[PATCH bpf-next 0/3] selftests/bpf: benchmark all symbols for kprobe-multi

[PATCH bpf-next 0/3] selftests/bpf: benchmark all symbols for kprobe-multi

[Menglong Dong]

Add the benchmark testcase "kprobe-multi-all", which will hook all the
kernel functions during the testing.

This series is separated out from [1].

Link: https://lore.kernel.org/bpf/20250817024607.296117-1-dongml2@chinatelecom.cn/ [1]
Menglong Dong (3):
  selftests/bpf: move get_ksyms and get_addrs to trace_helpers.c
  selftests/bpf: skip recursive functions for kprobe_multi
  selftests/bpf: add benchmark testing for kprobe-multi-all

 tools/testing/selftests/bpf/bench.c           |   4 +
 .../selftests/bpf/benchs/bench_trigger.c      |  54 ++++
 .../selftests/bpf/benchs/run_bench_trigger.sh |   4 +-
 .../bpf/prog_tests/kprobe_multi_test.c        | 220 +----------------
 .../selftests/bpf/progs/trigger_bench.c       |  12 +
 tools/testing/selftests/bpf/trace_helpers.c   | 233 ++++++++++++++++++
 tools/testing/selftests/bpf/trace_helpers.h   |   3 +
 7 files changed, 311 insertions(+), 219 deletions(-)

-- 
2.50.1

[PATCH bpf-next 1/3] selftests/bpf: move get_ksyms and get_addrs to trace_helpers.c

[Menglong Dong]

We need to get all the kernel function that can be traced sometimes, so we
move the get_syms() and get_addrs() in kprobe_multi_test.c to
trace_helpers.c and rename it to bpf_get_ksyms() and bpf_get_addrs().

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
 .../bpf/prog_tests/kprobe_multi_test.c        | 220 +-----------------
 tools/testing/selftests/bpf/trace_helpers.c   | 214 +++++++++++++++++
 tools/testing/selftests/bpf/trace_helpers.h   |   3 +
 3 files changed, 220 insertions(+), 217 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
index e19ef509ebf8..171706e78da8 100644
--- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
@@ -422,220 +422,6 @@ static void test_unique_match(void)
 	kprobe_multi__destroy(skel);
 }
 
