samples/bpf/tracex6_user.c

   1 #include <stdio.h>
   2 #include <unistd.h>
   3 #include <stdlib.h>
   4 #include <stdbool.h>
   5 #include <string.h>
   6 #include <fcntl.h>
   7 #include <poll.h>
   8 #include <sys/ioctl.h>
   9 #include <linux/perf_event.h>
  10 #include <linux/bpf.h>
  11 #include "libbpf.h"
  12 #include "bpf_load.h"
  13 #include "perf-sys.h"
  14
  15 #define SAMPLE_PERIOD  0x7fffffffffffffffULL
  16
  17 static void test_bpf_perf_event(void)
  18 {
  19         int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
  20         int *pmu_fd = malloc(nr_cpus * sizeof(int));
  21         int status, i;
  22
  23         struct perf_event_attr attr_insn_pmu = {
  24                 .freq = 0,
  25                 .sample_period = SAMPLE_PERIOD,
  26                 .inherit = 0,
  27                 .type = PERF_TYPE_HARDWARE,
  28                 .read_format = 0,
  29                 .sample_type = 0,
  30                 .config = 0,/* PMU: cycles */
  31         };
  32
  33         for (i = 0; i < nr_cpus; i++) {
  34                 pmu_fd[i] = sys_perf_event_open(&attr_insn_pmu, -1/*pid*/, i/*cpu*/, -1/*group_fd*/, 0);
  35                 if (pmu_fd[i] < 0) {
  36                         printf("event syscall failed\n");
  37                         goto exit;
  38                 }
  39
  40                 bpf_map_update_elem(map_fd[0], &i, &pmu_fd[i], BPF_ANY);
  41                 ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0);
  42         }
  43
  44         status = system("ls > /dev/null");
  45         if (status)
  46                 goto exit;
  47         status = system("sleep 2");
  48         if (status)
  49                 goto exit;
  50
  51 exit:
  52         for (i = 0; i < nr_cpus; i++)
  53                 close(pmu_fd[i]);
  54         close(map_fd[0]);
  55         free(pmu_fd);
  56 }
  57
  58 int main(int argc, char **argv)
  59 {
  60         char filename[256];
  61
  62         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
  63
  64         if (load_bpf_file(filename)) {
  65                 printf("%s", bpf_log_buf);
  66                 return 1;
  67         }
  68
  69         test_bpf_perf_event();
  70         read_trace_pipe();
  71
  72         return 0;
  73 }