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