
.value_size = sizeof(u64),
.max_entries = 64,
};
+struct bpf_map_def SEC("maps") values2 = {
+ .type = BPF_MAP_TYPE_HASH,
+ .key_size = sizeof(int),
+ .value_size = sizeof(struct bpf_perf_event_value),
+ .max_entries = 64,
+};
SEC("kprobe/htab_map_get_next_key")
int bpf_prog1(struct pt_regs *ctx)
@@ -37,5 +43,25 @@ int bpf_prog1(struct pt_regs *ctx)
return 0;
}
+SEC("kprobe/htab_map_lookup_elem")
+int bpf_prog2(struct pt_regs *ctx)
+{
+ u32 key = bpf_get_smp_processor_id();
+ struct bpf_perf_event_value *val, buf;
+ int error;
+
+ error = bpf_perf_event_read_value(&counters, key, &buf, sizeof(buf));
+ if (error)
+ return 0;
+
+ val = bpf_map_lookup_elem(&values2, &key);
+ if (val)
+ *val = buf;
+ else
+ bpf_map_update_elem(&values2, &key, &buf, BPF_NOEXIST);
+
+ return 0;
+}
+
char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;