tools/testing/selftests/bpf/prog_tests/task_fd_query_tp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <test_progs.h>
   3
   4 static void test_task_fd_query_tp_core(const char *probe_name,
   5                                        const char *tp_name)
   6 {
   7         const char *file = "./test_tracepoint.bpf.o";
   8         int err, bytes, efd, prog_fd, pmu_fd;
   9         struct perf_event_attr attr = {};
  10         __u64 probe_offset, probe_addr;
  11         __u32 len, prog_id, fd_type;
  12         struct bpf_object *obj = NULL;
  13         __u32 duration = 0;
  14         char buf[256];
  15
  16         err = bpf_prog_test_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
  17         if (CHECK(err, "bpf_prog_test_load", "err %d errno %d\n", err, errno))
  18                 goto close_prog;
  19
  20         if (access("/sys/kernel/tracing/trace", F_OK) == 0) {
  21                 snprintf(buf, sizeof(buf),
  22                          "/sys/kernel/tracing/events/%s/id", probe_name);
  23         } else {
  24                 snprintf(buf, sizeof(buf),
  25                          "/sys/kernel/debug/tracing/events/%s/id", probe_name);
  26         }
  27         efd = open(buf, O_RDONLY, 0);
  28         if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno))
  29                 goto close_prog;
  30         bytes = read(efd, buf, sizeof(buf));
  31         close(efd);
  32         if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "read",
  33                   "bytes %d errno %d\n", bytes, errno))
  34                 goto close_prog;
  35
  36         attr.config = strtol(buf, NULL, 0);
  37         attr.type = PERF_TYPE_TRACEPOINT;
  38         attr.sample_type = PERF_SAMPLE_RAW;
  39         attr.sample_period = 1;
  40         attr.wakeup_events = 1;
  41         pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
  42                          0 /* cpu 0 */, -1 /* group id */,
  43                          0 /* flags */);
  44         if (CHECK(err, "perf_event_open", "err %d errno %d\n", err, errno))
  45                 goto close_pmu;
  46
  47         err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
  48         if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n", err,
  49                   errno))
  50                 goto close_pmu;
  51
  52         err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
  53         if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n", err,
  54                   errno))
  55                 goto close_pmu;
  56
  57         /* query (getpid(), pmu_fd) */
  58         len = sizeof(buf);
  59         err = bpf_task_fd_query(getpid(), pmu_fd, 0, buf, &len, &prog_id,
  60                                 &fd_type, &probe_offset, &probe_addr);
  61         if (CHECK(err < 0, "bpf_task_fd_query", "err %d errno %d\n", err,
  62                   errno))
  63                 goto close_pmu;
  64
  65         err = (fd_type == BPF_FD_TYPE_TRACEPOINT) && !strcmp(buf, tp_name);
  66         if (CHECK(!err, "check_results", "fd_type %d tp_name %s\n",
  67                   fd_type, buf))
  68                 goto close_pmu;
  69
  70 close_pmu:
  71         close(pmu_fd);
  72 close_prog:
  73         bpf_object__close(obj);
  74 }
  75
  76 void test_task_fd_query_tp(void)
  77 {
  78         test_task_fd_query_tp_core("sched/sched_switch",
  79                                    "sched_switch");
  80         test_task_fd_query_tp_core("syscalls/sys_enter_read",
  81                                    "sys_enter_read");
  82 }