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 u8 cpumode; 297 int ret; 298 299 if (perf_evlist__parse_sample(evlist, event, &sample)) { 300 pr_debug("perf_evlist__parse_sample failed\n"); 301 return -1; 302 } 303 304 thread = machine__findnew_thread(machine, sample.pid, sample.tid); 305 if (!thread) { 306 pr_debug("machine__findnew_thread failed\n"); 307 return -1; 308 } 309 310 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK; 311 312 ret = read_object_code(sample.ip, READLEN, cpumode, thread, state); 313 thread__put(thread); 314 return ret; 315 } 316 317 static int process_event(struct machine *machine, struct perf_evlist *evlist, 318 union perf_event *event, struct state *state) 319 { 320 if (event->header.type == PERF_RECORD_SAMPLE) 321 return process_sample_event(machine, evlist, event, state); 322 323 if (event->header.type == PERF_RECORD_THROTTLE || 324 event->header.type == PERF_RECORD_UNTHROTTLE) 325 return 0; 326 327 if (event->header.type < PERF_RECORD_MAX) { 328 int ret; 329 330 ret = machine__process_event(machine, event, NULL); 331 if (ret < 0) 332 pr_debug("machine__process_event failed, event type %u\n", 333 event->header.type); 334 return ret; 335 } 336 337 return 0; 338 } 339 340 static int process_events(struct machine *machine, struct perf_evlist *evlist, 341 struct state *state) 342 { 343 union perf_event *event; 344 int i, ret; 345 346 for (i = 0; i < evlist->nr_mmaps; i++) { 347 while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) { 348 ret = process_event(machine, evlist, event, state); 349 perf_evlist__mmap_consume(evlist, i); 350 if (ret < 0) 351 return ret; 352 } 353 } 354 return 0; 355 } 356 357 static int comp(const void *a, const void *b) 358 { 359 return *(int *)a - *(int *)b; 360 } 361 362 static void do_sort_something(void) 363 { 364 int buf[40960], i; 365 366 for (i = 0; i < (int)ARRAY_SIZE(buf); i++) 367 buf[i] = ARRAY_SIZE(buf) - i - 1; 368 369 qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp); 370 371 for (i = 0; i < (int)ARRAY_SIZE(buf); i++) { 372 if (buf[i] != i) { 373 pr_debug("qsort failed\n"); 374 break; 375 } 376 } 377 } 378 379 static void sort_something(void) 380 { 381 int i; 382 383 for (i = 0; i < 10; i++) 384 do_sort_something(); 385 } 386 387 static void syscall_something(void) 388 { 389 int pipefd[2]; 390 int i; 391 392 for (i = 0; i < 1000; i++) { 393 if (pipe(pipefd) < 0) { 394 pr_debug("pipe failed\n"); 395 break; 396 } 397 close(pipefd[1]); 398 close(pipefd[0]); 399 } 400 } 401 402 static void fs_something(void) 403 { 404 const char *test_file_name = "temp-perf-code-reading-test-file--"; 405 FILE *f; 406 int i; 407 408 for (i = 0; i < 1000; i++) { 409 f = fopen(test_file_name, "w+"); 410 if (f) { 411 fclose(f); 412 unlink(test_file_name); 413 } 414 } 415 } 416 417 static void do_something(void) 418 { 419 fs_something(); 420 421 sort_something(); 422 423 syscall_something(); 424 } 425 426 enum { 427 TEST_CODE_READING_OK, 428 TEST_CODE_READING_NO_VMLINUX, 429 TEST_CODE_READING_NO_KCORE, 430 TEST_CODE_READING_NO_ACCESS, 431 TEST_CODE_READING_NO_KERNEL_OBJ, 432 }; 433 434 static int do_test_code_reading(bool try_kcore) 435 { 436 struct machines machines; 437 struct machine *machine; 438 struct thread *thread; 439 struct record_opts opts = { 440 .mmap_pages = UINT_MAX, 441 .user_freq = UINT_MAX, 442 .user_interval = ULLONG_MAX, 443 .freq = 4000, 444 .target = { 445 .uses_mmap = true, 446 }, 447 }; 448 struct state state = { 449 .done_cnt = 0, 450 }; 451 struct thread_map *threads = NULL; 452 struct cpu_map *cpus = NULL; 453 struct perf_evlist *evlist = NULL; 454 struct perf_evsel *evsel = NULL; 455 int err = -1, ret; 456 pid_t pid; 457 struct map *map; 458 bool have_vmlinux, have_kcore, excl_kernel = false; 459 460 pid = getpid(); 461 462 machines__init(&machines); 463 machine = &machines.host; 464 465 ret = machine__create_kernel_maps(machine); 