1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include "test_stacktrace_build_id.skel.h"
4
test_stacktrace_build_id(void)5 void test_stacktrace_build_id(void)
6 {
7
8 int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd;
9 struct test_stacktrace_build_id *skel;
10 int err, stack_trace_len, build_id_size;
11 __u32 key, prev_key, val, duration = 0;
12 char buf[BPF_BUILD_ID_SIZE];
13 struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH];
14 int build_id_matches = 0;
15 int i, retry = 1;
16
17 retry:
18 skel = test_stacktrace_build_id__open_and_load();
19 if (CHECK(!skel, "skel_open_and_load", "skeleton open/load failed\n"))
20 return;
21
22 err = test_stacktrace_build_id__attach(skel);
23 if (CHECK(err, "attach_tp", "err %d\n", err))
24 goto cleanup;
25
26 /* find map fds */
27 control_map_fd = bpf_map__fd(skel->maps.control_map);
28 stackid_hmap_fd = bpf_map__fd(skel->maps.stackid_hmap);
29 stackmap_fd = bpf_map__fd(skel->maps.stackmap);
30 stack_amap_fd = bpf_map__fd(skel->maps.stack_amap);
31
32 if (CHECK_FAIL(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null")))
33 goto cleanup;
34 if (CHECK_FAIL(system("./urandom_read")))
35 goto cleanup;
36 /* disable stack trace collection */
37 key = 0;
38 val = 1;
39 bpf_map_update_elem(control_map_fd, &key, &val, 0);
40
41 /* for every element in stackid_hmap, we can find a corresponding one
42 * in stackmap, and vise versa.
43 */
44 err = compare_map_keys(stackid_hmap_fd, stackmap_fd);
45 if (CHECK(err, "compare_map_keys stackid_hmap vs. stackmap",
46 "err %d errno %d\n", err, errno))
47 goto cleanup;
48
49 err = compare_map_keys(stackmap_fd, stackid_hmap_fd);
50 if (CHECK(err, "compare_map_keys stackmap vs. stackid_hmap",
51 "err %d errno %d\n", err, errno))
52 goto cleanup;
53
54 build_id_size = read_build_id("urandom_read", buf, sizeof(buf));
55 err = build_id_size < 0 ? build_id_size : 0;
56
57 if (CHECK(err, "read_build_id",
58 "err %d errno %d\n", err, errno))
59 goto cleanup;
60
61 err = bpf_map__get_next_key(skel->maps.stackmap, NULL, &key, sizeof(key));
62 if (CHECK(err, "get_next_key from stackmap",
63 "err %d, errno %d\n", err, errno))
64 goto cleanup;
65
66 do {
67 err = bpf_map_lookup_elem(stackmap_fd, &key, id_offs);
68 if (CHECK(err, "lookup_elem from stackmap",
69 "err %d, errno %d\n", err, errno))
70 goto cleanup;
71 for (i = 0; i < PERF_MAX_STACK_DEPTH; ++i)
72 if (id_offs[i].status == BPF_STACK_BUILD_ID_VALID &&
73 id_offs[i].offset != 0) {
74 if (memcmp(buf, id_offs[i].build_id, build_id_size) == 0)
75 build_id_matches = 1;
76 }
77 prev_key = key;
78 } while (bpf_map__get_next_key(skel->maps.stackmap, &prev_key, &key, sizeof(key)) == 0);
79
80 /* stack_map_get_build_id_offset() is racy and sometimes can return
81 * BPF_STACK_BUILD_ID_IP instead of BPF_STACK_BUILD_ID_VALID;
82 * try it one more time.
83 */
84 if (build_id_matches < 1 && retry--) {
85 test_stacktrace_build_id__destroy(skel);
86 printf("%s:WARN:Didn't find expected build ID from the map, retrying\n",
87 __func__);
88 goto retry;
89 }
90
91 if (CHECK(build_id_matches < 1, "build id match",
92 "Didn't find expected build ID from the map\n"))
93 goto cleanup;
94
95 stack_trace_len = PERF_MAX_STACK_DEPTH *
96 sizeof(struct bpf_stack_build_id);
97 err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len);
98 CHECK(err, "compare_stack_ips stackmap vs. stack_amap",
99 "err %d errno %d\n", err, errno);
100
101 cleanup:
102 test_stacktrace_build_id__destroy(skel);
103 }
104