selftests/bpf: Refactor some functions for kprobe_multi_test

Refactor some functions in kprobe_multi_test.c to extract
some helper functions who will be used in later patches
to avoid code duplication.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240326041503.1198982-1-yonghong.song@linux.devSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c

@@ -336,6 +336,37 @@ static bool symbol_equal(long key1, long key2, void *ctx __maybe_unused)
 	return strcmp((const char *) key1, (const char *) key2) == 0;
 }
 
+static bool is_invalid_entry(char *buf, bool kernel)
+{
+	if (kernel && strchr(buf, '['))
+		return true;
+	if (!kernel && !strchr(buf, '['))
+		return true;
+	return false;
+}
+
+static bool skip_entry(char *name)
+{
+	/*
+	 * We attach to almost all kernel functions and some of them
+	 * will cause 'suspicious RCU usage' when fprobe is attached
+	 * to them. Filter out the current culprits - arch_cpu_idle
+	 * default_idle and rcu_* functions.
+	 */
+	if (!strcmp(name, "arch_cpu_idle"))
+		return true;
+	if (!strcmp(name, "default_idle"))
+		return true;
+	if (!strncmp(name, "rcu_", 4))
+		return true;
+	if (!strcmp(name, "bpf_dispatcher_xdp_func"))
+		return true;
+	if (!strncmp(name, "__ftrace_invalid_address__",
+		     sizeof("__ftrace_invalid_address__") - 1))
+		return true;
+	return false;
+}
+
 static int get_syms(char ***symsp, size_t *cntp, bool kernel)
 {
 	size_t cap = 0, cnt = 0, i;
@@ -368,30 +399,13 @@ static int get_syms(char ***symsp, size_t *cntp, bool kernel)
 	}
 
 	while (fgets(buf, sizeof(buf), f)) {
-		if (kernel && strchr(buf, '['))
-			continue;
-		if (!kernel && !strchr(buf, '['))
+		if (is_invalid_entry(buf, kernel))
 			continue;
 
 		free(name);
 		if (sscanf(buf, "%ms$*[^\n]\n", &name) != 1)
 			continue;
-		/*
-		 * We attach to almost all kernel functions and some of them
-		 * will cause 'suspicious RCU usage' when fprobe is attached
-		 * to them. Filter out the current culprits - arch_cpu_idle
-		 * default_idle and rcu_* functions.
-		 */
-		if (!strcmp(name, "arch_cpu_idle"))
-			continue;
-		if (!strcmp(name, "default_idle"))
-			continue;
-		if (!strncmp(name, "rcu_", 4))
-			continue;
-		if (!strcmp(name, "bpf_dispatcher_xdp_func"))
-			continue;
-		if (!strncmp(name, "__ftrace_invalid_address__",
-			     sizeof("__ftrace_invalid_address__") - 1))
+		if (skip_entry(name))
 			continue;
 
 		err = hashmap__add(map, name, 0);
@@ -426,34 +440,20 @@ static int get_syms(char ***symsp, size_t *cntp, bool kernel)
 	return err;
 }
 
-static void test_kprobe_multi_bench_attach(bool kernel)
+static void do_bench_test(struct kprobe_multi_empty *skel, struct bpf_kprobe_multi_opts *opts)
 {
-	LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
-	struct kprobe_multi_empty *skel = NULL;
 	long attach_start_ns, attach_end_ns;
 	long detach_start_ns, detach_end_ns;
 	double attach_delta, detach_delta;
 	struct bpf_link *link = NULL;
-	char **syms = NULL;
-	size_t cnt = 0, i;
-
-	if (!ASSERT_OK(get_syms(&syms, &cnt, kernel), "get_syms"))
-		return;
-
-	skel = kprobe_multi_empty__open_and_load();
-	if (!ASSERT_OK_PTR(skel, "kprobe_multi_empty__open_and_load"))
-		goto cleanup;
-
-	opts.syms = (const char **) syms;
-	opts.cnt = cnt;
 
 	attach_start_ns = get_time_ns();
 	link = bpf_program__attach_kprobe_multi_opts(skel->progs.test_kprobe_empty,
-						     NULL, &opts);
+						     NULL, opts);
 	attach_end_ns = get_time_ns();
 
 	if (!ASSERT_OK_PTR(link, "bpf_program__attach_kprobe_multi_opts"))
-		goto cleanup;
+		return;
 
 	detach_start_ns = get_time_ns();
 	bpf_link__destroy(link);
@@ -462,9 +462,29 @@ static void test_kprobe_multi_bench_attach(bool kernel)
 	attach_delta = (attach_end_ns - attach_start_ns) / 1000000000.0;
 	detach_delta = (detach_end_ns - detach_start_ns) / 1000000000.0;
 
-	printf("%s: found %lu functions\n", __func__, cnt);
+	printf("%s: found %lu functions\n", __func__, opts->cnt);
 	printf("%s: attached in %7.3lfs\n", __func__, attach_delta);
 	printf("%s: detached in %7.3lfs\n", __func__, detach_delta);
+}
+
+static void test_kprobe_multi_bench_attach(bool kernel)
+{
+	LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
+	struct kprobe_multi_empty *skel = NULL;
+	char **syms = NULL;
+	size_t cnt = 0, i;
+
+	if (!ASSERT_OK(get_syms(&syms, &cnt, kernel), "get_syms"))
+		return;
+
+	skel = kprobe_multi_empty__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "kprobe_multi_empty__open_and_load"))
+		goto cleanup;
+
+	opts.syms = (const char **) syms;
+	opts.cnt = cnt;
+
+	do_bench_test(skel, &opts);
 
 cleanup:
 	kprobe_multi_empty__destroy(skel);