-static size_t symbol_hash(long key, void *ctx __maybe_unused)
-{
-	return str_hash((const char *) key);
-}
-
-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;
-}
-
-/* Do comparision by ignoring '.llvm.<hash>' suffixes. */
-static int compare_name(const char *name1, const char *name2)
-{
-	const char *res1, *res2;
-	int len1, len2;
-
-	res1 = strstr(name1, ".llvm.");
-	res2 = strstr(name2, ".llvm.");
-	len1 = res1 ? res1 - name1 : strlen(name1);
-	len2 = res2 ? res2 - name2 : strlen(name2);
-
-	if (len1 == len2)
-		return strncmp(name1, name2, len1);
-	if (len1 < len2)
-		return strncmp(name1, name2, len1) <= 0 ? -1 : 1;
-	return strncmp(name1, name2, len2) >= 0 ? 1 : -1;
-}
-
-static int load_kallsyms_compare(const void *p1, const void *p2)
-{
-	return compare_name(((const struct ksym *)p1)->name, ((const struct ksym *)p2)->name);
-}
-
-static int search_kallsyms_compare(const void *p1, const struct ksym *p2)
-{
-	return compare_name(p1, p2->name);
-}
-
-static int get_syms(char ***symsp, size_t *cntp, bool kernel)
-{
-	size_t cap = 0, cnt = 0;
-	char *name = NULL, *ksym_name, **syms = NULL;
-	struct hashmap *map;
-	struct ksyms *ksyms;
-	struct ksym *ks;
-	char buf[256];
-	FILE *f;
-	int err = 0;
-
-	ksyms = load_kallsyms_custom_local(load_kallsyms_compare);
-	if (!ASSERT_OK_PTR(ksyms, "load_kallsyms_custom_local"))
-		return -EINVAL;
-
-	/*
-	 * The available_filter_functions contains many duplicates,
-	 * but other than that all symbols are usable in kprobe multi
-	 * interface.
-	 * Filtering out duplicates by using hashmap__add, which won't
-	 * add existing entry.
-	 */
-
-	if (access("/sys/kernel/tracing/trace", F_OK) == 0)
-		f = fopen("/sys/kernel/tracing/available_filter_functions", "r");
-	else
-		f = fopen("/sys/kernel/debug/tracing/available_filter_functions", "r");
-
-	if (!f)
-		return -EINVAL;
-
-	map = hashmap__new(symbol_hash, symbol_equal, NULL);
-	if (IS_ERR(map)) {
-		err = libbpf_get_error(map);
-		goto error;
-	}
-
-	while (fgets(buf, sizeof(buf), f)) {
-		if (is_invalid_entry(buf, kernel))
-			continue;
-
-		free(name);
-		if (sscanf(buf, "%ms$*[^\n]\n", &name) != 1)
-			continue;
-		if (skip_entry(name))
-			continue;
-
-		ks = search_kallsyms_custom_local(ksyms, name, search_kallsyms_compare);
-		if (!ks) {
-			err = -EINVAL;
-			goto error;
-		}
-
-		ksym_name = ks->name;
-		err = hashmap__add(map, ksym_name, 0);
-		if (err == -EEXIST) {
-			err = 0;
-			continue;
-		}
-		if (err)
-			goto error;
-
-		err = libbpf_ensure_mem((void **) &syms, &cap,
-					sizeof(*syms), cnt + 1);
-		if (err)
-			goto error;
-
-		syms[cnt++] = ksym_name;
-	}
-
-	*symsp = syms;
-	*cntp = cnt;
-
-error:
-	free(name);
-	fclose(f);
-	hashmap__free(map);
-	if (err)
-		free(syms);
-	return err;
-}
-
-static int get_addrs(unsigned long **addrsp, size_t *cntp, bool kernel)
-{
-	unsigned long *addr, *addrs, *tmp_addrs;
-	int err = 0, max_cnt, inc_cnt;
-	char *name = NULL;
-	size_t cnt = 0;
-	char buf[256];
-	FILE *f;
-
-	if (access("/sys/kernel/tracing/trace", F_OK) == 0)
-		f = fopen("/sys/kernel/tracing/available_filter_functions_addrs", "r");
-	else
-		f = fopen("/sys/kernel/debug/tracing/available_filter_functions_addrs", "r");
-
-	if (!f)
-		return -ENOENT;
-
-	/* In my local setup, the number of entries is 50k+ so Let us initially
-	 * allocate space to hold 64k entries. If 64k is not enough, incrementally
-	 * increase 1k each time.
-	 */
-	max_cnt = 65536;
-	inc_cnt = 1024;
-	addrs = malloc(max_cnt * sizeof(long));
-	if (addrs == NULL) {
-		err = -ENOMEM;
-		goto error;
-	}
-
-	while (fgets(buf, sizeof(buf), f)) {
-		if (is_invalid_entry(buf, kernel))
-			continue;
-
-		free(name);
-		if (sscanf(buf, "%p %ms$*[^\n]\n", &addr, &name) != 2)
-			continue;
-		if (skip_entry(name))
-			continue;
-
-		if (cnt == max_cnt) {
-			max_cnt += inc_cnt;
-			tmp_addrs = realloc(addrs, max_cnt);
-			if (!tmp_addrs) {
-				err = -ENOMEM;
-				goto error;
-			}
-			addrs = tmp_addrs;
-		}
-
-		addrs[cnt++] = (unsigned long)addr;
-	}
-
-	*addrsp = addrs;
-	*cntp = cnt;
-
-error:
-	free(name);
-	fclose(f);
-	if (err)
-		free(addrs);
-	return err;
-}
-
 static void do_bench_test(struct kprobe_multi_empty *skel, struct bpf_kprobe_multi_opts *opts)
 {
 	long attach_start_ns, attach_end_ns;
@@ -670,7 +456,7 @@ static void test_kprobe_multi_bench_attach(bool kernel)
 	char **syms = NULL;
 	size_t cnt = 0;
 
-	if (!ASSERT_OK(get_syms(&syms, &cnt, kernel), "get_syms"))
+	if (!ASSERT_OK(bpf_get_ksyms(&syms, &cnt, kernel), "bpf_get_ksyms"))
 		return;
 
 	skel = kprobe_multi_empty__open_and_load();
@@ -696,13 +482,13 @@ static void test_kprobe_multi_bench_attach_addr(bool kernel)
 	size_t cnt = 0;
 	int err;
 
-	err = get_addrs(&addrs, &cnt, kernel);
+	err = bpf_get_addrs(&addrs, &cnt, kernel);
 	if (err == -ENOENT) {
 		test__skip();
 		return;
 	}
 
