353 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/* Copyright (c) 2016 Facebook3 */4#include <stdio.h>5#include <unistd.h>6#include <stdlib.h>7#include <stdbool.h>8#include <string.h>9#include <linux/perf_event.h>10#include <linux/bpf.h>11#include <signal.h>12#include <errno.h>13#include <sys/resource.h>14#include <bpf/bpf.h>15#include <bpf/libbpf.h>16#include "perf-sys.h"17#include "trace_helpers.h"18 19#define SAMPLE_FREQ 5020 21static int pid;22/* counts, stackmap */23static int map_fd[2];24struct bpf_program *prog;25static bool sys_read_seen, sys_write_seen;26 27static void print_ksym(__u64 addr)28{29 struct ksym *sym;30 31 if (!addr)32 return;33 sym = ksym_search(addr);34 if (!sym) {35 printf("ksym not found. Is kallsyms loaded?\n");36 return;37 }38 39 printf("%s;", sym->name);40 if (!strstr(sym->name, "sys_read"))41 sys_read_seen = true;42 else if (!strstr(sym->name, "sys_write"))43 sys_write_seen = true;44}45 46static void print_addr(__u64 addr)47{48 if (!addr)49 return;50 printf("%llx;", addr);51}52 53#define TASK_COMM_LEN 1654 55struct key_t {56 char comm[TASK_COMM_LEN];57 __u32 kernstack;58 __u32 userstack;59};60 61static void print_stack(struct key_t *key, __u64 count)62{63 __u64 ip[PERF_MAX_STACK_DEPTH] = {};64 static bool warned;65 int i;66 67 printf("%3lld %s;", count, key->comm);68 if (bpf_map_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {69 printf("---;");70 } else {71 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)72 print_ksym(ip[i]);73 }74 printf("-;");75 if (bpf_map_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {76 printf("---;");77 } else {78 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)79 print_addr(ip[i]);80 }81 if (count < 6)82 printf("\r");83 else84 printf("\n");85 86 if (key->kernstack == -EEXIST && !warned) {87 printf("stackmap collisions seen. Consider increasing size\n");88 warned = true;89 } else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {90 printf("err stackid %d %d\n", key->kernstack, key->userstack);91 }92}93 94static void err_exit(int err)95{96 kill(pid, SIGKILL);97 exit(err);98}99 100static void print_stacks(void)101{102 struct key_t key = {}, next_key;103 __u64 value;104 __u32 stackid = 0, next_id;105 int error = 1, fd = map_fd[0], stack_map = map_fd[1];106 107 sys_read_seen = sys_write_seen = false;108 while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {109 bpf_map_lookup_elem(fd, &next_key, &value);110 print_stack(&next_key, value);111 bpf_map_delete_elem(fd, &next_key);112 key = next_key;113 }114 printf("\n");115 if (!sys_read_seen || !sys_write_seen) {116 printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");117 err_exit(error);118 }119 120 /* clear stack map */121 while (bpf_map_get_next_key(stack_map, &stackid, &next_id) == 0) {122 bpf_map_delete_elem(stack_map, &next_id);123 stackid = next_id;124 }125}126 127static inline int generate_load(void)128{129 if (system("dd if=/dev/zero of=/dev/null count=5000k status=none") < 0) {130 printf("failed to generate some load with dd: %s\n", strerror(errno));131 return -1;132 }133 134 return 0;135}136 137static void test_perf_event_all_cpu(struct perf_event_attr *attr)138{139 int nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);140 struct bpf_link **links = calloc(nr_cpus, sizeof(struct bpf_link *));141 int i, pmu_fd, error = 1;142 143 if (!links) {144 printf("malloc of links failed\n");145 goto err;146 }147 148 /* system wide perf event, no need to inherit */149 attr->inherit = 0;150 151 /* open perf_event on all cpus */152 for (i = 0; i < nr_cpus; i++) {153 pmu_fd = sys_perf_event_open(attr, -1, i, -1, 0);154 if (pmu_fd < 0) {155 printf("sys_perf_event_open failed\n");156 goto all_cpu_err;157 }158 links[i] = bpf_program__attach_perf_event(prog, pmu_fd);159 if (libbpf_get_error(links[i])) {160 printf("bpf_program__attach_perf_event failed\n");161 links[i] = NULL;162 close(pmu_fd);163 goto all_cpu_err;164 }165 }166 167 if (generate_load() < 0)168 goto all_cpu_err;169 170 print_stacks();171 error = 0;172all_cpu_err:173 for (i--; i >= 0; i--)174 bpf_link__destroy(links[i]);175err:176 free(links);177 if (error)178 err_exit(error);179}180 181static void test_perf_event_task(struct perf_event_attr *attr)182{183 struct bpf_link *link = NULL;184 int pmu_fd, error = 1;185 186 /* per task perf