diff options
| author | Yonghong Song <yhs@fb.com> | 2017-10-05 19:19:21 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-10-08 01:05:57 +0300 |
| commit | 020a32d9581ac824d038b0b4e24e977e3cc8589f (patch) | |
| tree | f0256aea3e0a98cbba98b91248983b6d90793357 /samples | |
| parent | 908432ca84fc229e906ba164219e9ad0fe56f755 (diff) | |
| download | linux-020a32d9581ac824d038b0b4e24e977e3cc8589f.tar.xz | |
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>
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/bpf/tracex6_kern.c | 26 | ||||
| -rw-r--r-- | samples/bpf/tracex6_user.c | 13 |
2 files changed, 38 insertions, 1 deletions
diff --git a/samples/bpf/tracex6_kern.c b/samples/bpf/tracex6_kern.c index e7d180305974..46c557afac73 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; diff --git a/samples/bpf/tracex6_user.c b/samples/bpf/tracex6_user.c index a05a99a0752f..3341a96fc046 100644 --- a/samples/bpf/tracex6_user.c +++ b/samples/bpf/tracex6_user.c @@ -22,6 +22,7 @@ static void check_on_cpu(int cpu, struct perf_event_attr *attr) { + struct bpf_perf_event_value value2; int pmu_fd, error = 0; cpu_set_t set; __u64 value; @@ -46,8 +47,18 @@ static void check_on_cpu(int cpu, struct perf_event_attr *attr) fprintf(stderr, "Value missing for CPU %d\n", cpu); error = 1; goto on_exit; + } else { + fprintf(stderr, "CPU %d: %llu\n", cpu, value); + } + /* The above bpf_map_lookup_elem should trigger the second kprobe */ + if (bpf_map_lookup_elem(map_fd[2], &cpu, &value2)) { + fprintf(stderr, "Value2 missing for CPU %d\n", cpu); + error = 1; + goto on_exit; + } else { + fprintf(stderr, "CPU %d: counter: %llu, enabled: %llu, running: %llu\n", cpu, + value2.counter, value2.enabled, value2.running); } - fprintf(stderr, "CPU %d: %llu\n", cpu, value); on_exit: assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error); |