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: Song Liu <songliubraving@fb.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220615112118.497303-2-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c
index 83ef55e..2974b44 100644 (file)
--- 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/progs/kprobe_multi.c b/tools/testing/selftests/bpf/progs/kprobe_multi.c
index 93510f4..08f95a8 100644 (file)
--- 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);
        }