466 if (ret < 0) { 467 pr_debug("machine__create_kernel_maps failed\n"); 468 goto out_err; 469 } 470 471 /* Force the use of kallsyms instead of vmlinux to try kcore */ 472 if (try_kcore) 473 symbol_conf.kallsyms_name = "/proc/kallsyms"; 474 475 /* Load kernel map */ 476 map = machine__kernel_map(machine); 477 ret = map__load(map, NULL); 478 if (ret < 0) { 479 pr_debug("map__load failed\n"); 480 goto out_err; 481 } 482 have_vmlinux = dso__is_vmlinux(map->dso); 483 have_kcore = dso__is_kcore(map->dso); 484 485 /* 2nd time through we just try kcore */ 486 if (try_kcore && !have_kcore) 487 return TEST_CODE_READING_NO_KCORE; 488 489 /* No point getting kernel events if there is no kernel object */ 490 if (!have_vmlinux && !have_kcore) 491 excl_kernel = true; 492 493 threads = thread_map__new_by_tid(pid); 494 if (!threads) { 495 pr_debug("thread_map__new_by_tid failed\n"); 496 goto out_err; 497 } 498 499 ret = perf_event__synthesize_thread_map(NULL, threads, 500 perf_event__process, machine, false, 500); 501 if (ret < 0) { 502 pr_debug("perf_event__synthesize_thread_map failed\n"); 503 goto out_err; 504 } 505 506 thread = machine__findnew_thread(machine, pid, pid); 507 if (!thread) { 508 pr_debug("machine__findnew_thread failed\n"); 509 goto out_put; 510 } 511 512 cpus = cpu_map__new(NULL); 513 if (!cpus) { 514 pr_debug("cpu_map__new failed\n"); 515 goto out_put; 516 } 517 518 while (1) { 519 const char *str; 520 521 evlist = perf_evlist__new(); 522 if (!evlist) { 523 pr_debug("perf_evlist__new failed\n"); 524 goto out_put; 525 } 526 527 perf_evlist__set_maps(evlist, cpus, threads); 528 529 if (excl_kernel) 530 str = "cycles:u"; 531 else 532 str = "cycles"; 533 pr_debug("Parsing event '%s'\n", str); 534 ret = parse_events(evlist, str, NULL); 535 if (ret < 0) { 536 pr_debug("parse_events failed\n"); 537 goto out_put; 538 } 539 540 perf_evlist__config(evlist, &opts); 541 542 evsel = perf_evlist__first(evlist); 543 544 evsel->attr.comm = 1; 545 evsel->attr.disabled = 1; 546 evsel->attr.enable_on_exec = 0; 547 548 ret = perf_evlist__open(evlist); 549 if (ret < 0) { 550 if (!excl_kernel) { 551 excl_kernel = true; 552 perf_evlist__set_maps(evlist, NULL, NULL); 553 perf_evlist__delete(evlist); 554 evlist = NULL; 555 continue; 556 } 557 pr_debug("perf_evlist__open failed\n"); 558 goto out_put; 559 } 560 break; 561 } 562 563 ret = perf_evlist__mmap(evlist, UINT_MAX, false); 564 if (ret < 0) { 565 pr_debug("perf_evlist__mmap failed\n"); 566 goto out_put; 567 } 568 569 perf_evlist__enable(evlist); 570 571 do_something(); 572 573 perf_evlist__disable(evlist); 574 575 ret = process_events(machine, evlist, &state); 576 if (ret < 0) 577 goto out_put; 578 579 if (!have_vmlinux && !have_kcore && !try_kcore) 580 err = TEST_CODE_READING_NO_KERNEL_OBJ; 581 else if (!have_vmlinux && !try_kcore) 582 err = TEST_CODE_READING_NO_VMLINUX; 583 else if (excl_kernel) 584 err = TEST_CODE_READING_NO_ACCESS; 585 else 586 err = TEST_CODE_READING_OK; 587 out_put: 588 thread__put(thread); 589 out_err: 590 591 if (evlist) { 592 perf_evlist__delete(evlist); 593 } else { 594 cpu_map__put(cpus); 595 thread_map__put(threads); 596 } 597 machines__destroy_kernel_maps(&machines); 598 machine__delete_threads(machine); 599 machines__exit(&machines); 600 601 return err; 602 } 603 604 int test__code_reading(void) 605 { 606 int ret; 607 608 ret = do_test_code_reading(false); 609 if (!ret) 610 ret = do_test_code_reading(true); 611 612 switch (ret) { 613 case TEST_CODE_READING_OK: 614 return 0; 615 case TEST_CODE_READING_NO_VMLINUX: 616 pr_debug("no vmlinux\n"); 617 return 0; 618 case TEST_CODE_READING_NO_KCORE: 619 pr_debug("no kcore\n"); 620 return 0; 621 case TEST_CODE_READING_NO_ACCESS: 622 pr_debug("no access\n"); 623 return 0; 624 case TEST_CODE_READING_NO_KERNEL_OBJ: 625 pr_debug("no kernel obj\n"); 626 return 0; 627 default: 628 return -1; 629 }; 630 } 631