stacktrace_build_id.c (3361B)
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; 11 __u32 key, prev_key, val, duration = 0; 12 char buf[256]; 13 int i, j; 14 struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH]; 15 int build_id_matches = 0; 16 int retry = 1; 17 18retry: 19 skel = test_stacktrace_build_id__open_and_load(); 20 if (CHECK(!skel, "skel_open_and_load", "skeleton open/load failed\n")) 21 return; 22 23 err = test_stacktrace_build_id__attach(skel); 24 if (CHECK(err, "attach_tp", "err %d\n", err)) 25 goto cleanup; 26 27 /* find map fds */ 28 control_map_fd = bpf_map__fd(skel->maps.control_map); 29 stackid_hmap_fd = bpf_map__fd(skel->maps.stackid_hmap); 30 stackmap_fd = bpf_map__fd(skel->maps.stackmap); 31 stack_amap_fd = bpf_map__fd(skel->maps.stack_amap); 32 33 if (CHECK_FAIL(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null"))) 34 goto cleanup; 35 if (CHECK_FAIL(system("./urandom_read"))) 36 goto cleanup; 37 /* disable stack trace collection */ 38 key = 0; 39 val = 1; 40 bpf_map_update_elem(control_map_fd, &key, &val, 0); 41 42 /* for every element in stackid_hmap, we can find a corresponding one 43 * in stackmap, and vise versa. 44 */ 45 err = compare_map_keys(stackid_hmap_fd, stackmap_fd); 46 if (CHECK(err, "compare_map_keys stackid_hmap vs. stackmap", 47 "err %d errno %d\n", err, errno)) 48 goto cleanup; 49 50 err = compare_map_keys(stackmap_fd, stackid_hmap_fd); 51 if (CHECK(err, "compare_map_keys stackmap vs. stackid_hmap", 52 "err %d errno %d\n", err, errno)) 53 goto cleanup; 54 55 err = extract_build_id(buf, 256); 56 57 if (CHECK(err, "get build_id with readelf", 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 char build_id[64]; 68 69 err = bpf_map_lookup_elem(stackmap_fd, &key, id_offs); 70 if (CHECK(err, "lookup_elem from stackmap", 71 "err %d, errno %d\n", err, errno)) 72 goto cleanup; 73 for (i = 0; i < PERF_MAX_STACK_DEPTH; ++i) 74 if (id_offs[i].status == BPF_STACK_BUILD_ID_VALID && 75 id_offs[i].offset != 0) { 76 for (j = 0; j < 20; ++j) 77 sprintf(build_id + 2 * j, "%02x", 78 id_offs[i].build_id[j] & 0xff); 79 if (strstr(buf, build_id) != NULL) 80 build_id_matches = 1; 81 } 82 prev_key = key; 83 } while (bpf_map__get_next_key(skel->maps.stackmap, &prev_key, &key, sizeof(key)) == 0); 84 85 /* stack_map_get_build_id_offset() is racy and sometimes can return 86 * BPF_STACK_BUILD_ID_IP instead of BPF_STACK_BUILD_ID_VALID; 87 * try it one more time. 88 */ 89 if (build_id_matches < 1 && retry--) { 90 test_stacktrace_build_id__destroy(skel); 91 printf("%s:WARN:Didn't find expected build ID from the map, retrying\n", 92 __func__); 93 goto retry; 94 } 95 96 if (CHECK(build_id_matches < 1, "build id match", 97 "Didn't find expected build ID from the map\n")) 98 goto cleanup; 99 100 stack_trace_len = PERF_MAX_STACK_DEPTH * 101 sizeof(struct bpf_stack_build_id); 102 err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len); 103 CHECK(err, "compare_stack_ips stackmap vs. stack_amap", 104 "err %d errno %d\n", err, errno); 105 106cleanup: 107 test_stacktrace_build_id__destroy(skel); 108}