1 // SPDX-License-Identifier: GPL-2.0 2 #include <errno.h> 3 #include <stdlib.h> 4 #include <bpf/bpf.h> 5 #include <bpf/btf.h> 6 #include <bpf/libbpf.h> 7 #include <linux/btf.h> 8 #include <linux/err.h> 9 #include "bpf-event.h" 10 #include "debug.h" 11 #include "dso.h" 12 #include "symbol.h" 13 #include "machine.h" 14 #include "env.h" 15 #include "session.h" 16 #include "map.h" 17 #include "evlist.h" 18 #include "record.h" 19 #include "util/synthetic-events.h" 20 21 #define ptr_to_u64(ptr) ((__u64)(unsigned long)(ptr)) 22 23 static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len) 24 { 25 int ret = 0; 26 size_t i; 27 28 for (i = 0; i < len; i++) 29 ret += snprintf(buf + ret, size - ret, "%02x", data[i]); 30 return ret; 31 } 32 33 static int machine__process_bpf_event_load(struct machine *machine, 34 union perf_event *event, 35 struct perf_sample *sample __maybe_unused) 36 { 37 struct bpf_prog_info_linear *info_linear; 38 struct bpf_prog_info_node *info_node; 39 struct perf_env *env = machine->env; 40 int id = event->bpf.id; 41 unsigned int i; 42 43 /* perf-record, no need to handle bpf-event */ 44 if (env == NULL) 45 return 0; 46 47 info_node = perf_env__find_bpf_prog_info(env, id); 48 if (!info_node) 49 return 0; 50 info_linear = info_node->info_linear; 51 52 for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) { 53 u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms); 54 u64 addr = addrs[i]; 55 struct map *map; 56 57 map = map_groups__find(&machine->kmaps, addr); 58 59 if (map) { 60 map->dso->binary_type = DSO_BINARY_TYPE__BPF_PROG_INFO; 61 map->dso->bpf_prog.id = id; 62 map->dso->bpf_prog.sub_id = i; 63 map->dso->bpf_prog.env = env; 64 } 65 } 66 return 0; 67 } 68 69 int machine__process_bpf(struct machine *machine, union perf_event *event, 70 struct perf_sample *sample) 71 { 72 if (dump_trace) 73 perf_event__fprintf_bpf(event, stdout); 74 75 switch (event->bpf.type) { 76 case PERF_BPF_EVENT_PROG_LOAD: 77 return machine__process_bpf_event_load(machine, event, sample); 78 79 case PERF_BPF_EVENT_PROG_UNLOAD: 80 /* 81 * Do not free bpf_prog_info and btf of the program here, 82 * as annotation still need them. They will be freed at 83 * the end of the session. 84 */ 85 break; 86 default: 87 pr_debug("unexpected bpf event type of %d\n", event->bpf.type); 88 break; 89 } 90 return 0; 91 } 92 93 static int perf_env__fetch_btf(struct perf_env *env, 94 u32 btf_id, 95 struct btf *btf) 96 { 97 struct btf_node *node; 98 u32 data_size; 99 const void *data; 100 101 data = btf__get_raw_data(btf, &data_size); 102 103 node = malloc(data_size + sizeof(struct btf_node)); 104 if (!node) 105 return -1; 106 107 node->id = btf_id; 108 node->data_size = data_size; 109 memcpy(node->data, data, data_size); 110 111 perf_env__insert_btf(env, node); 112 return 0; 113 } 114 115 static int synthesize_bpf_prog_name(char *buf, int size, 116 struct bpf_prog_info *info, 117 struct btf *btf, 118 u32 sub_id) 119 { 120 u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags); 121 void *func_infos = (void *)(uintptr_t)(info->func_info); 122 u32 sub_prog_cnt = info->nr_jited_ksyms; 123 const struct bpf_func_info *finfo; 124 const char *short_name = NULL; 125 const struct btf_type *t; 126 int name_len; 127 128 name_len = snprintf(buf, size, "bpf_prog_"); 129 name_len += snprintf_hex(buf + name_len, size - name_len, 130 prog_tags[sub_id], BPF_TAG_SIZE); 131 if (btf) { 132 finfo = func_infos + sub_id * info->func_info_rec_size; 133 t = btf__type_by_id(btf, finfo->type_id); 134 short_name = btf__name_by_offset(btf, t->name_off); 135 } else if (sub_id == 0 && sub_prog_cnt == 1) { 136 /* no subprog */ 137 if (info->name[0]) 138 short_name = info->name; 139 } else 140 short_name = "F"; 141 if (short_name) 142 name_len += snprintf(buf + name_len, size - name_len, 143 "_%s", short_name); 144 return name_len; 145 } 146 147 /* 148 * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf 149 * program. One PERF_RECORD_BPF_EVENT is generated for the program. And 150 * one PERF_RECORD_KSYMBOL is generated for each sub program. 151 * 152 * Returns: 153 * 0 for success; 154 * -1 for failures; 155 * -2 for lack of kernel support. 