Merge branch 'bpf: Fix cookie values for kprobe multi'

Jiri Olsa says:

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

hi,
there's bug in kprobe_multi link that makes cookies misplaced when
using symbols to attach. The reason is that we sort symbols by name
but not adjacent cookie values. Current test did not find it because
bpf_fentry_test* are already sorted by name.

v3 changes:
  - fixed kprobe_multi bench test to filter out invalid entries
    from available_filter_functions

v2 changes:
  - rebased on top of bpf/master
  - checking if cookies are defined later in swap function [Andrii]
  - added acks

thanks,
jirka
====================

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

3 files changed, 54 insertions, 51 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c
index 83ef55e3caa4..2974b44f80fa 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c
@@ -121,24 +121,24 @@ static void kprobe_multi_link_api_subtest(void)
 })
 
 	GET_ADDR("bpf_fentry_test1", addrs[0]);
-	GET_ADDR("bpf_fentry_test2", addrs[1]);
-	GET_ADDR("bpf_fentry_test3", addrs[2]);
-	GET_ADDR("bpf_fentry_test4", addrs[3]);
-	GET_ADDR("bpf_fentry_test5", addrs[4]);
-	GET_ADDR("bpf_fentry_test6", addrs[5]);
-	GET_ADDR("bpf_fentry_test7", addrs[6]);
+	GET_ADDR("bpf_fentry_test3", addrs[1]);
+	GET_ADDR("bpf_fentry_test4", addrs[2]);
+	GET_ADDR("bpf_fentry_test5", addrs[3]);
+	GET_ADDR("bpf_fentry_test6", addrs[4]);
+	GET_ADDR("bpf_fentry_test7", addrs[5]);
+	GET_ADDR("bpf_fentry_test2", addrs[6]);
 	GET_ADDR("bpf_fentry_test8", addrs[7]);
 
 #undef GET_ADDR
 
-	cookies[0] = 1;
-	cookies[1] = 2;
-	cookies[2] = 3;
-	cookies[3] = 4;
-	cookies[4] = 5;
-	cookies[5] = 6;
-	cookies[6] = 7;
-	cookies[7] = 8;
+	cookies[0] = 1; /* bpf_fentry_test1 */
+	cookies[1] = 2; /* bpf_fentry_test3 */
+	cookies[2] = 3; /* bpf_fentry_test4 */
+	cookies[3] = 4; /* bpf_fentry_test5 */
+	cookies[4] = 5; /* bpf_fentry_test6 */
+	cookies[5] = 6; /* bpf_fentry_test7 */
+	cookies[6] = 7; /* bpf_fentry_test2 */
+	cookies[7] = 8; /* bpf_fentry_test8 */
 
 	opts.kprobe_multi.addrs = (const unsigned long *) &addrs;
 	opts.kprobe_multi.cnt = ARRAY_SIZE(addrs);
@@ -149,14 +149,14 @@ static void kprobe_multi_link_api_subtest(void)
 	if (!ASSERT_GE(link1_fd, 0, "link1_fd"))
 		goto cleanup;
 
-	cookies[0] = 8;
-	cookies[1] = 7;
-	cookies[2] = 6;
-	cookies[3] = 5;
-	cookies[4] = 4;
-	cookies[5] = 3;
-	cookies[6] = 2;
-	cookies[7] = 1;
+	cookies[0] = 8; /* bpf_fentry_test1 */
+	cookies[1] = 7; /* bpf_fentry_test3 */
+	cookies[2] = 6; /* bpf_fentry_test4 */
+	cookies[3] = 5; /* bpf_fentry_test5 */
+	cookies[4] = 4; /* bpf_fentry_test6 */
+	cookies[5] = 3; /* bpf_fentry_test7 */
+	cookies[6] = 2; /* bpf_fentry_test2 */
+	cookies[7] = 1; /* bpf_fentry_test8 */
 
 	opts.kprobe_multi.flags = BPF_F_KPROBE_MULTI_RETURN;
 	prog_fd = bpf_program__fd(skel->progs.test_kretprobe);
@@ -181,12 +181,12 @@ static void kprobe_multi_attach_api_subtest(void)
 	struct kprobe_multi *skel = NULL;
 	const char *syms[8] = {
 		"bpf_fentry_test1",
-		"bpf_fentry_test2",
 		"bpf_fentry_test3",
 		"bpf_fentry_test4",
 		"bpf_fentry_test5",
 		"bpf_fentry_test6",
 		"bpf_fentry_test7",
+		"bpf_fentry_test2",
 		"bpf_fentry_test8",
 	};
 	__u64 cookies[8];
@@ -198,14 +198,14 @@ static void kprobe_multi_attach_api_subtest(void)
 	skel->bss->pid = getpid();
 	skel->bss->test_cookie = true;
 
