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_nmi(void) 6{ 7 int control_map_fd, stackid_hmap_fd, stackmap_fd; 8 struct test_stacktrace_build_id *skel; 9 int err, pmu_fd; 10 struct perf_event_attr attr = { 11 .freq = 1, 12 .type = PERF_TYPE_HARDWARE, 13 .config = PERF_COUNT_HW_CPU_CYCLES, 14 }; 15 __u32 key, prev_key, val, duration = 0; 16 char buf[BPF_BUILD_ID_SIZE]; 17 struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH]; 18 int build_id_matches = 0, build_id_size; 19 int i, retry = 1; 20 21 attr.sample_freq = read_perf_max_sample_freq(); 22 23retry: 24 skel = test_stacktrace_build_id__open(); 25 if (CHECK(!skel, "skel_open", "skeleton open failed\n")) 26 return; 27 28 /* override program type */ 29 bpf_program__set_type(skel->progs.oncpu, BPF_PROG_TYPE_PERF_EVENT); 30 31 err = test_stacktrace_build_id__load(skel); 32 if (CHECK(err, "skel_load", "skeleton load failed: %d\n", err)) 33 goto cleanup; 34 35 pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, 36 0 /* cpu 0 */, -1 /* group id */, 37 0 /* flags */); 38 if (pmu_fd < 0 && errno == ENOENT) { 39 printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n", __func__); 40 test__skip(); 41 goto cleanup; 42 } 43 if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", 44 pmu_fd, errno)) 45 goto cleanup; 46 47 skel->links.oncpu = bpf_program__attach_perf_event(skel->progs.oncpu, 48 pmu_fd); 49 if (!ASSERT_OK_PTR(skel->links.oncpu, "attach_perf_event")) { 50 close(pmu_fd); 51 goto cleanup; 52 } 53 54 /* find map fds */ 55 control_map_fd = bpf_map__fd(skel->maps.control_map); 56 stackid_hmap_fd = bpf_map__fd(skel->maps.stackid_hmap); 57 stackmap_fd = bpf_map__fd(skel->maps.stackmap); 58 59 if (CHECK_FAIL(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null"))) 60 goto cleanup; 61 if (CHECK_FAIL(system("taskset 0x1 ./urandom_read 100000"))) 62 goto cleanup; 63 /* disable stack trace collection */ 64 key = 0; 65 val = 1; 66 bpf_map_update_elem(control_map_fd, &key, &val, 0); 67 68 /* for every element in stackid_hmap, we can find a corresponding one 69 * in stackmap, and vise versa. 70 */ 71 err = compare_map_keys(stackid_hmap_fd, stackmap_fd); 72 if (CHECK(err, "compare_map_keys stackid_hmap vs. stackmap", 73 "err %d errno %d\n", err, errno)) 74 goto cleanup; 75 76 err = compare_map_keys(stackmap_fd, stackid_hmap_fd); 77 if (CHECK(err, "compare_map_keys stackmap vs. stackid_hmap", 78 "err %d errno %d\n", err, errno)) 79 goto cleanup; 80 81 build_id_size = read_build_id("urandom_read", buf, sizeof(buf)); 82 err = build_id_size < 0 ? build_id_size : 0; 83 84 if (CHECK(err, "get build_id with readelf", 85 "err %d errno %d\n", err, errno)) 86 goto cleanup; 87 88 err = bpf_map__get_next_key(skel->maps.stackmap, NULL, &key, sizeof(key)); 89 if (CHECK(err, "get_next_key from stackmap", 90 "err %d, errno %d\n", err, errno)) 91 goto cleanup; 92 93 do { 94 err = bpf_map__lookup_elem(skel->maps.stackmap, &key, sizeof(key), 95 id_offs, sizeof(id_offs), 0); 96 if (CHECK(err, "lookup_elem from stackmap", 97 "err %d, errno %d\n", err, errno)) 98 goto cleanup; 99 for (i = 0; i < PERF_MAX_STACK_DEPTH; ++i) 100 if (id_offs[i].status == BPF_STACK_BUILD_ID_VALID && 101 id_offs[i].offset != 0) { 102 if (memcmp(buf, id_offs[i].build_id, build_id_size) == 0) 103 build_id_matches = 1; 104 } 105 prev_key = key; 106 } while (bpf_map__get_next_key(skel->maps.stackmap, &prev_key, &key, sizeof(key)) == 0); 107 108 /* stack_map_get_build_id_offset() is racy and sometimes can return 109 * BPF_STACK_BUILD_ID_IP instead of BPF_STACK_BUILD_ID_VALID; 110 * try it one more time. 111 */ 112 if (build_id_matches < 1 && retry--) { 113 test_stacktrace_build_id__destroy(skel); 114 printf("%s:WARN:Didn't find expected build ID from the map, retrying\n", 115 __func__); 116 goto retry; 117 } 118 119 if (CHECK(build_id_matches < 1, "build id match", 120 "Didn't find expected build ID from the map\n")) 121 goto cleanup; 122 123 /* 124 * We intentionally skip compare_stack_ips(). This is because we 125 * only support one in_nmi() ips-to-build_id translation per cpu 126 * at any time, thus stack_amap here will always fallback to 127 * BPF_STACK_BUILD_ID_IP; 128 */ 129 130cleanup: 131 test_stacktrace_build_id__destroy(skel); 132} 133