[PATCH v4 bpf-next 7/9] selftests/bpf: switch test to new attach_perf_event API

[Andrii Nakryiko <andriin@fb.com>]

Use new bpf_program__attach_perf_event() in test previously relying on
direct ioctl manipulations.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Song Liu <songliubraving@fb.com>
---
 .../bpf/prog_tests/stacktrace_build_id_nmi.c  | 31 +++++++++----------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
index 1c1a2f75f3d8..9557b7dfb782 100644
--- a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
+++ b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
@@ -17,6 +17,7 @@ static __u64 read_perf_max_sample_freq(void)
 void test_stacktrace_build_id_nmi(void)
 {
 	int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd;
+	const char *prog_name = "tracepoint/random/urandom_read";
 	const char *file = "./test_stacktrace_build_id.o";
 	int err, pmu_fd, prog_fd;
 	struct perf_event_attr attr = {
@@ -25,7 +26,9 @@ void test_stacktrace_build_id_nmi(void)
 		.config = PERF_COUNT_HW_CPU_CYCLES,
 	};
 	__u32 key, previous_key, val, duration = 0;
+	struct bpf_program *prog;
 	struct bpf_object *obj;
+	struct bpf_link *link;
 	char buf[256];
 	int i, j;
 	struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH];
@@ -39,6 +42,10 @@ void test_stacktrace_build_id_nmi(void)
 	if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno))
 		return;
 
+	prog = bpf_object__find_program_by_title(obj, prog_name);
+	if (CHECK(!prog, "find_prog", "prog '%s' not found\n", prog_name))
+		goto close_prog;
+
 	pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
 			 0 /* cpu 0 */, -1 /* group id */,
 			 0 /* flags */);
@@ -47,15 +54,12 @@ void test_stacktrace_build_id_nmi(void)
 		  pmu_fd, errno))
 		goto close_prog;
 
-	err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
-	if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n",
-		  err, errno))
-		goto close_pmu;
-
-	err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
-	if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n",
-		  err, errno))
-		goto disable_pmu;
+	link = bpf_program__attach_perf_event(prog, pmu_fd);
+	if (CHECK(IS_ERR(link), "attach_perf_event",
+		  "err %ld\n", PTR_ERR(link))) {
+		close(pmu_fd);
+		goto close_prog;
+	}
 
 	/* find map fds */
 	control_map_fd = bpf_find_map(__func__, obj, "control_map");
@@ -134,8 +138,7 @@ void test_stacktrace_build_id_nmi(void)
 	 * try it one more time.
 	 */
 	if (build_id_matches < 1 && retry--) {
-		ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
-		close(pmu_fd);
+		bpf_link__destroy(link);
 		bpf_object__close(obj);
 		printf("%s:WARN:Didn't find expected build ID from the map, retrying\n",
 		       __func__);
@@ -154,11 +157,7 @@ void test_stacktrace_build_id_nmi(void)
 	 */
 
 disable_pmu:
-	ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
-
-close_pmu:
-	close(pmu_fd);
-
+	bpf_link__destroy(link);
 close_prog:
 	bpf_object__close(obj);
 }
-- 
2.17.1