LXR linux/tools/testing/selftests/bpf/prog_tests/task_fd_query

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