1 #include <linux/types.h> 2 #include <stdlib.h> 3 #include <unistd.h> 4 #include <stdio.h> 5 #include <ctype.h> 6 #include <string.h> 7 8 #include "parse-events.h" 9 #include "evlist.h" 10 #include "evsel.h" 11 #include "thread_map.h" 12 #include "cpumap.h" 13 #include "machine.h" 14 #include "event.h" 15 #include "thread.h" 16 17 #include "tests.h" 18 19 #define BUFSZ 1024 20 #define READLEN 128 21 22 struct state { 23 u64 done[1024]; 24 size_t done_cnt; 25 }; 26 27 static unsigned int hex(char c) 28 { 29 if (c >= '0' && c <= '9') 30 return c - '0'; 31 if (c >= 'a' && c <= 'f') 32 return c - 'a' + 10; 33 return c - 'A' + 10; 34 } 35 36 static size_t read_objdump_line(const char *line, size_t line_len, void *buf, 37 size_t len) 38 { 39 const char *p; 40 size_t i, j = 0; 41 42 /* Skip to a colon */ 43 p = strchr(line, ':'); 44 if (!p) 45 return 0; 46 i = p + 1 - line; 47 48 /* Read bytes */ 49 while (j < len) { 50 char c1, c2; 51 52 /* Skip spaces */ 53 for (; i < line_len; i++) { 54 if (!isspace(line[i])) 55 break; 56 } 57 /* Get 2 hex digits */ 58 if (i >= line_len || !isxdigit(line[i])) 59 break; 60 c1 = line[i++]; 61 if (i >= line_len || !isxdigit(line[i])) 62 break; 63 c2 = line[i++]; 64 /* Followed by a space */ 65 if (i < line_len && line[i] && !isspace(line[i])) 66 break; 67 /* Store byte */ 68 *(unsigned char *)buf = (hex(c1) << 4) | hex(c2); 69 buf += 1; 70 j++; 71 } 72 /* return number of successfully read bytes */ 73 return j; 74 } 75 76 static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr) 77 { 78 char *line = NULL; 79 size_t line_len, off_last = 0; 80 ssize_t ret; 81 int err = 0; 82 u64 addr, last_addr = start_addr; 83 84 while (off_last < *len) { 85 size_t off, read_bytes, written_bytes; 86 unsigned char tmp[BUFSZ]; 87 88 ret = getline(&line, &line_len, f); 89 if (feof(f)) 90 break; 91 if (ret < 0) { 92 pr_debug("getline failed\n"); 93 err = -1; 94 break; 95 } 96 97 /* read objdump data into temporary buffer */ 98 read_bytes = read_objdump_line(line, ret, tmp, sizeof(tmp)); 99 if (!read_bytes) 100 continue; 101 102 if (sscanf(line, "%"PRIx64, &addr) != 1) 103 continue; 104 if (addr < last_addr) { 105 pr_debug("addr going backwards, read beyond section?\n"); 106 break; 107 } 108 last_addr = addr; 109 110 /* copy it from temporary buffer to 'buf' according 111 * to address on current objdump line */ 112 off = addr - start_addr; 113 if (off >= *len) 114 break; 115 written_bytes = MIN(read_bytes, *len - off); 116 memcpy(buf + off, tmp, written_bytes); 117 off_last = off + written_bytes; 118 } 119 120 /* len returns number of bytes that could not be read */ 121 *len -= off_last; 122 123 free(line); 124 125 return err; 126 } 127 128 static int read_via_objdump(const char *filename, u64 addr, void *buf, 129 size_t len) 130 { 131 char cmd[PATH_MAX * 2]; 132 const char *fmt; 133 FILE *f; 134 int ret; 135 136 fmt = "%s -z -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s"; 137 ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len, 138 filename); 139 if (ret <= 0 || (size_t)ret >= sizeof(cmd)) 140 return -1; 141 142 pr_debug("Objdump command is: %s\n", cmd); 143 144 /* Ignore objdump errors */ 145 strcat(cmd, " 2>/dev/null"); 146 147 f = popen(cmd, "r"); 148 if (!f) { 149 pr_debug("popen failed\n"); 150 return -1; 151 } 152 153 ret = read_objdump_output(f, buf, &len, addr); 154 if (len) { 155 pr_debug("objdump read too few bytes\n"); 156 if (!ret) 157 ret = len; 158 } 159 160 pclose(f); 161 162 return ret; 163 } 164 165 static void dump_buf(unsigned char *buf, size_t len) 166 { 167 size_t i; 168 169 for (i = 0; i < len; i++) { 170 pr_debug("0x%02x ", buf[i]); 171 if (i % 16 == 15) 172 pr_debug("\n"); 173 } 174 pr_debug("\n"); 175 } 176 177 static