samples/bpf/tracex6_user.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #define _GNU_SOURCE
   3
   4 #include <assert.h>
   5 #include <fcntl.h>
   6 #include <linux/perf_event.h>
   7 #include <linux/bpf.h>
   8 #include <sched.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <sys/ioctl.h>
  12 #include <sys/resource.h>
  13 #include <sys/time.h>
  14 #include <sys/types.h>
  15 #include <sys/wait.h>
  16 #include <unistd.h>
  17
  18 #include "bpf_load.h"
  19 #include "libbpf.h"
  20 #include "perf-sys.h"
  21
  22 #define SAMPLE_PERIOD  0x7fffffffffffffffULL
  23
  24 static void check_on_cpu(int cpu, struct perf_event_attr *attr)
  25 {
  26         int pmu_fd, error = 0;
  27         cpu_set_t set;
  28         __u64 value;
  29
  30         /* Move to target CPU */
  31         CPU_ZERO(&set);
  32         CPU_SET(cpu, &set);
  33         assert(sched_setaffinity(0, sizeof(set), &set) == 0);
  34         /* Open perf event and attach to the perf_event_array */
  35         pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0);
  36         if (pmu_fd < 0) {
  37                 fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
  38                 error = 1;
  39                 goto on_exit;
  40         }
  41         assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
  42         assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
  43         /* Trigger the kprobe */
  44         bpf_map_get_next_key(map_fd[1], &cpu, NULL);
  45         /* Check the value */
  46         if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
  47                 fprintf(stderr, "Value missing for CPU %d\n", cpu);
  48                 error = 1;
  49                 goto on_exit;
  50         }
  51         fprintf(stderr, "CPU %d: %llu\n", cpu, value);
  52
  53 on_exit:
  54         assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
  55         assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
  56         assert(close(pmu_fd) == 0 || error);
  57         assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
  58         exit(error);
  59 }
  60
  61 static void test_perf_event_array(struct perf_event_attr *attr,
  62                                   const char *name)
  63 {
  64         int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
  65         pid_t pid[nr_cpus];
  66         int err = 0;
  67
  68         printf("Test reading %s counters\n", name);
  69
  70         for (i = 0; i < nr_cpus; i++) {
  71                 pid[i] = fork();
  72                 assert(pid[i] >= 0);
  73                 if (pid[i] == 0) {
  74                         check_on_cpu(i, attr);
  75                         exit(1);
  76                 }
  77         }
  78
  79         for (i = 0; i < nr_cpus; i++) {
  80                 assert(waitpid(pid[i], &status, 0) == pid[i]);
  81                 err |= status;
  82         }
  83
  84         if (err)
  85                 printf("Test: %s FAILED\n", name);
  86 }
  87
  88 static void test_bpf_perf_event(void)
  89 {
  90         struct perf_event_attr attr_cycles = {
  91                 .freq = 0,
  92                 .sample_period = SAMPLE_PERIOD,
  93                 .inherit = 0,
  94                 .type = PERF_TYPE_HARDWARE,
  95                 .read_format = 0,
  96                 .sample_type = 0,
  97                 .config = PERF_COUNT_HW_CPU_CYCLES,
  98         };
  99         struct perf_event_attr attr_clock = {
 100                 .freq = 0,
 101                 .sample_period = SAMPLE_PERIOD,
 102                 .inherit = 0,
 103                 .type = PERF_TYPE_SOFTWARE,
 104                 .read_format = 0,
 105                 .sample_type = 0,
 106                 .config = PERF_COUNT_SW_CPU_CLOCK,
 107         };
 108         struct perf_event_attr attr_raw = {
 109                 .freq = 0,
 110                 .sample_period = SAMPLE_PERIOD,
 111                 .inherit = 0,
 112                 .type = PERF_TYPE_RAW,
 113                 .read_format = 0,
 114                 .sample_type = 0,
 115                 /* Intel Instruction Retired */
 116                 .config = 0xc0,
 117         };
 118         struct perf_event_attr attr_l1d_load = {
 119                 .freq = 0,
 120                 .sample_period = SAMPLE_PERIOD,
 121                 .inherit = 0,
 122                 .type = PERF_TYPE_HW_CACHE,
 123                 .read_format = 0,
 124                 .sample_type = 0,
 125                 .config =
 126                         PERF_COUNT_HW_CACHE_L1D |
 127                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
 128                         (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
 129         };
 130         struct perf_event_attr attr_llc_miss = {
 131                 .freq = 0,
 132                 .sample_period = SAMPLE_PERIOD,
 133                 .inherit = 0,
 134                 .type = PERF_TYPE_HW_CACHE,
 135                 .read_format = 0,
 136                 .sample_type = 0,
 137                 .config =
 138                         PERF_COUNT_HW_CACHE_LL |
 139                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
 140                         (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
 141         };
 142         struct perf_event_attr attr_msr_tsc = {
 143                 .freq = 0,
 144                 .sample_period = 0,
 145                 .inherit = 0,
 146                 /* From /sys/bus/event_source/devices/msr/ */
 147                 .type = 7,
 148                 .read_format = 0,
 149                 .sample_type = 0,
 150                 .config = 0,
 151         };
 152
 153         test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
 154         test_perf_event_array(&attr_clock, "SOFTWARE-clock");
 155         test_perf_event_array(&attr_raw, "RAW-instruction-retired");
 156         test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
 157
 158         /* below tests may fail in qemu */
 159         test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
 160         test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
 161 }
 162
 163 int main(int argc, char **argv)
 164 {
 165         struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 166         char filename[256];
 167
 168         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 169
 170         setrlimit(RLIMIT_MEMLOCK, &r);
 171         if (load_bpf_file(filename)) {
 172                 printf("%s", bpf_log_buf);
 173                 return 1;
 174         }
 175
 176         test_bpf_perf_event();
 177         return 0;
 178 }