From: Teng Qin <qinteng@fb.com>
Date: Tue, 6 Mar 2018 10:55:02 -0800
Subject: samples/bpf: add example to test reading address
Patch-mainline: v4.17-rc1
Git-commit: 12fe12253c56a26e591ceefbdf0998b391022003
References: bsc#1109837
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 <qinteng@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
samples/bpf/trace_event_kern.c | 4 ++++
samples/bpf/trace_event_user.c | 15 +++++++++++++++
2 files changed, 19 insertions(+)
--- 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
{
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
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)++;
--- 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");
}