kernel/tools/perf/tests/open-syscall.c

   1 #include "thread_map.h"
   2 #include "evsel.h"
   3 #include "debug.h"
   4 #include "tests.h"
   5
   6 int test__open_syscall_event(void)
   7 {
   8         int err = -1, fd;
   9         struct perf_evsel *evsel;
  10         unsigned int nr_open_calls = 111, i;
  11         struct thread_map *threads = thread_map__new(-1, getpid(), UINT_MAX);
  12         char sbuf[STRERR_BUFSIZE];
  13
  14         if (threads == NULL) {
  15                 pr_debug("thread_map__new\n");
  16                 return -1;
  17         }
  18
  19         evsel = perf_evsel__newtp("syscalls", "sys_enter_open");
  20         if (evsel == NULL) {
  21                 if (tracefs_configured())
  22                         pr_debug("is tracefs mounted on /sys/kernel/tracing?\n");
  23                 else if (debugfs_configured())
  24                         pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
  25                 else
  26                         pr_debug("Neither tracefs or debugfs is enabled in this kernel\n");
  27                 goto out_thread_map_delete;
  28         }
  29
  30         if (perf_evsel__open_per_thread(evsel, threads) < 0) {
  31                 pr_debug("failed to open counter: %s, "
  32                          "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  33                          strerror_r(errno, sbuf, sizeof(sbuf)));
  34                 goto out_evsel_delete;
  35         }
  36
  37         for (i = 0; i < nr_open_calls; ++i) {
  38                 fd = open("/etc/passwd", O_RDONLY);
  39                 close(fd);
  40         }
  41
  42         if (perf_evsel__read_on_cpu(evsel, 0, 0) < 0) {
  43                 pr_debug("perf_evsel__read_on_cpu\n");
  44                 goto out_close_fd;
  45         }
  46
  47         if (evsel->counts->cpu[0].val != nr_open_calls) {
  48                 pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls, got %" PRIu64 "\n",
  49                          nr_open_calls, evsel->counts->cpu[0].val);
  50                 goto out_close_fd;
  51         }
  52
  53         err = 0;
  54 out_close_fd:
  55         perf_evsel__close_fd(evsel, 1, threads->nr);
  56 out_evsel_delete:
  57         perf_evsel__delete(evsel);
  58 out_thread_map_delete:
  59         thread_map__delete(threads);
  60         return err;
  61 }