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 <sched.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <sys/ioctl.h>
  11 #include <sys/time.h>
  12 #include <sys/types.h>
  13 #include <sys/wait.h>
  14 #include <unistd.h>
  15
  16 #include <bpf/bpf.h>
  17 #include <bpf/libbpf.h>
  18 #include "perf-sys.h"
  19
  20 #define SAMPLE_PERIOD  0x7fffffffffffffffULL
  21
  22 /* counters, values, values2 */
  23 static int map_fd[3];
  24
  25 static void check_on_cpu(int cpu, struct perf_event_attr *attr)
  26 {
  27         struct bpf_perf_event_value value2;
  28         int pmu_fd, error = 0;
  29         cpu_set_t set;
  30         __u64 value;
  31
  32         /* Move to target CPU */
  33         CPU_ZERO(&set);
  34         CPU_SET(cpu, &set);
  35         assert(sched_setaffinity(0, sizeof(set), &set) == 0);
  36         /* Open perf event and attach to the perf_event_array */
  37         pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0);
  38         if (pmu_fd < 0) {
  39                 fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
  40                 error = 1;
  41                 goto on_exit;
  42         }
  43         assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
  44         assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
  45         /* Trigger the kprobe */
  46         bpf_map_get_next_key(map_fd[1], &cpu, NULL);
  47         /* Check the value */
  48         if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
  49                 fprintf(stderr, "Value missing for CPU %d\n", cpu);
  50                 error = 1;
  51                 goto on_exit;
  52         } else {
  53                 fprintf(stderr, "CPU %d: %llu\n", cpu, value);
  54         }
  55         /* The above bpf_map_lookup_elem should trigger the second kprobe */
  56         if (bpf_map_lookup_elem(map_fd[2], &cpu, &value2)) {
  57                 fprintf(stderr, "Value2 missing for CPU %d\n", cpu);
  58                 error = 1;
  59                 goto on_exit;
  60         } else {
  61                 fprintf(stderr, "CPU %d: counter: %llu, enabled: %llu, running: %llu\n", cpu,
  62                         value2.counter, value2.enabled, value2.running);
  63         }
  64
  65 on_exit:
  66         assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
  67         assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
  68         assert(close(pmu_fd) == 0 || error);
  69         assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
  70         exit(error);
  71 }
  72
  73 static void test_perf_event_array(struct perf_event_attr *attr,
  74                                   const char *name)
  75 {
  76         int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
  77         pid_t pid[nr_cpus];
  78         int err = 0;
  79
  80         printf("Test reading %s counters\n", name);
  81
  82         for (i = 0; i < nr_cpus; i++) {
  83                 pid[i] = fork();
  84                 assert(pid[i] >= 0);
  85                 if (pid[i] == 0) {
  86                         check_on_cpu(i, attr);
  87                         exit(1);
  88                 }
  89         }
  90
  91         for (i = 0; i < nr_cpus; i++) {
  92                 assert(waitpid(pid[i], &status, 0) == pid[i]);
  93                 err |= status;
  94         }
  95
  96         if (err)
  97                 printf("Test: %s FAILED\n", name);
  98 }
  99
 100 static void test_bpf_perf_event(void)
 101 {
 102         struct perf_event_attr attr_cycles = {
 103                 .freq = 0,
 104                 .sample_period = SAMPLE_PERIOD,
 105                 .inherit = 0,
 106                 .type = PERF_TYPE_HARDWARE,
 107                 .read_format = 0,
 108                 .sample_type = 0,
 109                 .config = PERF_COUNT_HW_CPU_CYCLES,
 110         };
 111         struct perf_event_attr attr_clock = {
 112                 .freq = 0,
 113                 .sample_period = SAMPLE_PERIOD,
 114                 .inherit = 0,
 115                 .type = PERF_TYPE_SOFTWARE,
 116                 .read_format = 0,
 117                 .sample_type = 0,
 118                 .config = PERF_COUNT_SW_CPU_CLOCK,
 119         };
 120         struct perf_event_attr attr_raw = {
 121                 .freq = 0,
 122                 .sample_period = SAMPLE_PERIOD,
 123                 .inherit = 0,
 124                 .type = PERF_TYPE_RAW,
 125                 .read_format = 0,
 126                 .sample_type = 0,
 127                 /* Intel Instruction Retired */
 128                 .config = 0xc0,
 129         };
 130         struct perf_event_attr attr_l1d_load = {
 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_L1D |
 139                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
 140                         (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
 141         };
 142         struct perf_event_attr attr_llc_miss = {
 143                 .freq = 0,
 144                 .sample_period = SAMPLE_PERIOD,
 145                 .inherit = 0,
 146                 .type = PERF_TYPE_HW_CACHE,
 147                 .read_format = 0,
 148                 .sample_type = 0,
 149                 .config =
 150                         PERF_COUNT_HW_CACHE_LL |
 151                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
 152                         (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
 153         };
 154         struct perf_event_attr attr_msr_tsc = {
 155                 .freq = 0,
 156                 .sample_period = 0,
 157                 .inherit = 0,
 158                 /* From /sys/bus/event_source/devices/msr/ */
 159                 .type = 7,
 160                 .read_format = 0,
 161                 .sample_type = 0,
 162                 .config = 0,
 163         };
 164
 165         test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
 166         test_perf_event_array(&attr_clock, "SOFTWARE-clock");
 167         test_perf_event_array(&attr_raw, "RAW-instruction-retired");
 168         test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
 169
 170         /* below tests may fail in qemu */
 171         test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
 172         test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
 173 }
 174
 175 int main(int argc, char **argv)
 176 {
 177         struct bpf_link *links[2];
 178         struct bpf_program *prog;
 179         struct bpf_object *obj;
 180         char filename[256];
 181         int i = 0;
 182
 183         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 184         obj = bpf_object__open_file(filename, NULL);
 185         if (libbpf_get_error(obj)) {
 186                 fprintf(stderr, "ERROR: opening BPF object file failed\n");
 187                 return 0;
 188         }
 189
 190         /* load BPF program */
 191         if (bpf_object__load(obj)) {
 192                 fprintf(stderr, "ERROR: loading BPF object file failed\n");
 193                 goto cleanup;
 194         }
 195
 196         map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counters");
 197         map_fd[1] = bpf_object__find_map_fd_by_name(obj, "values");
 198         map_fd[2] = bpf_object__find_map_fd_by_name(obj, "values2");
 199         if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0) {
 200                 fprintf(stderr, "ERROR: finding a map in obj file failed\n");
 201                 goto cleanup;
 202         }
 203
 204         bpf_object__for_each_program(prog, obj) {
 205                 links[i] = bpf_program__attach(prog);
 206                 if (libbpf_get_error(links[i])) {
 207                         fprintf(stderr, "ERROR: bpf_program__attach failed\n");
 208                         links[i] = NULL;
 209                         goto cleanup;
 210                 }
 211                 i++;
 212         }
 213
 214         test_bpf_perf_event();
 215
 216 cleanup:
 217         for (i--; i >= 0; i--)
 218                 bpf_link__destroy(links[i]);
 219
 220         bpf_object__close(obj);
 221         return 0;
 222 }