Commit ad884853 authored by Jiri Olsa's avatar Jiri Olsa Committed by Alexei Starovoitov
Browse files

selftests/bpf: Shuffle cookies symbols in kprobe multi test 



There's a kernel bug that causes cookies to be misplaced and
the reason we did not catch this with this test is that we
provide bpf_fentry_test* functions already sorted by name.

Shuffling function bpf_fentry_test2 deeper in the list and
keeping the current cookie values as before will trigger
the bug.

The kernel fix is coming in following changes.

Acked-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220615112118.497303-2-jolsa@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 5e0b0a4c

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

+39 −39
Original line number Diff line number Diff line
@@ -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;

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

+12 −12
Original line number Diff line number Diff line
@@ -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);

	}