diff options
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/stacktrace_build_id.c')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/stacktrace_build_id.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id.c b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id.c new file mode 100644 index 000000000..e8399ae50 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id.c @@ -0,0 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include "test_stacktrace_build_id.skel.h" + +void test_stacktrace_build_id(void) +{ + + int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd; + struct test_stacktrace_build_id *skel; + int err, stack_trace_len; + __u32 key, previous_key, val, duration = 0; + char buf[256]; + int i, j; + struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH]; + int build_id_matches = 0; + int retry = 1; + +retry: + skel = test_stacktrace_build_id__open_and_load(); + if (CHECK(!skel, "skel_open_and_load", "skeleton open/load failed\n")) + return; + + err = test_stacktrace_build_id__attach(skel); + if (CHECK(err, "attach_tp", "err %d\n", err)) + goto cleanup; + + /* find map fds */ + control_map_fd = bpf_map__fd(skel->maps.control_map); + stackid_hmap_fd = bpf_map__fd(skel->maps.stackid_hmap); + stackmap_fd = bpf_map__fd(skel->maps.stackmap); + stack_amap_fd = bpf_map__fd(skel->maps.stack_amap); + + if (CHECK_FAIL(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null"))) + goto cleanup; + if (CHECK_FAIL(system("./urandom_read"))) + goto cleanup; + /* disable stack trace collection */ + key = 0; + val = 1; + bpf_map_update_elem(control_map_fd, &key, &val, 0); + + /* for every element in stackid_hmap, we can find a corresponding one + * in stackmap, and vise versa. + */ + err = compare_map_keys(stackid_hmap_fd, stackmap_fd); + if (CHECK(err, "compare_map_keys stackid_hmap vs. stackmap", + "err %d errno %d\n", err, errno)) + goto cleanup; + + err = compare_map_keys(stackmap_fd, stackid_hmap_fd); + if (CHECK(err, "compare_map_keys stackmap vs. stackid_hmap", + "err %d errno %d\n", err, errno)) + goto cleanup; + + err = extract_build_id(buf, 256); + + if (CHECK(err, "get build_id with readelf", + "err %d errno %d\n", err, errno)) + goto cleanup; + + err = bpf_map_get_next_key(stackmap_fd, NULL, &key); + if (CHECK(err, "get_next_key from stackmap", + "err %d, errno %d\n", err, errno)) + goto cleanup; + + do { + char build_id[64]; + + err = bpf_map_lookup_elem(stackmap_fd, &key, id_offs); + if (CHECK(err, "lookup_elem from stackmap", + "err %d, errno %d\n", err, errno)) + goto cleanup; + for (i = 0; i < PERF_MAX_STACK_DEPTH; ++i) + if (id_offs[i].status == BPF_STACK_BUILD_ID_VALID && + id_offs[i].offset != 0) { + for (j = 0; j < 20; ++j) + sprintf(build_id + 2 * j, "%02x", + id_offs[i].build_id[j] & 0xff); + if (strstr(buf, build_id) != NULL) + build_id_matches = 1; + } + previous_key = key; + } while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0); + + /* stack_map_get_build_id_offset() is racy and sometimes can return + * BPF_STACK_BUILD_ID_IP instead of BPF_STACK_BUILD_ID_VALID; + * try it one more time. + */ + if (build_id_matches < 1 && retry--) { + test_stacktrace_build_id__destroy(skel); + printf("%s:WARN:Didn't find expected build ID from the map, retrying\n", + __func__); + goto retry; + } + + if (CHECK(build_id_matches < 1, "build id match", + "Didn't find expected build ID from the map\n")) + goto cleanup; + + stack_trace_len = PERF_MAX_STACK_DEPTH * + sizeof(struct bpf_stack_build_id); + err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len); + CHECK(err, "compare_stack_ips stackmap vs. stack_amap", + "err %d errno %d\n", err, errno); + +cleanup: + test_stacktrace_build_id__destroy(skel); +} |