event, enable inherit so the "dd ..." command can be traced properly.187 * Enabling inherit will cause bpf_perf_prog_read_time helper failure.188 */189 attr->inherit = 1;190 191 /* open task bound event */192 pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0);193 if (pmu_fd < 0) {194 printf("sys_perf_event_open failed\n");195 goto err;196 }197 link = bpf_program__attach_perf_event(prog, pmu_fd);198 if (libbpf_get_error(link)) {199 printf("bpf_program__attach_perf_event failed\n");200 link = NULL;201 close(pmu_fd);202 goto err;203 }204 205 if (generate_load() < 0)206 goto err;207 208 print_stacks();209 error = 0;210err:211 bpf_link__destroy(link);212 if (error)213 err_exit(error);214}215 216static void test_bpf_perf_event(void)217{218 struct perf_event_attr attr_type_hw = {219 .sample_freq = SAMPLE_FREQ,220 .freq = 1,221 .type = PERF_TYPE_HARDWARE,222 .config = PERF_COUNT_HW_CPU_CYCLES,223 };224 struct perf_event_attr attr_type_sw = {225 .sample_freq = SAMPLE_FREQ,226 .freq = 1,227 .type = PERF_TYPE_SOFTWARE,228 .config = PERF_COUNT_SW_CPU_CLOCK,229 };230 struct perf_event_attr attr_hw_cache_l1d = {231 .sample_freq = SAMPLE_FREQ,232 .freq = 1,233 .type = PERF_TYPE_HW_CACHE,234 .config =235 PERF_COUNT_HW_CACHE_L1D |236 (PERF_COUNT_HW_CACHE_OP_READ << 8) |237 (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),238 };239 struct perf_event_attr attr_hw_cache_branch_miss = {240 .sample_freq = SAMPLE_FREQ,241 .freq = 1,242 .type = PERF_TYPE_HW_CACHE,243 .config =244 PERF_COUNT_HW_CACHE_BPU |245 (PERF_COUNT_HW_CACHE_OP_READ << 8) |246 (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),247 };248 struct perf_event_attr attr_type_raw = {249 .sample_freq = SAMPLE_FREQ,250 .freq = 1,251 .type = PERF_TYPE_RAW,252 /* Intel Instruction Retired */253 .config = 0xc0,254 };255 struct perf_event_attr attr_type_raw_lock_load = {256 .sample_freq = SAMPLE_FREQ,257 .freq = 1,258 .type = PERF_TYPE_RAW,259 /* Intel MEM_UOPS_RETIRED.LOCK_LOADS */260 .config = 0x21d0,261 /* Request to record lock address from PEBS */262 .sample_type = PERF_SAMPLE_ADDR,263 /* Record address value requires precise event */264 .precise_ip = 2,265 };266 267 printf("Test HW_CPU_CYCLES\n");268 test_perf_event_all_cpu(&attr_type_hw);269 test_perf_event_task(&attr_type_hw);270 271 printf("Test SW_CPU_CLOCK\n");272 test_perf_event_all_cpu(&attr_type_sw);273 test_perf_event_task(&attr_type_sw);274 275 printf("Test HW_CACHE_L1D\n");276 test_perf_event_all_cpu(&attr_hw_cache_l1d);277 test_perf_event_task(&attr_hw_cache_l1d);278 279 printf("Test HW_CACHE_BPU\n");280 test_perf_event_all_cpu(&attr_hw_cache_branch_miss);281 test_perf_event_task(&attr_hw_cache_branch_miss);282 283 printf("Test Instruction Retired\n");284 test_perf_event_all_cpu(&attr_type_raw);285 test_perf_event_task(&attr_type_raw);286 287 printf("Test Lock Load\n");288 test_perf_event_all_cpu(&attr_type_raw_lock_load);289 test_perf_event_task(&attr_type_raw_lock_load);290 291 printf("*** PASS ***\n");292}293 294 295int main(int argc, char **argv)296{297 struct bpf_object *obj = NULL;298 char filename[256];299 int error = 1;300 301 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);302 303 signal(SIGINT, err_exit);304 signal(SIGTERM, err_exit);305 306 if (load_kallsyms()) {307 printf("failed to process /proc/kallsyms\n");308 goto cleanup;309 }310 311 obj = bpf_object__open_file(filename, NULL);312 if (libbpf_get_error(obj)) {313 printf("opening BPF object file failed\n");314 obj = NULL;315 goto cleanup;316 }317 318 prog = bpf_object__find_program_by_name(obj, "bpf_prog1");319 if (!prog) {320 printf("finding a prog in obj file failed\n");321 goto cleanup;322 }323 324 /* load BPF program */325 if (bpf_object__load(obj)) {326 printf("loading BPF object file failed\n");327 goto cleanup;328 }329 330 map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counts");331 map_fd[1] = bpf_object__find_map_fd_by_name(obj, "stackmap");332 if (map_fd[0] < 0 || map_fd[1] < 0) {333 printf("finding a counts/stackmap map in obj file failed\n");334 goto cleanup;335 }336 337 pid = fork();338 if (pid == 0) {339 read_trace_pipe();340 return 0;341 } else if (pid == -1) {342 printf("couldn't spawn process\n");343 goto cleanup;344 }345 346 test_bpf_perf_event();347 error = 0;348 349cleanup:350 bpf_object__close(obj);351 err_exit(error);352}353