int read_object_code(u64 addr, size_t len, u8 cpumode, 178 struct thread *thread, struct state *state) 179 { 180 struct addr_location al; 181 unsigned char buf1[BUFSZ]; 182 unsigned char buf2[BUFSZ]; 183 size_t ret_len; 184 u64 objdump_addr; 185 int ret; 186 187 pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr); 188 189 thread__find_addr_map(thread, cpumode, MAP__FUNCTION, addr, &al); 190 if (!al.map || !al.map->dso) { 191 pr_debug("thread__find_addr_map failed\n"); 192 return -1; 193 } 194 195 pr_debug("File is: %s\n", al.map->dso->long_name); 196 197 if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS && 198 !dso__is_kcore(al.map->dso)) { 199 pr_debug("Unexpected kernel address - skipping\n"); 200 return 0; 201 } 202 203 pr_debug("On file address is: %#"PRIx64"\n", al.addr); 204 205 if (len > BUFSZ) 206 len = BUFSZ; 207 208 /* Do not go off the map */ 209 if (addr + len > al.map->end) 210 len = al.map->end - addr; 211 212 /* Read the object code using perf */ 213 ret_len = dso__data_read_offset(al.map->dso, thread->mg->machine, 214 al.addr, buf1, len); 215 if (ret_len != len) { 216 pr_debug("dso__data_read_offset failed\n"); 217 return -1; 218 } 219 220 /* 221 * Converting addresses for use by objdump requires more information. 222 * map__load() does that. See map__rip_2objdump() for details. 223 */ 224 if (map__load(al.map, NULL)) 225 return -1; 226 227 /* objdump struggles with kcore - try each map only once */ 228 if (dso__is_kcore(al.map->dso)) { 229 size_t d; 230 231 for (d = 0; d < state->done_cnt; d++) { 232 if (state->done[d] == al.map->start) { 233 pr_debug("kcore map tested already"); 234 pr_debug(" - skipping\n"); 235 return 0; 236 } 237 } 238 if (state->done_cnt >= ARRAY_SIZE(state->done)) { 239 pr_debug("Too many kcore maps - skipping\n"); 240 return 0; 241 } 242 state->done[state->done_cnt++] = al.map->start; 243 } 244 245 /* Read the object code using objdump */ 246 objdump_addr = map__rip_2objdump(al.map, al.addr); 247 ret = read_via_objdump(al.map->dso->long_name, objdump_addr, buf2, len); 248 if (ret > 0) { 249 /* 250 * The kernel maps are inaccurate - assume objdump is right in 251 * that case. 252 */ 253 if (cpumode == PERF_RECORD_MISC_KERNEL || 254 cpumode == PERF_RECORD_MISC_GUEST_KERNEL) { 255 len -= ret; 256 if (len) { 257 pr_debug("Reducing len to %zu\n", len); 258 } else if (dso__is_kcore(al.map->dso)) { 259 /* 260 * objdump cannot handle very large segments 261 * that may be found in kcore. 262 */ 263 pr_debug("objdump failed for kcore"); 264 pr_debug(" - skipping\n"); 265 return 0; 266 } else { 267 return -1; 268 } 269 } 270 } 271 if (ret < 0) { 272 pr_debug("read_via_objdump failed\n"); 273 return -1; 274 } 275 276 /* The results should be identical */ 277 if (memcmp(buf1, buf2, len)) { 278 pr_debug("Bytes read differ from those read by objdump\n"); 279 pr_debug("buf1 (dso):\n"); 280 dump_buf(buf1, len); 281 pr_debug("buf2 (objdump):\n"); 282 dump_buf(buf2, len); 283 return -1; 284 } 285 pr_debug("Bytes read match those read by objdump\n"); 286 287 return 0; 288 } 289 290 static int process_sample_event(struct machine *machine, 291 struct perf_evlist *evlist, 292 union perf_event *event, struct state *state) 293 { 294 struct perf_sample sample; 295 struct thread *thread; 296 int ret; 297 298 if (perf_evlist__parse_sample(evlist, event, &sample)) { 299 pr_debug("perf_evlist__parse_sample failed\n"); 300 return -1; 301 } 302 303 thread = machine__findnew_thread(machine, sample.pid, sample.tid); 304 if (!thread) { 305 pr_debug("machine__findnew_thread failed\n"); 306 return -1; 307 } 308 309 ret = read_object_code(sample.ip, READLEN, sample.cpumode, thread, state); 310 thread__put(thread); 311 return ret; 312 } 313 314 static int