1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2016 Facebook 3 */ 4 #include <stdio.h> 5 #include <unistd.h> 6 #include <stdlib.h> 7 #include <stdbool.h> 8 #include <string.h> 9 #include <fcntl.h> 10 #include <poll.h> 11 #include <sys/ioctl.h> 12 #include <linux/perf_event.h> 13 #include <linux/bpf.h> 14 #include <signal.h> 15 #include <assert.h> 16 #include <errno.h> 17 #include <sys/resource.h> 18 #include "libbpf.h" 19 #include "bpf_load.h" 20 #include "perf-sys.h" 21 #include "trace_helpers.h" 22 23 #define SAMPLE_FREQ 50 24 25 static bool sys_read_seen, sys_write_seen; 26 27 static 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 46 static void print_addr(__u64 addr) 47 { 48 if (!addr) 49 return; 50 printf("%llx;", addr); 51 } 52 53 #define TASK_COMM_LEN 16 54 55 struct key_t { 56 char comm[TASK_COMM_LEN]; 57 __u32 kernstack; 58 __u32 userstack; 59 }; 60 61 static 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 else 84 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 94 static void int_exit(int sig) 95 { 96 kill(0, SIGKILL); 97 exit(0); 98 } 99 100 static void print_stacks(void) 101 { 102 struct key_t key = {}, next_key; 103 __u64 value; 104 __u32 stackid = 0, next_id; 105 int 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 int_exit(0); 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 } 126 127 static 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 } 136 137 static void test_perf_event_all_cpu(struct perf_event_attr *attr) 138 { 139 int nr_cpus = sysconf(_SC_NPROCESSORS_CONF); 140 int *pmu_fd = malloc(nr_cpus * sizeof(int)); 141 int i, error = 0; 142 143 /* system wide perf event, no need to inherit */ 144 attr->inherit = 0; 145 146 /* open perf_event on all cpus */ 147 for (i = 0; i < nr_cpus; i++) { 148 pmu_fd[i] = sys_perf_event_open(attr, -1, i, -1, 0); 149 if (pmu_fd[i] < 0) { 150 printf("sys_perf_event_open failed\n"); 151 error = 1; 152 goto all_cpu_err; 153 } 154 assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0); 155 assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE) == 0); 156 } 157 158 if (generate_load() < 0) { 159 error = 1; 160 goto all_cpu_err; 161 } 162 print_stacks(); 163 all_cpu_err: 164 for (i--; i >= 0; i--) { 165 ioctl(pmu_fd[i], PERF_EVENT_IOC_DISABLE); 166 close(pmu_fd[i]); 167 } 168 free(pmu_fd); 169 if (error) 170 int_exit(0); 171 } 172 173 static void test_perf_event_task(struct perf_event_attr *attr) 174 { 175 int pmu_fd, error = 0; 176 177 /* per task perf event, enable inherit so the "dd ..." command can be traced properly. 178 * Enabling inherit will cause bpf_perf_prog_read_time helper failure. 179 */ 180 attr->inherit = 1; 181 182 /* open task bound event */ 183 pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0); 184 if (pmu_fd < 0) { 185 printf("sys_perf_event_open failed\n"); 186 int_exit(0); 187 } 188 assert(ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0); 189 assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE) == 0); 190 191 if (generate_load() < 0) { 192 error = 1; 193 goto err; 194 } 195 print_stacks(); 196 err: 197 ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE); 198 close(pmu_fd); 199 if (error) 200 int_exit(0); 201 } 202 203 static void test_bpf_perf_event(void) 204 { 205 struct perf_event_attr attr_type_hw = { 206 .sample_freq = SAMPLE_FREQ, 207 .freq = 1, 208 .type = PERF_TYPE_HARDWARE, 209 .config = PERF_COUNT_HW_CPU_CYCLES, 210 }; 211 struct perf_event_attr attr_type_sw = { 212 .sample_freq = SAMPLE_FREQ, 213 .freq = 1, 214 .type = PERF_TYPE_SOFTWARE, 215 .config = PERF_COUNT_SW_CPU_CLOCK, 216 }; 217 struct perf_event_attr attr_hw_cache_l1d = { 218 .sample_freq = SAMPLE_FREQ, 219 .freq = 1, 220 .type = PERF_TYPE_HW_CACHE, 221 .config = 222 PERF_COUNT_HW_CACHE_L1D | 223 (PERF_COUNT_HW_CACHE_OP_READ << 8) | 224 (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16), 225 }; 226 struct perf_event_attr attr_hw_cache_branch_miss = { 227 .sample_freq = SAMPLE_FREQ, 228 .freq = 1, 229 .type = PERF_TYPE_HW_CACHE, 230 .config = 231 PERF_COUNT_HW_CACHE_BPU | 232 (PERF_COUNT_HW_CACHE_OP_READ << 8) | 233 (PERF_COUNT_HW_CACHE_RESULT_MISS << 16), 234 }; 235 struct perf_event_attr attr_type_raw = { 236 .sample_freq = SAMPLE_FREQ, 237 .freq = 1, 238 .type = PERF_TYPE_RAW, 239 /* Intel Instruction Retired */ 240 .config = 0xc0, 241 }; 242 struct perf_event_attr attr_type_raw_lock_load = { 243 .sample_freq = SAMPLE_FREQ, 244 .freq = 1, 245 .type = PERF_TYPE_RAW, 246 /* Intel MEM_UOPS_RETIRED.LOCK_LOADS */ 247 .config = 0x21d0, 248 /* Request to record lock address from PEBS */ 249 .sample_type = PERF_SAMPLE_ADDR, 250 /* Record address value requires precise event */ 251 .precise_ip = 2, 252 }; 253 254 printf("Test HW_CPU_CYCLES\n"); 255 test_perf_event_all_cpu(&attr_type_hw); 256 test_perf_event_task(&attr_type_hw); 257 258 printf("Test SW_CPU_CLOCK\n"); 259 test_perf_event_all_cpu(&attr_type_sw); 260 test_perf_event_task(&attr_type_sw); 261 262 printf("Test HW_CACHE_L1D\n"); 263 test_perf_event_all_cpu(&attr_hw_cache_l1d); 264 test_perf_event_task(&attr_hw_cache_l1d); 265 266 printf("Test HW_CACHE_BPU\n"); 267 test_perf_event_all_cpu(&attr_hw_cache_branch_miss); 268 test_perf_event_task(&attr_hw_cache_branch_miss); 269 270 printf("Test Instruction Retired\n"); 271 test_perf_event_all_cpu(&attr_type_raw); 272 test_perf_event_task(&attr_type_raw); 273 274 printf("Test Lock Load\n"); 275 test_perf_event_all_cpu(&attr_type_raw_lock_load); 276 test_perf_event_task(&attr_type_raw_lock_load); 277 278 printf("*** PASS ***\n"); 279 } 280 281 282 int main(int argc, char **argv) 283 { 284 struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; 285 char filename[256]; 286 287 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 288 setrlimit(RLIMIT_MEMLOCK, &r); 289 290 signal(SIGINT, int_exit); 291 signal(SIGTERM, int_exit); 292 293 if (load_kallsyms()) { 294 printf("failed to process /proc/kallsyms\n"); 295 return 1; 296 } 297 298 if (load_bpf_file(filename)) { 299 printf("%s", bpf_log_buf); 300 return 2; 301 } 302 303 if (fork() == 0) { 304 read_trace_pipe(); 305 return 0; 306 } 307 test_bpf_perf_event(); 308 int_exit(0); 309 return 0; 310 } 311