Merge branch 'kallsyms: Optimize the search for module symbols by livepatch and bpf'

Jiri Olsa says:

====================

hi,
sending new version of [1] patchset posted originally by Zhen Lei.
It contains 2 changes that improove search performance for livepatch
and bpf.

v3 changes:
  - fixed off by 1 issue, simplified condition, added acks [Song]
  - added module attach as subtest [Andrii]

v2 changes:
  - reworked the bpf change and meassured the performance
  - adding new selftest to benchmark kprobe multi module attachment
  - skipping patch 3 as requested by Zhen Lei
  - added Reviewed-by for patch 1 [Petr Mladek]

thanks,
jirka

[1] https://lore.kernel.org/bpf/20221230112729.351-1-thunder.leizhen@huawei.com/
---
Jiri Olsa (2):
      selftests/bpf: Add serial_test_kprobe_multi_bench_attach_kernel/module tests
      bpf: Change modules resolving for kprobe multi link
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 14 insertions, 5 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 c6f37e825f11..113dba349a57 100644
--- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
@@ -322,7 +322,7 @@ static bool symbol_equal(long key1, long key2, void *ctx __maybe_unused)
 	return strcmp((const char *) key1, (const char *) key2) == 0;
 }
 
-static int get_syms(char ***symsp, size_t *cntp)
+static int get_syms(char ***symsp, size_t *cntp, bool kernel)
 {
 	size_t cap = 0, cnt = 0, i;
 	char *name = NULL, **syms = NULL;
@@ -349,8 +349,9 @@ static int get_syms(char ***symsp, size_t *cntp)
 	}
 
 	while (fgets(buf, sizeof(buf), f)) {
-		/* skip modules */
-		if (strchr(buf, '['))
+		if (kernel && strchr(buf, '['))
+			continue;
+		if (!kernel && !strchr(buf, '['))
 			continue;
 
 		free(name);
@@ -404,7 +405,7 @@ error:
 	return err;
 }
 
-void serial_test_kprobe_multi_bench_attach(void)
+static void test_kprobe_multi_bench_attach(bool kernel)
 {
 	LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);
 	struct kprobe_multi_empty *skel = NULL;
@@ -415,7 +416,7 @@ void serial_test_kprobe_multi_bench_attach(void)
 	char **syms = NULL;
 	size_t cnt = 0, i;
 
-	if (!ASSERT_OK(get_syms(&syms, &cnt), "get_syms"))
+	if (!ASSERT_OK(get_syms(&syms, &cnt, kernel), "get_syms"))
 		return;
 
 	skel = kprobe_multi_empty__open_and_load();
@@ -453,6 +454,14 @@ cleanup:
 	}
 }
 
+void serial_test_kprobe_multi_bench_attach(void)
+{
+	if (test__start_subtest("kernel"))
+		test_kprobe_multi_bench_attach(true);
+	if (test__start_subtest("modules"))
+		test_kprobe_multi_bench_attach(false);
+}
+
 void test_kprobe_multi_test(void)
 {
 	if (!ASSERT_OK(load_kallsyms(), "load_kallsyms"))