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}