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/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/bpf.h>
  18 #include <bpf/libbpf.h>
  19 #include "perf-sys.h"
  20
  21 #define SAMPLE_PERIOD  0x7fffffffffffffffULL
  22
  23 /* counters, values, values2 */
  24 static int map_fd[3];
  25
  26 static void check_on_cpu(int cpu, struct perf_event_attr *attr)
  27 {
  28         struct bpf_perf_event_value value2;
  29         int pmu_fd, error = 0;
  30         cpu_set_t set;
  31         __u64 value;
  32
  33         /* Move to target CPU */
  34         CPU_ZERO(&set);
  35         CPU_SET(cpu, &set);
  36         assert(sched_setaffinity(0, sizeof(set), &set) == 0);
  37         /* Open perf event and attach to the perf_event_array */
  38         pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0);
  39         if (pmu_fd < 0) {
  40                 fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
  41                 error = 1;
  42                 goto on_exit;
  43         }
  44         assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
  45         assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
  46         /* Trigger the kprobe */
  47         bpf_map_get_next_key(map_fd[1], &cpu, NULL);
  48         /* Check the value */
  49         if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
  50                 fprintf(stderr, "Value missing for CPU %d\n", cpu);
  51                 error = 1;
  52                 goto on_exit;
  53         } else {
  54                 fprintf(stderr, "CPU %d: %llu\n", cpu, value);
  55         }
  56         /* The above bpf_map_lookup_elem should trigger the second kprobe */
  57         if (bpf_map_lookup_elem(map_fd[2], &cpu, &value2)) {
  58                 fprintf(stderr, "Value2 missing for CPU %d\n", cpu);
  59                 error = 1;
  60                 goto on_exit;
  61         } else {
  62                 fprintf(stderr, "CPU %d: counter: %llu, enabled: %llu, running: %llu\n", cpu,
  63                         value2.counter, value2.enabled, value2.running);
  64         }
  65
  66 on_exit:
  67         assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
  68         assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
  69         assert(close(pmu_fd) == 0 || error);
  70         assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
  71         exit(error);
  72 }
  73
  74 static void test_perf_event_array(struct perf_event_attr *attr,
  75                                   const char *name)
  76 {
  77         int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
  78         pid_t pid[nr_cpus];
  79         int err = 0;
  80
  81         printf("Test reading %s counters\n", name);
  82
  83         for (i = 0; i < nr_cpus; i++) {
  84                 pid[i] = fork();
  85                 assert(pid[i] >= 0);
  86                 if (pid[i] == 0) {
  87                         check_on_cpu(i, attr);
  88                         exit(1);
  89                 }
  90         }
  91
  92         for (i = 0; i < nr_cpus; i++) {
  93                 assert(waitpid(pid[i], &status, 0) == pid[i]);
  94                 err |= status;
  95         }
  96
  97         if (err)
  98                 printf("Test: %s FAILED\n", name);
  99 }
 100
 101 static void test_bpf_perf_event(void)
 102 {
 103         struct perf_event_attr attr_cycles = {
 104                 .freq = 0,
 105                 .sample_period = SAMPLE_PERIOD,
 106                 .inherit = 0,
 107                 .type = PERF_TYPE_HARDWARE,
 108                 .read_format = 0,
 109                 .sample_type = 0,
 110                 .config = PERF_COUNT_HW_CPU_CYCLES,
 111         };
 112         struct perf_event_attr attr_clock = {
 113                 .freq = 0,
 114                 .sample_period = SAMPLE_PERIOD,
 115                 .inherit = 0,
 116                 .type = PERF_TYPE_SOFTWARE,
 117                 .read_format = 0,
 118                 .sample_type = 0,
 119                 .config = PERF_COUNT_SW_CPU_CLOCK,
 120         };
 121         struct perf_event_attr attr_raw = {
 122                 .freq = 0,
 123                 .sample_period = SAMPLE_PERIOD,
 124                 .inherit = 0,
 125                 .type = PERF_TYPE_RAW,
 126                 .read_format = 0,
 127                 .sample_type = 0,
 128                 /* Intel Instruction Retired */
 129                 .config = 0xc0,
 130         };
 131         struct perf_event_attr attr_l1d_load = {
 132                 .freq = 0,
 133                 .sample_period = SAMPLE_PERIOD,
 134                 .inherit = 0,
 135                 .type = PERF_TYPE_HW_CACHE,
 136                 .read_format = 0,
 137                 .sample_type = 0,
 138                 .config =
 139                         PERF_COUNT_HW_CACHE_L1D |
 140                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
 141                         (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
 142         };
 143         struct perf_event_attr attr_llc_miss = {
 144                 .freq = 0,
 145                 .sample_period = SAMPLE_PERIOD,
 146                 .inherit = 0,
 147                 .type = PERF_TYPE_HW_CACHE,
 148                 .read_format = 0,
 149                 .sample_type = 0,
 150                 .config =
 151                         PERF_COUNT_HW_CACHE_LL |
 152                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
 153                         (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
 154         };
 155         struct perf_event_attr attr_msr_tsc = {
 156                 .freq = 0,
 157                 .sample_period = 0,
 158                 .inherit = 0,
 159                 /* From /sys/bus/event_source/devices/msr/ */
 160                 .type = 7,
 161                 .read_format = 0,
 162                 .sample_type = 0,
 163                 .config = 0,
 164         };
 165
 166         test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
 167         test_perf_event_array(&attr_clock, "SOFTWARE-clock");
 168         test_perf_event_array(&attr_raw, "RAW-instruction-retired");
 169         test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
 170
 171         /* below tests may fail in qemu */
 172         test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
 173         test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
 174 }
 175
 176 int main(int argc, char **argv)
 177 {
 178         struct bpf_link *links[2];
 179         struct bpf_program *prog;
 180         struct bpf_object *obj;
 181         char filename[256];
 182         int i = 0;
 183
 184         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 185         obj = bpf_object__open_file(filename, NULL);
 186         if (libbpf_get_error(obj)) {
 187                 fprintf(stderr, "ERROR: opening BPF object file failed\n");
 188                 return 0;
 189         }
 190
 191         /* load BPF program */
 192         if (bpf_object__load(obj)) {
 193                 fprintf(stderr, "ERROR: loading BPF object file failed\n");
 194                 goto cleanup;
 195         }
 196
 197         map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counters");
 198         map_fd[1] = bpf_object__find_map_fd_by_name(obj, "values");
 199         map_fd[2] = bpf_object__find_map_fd_by_name(obj, "values2");
 200         if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0) {
 201                 fprintf(stderr, "ERROR: finding a map in obj file failed\n");
 202                 goto cleanup;
 203         }
 204
 205         bpf_object__for_each_program(prog, obj) {
 206                 links[i] = bpf_program__attach(prog);
 207                 if (libbpf_get_error(links[i])) {
 208                         fprintf(stderr, "ERROR: bpf_program__attach failed\n");
 209                         links[i] = NULL;
 210                         goto cleanup;
 211                 }
 212                 i++;
 213         }
 214
 215         test_bpf_perf_event();
 216
 217 cleanup:
 218         for (i--; i >= 0; i--)
 219                 bpf_link__destroy(links[i]);
 220
 221         bpf_object__close(obj);
 222         return 0;
 223 }