223 lines · c
1// SPDX-License-Identifier: GPL-2.02#define _GNU_SOURCE3 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 0x7fffffffffffffffULL21 22/* counters, values, values2 */23static int map_fd[3];24 25static 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 65on_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 73static 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 100static 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 175int 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.bpf.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 216cleanup:217 for (i--; i >= 0; i--)218 bpf_link__destroy(links[i]);219 220 bpf_object__close(obj);221 return 0;222}223