LXR linux/samples/bpf/tracex6

   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
  16static 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
  50exit:
  51        for (i = 0; i < nr_cpus; i++)
  52                close(pmu_fd[i]);
  53        close(map_fd[0]);
  54        free(pmu_fd);
  55}
  56
  57int 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}
  73