-	if (!ASSERT_OK(err, "get_addrs"))
+	if (!ASSERT_OK(err, "bpf_get_addrs"))
 		return;
 
 	skel = kprobe_multi_empty__open_and_load();
diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
index 81943c6254e6..d24baf244d1f 100644
--- a/tools/testing/selftests/bpf/trace_helpers.c
+++ b/tools/testing/selftests/bpf/trace_helpers.c
@@ -17,6 +17,7 @@
 #include <linux/limits.h>
 #include <libelf.h>
 #include <gelf.h>
+#include "bpf/hashmap.h"
 #include "bpf/libbpf_internal.h"
 
 #define TRACEFS_PIPE	"/sys/kernel/tracing/trace_pipe"
@@ -519,3 +520,216 @@ void read_trace_pipe(void)
 {
 	read_trace_pipe_iter(trace_pipe_cb, NULL, 0);
 }
+
+static size_t symbol_hash(long key, void *ctx __maybe_unused)
+{
+	return str_hash((const char *) key);
+}
+
+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;
+}
+
+/* Do comparison by ignoring '.llvm.<hash>' suffixes. */
+static int compare_name(const char *name1, const char *name2)
+{
+	const char *res1, *res2;
+	int len1, len2;
+
+	res1 = strstr(name1, ".llvm.");
+	res2 = strstr(name2, ".llvm.");
+	len1 = res1 ? res1 - name1 : strlen(name1);
+	len2 = res2 ? res2 - name2 : strlen(name2);
+
+	if (len1 == len2)
+		return strncmp(name1, name2, len1);
+	if (len1 < len2)
+		return strncmp(name1, name2, len1) <= 0 ? -1 : 1;
+	return strncmp(name1, name2, len2) >= 0 ? 1 : -1;
+}
+
+static int load_kallsyms_compare(const void *p1, const void *p2)
+{
+	return compare_name(((const struct ksym *)p1)->name, ((const struct ksym *)p2)->name);
+}
+
+static int search_kallsyms_compare(const void *p1, const struct ksym *p2)
+{
+	return compare_name(p1, p2->name);
+}
+
+int bpf_get_ksyms(char ***symsp, size_t *cntp, bool kernel)
+{
+	size_t cap = 0, cnt = 0;
+	char *name = NULL, *ksym_name, **syms = NULL;
+	struct hashmap *map;
+	struct ksyms *ksyms;
+	struct ksym *ks;
+	char buf[256];
+	FILE *f;
+	int err = 0;
+
+	ksyms = load_kallsyms_custom_local(load_kallsyms_compare);
+	if (!ksyms)
+		return -EINVAL;
+
+	/*
+	 * The available_filter_functions contains many duplicates,
+	 * but other than that all symbols are usable to trace.
+	 * Filtering out duplicates by using hashmap__add, which won't
+	 * add existing entry.
+	 */
+
+	if (access("/sys/kernel/tracing/trace", F_OK) == 0)
+		f = fopen("/sys/kernel/tracing/available_filter_functions", "r");
+	else
+		f = fopen("/sys/kernel/debug/tracing/available_filter_functions", "r");
+
+	if (!f)
+		return -EINVAL;
+
+	map = hashmap__new(symbol_hash, symbol_equal, NULL);
+	if (IS_ERR(map)) {
+		err = libbpf_get_error(map);
+		goto error;
+	}
+
+	while (fgets(buf, sizeof(buf), f)) {
+		if (is_invalid_entry(buf, kernel))
+			continue;
+
+		free(name);
+		if (sscanf(buf, "%ms$*[^\n]\n", &name) != 1)
+			continue;
+		if (skip_entry(name))
+			continue;
+
+		ks = search_kallsyms_custom_local(ksyms, name, search_kallsyms_compare);
+		if (!ks) {
+			err = -EINVAL;
+			goto error;
+		}
+
+		ksym_name = ks->name;
+		err = hashmap__add(map, ksym_name, 0);
+		if (err == -EEXIST) {
+			err = 0;
+			continue;
+		}
+		if (err)
+			goto error;
+
+		err = libbpf_ensure_mem((void **) &syms, &cap,
+					sizeof(*syms), cnt + 1);
+		if (err)
+			goto error;
+
+		syms[cnt++] = ksym_name;
+	}
+
+	*symsp = syms;
+	*cntp = cnt;
+
+error:
+	free(name);
+	fclose(f);
+	hashmap__free(map);
+	if (err)
+		free(syms);
+	return err;
+}
+
+int bpf_get_addrs(unsigned long **addrsp, size_t *cntp, bool kernel)
+{
+	unsigned long *addr, *addrs, *tmp_addrs;
+	int err = 0, max_cnt, inc_cnt;
+	char *name = NULL;
+	size_t cnt = 0;
+	char buf[256];
+	FILE *f;
+
+	if (access("/sys/kernel/tracing/trace", F_OK) == 0)
+		f = fopen("/sys/kernel/tracing/available_filter_functions_addrs", "r");
+	else
+		f = fopen("/sys/kernel/debug/tracing/available_filter_functions_addrs", "r");
+
+	if (!f)
+		return -ENOENT;
+
+	/* In my local setup, the number of entries is 50k+ so Let us initially
+	 * allocate space to hold 64k entries. If 64k is not enough, incrementally
+	 * increase 1k each time.
+	 */
+	max_cnt = 65536;
+	inc_cnt = 1024;
+	addrs = malloc(max_cnt * sizeof(long));
+	if (addrs == NULL) {
+		err = -ENOMEM;
+		goto error;
+	}
+
+	while (fgets(buf, sizeof(buf), f)) {
+		if (is_invalid_entry(buf, kernel))
+			continue;
+
+		free(name);
+		if (sscanf(buf, "%p %ms$*[^\n]\n", &addr, &name) != 2)
+			continue;
+		if (skip_entry(name))
+			continue;
+
+		if (cnt == max_cnt) {
+			max_cnt += inc_cnt;
+			tmp_addrs = realloc(addrs, max_cnt);
+			if (!tmp_addrs) {
+				err = -ENOMEM;
+				goto error;
+			}
+			addrs = tmp_addrs;
+		}
+
+		addrs[cnt++] = (unsigned long)addr;
+	}
+
+	*addrsp = addrs;
+	*cntp = cnt;
+
+error:
+	free(name);
+	fclose(f);
+	if (err)
+		free(addrs);
+	return err;
+}
diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h
index 2ce873c9f9aa..9437bdd4afa5 100644
--- a/tools/testing/selftests/bpf/trace_helpers.h
+++ b/tools/testing/selftests/bpf/trace_helpers.h
@@ -41,4 +41,7 @@ ssize_t get_rel_offset(uintptr_t addr);
 
