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 <qinteng@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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)++;