-	cookies[0] = 1;
-	cookies[1] = 2;
-	cookies[2] = 3;
-	cookies[3] = 4;
-	cookies[4] = 5;
-	cookies[5] = 6;
-	cookies[6] = 7;
-	cookies[7] = 8;
+	cookies[0] = 1; /* bpf_fentry_test1 */
+	cookies[1] = 2; /* bpf_fentry_test3 */
+	cookies[2] = 3; /* bpf_fentry_test4 */
+	cookies[3] = 4; /* bpf_fentry_test5 */
+	cookies[4] = 5; /* bpf_fentry_test6 */
+	cookies[5] = 6; /* bpf_fentry_test7 */
+	cookies[6] = 7; /* bpf_fentry_test2 */
+	cookies[7] = 8; /* bpf_fentry_test8 */
 
 	opts.syms = syms;
 	opts.cnt = ARRAY_SIZE(syms);
@@ -216,14 +216,14 @@ static void kprobe_multi_attach_api_subtest(void)
 	if (!ASSERT_OK_PTR(link1, "bpf_program__attach_kprobe_multi_opts"))
 		goto cleanup;
 
-	cookies[0] = 8;
-	cookies[1] = 7;
-	cookies[2] = 6;
-	cookies[3] = 5;
-	cookies[4] = 4;
-	cookies[5] = 3;
-	cookies[6] = 2;
-	cookies[7] = 1;
+	cookies[0] = 8; /* bpf_fentry_test1 */
+	cookies[1] = 7; /* bpf_fentry_test3 */
+	cookies[2] = 6; /* bpf_fentry_test4 */
+	cookies[3] = 5; /* bpf_fentry_test5 */
+	cookies[4] = 4; /* bpf_fentry_test6 */
+	cookies[5] = 3; /* bpf_fentry_test7 */
+	cookies[6] = 2; /* bpf_fentry_test2 */
+	cookies[7] = 1; /* bpf_fentry_test8 */
 
 	opts.retprobe = true;
 
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 586dc52d6fb9..5b93d5d0bd93 100644
--- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
@@ -364,6 +364,9 @@ static int get_syms(char ***symsp, size_t *cntp)
 			continue;
 		if (!strncmp(name, "rcu_", 4))
 			continue;
+		if (!strncmp(name, "__ftrace_invalid_address__",
+			     sizeof("__ftrace_invalid_address__") - 1))
+			continue;
 		err = hashmap__add(map, name, NULL);
 		if (err) {
 			free(name);
diff --git a/tools/testing/selftests/bpf/progs/kprobe_multi.c b/tools/testing/selftests/bpf/progs/kprobe_multi.c
index 93510f4f0f3a..08f95a8155d1 100644
--- a/tools/testing/selftests/bpf/progs/kprobe_multi.c
+++ b/tools/testing/selftests/bpf/progs/kprobe_multi.c
@@ -54,21 +54,21 @@ static void kprobe_multi_check(void *ctx, bool is_return)
 
 	if (is_return) {
 		SET(kretprobe_test1_result, &bpf_fentry_test1, 8);
-		SET(kretprobe_test2_result, &bpf_fentry_test2, 7);
-		SET(kretprobe_test3_result, &bpf_fentry_test3, 6);
-		SET(kretprobe_test4_result, &bpf_fentry_test4, 5);
-		SET(kretprobe_test5_result, &bpf_fentry_test5, 4);
-		SET(kretprobe_test6_result, &bpf_fentry_test6, 3);
-		SET(kretprobe_test7_result, &bpf_fentry_test7, 2);
+		SET(kretprobe_test2_result, &bpf_fentry_test2, 2);
+		SET(kretprobe_test3_result, &bpf_fentry_test3, 7);
+		SET(kretprobe_test4_result, &bpf_fentry_test4, 6);
+		SET(kretprobe_test5_result, &bpf_fentry_test5, 5);
+		SET(kretprobe_test6_result, &bpf_fentry_test6, 4);
+		SET(kretprobe_test7_result, &bpf_fentry_test7, 3);
 		SET(kretprobe_test8_result, &bpf_fentry_test8, 1);
 	} else {
 		SET(kprobe_test1_result, &bpf_fentry_test1, 1);
-		SET(kprobe_test2_result, &bpf_fentry_test2, 2);
-		SET(kprobe_test3_result, &bpf_fentry_test3, 3);
-		SET(kprobe_test4_result, &bpf_fentry_test4, 4);
-		SET(kprobe_test5_result, &bpf_fentry_test5, 5);
-		SET(kprobe_test6_result, &bpf_fentry_test6, 6);
-		SET(kprobe_test7_result, &bpf_fentry_test7, 7);
+		SET(kprobe_test2_result, &bpf_fentry_test2, 7);
+		SET(kprobe_test3_result, &bpf_fentry_test3, 2);
+		SET(kprobe_test4_result, &bpf_fentry_test4, 3);
+		SET(kprobe_test5_result, &bpf_fentry_test5, 4);
+		SET(kprobe_test6_result, &bpf_fentry_test6, 5);
+		SET(kprobe_test7_result, &bpf_fentry_test7, 6);
 		SET(kprobe_test8_result, &bpf_fentry_test8, 8);
 	}