 int read_build_id(const char *path, char *build_id, size_t size);
 
+int bpf_get_ksyms(char ***symsp, size_t *cntp, bool kernel);
+int bpf_get_addrs(unsigned long **addrsp, size_t *cntp, bool kernel);
+
 #endif
-- 
2.50.1

[PATCH bpf-next 2/3] selftests/bpf: skip recursive functions for kprobe_multi

[Menglong Dong]

Some functions is recursive for the kprobe_multi and impact the benchmark
results. So just skip them.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
 tools/testing/selftests/bpf/trace_helpers.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
index d24baf244d1f..9da9da51b132 100644
--- a/tools/testing/selftests/bpf/trace_helpers.c
+++ b/tools/testing/selftests/bpf/trace_helpers.c
@@ -559,6 +559,22 @@ static bool skip_entry(char *name)
 	if (!strncmp(name, "__ftrace_invalid_address__",
 		     sizeof("__ftrace_invalid_address__") - 1))
 		return true;
+
+	if (!strcmp(name, "migrate_disable"))
+		return true;
+	if (!strcmp(name, "migrate_enable"))
+		return true;
+	if (!strcmp(name, "rcu_read_unlock_strict"))
+		return true;
+	if (!strcmp(name, "preempt_count_add"))
+		return true;
+	if (!strcmp(name, "preempt_count_sub"))
+		return true;
+	if (!strcmp(name, "__rcu_read_lock"))
+		return true;
+	if (!strcmp(name, "__rcu_read_unlock"))
+		return true;
+
 	return false;
 }
 
-- 
2.50.1

[PATCH bpf-next 3/3] selftests/bpf: add benchmark testing for kprobe-multi-all

[Menglong Dong]