156 */ 157 static int perf_event__synthesize_one_bpf_prog(struct perf_session *session, 158 perf_event__handler_t process, 159 struct machine *machine, 160 int fd, 161 union perf_event *event, 162 struct record_opts *opts) 163 { 164 struct perf_record_ksymbol *ksymbol_event = &event->ksymbol; 165 struct perf_record_bpf_event *bpf_event = &event->bpf; 166 struct bpf_prog_info_linear *info_linear; 167 struct perf_tool *tool = session->tool; 168 struct bpf_prog_info_node *info_node; 169 struct bpf_prog_info *info; 170 struct btf *btf = NULL; 171 struct perf_env *env; 172 u32 sub_prog_cnt, i; 173 int err = 0; 174 u64 arrays; 175 176 /* 177 * for perf-record and perf-report use header.env; 178 * otherwise, use global perf_env. 179 */ 180 env = session->data ? &session->header.env : &perf_env; 181 182 arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS; 183 arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS; 184 arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO; 185 arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS; 186 arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS; 187 arrays |= 1UL << BPF_PROG_INFO_LINE_INFO; 188 arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO; 189 190 info_linear = bpf_program__get_prog_info_linear(fd, arrays); 191 if (IS_ERR_OR_NULL(info_linear)) { 192 info_linear = NULL; 193 pr_debug("%s: failed to get BPF program info. aborting\n", __func__); 194 return -1; 195 } 196 197 if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) { 198 pr_debug("%s: the kernel is too old, aborting\n", __func__); 199 return -2; 200 } 201 202 info = &info_linear->info; 203 204 /* number of ksyms, func_lengths, and tags should match */ 205 sub_prog_cnt = info->nr_jited_ksyms; 206 if (sub_prog_cnt != info->nr_prog_tags || 207 sub_prog_cnt != info->nr_jited_func_lens) 208 return -1; 209 210 /* check BTF func info support */ 211 if (info->btf_id && info->nr_func_info && info->func_info_rec_size) { 212 /* btf func info number should be same as sub_prog_cnt */ 213 if (sub_prog_cnt != info->nr_func_info) { 214 pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__); 215 err = -1; 216 goto out; 217 } 218 if (btf__get_from_id(info->btf_id, &btf)) { 219 pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id); 220 err = -1; 221 btf = NULL; 222 goto out; 223 } 224 perf_env__fetch_btf(env, info->btf_id, btf); 225 } 226 227 /* Synthesize PERF_RECORD_KSYMBOL */ 228 for (i = 0; i < sub_prog_cnt; i++) { 229 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); 230 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); 231 int name_len; 232 233 *ksymbol_event = (struct perf_record_ksymbol) { 234 .header = { 235 .type = PERF_RECORD_KSYMBOL, 236 .size = offsetof(struct perf_record_ksymbol, name), 237 }, 238 .addr = prog_addrs[i], 239 .len = prog_lens[i], 240 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, 241 .flags = 0, 242 }; 243 244 name_len = synthesize_bpf_prog_name(ksymbol_event->name, 245 KSYM_NAME_LEN, info, btf, i); 246 ksymbol_event->header.size += PERF_ALIGN(name_len + 1, 247 sizeof(u64)); 248 249 memset((void *)event + event->header.size, 0, machine->id_hdr_size); 250 event->header.size += machine->id_hdr_size; 251 err = perf_tool__process_synth_event(tool, event, 252 machine, process); 253 } 254 255 if (!opts->no_bpf_event) { 256 /* Synthesize PERF_RECORD_BPF_EVENT */ 257 *bpf_event = (struct perf_record_bpf_event) { 258 .header = { 259 .type = PERF_RECORD_BPF_EVENT, 260 .size = sizeof(struct perf_record_bpf_event), 261 }, 262 .type = PERF_BPF_EVENT_PROG_LOAD, 263 .flags = 0, 264 .id = info->id, 265 }; 266 memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE); 267 memset((void *)event + event->header.size, 0, machine->id_hdr_size); 268 event->header.size += machine->id_hdr_size; 269 270 /* save bpf_prog_info to env */ 271 info_node = malloc(sizeof(struct bpf_prog_info_node)); 272 if (!info_node) { 273 err = -1; 274 goto out; 275 } 276 277 info_node->info_linear = info_linear; 278 perf_env__insert_bpf_prog_info(env, info_node); 279 info_linear = NULL; 280 281 /* 282 * process after saving bpf_prog_info to env, so that 283 * required information is ready for look up 284 */ 285 err = perf_tool__process_synth_event(tool, event, 286 machine, process); 287 } 288 289 out: 290 free(info_linear); 291 free(btf); 292 return err ? -1 : 0; 293 } 294 295 int perf_event__synthesize_bpf_events(struct perf_session *session, 296 perf_event__handler_t process, 297 struct machine *machine, 298 struct record_opts *opts) 299 { 300 union perf_event *event; 301 __u32 id = 0; 302 int err; 303 int fd; 304 305 event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size); 306 if (!event) 307 return -1; 308 while (true) { 309 err = bpf_prog_get_next_id(id, &id); 310 if (err) { 311 if (errno == ENOENT) { 312 err = 0; 313 break; 314 } 315 pr_debug("%s: can't get next program: %s%s\n", 316 __func__, strerror(errno), 317 errno == EINVAL ? " -- kernel too old?" : ""); 318 /* don't report error on old kernel or EPERM */ 319 err = (errno == EINVAL || errno == EPERM) ? 