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 <bpf/bpf.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         struct bpf_perf_event_value value2;
  27         int pmu_fd, error = 0;
  28         cpu_set_t set;
  29         __u64 value;
  30
  31         /* Move to target CPU */
  32         CPU_ZERO(&set);
  33         CPU_SET(cpu, &set);
  34         assert(sched_setaffinity(0, sizeof(set), &set) == 0);
  35         /* Open perf event and attach to the perf_event_array */
  36         pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0);
  37         if (pmu_fd < 0) {
  38                 fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
  39                 error = 1;
  40                 goto on_exit;
  41         }
  42         assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
  43         assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
  44         /* Trigger the kprobe */
  45         bpf_map_get_next_key(map_fd[1], &cpu, NULL);
  46         /* Check the value */
  47         if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
  48                 fprintf(stderr, "Value missing for CPU %d\n", cpu);
  49                 error = 1;
  50                 goto on_exit;
  51         } else {
  52                 fprintf(stderr, "CPU %d: %llu\n", cpu, value);
  53         }
  54         /* The above bpf_map_lookup_elem should trigger the second kprobe */
  55         if (bpf_map_lookup_elem(map_fd[2], &cpu, &value2)) {
  56                 fprintf(stderr, "Value2 missing for CPU %d\n", cpu);
  57                 error = 1;
  58                 goto on_exit;
  59         } else {
  60                 fprintf(stderr, "CPU %d: counter: %llu, enabled: %llu, running: %llu\n", cpu,
  61                         value2.counter, value2.enabled, value2.running);
  62         }
  63
  64 on_exit:
  65         assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
  66         assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
  67         assert(close(pmu_fd) == 0 || error);
  68         assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
  69         exit(error);
  70 }
  71
  72 static void test_perf_event_array(struct perf_event_attr *attr,
  73                                   const char *name)
  74 {
  75         int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
  76         pid_t pid[nr_cpus];
  77         int err = 0;
  78
  79         printf("Test reading %s counters\n", name);
  80
  81         for (i = 0; i < nr_cpus; i++) {
  82                 pid[i] = fork();
  83                 assert(pid[i] >= 0);
  84                 if (pid[i] == 0) {
  85                         check_on_cpu(i, attr);
  86                         exit(1);
  87                 }
  88         }
  89
  90         for (i = 0; i < nr_cpus; i++) {
  91                 assert(waitpid(pid[i], &status, 0) == pid[i]);
  92                 err |= status;
  93         }
  94
  95         if (err)
  96                 printf("Test: %s FAILED\n", name);
  97 }
  98
  99 static void test_bpf_perf_event(void)
 100 {
 101         struct perf_event_attr attr_cycles = {
 102                 .freq = 0,
 103                 .sample_period = SAMPLE_PERIOD,
 104                 .inherit = 0,
 105                 .type = PERF_TYPE_HARDWARE,
 106                 .read_format = 0,
 107                 .sample_type = 0,
 108                 .config = PERF_COUNT_HW_CPU_CYCLES,
 109         };
 110         struct perf_event_attr attr_clock = {
 111                 .freq = 0,
 112                 .sample_period = SAMPLE_PERIOD,
 113                 .inherit = 0,
 114                 .type = PERF_TYPE_SOFTWARE,
 115                 .read_format = 0,
 116                 .sample_type = 0,
 117                 .config = PERF_COUNT_SW_CPU_CLOCK,
 118         };
 119         struct perf_event_attr attr_raw = {
 120                 .freq = 0,
 121                 .sample_period = SAMPLE_PERIOD,
 122                 .inherit = 0,
 123                 .type = PERF_TYPE_RAW,
 124                 .read_format = 0,
 125                 .sample_type = 0,
 126                 /* Intel Instruction Retired */
 127                 .config = 0xc0,
 128         };
 129         struct perf_event_attr attr_l1d_load = {
 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_L1D |
 138                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
 139                         (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
 140         };
 141         struct perf_event_attr attr_llc_miss = {
 142                 .freq = 0,
 143                 .sample_period = SAMPLE_PERIOD,
 144                 .inherit = 0,
 145                 .type = PERF_TYPE_HW_CACHE,
 146                 .read_format = 0,
 147                 .sample_type = 0,
 148                 .config =
 149                         PERF_COUNT_HW_CACHE_LL |
 150                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
 151                         (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
 152         };
 153         struct perf_event_attr attr_msr_tsc = {
 154                 .freq = 0,
 155                 .sample_period = 0,
 156                 .inherit = 0,
 157                 /* From /sys/bus/event_source/devices/msr/ */
 158                 .type = 7,
 159                 .read_format = 0,
 160                 .sample_type = 0,
 161                 .config = 0,
 162         };
 163
 164         test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
 165         test_perf_event_array(&attr_clock, "SOFTWARE-clock");
 166         test_perf_event_array(&attr_raw, "RAW-instruction-retired");
 167         test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
 168
 169         /* below tests may fail in qemu */
 170         test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
 171         test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
 172 }
 173
 174 int main(int argc, char **argv)
 175 {
 176         struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 177         char filename[256];
 178
 179         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 180
 181         setrlimit(RLIMIT_MEMLOCK, &r);
 182         if (load_bpf_file(filename)) {
 183                 printf("%s", bpf_log_buf);
 184                 return 1;
 185         }
 186
 187         test_bpf_perf_event();
 188         return 0;
 189 }