For now, the benchmark for kprobe-multi is single, which means there is
only 1 function is hooked during testing. Add the testing
"kprobe-multi-all", which will hook all the kernel functions during
the benchmark. And the "kretprobe-multi-all" is added too.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
 tools/testing/selftests/bpf/bench.c           |  4 ++
 .../selftests/bpf/benchs/bench_trigger.c      | 54 +++++++++++++++++++
 .../selftests/bpf/benchs/run_bench_trigger.sh |  4 +-
 .../selftests/bpf/progs/trigger_bench.c       | 12 +++++
 tools/testing/selftests/bpf/trace_helpers.c   |  3 ++
 5 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c
index ddd73d06a1eb..29dbf937818a 100644
--- a/tools/testing/selftests/bpf/bench.c
+++ b/tools/testing/selftests/bpf/bench.c
@@ -510,6 +510,8 @@ extern const struct bench bench_trig_kretprobe;
 extern const struct bench bench_trig_kprobe_multi;
 extern const struct bench bench_trig_kretprobe_multi;
 extern const struct bench bench_trig_fentry;
+extern const struct bench bench_trig_kprobe_multi_all;
+extern const struct bench bench_trig_kretprobe_multi_all;
 extern const struct bench bench_trig_fexit;
 extern const struct bench bench_trig_fmodret;
 extern const struct bench bench_trig_tp;
@@ -578,6 +580,8 @@ static const struct bench *benchs[] = {
 	&bench_trig_kprobe_multi,
 	&bench_trig_kretprobe_multi,
 	&bench_trig_fentry,
+	&bench_trig_kprobe_multi_all,
+	&bench_trig_kretprobe_multi_all,
 	&bench_trig_fexit,
 	&bench_trig_fmodret,
 	&bench_trig_tp,
diff --git a/tools/testing/selftests/bpf/benchs/bench_trigger.c b/tools/testing/selftests/bpf/benchs/bench_trigger.c
index 82327657846e..c6634a64a7c0 100644
--- a/tools/testing/selftests/bpf/benchs/bench_trigger.c
+++ b/tools/testing/selftests/bpf/benchs/bench_trigger.c
@@ -226,6 +226,58 @@ static void trigger_fentry_setup(void)
 	attach_bpf(ctx.skel->progs.bench_trigger_fentry);
 }
 
+static void attach_ksyms_all(struct bpf_program *empty, bool kretprobe)
+{
+	LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
+	char **syms = NULL;
+	size_t cnt = 0;
+
+	if (bpf_get_ksyms(&syms, &cnt, true)) {
+		printf("failed to get ksyms\n");
+		exit(1);
+	}
+
+	printf("found %zu ksyms\n", cnt);
+	opts.syms = (const char **) syms;
+	opts.cnt = cnt;
+	opts.retprobe = kretprobe;
+	/* attach empty to all the kernel functions except bpf_get_numa_node_id. */
+	if (!bpf_program__attach_kprobe_multi_opts(empty, NULL, &opts)) {
+		printf("failed to attach bpf_program__attach_kprobe_multi_opts to all\n");
+		exit(1);
+	}
+}
+
+static void trigger_kprobe_multi_all_setup(void)
+{
+	struct bpf_program *prog, *empty;
+
+	setup_ctx();
+	empty = ctx.skel->progs.bench_kprobe_multi_empty;
+	prog = ctx.skel->progs.bench_trigger_kprobe_multi;
+	bpf_program__set_autoload(empty, true);
+	bpf_program__set_autoload(prog, true);
+	load_ctx();
+
+	attach_ksyms_all(empty, false);
+	attach_bpf(prog);
+}
+
+static void trigger_kretprobe_multi_all_setup(void)
+{
+	struct bpf_program *prog, *empty;
+
+	setup_ctx();
+	empty = ctx.skel->progs.bench_kretprobe_multi_empty;
+	prog = ctx.skel->progs.bench_trigger_kretprobe_multi;
+	bpf_program__set_autoload(empty, true);
+	bpf_program__set_autoload(prog, true);
+	load_ctx();
+
+	attach_ksyms_all(empty, true);
+	attach_bpf(prog);
+}
+
 static void trigger_fexit_setup(void)
 {
 	setup_ctx();
@@ -512,6 +564,8 @@ BENCH_TRIG_KERNEL(kretprobe, "kretprobe");
 BENCH_TRIG_KERNEL(kprobe_multi, "kprobe-multi");
 BENCH_TRIG_KERNEL(kretprobe_multi, "kretprobe-multi");
 BENCH_TRIG_KERNEL(fentry, "fentry");
+BENCH_TRIG_KERNEL(kprobe_multi_all, "kprobe-multi-all");
+BENCH_TRIG_KERNEL(kretprobe_multi_all, "kretprobe-multi-all");
 BENCH_TRIG_KERNEL(fexit, "fexit");
 BENCH_TRIG_KERNEL(fmodret, "fmodret");
 BENCH_TRIG_KERNEL(tp, "tp");
diff --git a/tools/testing/selftests/bpf/benchs/run_bench_trigger.sh b/tools/testing/selftests/bpf/benchs/run_bench_trigger.sh
index a690f5a68b6b..f7573708a0c3 100755
--- a/tools/testing/selftests/bpf/benchs/run_bench_trigger.sh
+++ b/tools/testing/selftests/bpf/benchs/run_bench_trigger.sh
@@ -6,8 +6,8 @@ def_tests=( \
 	usermode-count kernel-count syscall-count \
 	fentry fexit fmodret \
 	rawtp tp \
-	kprobe kprobe-multi \
-	kretprobe kretprobe-multi \
+	kprobe kprobe-multi kprobe-multi-all \
+	kretprobe kretprobe-multi kretprobe-multi-all \
 )
 