0 : -1; 320 break; 321 } 322 fd = bpf_prog_get_fd_by_id(id); 323 if (fd < 0) { 324 pr_debug("%s: failed to get fd for prog_id %u\n", 325 __func__, id); 326 continue; 327 } 328 329 err = perf_event__synthesize_one_bpf_prog(session, process, 330 machine, fd, 331 event, opts); 332 close(fd); 333 if (err) { 334 /* do not return error for old kernel */ 335 if (err == -2) 336 err = 0; 337 break; 338 } 339 } 340 free(event); 341 return err; 342 } 343 344 static void perf_env__add_bpf_info(struct perf_env *env, u32 id) 345 { 346 struct bpf_prog_info_linear *info_linear; 347 struct bpf_prog_info_node *info_node; 348 struct btf *btf = NULL; 349 u64 arrays; 350 u32 btf_id; 351 int fd; 352 353 fd = bpf_prog_get_fd_by_id(id); 354 if (fd < 0) 355 return; 356 357 arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS; 358 arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS; 359 arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO; 360 arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS; 361 arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS; 362 arrays |= 1UL << BPF_PROG_INFO_LINE_INFO; 363 arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO; 364 365 info_linear = bpf_program__get_prog_info_linear(fd, arrays); 366 if (IS_ERR_OR_NULL(info_linear)) { 367 pr_debug("%s: failed to get BPF program info. aborting\n", __func__); 368 goto out; 369 } 370 371 btf_id = info_linear->info.btf_id; 372 373 info_node = malloc(sizeof(struct bpf_prog_info_node)); 374 if (info_node) { 375 info_node->info_linear = info_linear; 376 perf_env__insert_bpf_prog_info(env, info_node); 377 } else 378 free(info_linear); 379 380 if (btf_id == 0) 381 goto out; 382 383 if (btf__get_from_id(btf_id, &btf)) { 384 pr_debug("%s: failed to get BTF of id %u, aborting\n", 385 __func__, btf_id); 386 goto out; 387 } 388 perf_env__fetch_btf(env, btf_id, btf); 389 390 out: 391 free(btf); 392 close(fd); 393 } 394 395 static int bpf_event__sb_cb(union perf_event *event, void *data) 396 { 397 struct perf_env *env = data; 398 399 if (event->header.type != PERF_RECORD_BPF_EVENT) 400 return -1; 401 402 switch (event->bpf.type) { 403 case PERF_BPF_EVENT_PROG_LOAD: 404 perf_env__add_bpf_info(env, event->bpf.id); 405 406 case PERF_BPF_EVENT_PROG_UNLOAD: 407 /* 408 * Do not free bpf_prog_info and btf of the program here, 409 * as annotation still need them. They will be freed at 410 * the end of the session. 411 */ 412 break; 413 default: 414 pr_debug("unexpected bpf event type of %d\n", event->bpf.type); 415 break; 416 } 417 418 return 0; 419 } 420 421 int bpf_event__add_sb_event(struct evlist **evlist, 422 struct perf_env *env) 423 { 424 struct perf_event_attr attr = { 425 .type = PERF_TYPE_SOFTWARE, 426 .config = PERF_COUNT_SW_DUMMY, 427 .sample_id_all = 1, 428 .watermark = 1, 429 .bpf_event = 1, 430 .size = sizeof(attr), /* to capture ABI version */ 431 }; 432 433 /* 434 * Older gcc versions don't support designated initializers, like above, 435 * for unnamed union members, such as the following: 436 */ 437 attr.wakeup_watermark = 1; 438 439 return perf_evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env); 440 } 441 442 void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info, 443 struct perf_env *env, 444 FILE *fp) 445 { 446 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); 447 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); 448 char name[KSYM_NAME_LEN]; 449 struct btf *btf = NULL; 450 u32 sub_prog_cnt, i; 451 452 sub_prog_cnt = info->nr_jited_ksyms; 453 if (sub_prog_cnt != info->nr_prog_tags || 454 sub_prog_cnt != info->nr_jited_func_lens) 455 return; 456 457 if (info->btf_id) { 458 struct btf_node *node; 459 460 node = perf_env__find_btf(env, info->btf_id); 461 if (node) 462 btf = btf__new((__u8 *)(node->data), 463 node->data_size); 464 } 465 466 if (sub_prog_cnt == 1) { 467 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0); 468 fprintf(fp, "# bpf_prog_info %u: %s addr 0x%llx size %u\n", 469 info->id, name, prog_addrs[0], prog_lens[0]); 470 return; 471 } 472 473 fprintf(fp, "# bpf_prog_info %u:\n", info->id); 474 for (i = 0; i < sub_prog_cnt; i++) { 475 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i); 476 477 fprintf(fp, "# \tsub_prog %u: %s addr 0x%llx size %u\n", 478 i, name, prog_addrs[i], prog_lens[i]); 479 } 480 } 481