[PATCH bpf-next 2/2] samples/bpf: add example to test reading address
flat view
STALE3155d
From: Teng Qin <hidden>
Date: 2018-03-06 18:55:14
Subsystem:
bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
This commit adds additional test in the trace_event example, by attaching the bpf program to MEM_UOPS_RETIRED.LOCK_LOADS event with PERF_SAMPLE_ADDR requested, and print the lock address value read from the bpf program to trace_pipe. Signed-off-by: Teng Qin <redacted> --- samples/bpf/trace_event_kern.c | 4 ++++ samples/bpf/trace_event_user.c | 15 +++++++++++++++ 2 files changed, 19 insertions(+)
diff --git a/samples/bpf/trace_event_kern.c b/samples/bpf/trace_event_kern.c
index a77a583d..7068fbd 100644
--- a/samples/bpf/trace_event_kern.c
+++ b/samples/bpf/trace_event_kern.c@@ -39,6 +39,7 @@ int bpf_prog1(struct bpf_perf_event_data *ctx) { char time_fmt1[] = "Time Enabled: %llu, Time Running: %llu"; char time_fmt2[] = "Get Time Failed, ErrCode: %d"; + char addr_fmt[] = "Address recorded on event: %llx"; char fmt[] = "CPU-%d period %lld ip %llx"; u32 cpu = bpf_get_smp_processor_id(); struct bpf_perf_event_value value_buf;
@@ -64,6 +65,9 @@ int bpf_prog1(struct bpf_perf_event_data *ctx) else bpf_trace_printk(time_fmt2, sizeof(time_fmt2), ret); + if (ctx->addr != 0) + bpf_trace_printk(addr_fmt, sizeof(addr_fmt), ctx->addr); + val = bpf_map_lookup_elem(&counts, &key); if (val) (*val)++;
diff --git a/samples/bpf/trace_event_user.c b/samples/bpf/trace_event_user.c
index bf4f1b6..56f7a25 100644
--- a/samples/bpf/trace_event_user.c
+++ b/samples/bpf/trace_event_user.c@@ -215,6 +215,17 @@ static void test_bpf_perf_event(void) /* Intel Instruction Retired */ .config = 0xc0, }; + struct perf_event_attr attr_type_raw_lock_load = { + .sample_freq = SAMPLE_FREQ, + .freq = 1, + .type = PERF_TYPE_RAW, + /* Intel MEM_UOPS_RETIRED.LOCK_LOADS */ + .config = 0x21d0, + /* Request to record lock address from PEBS */ + .sample_type = PERF_SAMPLE_ADDR, + /* Record address value requires precise event */ + .precise_ip = 2, + }; printf("Test HW_CPU_CYCLES\n"); test_perf_event_all_cpu(&attr_type_hw);
@@ -236,6 +247,10 @@ static void test_bpf_perf_event(void) test_perf_event_all_cpu(&attr_type_raw); test_perf_event_task(&attr_type_raw); + printf("Test Lock Load\n"); + test_perf_event_all_cpu(&attr_type_raw_lock_load); + test_perf_event_task(&attr_type_raw_lock_load); + printf("*** PASS ***\n"); }
--
2.9.5