 tests=("$@")
diff --git a/tools/testing/selftests/bpf/progs/trigger_bench.c b/tools/testing/selftests/bpf/progs/trigger_bench.c
index 044a6d78923e..3d5f30c29ae3 100644
--- a/tools/testing/selftests/bpf/progs/trigger_bench.c
+++ b/tools/testing/selftests/bpf/progs/trigger_bench.c
@@ -97,6 +97,12 @@ int bench_trigger_kprobe_multi(void *ctx)
 	return 0;
 }
 
+SEC("?kprobe.multi/bpf_get_numa_node_id")
+int bench_kprobe_multi_empty(void *ctx)
+{
+	return 0;
+}
+
 SEC("?kretprobe.multi/bpf_get_numa_node_id")
 int bench_trigger_kretprobe_multi(void *ctx)
 {
@@ -104,6 +110,12 @@ int bench_trigger_kretprobe_multi(void *ctx)
 	return 0;
 }
 
+SEC("?kretprobe.multi/bpf_get_numa_node_id")
+int bench_kretprobe_multi_empty(void *ctx)
+{
+	return 0;
+}
+
 SEC("?fentry/bpf_get_numa_node_id")
 int bench_trigger_fentry(void *ctx)
 {
diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
index 9da9da51b132..78cf1aab09d8 100644
--- a/tools/testing/selftests/bpf/trace_helpers.c
+++ b/tools/testing/selftests/bpf/trace_helpers.c
@@ -575,6 +575,9 @@ static bool skip_entry(char *name)
 	if (!strcmp(name, "__rcu_read_unlock"))
 		return true;
 
+	if (!strcmp(name, "bpf_get_numa_node_id"))
+		return true;
+
 	return false;
 }
 
-- 
2.50.1

Re: [PATCH bpf-next 2/3] selftests/bpf: skip recursive functions for kprobe_multi

[Andrii Nakryiko]

On Mon, Aug 18, 2025 at 8:40 PM Menglong Dong <menglong8.dong@gmail.com> wrote:
>
> Some functions is recursive for the kprobe_multi and impact the benchmark
> results. So just skip them.
>
> Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
> ---
>  tools/testing/selftests/bpf/trace_helpers.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
> index d24baf244d1f..9da9da51b132 100644
> --- a/tools/testing/selftests/bpf/trace_helpers.c
> +++ b/tools/testing/selftests/bpf/trace_helpers.c
> @@ -559,6 +559,22 @@ static bool skip_entry(char *name)
>         if (!strncmp(name, "__ftrace_invalid_address__",
>                      sizeof("__ftrace_invalid_address__") - 1))
>                 return true;
> +
> +       if (!strcmp(name, "migrate_disable"))
> +               return true;
> +       if (!strcmp(name, "migrate_enable"))
> +               return true;
> +       if (!strcmp(name, "rcu_read_unlock_strict"))
> +               return true;
> +       if (!strcmp(name, "preempt_count_add"))
> +               return true;
> +       if (!strcmp(name, "preempt_count_sub"))
> +               return true;
> +       if (!strcmp(name, "__rcu_read_lock"))
> +               return true;
> +       if (!strcmp(name, "__rcu_read_unlock"))
> +               return true;
> +

static const char *trace_blacklist[] = {
    "migrate_disable",
    "migrate_enable",
    ...
};

it's not like it's one or two functions where copy-pasting strcmp might be fine

pw-bot: cr


>         return false;
>  }
>
> --
> 2.50.1
>

Re: [PATCH bpf-next 3/3] selftests/bpf: add benchmark testing for kprobe-multi-all

[Andrii Nakryiko]

