selftests/bpf: Add fexit and kretprobe triggering benchmarks

We already have kprobe and fentry benchmarks. Let's add kretprobe and
fexit ones for completeness.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240309005124.3004446-1-andrii@kernel.org

Author: anakryiko

tools/testing/selftests/bpf/bench.c

@@ -495,7 +495,9 @@ extern const struct bench bench_trig_base;
 extern const struct bench bench_trig_tp;
 extern const struct bench bench_trig_rawtp;
 extern const struct bench bench_trig_kprobe;
+extern const struct bench bench_trig_kretprobe;
 extern const struct bench bench_trig_fentry;
+extern const struct bench bench_trig_fexit;
 extern const struct bench bench_trig_fentry_sleep;
 extern const struct bench bench_trig_fmodret;
 extern const struct bench bench_trig_uprobe_base;
@@ -539,7 +541,9 @@ static const struct bench *benchs[] = {
 	&bench_trig_tp,
 	&bench_trig_rawtp,
 	&bench_trig_kprobe,
+	&bench_trig_kretprobe,
 	&bench_trig_fentry,
+	&bench_trig_fexit,
 	&bench_trig_fentry_sleep,
 	&bench_trig_fmodret,
 	&bench_trig_uprobe_base,

tools/testing/selftests/bpf/benchs/bench_trigger.c

@@ -85,12 +85,24 @@ static void trigger_kprobe_setup(void)
 	attach_bpf(ctx.skel->progs.bench_trigger_kprobe);
 }
 
+static void trigger_kretprobe_setup(void)
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.bench_trigger_kretprobe);
+}
+
 static void trigger_fentry_setup(void)
 {
 	setup_ctx();
 	attach_bpf(ctx.skel->progs.bench_trigger_fentry);
 }
 
+static void trigger_fexit_setup(void)
+{
+	setup_ctx();
+	attach_bpf(ctx.skel->progs.bench_trigger_fexit);
+}
+
 static void trigger_fentry_sleep_setup(void)
 {
 	setup_ctx();
@@ -261,6 +273,16 @@ const struct bench bench_trig_kprobe = {
 	.report_final = hits_drops_report_final,
 };
 
+const struct bench bench_trig_kretprobe = {
+	.name = "trig-kretprobe",
+	.validate = trigger_validate,
+	.setup = trigger_kretprobe_setup,
+	.producer_thread = trigger_producer,
+	.measure = trigger_measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
 const struct bench bench_trig_fentry = {
 	.name = "trig-fentry",
 	.validate = trigger_validate,
@@ -271,6 +293,16 @@ const struct bench bench_trig_fentry = {
 	.report_final = hits_drops_report_final,
 };
 
+const struct bench bench_trig_fexit = {
+	.name = "trig-fexit",
+	.validate = trigger_validate,
+	.setup = trigger_fexit_setup,
+	.producer_thread = trigger_producer,
+	.measure = trigger_measure,
+	.report_progress = hits_drops_report_progress,
+	.report_final = hits_drops_report_final,
+};
+
 const struct bench bench_trig_fentry_sleep = {
 	.name = "trig-fentry-sleep",
 	.validate = trigger_validate,

tools/testing/selftests/bpf/progs/trigger_bench.c

@@ -33,13 +33,27 @@ int bench_trigger_kprobe(void *ctx)
 	return 0;
 }
 
+SEC("kretprobe/" SYS_PREFIX "sys_getpgid")
+int bench_trigger_kretprobe(void *ctx)
+{
+	__sync_add_and_fetch(&hits, 1);
+	return 0;
+}
+
 SEC("fentry/" SYS_PREFIX "sys_getpgid")
 int bench_trigger_fentry(void *ctx)
 {
 	__sync_add_and_fetch(&hits, 1);
 	return 0;
 }
 
+SEC("fexit/" SYS_PREFIX "sys_getpgid")
+int bench_trigger_fexit(void *ctx)
+{
+	__sync_add_and_fetch(&hits, 1);
+	return 0;
+}
+
 SEC("fentry.s/" SYS_PREFIX "sys_getpgid")
 int bench_trigger_fentry_sleep(void *ctx)
 {