samples/bpf/tracex6_user.c

   1 #define _GNU_SOURCE
   2
   3 #include <assert.h>
   4 #include <fcntl.h>
   5 #include <linux/perf_event.h>
   6 #include <linux/bpf.h>
   7 #include <sched.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <sys/ioctl.h>
  11 #include <sys/resource.h>
  12 #include <sys/time.h>
  13 #include <sys/types.h>
  14 #include <sys/wait.h>
  15 #include <unistd.h>
  16
  17 #include "bpf_load.h"
  18 #include "libbpf.h"
  19 #include "perf-sys.h"
  20
  21 #define SAMPLE_PERIOD  0x7fffffffffffffffULL
  22
  23 static void check_on_cpu(int cpu, struct perf_event_attr *attr)
  24 {
  25         int pmu_fd, error = 0;
  26         cpu_set_t set;
  27         __u64 value;
  28
  29         /* Move to target CPU */
  30         CPU_ZERO(&set);
  31         CPU_SET(cpu, &set);
  32         assert(sched_setaffinity(0, sizeof(set), &set) == 0);
  33         /* Open perf event and attach to the perf_event_array */
  34         pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0);
  35         if (pmu_fd < 0) {
  36                 fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
  37                 error = 1;
  38                 goto on_exit;
  39         }
  40         assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
  41         assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
  42         /* Trigger the kprobe */
  43         bpf_map_get_next_key(map_fd[1], &cpu, NULL);
  44         /* Check the value */
  45         if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
  46                 fprintf(stderr, "Value missing for CPU %d\n", cpu);
  47                 error = 1;
  48                 goto on_exit;
  49         }
  50         fprintf(stderr, "CPU %d: %llu\n", cpu, value);
  51
  52 on_exit:
  53         assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
  54         assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
  55         assert(close(pmu_fd) == 0 || error);
  56         assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
  57         exit(error);
  58 }
  59
  60 static void test_perf_event_array(struct perf_event_attr *attr,
  61                                   const char *name)
  62 {
  63         int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
  64         pid_t pid[nr_cpus];
  65         int err = 0;
  66
  67         printf("Test reading %s counters\n", name);
  68
  69         for (i = 0; i < nr_cpus; i++) {
  70                 pid[i] = fork();
  71                 assert(pid[i] >= 0);
  72                 if (pid[i] == 0) {
  73                         check_on_cpu(i, attr);
  74                         exit(1);
  75                 }
  76         }
  77
  78         for (i = 0; i < nr_cpus; i++) {
  79                 assert(waitpid(pid[i], &status, 0) == pid[i]);
  80                 err |= status;
  81         }
  82
  83         if (err)
  84                 printf("Test: %s FAILED\n", name);
  85 }
  86
  87 static void test_bpf_perf_event(void)
  88 {
  89         struct perf_event_attr attr_cycles = {
  90                 .freq = 0,
  91                 .sample_period = SAMPLE_PERIOD,
  92                 .inherit = 0,
  93                 .type = PERF_TYPE_HARDWARE,
  94                 .read_format = 0,
  95                 .sample_type = 0,
  96                 .config = PERF_COUNT_HW_CPU_CYCLES,
  97         };
  98         struct perf_event_attr attr_clock = {
  99                 .freq = 0,
 100                 .sample_period = SAMPLE_PERIOD,
 101                 .inherit = 0,
 102                 .type = PERF_TYPE_SOFTWARE,
 103                 .read_format = 0,
 104                 .sample_type = 0,
 105                 .config = PERF_COUNT_SW_CPU_CLOCK,
 106         };
 107         struct perf_event_attr attr_raw = {
 108                 .freq = 0,
 109                 .sample_period = SAMPLE_PERIOD,
 110                 .inherit = 0,
 111                 .type = PERF_TYPE_RAW,
 112                 .read_format = 0,
 113                 .sample_type = 0,
 114                 /* Intel Instruction Retired */
 115                 .config = 0xc0,
 116         };
 117         struct perf_event_attr attr_l1d_load = {
 118                 .freq = 0,
 119                 .sample_period = SAMPLE_PERIOD,
 120                 .inherit = 0,
 121                 .type = PERF_TYPE_HW_CACHE,
 122                 .read_format = 0,
 123                 .sample_type = 0,
 124                 .config =
 125                         PERF_COUNT_HW_CACHE_L1D |
 126                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
 127                         (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
 128         };
 129         struct perf_event_attr attr_llc_miss = {
 130                 .freq = 0,
 131                 .sample_period = SAMPLE_PERIOD,
 132                 .inherit = 0,
 133                 .type = PERF_TYPE_HW_CACHE,
 134                 .read_format = 0,
 135                 .sample_type = 0,
 136                 .config =
 137                         PERF_COUNT_HW_CACHE_LL |
 138                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
 139                         (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
 140         };
 141         struct perf_event_attr attr_msr_tsc = {
 142                 .freq = 0,
 143                 .sample_period = 0,
 144                 .inherit = 0,
 145                 /* From /sys/bus/event_source/devices/msr/ */
 146                 .type = 7,
 147                 .read_format = 0,
 148                 .sample_type = 0,
 149                 .config = 0,
 150         };
 151
 152         test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
 153         test_perf_event_array(&attr_clock, "SOFTWARE-clock");
 154         test_perf_event_array(&attr_raw, "RAW-instruction-retired");
 155         test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
 156
 157         /* below tests may fail in qemu */
 158         test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
 159         test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
 160 }
 161
 162 int main(int argc, char **argv)
 163 {
 164         struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 165         char filename[256];
 166
 167         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 168
 169         setrlimit(RLIMIT_MEMLOCK, &r);
 170         if (load_bpf_file(filename)) {
 171                 printf("%s", bpf_log_buf);
 172                 return 1;
 173         }
 174
 175         test_bpf_perf_event();
 176         return 0;
 177 }