On Mon, Aug 18, 2025 at 8:40 PM Menglong Dong <menglong8.dong@gmail.com> wrote:
>
> For now, the benchmark for kprobe-multi is single, which means there is
> only 1 function is hooked during testing. Add the testing
> "kprobe-multi-all", which will hook all the kernel functions during
> the benchmark. And the "kretprobe-multi-all" is added too.
>
> Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
> ---
>  tools/testing/selftests/bpf/bench.c           |  4 ++
>  .../selftests/bpf/benchs/bench_trigger.c      | 54 +++++++++++++++++++
>  .../selftests/bpf/benchs/run_bench_trigger.sh |  4 +-
>  .../selftests/bpf/progs/trigger_bench.c       | 12 +++++
>  tools/testing/selftests/bpf/trace_helpers.c   |  3 ++
>  5 files changed, 75 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c
> index ddd73d06a1eb..29dbf937818a 100644
> --- a/tools/testing/selftests/bpf/bench.c
> +++ b/tools/testing/selftests/bpf/bench.c
> @@ -510,6 +510,8 @@ extern const struct bench bench_trig_kretprobe;
>  extern const struct bench bench_trig_kprobe_multi;
>  extern const struct bench bench_trig_kretprobe_multi;
>  extern const struct bench bench_trig_fentry;
> +extern const struct bench bench_trig_kprobe_multi_all;
> +extern const struct bench bench_trig_kretprobe_multi_all;
>  extern const struct bench bench_trig_fexit;
>  extern const struct bench bench_trig_fmodret;
>  extern const struct bench bench_trig_tp;
> @@ -578,6 +580,8 @@ static const struct bench *benchs[] = {
>         &bench_trig_kprobe_multi,
>         &bench_trig_kretprobe_multi,
>         &bench_trig_fentry,
> +       &bench_trig_kprobe_multi_all,
> +       &bench_trig_kretprobe_multi_all,
>         &bench_trig_fexit,
>         &bench_trig_fmodret,
>         &bench_trig_tp,
> diff --git a/tools/testing/selftests/bpf/benchs/bench_trigger.c b/tools/testing/selftests/bpf/benchs/bench_trigger.c
> index 82327657846e..c6634a64a7c0 100644
> --- a/tools/testing/selftests/bpf/benchs/bench_trigger.c
> +++ b/tools/testing/selftests/bpf/benchs/bench_trigger.c
> @@ -226,6 +226,58 @@ static void trigger_fentry_setup(void)
>         attach_bpf(ctx.skel->progs.bench_trigger_fentry);
>  }
>
> +static void attach_ksyms_all(struct bpf_program *empty, bool kretprobe)
> +{
> +       LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
> +       char **syms = NULL;
> +       size_t cnt = 0;
> +
> +       if (bpf_get_ksyms(&syms, &cnt, true)) {
> +               printf("failed to get ksyms\n");

we seem to be using fprintf(stderr, "...") for emitting errors like
this (at least in some benchmarks, and it makes sense to me). Do the
same?

> +               exit(1);
> +       }
> +
> +       printf("found %zu ksyms\n", cnt);

stray debug output?

> +       opts.syms = (const char **) syms;
> +       opts.cnt = cnt;
> +       opts.retprobe = kretprobe;
> +       /* attach empty to all the kernel functions except bpf_get_numa_node_id. */
> +       if (!bpf_program__attach_kprobe_multi_opts(empty, NULL, &opts)) {
> +               printf("failed to attach bpf_program__attach_kprobe_multi_opts to all\n");
> +               exit(1);
> +       }
> +}
> +

[...]

Re: [PATCH bpf-next 2/3] selftests/bpf: skip recursive functions for kprobe_multi

[Menglong Dong]

On Thu, Aug 21, 2025 at 6:47 AM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Mon, Aug 18, 2025 at 8:40 PM Menglong Dong <menglong8.dong@gmail.com> wrote:
> >
> > Some functions is recursive for the kprobe_multi and impact the benchmark
> > results. So just skip them.
> >
> > Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
> > ---
> >  tools/testing/selftests/bpf/trace_helpers.c | 16 ++++++++++++++++
> >  1 file changed, 16 insertions(+)
> >
> > diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
> > index d24baf244d1f..9da9da51b132 100644
> > --- a/tools/testing/selftests/bpf/trace_helpers.c
> > +++ b/tools/testing/selftests/bpf/trace_helpers.c
> > @@ -559,6 +559,22 @@ static bool skip_entry(char *name)
> >         if (!strncmp(name, "__ftrace_invalid_address__",
> >                      sizeof("__ftrace_invalid_address__") - 1))
> >                 return true;
> > +
> > +       if (!strcmp(name, "migrate_disable"))
> > +               return true;
> > +       if (!strcmp(name, "migrate_enable"))
> > +               return true;
> > +       if (!strcmp(name, "rcu_read_unlock_strict"))
> > +               return true;
> > +       if (!strcmp(name, "preempt_count_add"))
> > +               return true;
> > +       if (!strcmp(name, "preempt_count_sub"))
> > +               return true;
> > +       if (!strcmp(name, "__rcu_read_lock"))
> > +               return true;
> > +       if (!strcmp(name, "__rcu_read_unlock"))
> > +               return true;
> > +
>
> static const char *trace_blacklist[] = {
>     "migrate_disable",
>     "migrate_enable",
>     ...
> };
>
> it's not like it's one or two functions where copy-pasting strcmp might be fine

OK!

