bpf/prog_tests/task_fd_query_tp.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <test_progs.h>
0003
0004 static void test_task_fd_query_tp_core(const char *probe_name,
0005                        const char *tp_name)
0006 {
0007     const char *file = "./test_tracepoint.o";
0008     int err, bytes, efd, prog_fd, pmu_fd;
0009     struct perf_event_attr attr = {};
0010     __u64 probe_offset, probe_addr;
0011     __u32 len, prog_id, fd_type;
0012     struct bpf_object *obj = NULL;
0013     __u32 duration = 0;
0014     char buf[256];
0015
0016     err = bpf_prog_test_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
0017     if (CHECK(err, "bpf_prog_test_load", "err %d errno %d\n", err, errno))
0018         goto close_prog;
0019
0020     snprintf(buf, sizeof(buf),
0021          "/sys/kernel/debug/tracing/events/%s/id", probe_name);
0022     efd = open(buf, O_RDONLY, 0);
0023     if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno))
0024         goto close_prog;
0025     bytes = read(efd, buf, sizeof(buf));
0026     close(efd);
0027     if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "read",
0028           "bytes %d errno %d\n", bytes, errno))
0029         goto close_prog;
0030
0031     attr.config = strtol(buf, NULL, 0);
0032     attr.type = PERF_TYPE_TRACEPOINT;
0033     attr.sample_type = PERF_SAMPLE_RAW;
0034     attr.sample_period = 1;
0035     attr.wakeup_events = 1;
0036     pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
0037              0 /* cpu 0 */, -1 /* group id */,
0038              0 /* flags */);
0039     if (CHECK(err, "perf_event_open", "err %d errno %d\n", err, errno))
0040         goto close_pmu;
0041
0042     err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
0043     if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n", err,
0044           errno))
0045         goto close_pmu;
0046
0047     err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
0048     if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n", err,
0049           errno))
0050         goto close_pmu;
0051
0052     /* query (getpid(), pmu_fd) */
0053     len = sizeof(buf);
0054     err = bpf_task_fd_query(getpid(), pmu_fd, 0, buf, &len, &prog_id,
0055                 &fd_type, &probe_offset, &probe_addr);
0056     if (CHECK(err < 0, "bpf_task_fd_query", "err %d errno %d\n", err,
0057           errno))
0058         goto close_pmu;
0059
0060     err = (fd_type == BPF_FD_TYPE_TRACEPOINT) && !strcmp(buf, tp_name);
0061     if (CHECK(!err, "check_results", "fd_type %d tp_name %s\n",
0062           fd_type, buf))
0063         goto close_pmu;
0064
0065 close_pmu:
0066     close(pmu_fd);
0067 close_prog:
0068     bpf_object__close(obj);
0069 }
0070
0071 void test_task_fd_query_tp(void)
0072 {
0073     test_task_fd_query_tp_core("sched/sched_switch",
0074                    "sched_switch");
0075     test_task_fd_query_tp_core("syscalls/sys_enter_read",
0076                    "sys_enter_read");
0077 }