process_event(struct machine *machine, struct perf_evlist *evlist, 315 union perf_event *event, struct state *state) 316 { 317 if (event->header.type == PERF_RECORD_SAMPLE) 318 return process_sample_event(machine, evlist, event, state); 319 320 if (event->header.type == PERF_RECORD_THROTTLE || 321 event->header.type == PERF_RECORD_UNTHROTTLE) 322 return 0; 323 324 if (event->header.type < PERF_RECORD_MAX) { 325 int ret; 326 327 ret = machine__process_event(machine, event, NULL); 328 if (ret < 0) 329 pr_debug("machine__process_event failed, event type %u\n", 330 event->header.type); 331 return ret; 332 } 333 334 return 0; 335 } 336 337 static int process_events(struct machine *machine, struct perf_evlist *evlist, 338 struct state *state) 339 { 340 union perf_event *event; 341 int i, ret; 342 343 for (i = 0; i < evlist->nr_mmaps; i++) { 344 while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) { 345 ret = process_event(machine, evlist, event, state); 346 perf_evlist__mmap_consume(evlist, i); 347 if (ret < 0) 348 return ret; 349 } 350 } 351 return 0; 352 } 353 354 static int comp(const void *a, const void *b) 355 { 356 return *(int *)a - *(int *)b; 357 } 358 359 static void do_sort_something(void) 360 { 361 int buf[40960], i; 362 363 for (i = 0; i < (int)ARRAY_SIZE(buf); i++) 364 buf[i] = ARRAY_SIZE(buf) - i - 1; 365 366 qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp); 367 368 for (i = 0; i < (int)ARRAY_SIZE(buf); i++) { 369 if (buf[i] != i) { 370 pr_debug("qsort failed\n"); 371 break; 372 } 373 } 374 } 375 376 static void sort_something(void) 377 { 378 int i; 379 380 for (i = 0; i < 10; i++) 381 do_sort_something(); 382 } 383 384 static void syscall_something(void) 385 { 386 int pipefd[2]; 387 int i; 388 389 for (i = 0; i < 1000; i++) { 390 if (pipe(pipefd) < 0) { 391 pr_debug("pipe failed\n"); 392 break; 393 } 394 close(pipefd[1]); 395 close(pipefd[0]); 396 } 397 } 398 399 static void fs_something(void) 400 { 401 const char *test_file_name = "temp-perf-code-reading-test-file--"; 402 FILE *f; 403 int i; 404 405 for (i = 0; i < 1000; i++) { 406 f = fopen(test_file_name, "w+"); 407 if (f) { 408 fclose(f); 409 unlink(test_file_name); 410 } 411 } 412 } 413 414 static void do_something(void) 415 { 416 fs_something(); 417 418 sort_something(); 419 420 syscall_something(); 421 } 422 423 enum { 424 TEST_CODE_READING_OK, 425 TEST_CODE_READING_NO_VMLINUX, 426 TEST_CODE_READING_NO_KCORE, 427 TEST_CODE_READING_NO_ACCESS, 428 TEST_CODE_READING_NO_KERNEL_OBJ, 429 }; 430 431 static int do_test_code_reading(bool try_kcore) 432 { 433 struct machine *machine; 434 struct thread *thread; 435 struct record_opts opts = { 436 .mmap_pages = UINT_MAX, 437 .user_freq = UINT_MAX, 438 .user_interval = ULLONG_MAX, 439 .freq = 500, 440 .target = { 441 .uses_mmap = true, 442 }, 443 }; 444 struct state state = { 445 .done_cnt = 0, 446 }; 447 struct thread_map *threads = NULL; 448 struct cpu_map *cpus = NULL; 449 struct perf_evlist *evlist = NULL; 450 struct perf_evsel *evsel = NULL; 451 int err = -1, ret; 452 pid_t pid; 453 struct map *map; 454 bool have_vmlinux, have_kcore, excl_kernel = false; 455 456 pid = getpid(); 457 458 machine = machine__new_host(); 459 460 ret = machine__create_kernel_maps(machine); 461 if (ret < 0) { 462 pr_debug("machine__create_kernel_maps failed\n"); 463 goto out_err; 464 } 465 466 /* Force the use of kallsyms instead of vmlinux to try kcore */ 467 if (try_kcore) 468 symbol_conf.kallsyms_name = "/proc/kallsyms"; 469 470 /* Load kernel map */ 471 map = machine__kernel_map(machine); 472 ret = map__load(map, NULL); 473 if (ret < 0) { 474 pr_debug("map__load failed\n"); 475 goto out_err; 476 } 477 have_vmlinux = dso__is_vmlinux(map->dso); 478 have_kcore = dso__is_kcore(map->dso); 479 480 /* 2nd time through we just try kcore */ 481 if (try_kcore && !have_kcore) 482 return TEST_CODE_READING_NO_KCORE; 483 484 /* No point getting kernel events if there is no kernel object */ 485 if (!have_vmlinux && !have_kcore) 486 excl_kernel = true; 487 488 threads = thread_map__new_by_tid(pid); 489 if (!threads) { 490 pr_debug("thread_map__new_by_tid failed\n"); 491 goto out_err; 492 } 493 494 ret = perf_event__synthesize_thread_map(NULL, threads, 495 perf_event__process, machine, false, 500); 496 if (ret < 0) { 497 pr_debug("perf_event__synthesize_thread_map failed\n"); 498 goto out_err; 499 } 500 501 thread = machine__findnew_thread(machine, pid, pid); 502 if (!thread) { 503 pr_debug("machine__findnew_thread failed\n"); 504 goto out_put; 505 } 506 507 cpus = cpu_map__new(NULL); 508 if (!cpus) { 509 pr_debug("cpu_map__new failed\n"); 510 goto out_put; 511 } 512 513 while (1) { 514 const char *str; 515 516 evlist = perf_evlist__new(); 517 if (!evlist) { 518 pr_debug("perf_evlist__new failed\n"); 519 goto out_put; 520 } 521 522 perf_evlist__set_maps(evlist, cpus, threads); 523 524 if (excl_kernel) 525 str = "cycles:u"; 526 else 527 str = "cycles"; 528 pr_debug("Parsing event '%s'\n", str); 529 ret = parse_events(evlist, str, NULL); 530 if (ret < 0) { 531 pr_debug("parse_events failed\n"); 532 goto out_put; 533 } 534 535 perf_evlist__config(evlist, &opts, NULL); 536 537 evsel = perf_evlist__first(evlist); 538 539 evsel->attr.comm = 1; 540 evsel->attr.disabled = 1; 541 evsel->attr.enable_on_exec = 0; 542 543 ret = perf_evlist__open(evlist); 544 if (ret < 0) { 545 if (!excl_kernel) { 546 excl_kernel = true; 547 /* 548 * Both cpus and threads are now owned by evlist 549 * and will be freed by following perf_evlist__set_maps 550 * call. Getting refference to keep them alive. 551 */ 552 cpu_map__get(cpus); 553 thread_map__get(threads); 554 perf_evlist__set_maps(evlist, NULL, NULL); 555 perf_evlist__delete(evlist); 556 evlist = NULL; 557 continue; 558 } 559 560 if (verbose) { 561 char errbuf[512]; 562 perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf)); 563 pr_debug("perf_evlist__open() failed!\n%s\n", errbuf); 564 } 565 566 goto out_put; 567 } 568 break; 569 } 570 571 ret = perf_evlist__mmap(evlist, UINT_MAX, false); 572 if (ret < 0) { 573 pr_debug("perf_evlist__mmap failed\n"); 574 goto out_put; 575 } 576 577 perf_evlist__enable(evlist); 578 579 do_something(); 580 581 perf_evlist__disable(evlist); 582 583 ret = process_events(machine, evlist, &state); 584 if (ret < 0) 585 goto out_put; 586 587 if (!have_vmlinux && !have_kcore && !try_kcore) 588 err = TEST_CODE_READING_NO_KERNEL_OBJ; 589 else if (!have_vmlinux && !try_kcore) 590 err = TEST_CODE_READING_NO_VMLINUX; 591 else if (excl_kernel) 592 err = TEST_CODE_READING_NO_ACCESS; 593 else 594 err = TEST_CODE_READING_OK; 595 out_put: 596 thread__put(thread); 597 out_err: 598 599 if (evlist) { 600 perf_evlist__delete(evlist); 601 } else { 602 cpu_map__put(cpus); 603 thread_map__put(threads); 604 } 605 machine__delete_threads(machine); 606 machine__delete(machine); 607 608 return err; 609 } 610 611 int test__code_reading(int subtest __maybe_unused) 612 { 613 int ret; 614 615 ret = do_test_code_reading(false); 616 if (!ret) 617 ret = do_test_code_reading(true); 618 619 switch (ret) { 620 case TEST_CODE_READING_OK: 621 return 0; 622 case TEST_CODE_READING_NO_VMLINUX: 623 pr_debug("no vmlinux\n"); 624 return 0; 625 case TEST_CODE_READING_NO_KCORE: 626 pr_debug("no kcore\n"); 627 return 0; 628 case TEST_CODE_READING_NO_ACCESS: 629 pr_debug("no access\n"); 630 return 0; 631 case TEST_CODE_READING_NO_KERNEL_OBJ: 632 pr_debug("no kernel obj\n"); 633 return 0; 634 default: 635 return -1; 636 }; 637 } 638