>
> pw-bot: cr
>
>
> >         return false;
> >  }
> >
> > --
> > 2.50.1
> >

Re: [PATCH bpf-next 3/3] selftests/bpf: add benchmark testing for kprobe-multi-all

[Menglong Dong]

On Thu, Aug 21, 2025 at 6:54 AM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Mon, Aug 18, 2025 at 8:40 PM Menglong Dong <menglong8.dong@gmail.com> wrote:
> >
> > For now, the benchmark for kprobe-multi is single, which means there is
> > only 1 function is hooked during testing. Add the testing
> > "kprobe-multi-all", which will hook all the kernel functions during
> > the benchmark. And the "kretprobe-multi-all" is added too.
> >
> > Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
> > ---
> >  tools/testing/selftests/bpf/bench.c           |  4 ++
> >  .../selftests/bpf/benchs/bench_trigger.c      | 54 +++++++++++++++++++
> >  .../selftests/bpf/benchs/run_bench_trigger.sh |  4 +-
> >  .../selftests/bpf/progs/trigger_bench.c       | 12 +++++
> >  tools/testing/selftests/bpf/trace_helpers.c   |  3 ++
> >  5 files changed, 75 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c
> > index ddd73d06a1eb..29dbf937818a 100644
> > --- a/tools/testing/selftests/bpf/bench.c
> > +++ b/tools/testing/selftests/bpf/bench.c
> > @@ -510,6 +510,8 @@ extern const struct bench bench_trig_kretprobe;
> >  extern const struct bench bench_trig_kprobe_multi;
> >  extern const struct bench bench_trig_kretprobe_multi;
> >  extern const struct bench bench_trig_fentry;
> > +extern const struct bench bench_trig_kprobe_multi_all;
> > +extern const struct bench bench_trig_kretprobe_multi_all;
> >  extern const struct bench bench_trig_fexit;
> >  extern const struct bench bench_trig_fmodret;
> >  extern const struct bench bench_trig_tp;
> > @@ -578,6 +580,8 @@ static const struct bench *benchs[] = {
> >         &bench_trig_kprobe_multi,
> >         &bench_trig_kretprobe_multi,
> >         &bench_trig_fentry,
> > +       &bench_trig_kprobe_multi_all,
> > +       &bench_trig_kretprobe_multi_all,
> >         &bench_trig_fexit,
> >         &bench_trig_fmodret,
> >         &bench_trig_tp,
> > diff --git a/tools/testing/selftests/bpf/benchs/bench_trigger.c b/tools/testing/selftests/bpf/benchs/bench_trigger.c
> > index 82327657846e..c6634a64a7c0 100644
> > --- a/tools/testing/selftests/bpf/benchs/bench_trigger.c
> > +++ b/tools/testing/selftests/bpf/benchs/bench_trigger.c
> > @@ -226,6 +226,58 @@ static void trigger_fentry_setup(void)
> >         attach_bpf(ctx.skel->progs.bench_trigger_fentry);
> >  }
> >
> > +static void attach_ksyms_all(struct bpf_program *empty, bool kretprobe)
> > +{
> > +       LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
> > +       char **syms = NULL;
> > +       size_t cnt = 0;
> > +
> > +       if (bpf_get_ksyms(&syms, &cnt, true)) {
> > +               printf("failed to get ksyms\n");
>
> we seem to be using fprintf(stderr, "...") for emitting errors like
> this (at least in some benchmarks, and it makes sense to me). Do the
> same?

OK!

>
> > +               exit(1);
> > +       }
> > +
> > +       printf("found %zu ksyms\n", cnt);
>
> stray debug output?

OK!

Thanks!
Menglong Dong

>
> > +       opts.syms = (const char **) syms;
> > +       opts.cnt = cnt;
> > +       opts.retprobe = kretprobe;
> > +       /* attach empty to all the kernel functions except bpf_get_numa_node_id. */
> > +       if (!bpf_program__attach_kprobe_multi_opts(empty, NULL, &opts)) {
> > +               printf("failed to attach bpf_program__attach_kprobe_multi_opts to all\n");
> > +               exit(1);
> > +       }
> > +}
> > +
>
> [...]