From 12fe12253c56a26e591ceefbdf0998b391022003 Mon Sep 17 00:00:00 2001 From: Teng Qin Date: Tue, 6 Mar 2018 10:55:02 -0800 Subject: [PATCH] samples/bpf: add example to test reading address 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 Signed-off-by: Daniel Borkmann --- 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 a77a583d94d4..7068fbdde951 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 bf4f1b6d9a52..56f7a259a7c9 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"); } -- 2.30.2