133 lines · c
1// SPDX-License-Identifier: GPL-2.02#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 || errno == EOPNOTSUPP)) {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 one69 * 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 return109 * 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 we125 * only support one in_nmi() ips-to-build_id translation per cpu126 * at any time, thus stack_amap here will always fallback to127 * BPF_STACK_BUILD_ID_IP;128 */129 130cleanup:131 test_stacktrace_build_id__destroy(skel);132}133