// SPDX-License-Identifier: GPL-2.0 #include void test_stacktrace_map(void) { int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd; const char *file = "./test_stacktrace_map.o"; int bytes, efd, err, pmu_fd, prog_fd, stack_trace_len; struct perf_event_attr attr = {}; __u32 key, val, duration = 0; struct bpf_object *obj; char buf[256]; err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd); if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno)) return; /* Get the ID for the sched/sched_switch tracepoint */ snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/sched/sched_switch/id"); efd = open(buf, O_RDONLY, 0); if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno)) goto close_prog; bytes = read(efd, buf, sizeof(buf)); close(efd); if (bytes <= 0 || bytes >= sizeof(buf)) goto close_prog; /* Open the perf event and attach bpf progrram */ attr.config = strtol(buf, NULL, 0); attr.type = PERF_TYPE_TRACEPOINT; attr.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CALLCHAIN; attr.sample_period = 1; attr.wakeup_events = 1; pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, 0 /* cpu 0 */, -1 /* group id */, 0 /* flags */); if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", pmu_fd, errno)) goto close_prog; err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0); if (err) goto disable_pmu; err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); if (err) goto disable_pmu; /* find map fds */ control_map_fd = bpf_find_map(__func__, obj, "control_map"); if (control_map_fd < 0) goto disable_pmu; stackid_hmap_fd = bpf_find_map(__func__, obj, "stackid_hmap"); if (stackid_hmap_fd < 0) goto disable_pmu; stackmap_fd = bpf_find_map(__func__, obj, "stackmap"); if (stackmap_fd < 0) goto disable_pmu; stack_amap_fd = bpf_find_map(__func__, obj, "stack_amap"); if (stack_amap_fd < 0) goto disable_pmu; /* give some time for bpf program run */ sleep(1); /* 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 disable_pmu_noerr; 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 disable_pmu_noerr; stack_trace_len = PERF_MAX_STACK_DEPTH * sizeof(__u64); err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len); if (CHECK(err, "compare_stack_ips stackmap vs. stack_amap", "err %d errno %d\n", err, errno)) goto disable_pmu_noerr; goto disable_pmu_noerr; disable_pmu: error_cnt++; disable_pmu_noerr: ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE); close(pmu_fd); close_prog: bpf_object__close(obj); }