1// SPDX-License-Identifier: GPL-2.0
2#include <test_progs.h>
3#include "test_stacktrace_build_id.skel.h"
4
5void 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
17retry:
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
101cleanup:
102	test_stacktrace_build_id__destroy(skel);
103}
104