1 // SPDX-License-Identifier: GPL-2.0 2 #include <errno.h> 3 #include <linux/kernel.h> 4 #include <linux/types.h> 5 #include <inttypes.h> 6 #include <stdlib.h> 7 #include <unistd.h> 8 #include <stdio.h> 9 #include <string.h> 10 #include <sys/param.h> 11 #include <perf/cpumap.h> 12 #include <perf/evlist.h> 13 14 #include "debug.h" 15 #include "dso.h" 16 #include "env.h" 17 #include "parse-events.h" 18 #include "trace-event.h" 19 #include "evlist.h" 20 #include "evsel.h" 21 #include "thread_map.h" 22 #include "cpumap.h" 23 #include "machine.h" 24 #include "map.h" 25 #include "symbol.h" 26 #include "event.h" 27 #include "record.h" 28 #include "thread.h" 29 30 #include "tests.h" 31 32 #include <linux/ctype.h> 33 34 #define BUFSZ 1024 35 #define READLEN 128 36 37 struct state { 38 u64 done[1024]; 39 size_t done_cnt; 40 }; 41 42 static unsigned int hex(char c) 43 { 44 if (c >= '0' && c <= '9') 45 return c - '0'; 46 if (c >= 'a' && c <= 'f') 47 return c - 'a' + 10; 48 return c - 'A' + 10; 49 } 50 51 static size_t read_objdump_chunk(const char **line, unsigned char **buf, 52 size_t *buf_len) 53 { 54 size_t bytes_read = 0; 55 unsigned char *chunk_start = *buf; 56 57 /* Read bytes */ 58 while (*buf_len > 0) { 59 char c1, c2; 60 61 /* Get 2 hex digits */ 62 c1 = *(*line)++; 63 if (!isxdigit(c1)) 64 break; 65 c2 = *(*line)++; 66 if (!isxdigit(c2)) 67 break; 68 69 /* Store byte and advance buf */ 70 **buf = (hex(c1) << 4) | hex(c2); 71 (*buf)++; 72 (*buf_len)--; 73 bytes_read++; 74 75 /* End of chunk? */ 76 if (isspace(**line)) 77 break; 78 } 79 80 /* 81 * objdump will display raw insn as LE if code endian 82 * is LE and bytes_per_chunk > 1. In that case reverse 83 * the chunk we just read. 84 * 85 * see disassemble_bytes() at binutils/objdump.c for details 86 * how objdump chooses display endian) 87 */ 88 if (bytes_read > 1 && !bigendian()) { 89 unsigned char *chunk_end = chunk_start + bytes_read - 1; 90 unsigned char tmp; 91 92 while (chunk_start < chunk_end) { 93 tmp = *chunk_start; 94 *chunk_start = *chunk_end; 95 *chunk_end = tmp; 96 chunk_start++; 97 chunk_end--; 98 } 99 } 100 101 return bytes_read; 102 } 103 104 static size_t read_objdump_line(const char *line, unsigned char *buf, 105 size_t buf_len) 106 { 107 const char *p; 108 size_t ret, bytes_read = 0; 109 110 /* Skip to a colon */ 111 p = strchr(line, ':'); 112 if (!p) 113 return 0; 114 p++; 115 116 /* Skip initial spaces */ 117 while (*p) { 118 if (!isspace(*p)) 119 break; 120 p++; 121 } 122 123 do { 124 ret = read_objdump_chunk(&p, &buf, &buf_len); 125 bytes_read += ret; 126 p++; 127 } while (ret > 0); 128 129 /* return number of successfully read bytes */ 130 return bytes_read; 131 } 132 133 static int read_objdump_output(FILE *f, void *buf, size_t *len, u64 start_addr) 134 { 135 char *line = NULL; 136 size_t line_len, off_last = 0; 137 ssize_t ret; 138 int err = 0; 139 u64 addr, last_addr = start_addr; 140 141 while (off_last < *len) { 142 size_t off, read_bytes, written_bytes; 143 unsigned char tmp[BUFSZ]; 144 145 ret = getline(&line, &line_len, f); 146 if (feof(f)) 147 break; 148 if (ret < 0) { 149 pr_debug("getline failed\n"); 150 err = -1; 151 break; 152 } 153 154 /* read objdump data into temporary buffer */ 155 read_bytes = read_objdump_line(line, tmp, sizeof(tmp)); 156 if (!read_bytes) 157 continue; 158 159 if (sscanf(line, "%"PRIx64, &addr) != 1) 160 continue; 161 if (addr < last_addr) { 162 pr_debug("addr going backwards, read beyond section?\n"); 163 break; 164 } 165 last_addr = addr; 166 167 /* copy it from temporary buffer to 'buf' according 168 * to address on current objdump line */ 169 off = addr - start_addr; 170 if (off >= *len) 171 break; 172 written_bytes = MIN(read_bytes, *len - off); 173 memcpy(buf + off, tmp, written_bytes); 174 off_last = off + written_bytes; 175 } 176 177 /* len returns number of bytes that could not be read */ 178 *len -= off_last; 179 180 free(line); 181 182 return err; 183 } 184 185 static int read_via_objdump(const char *filename, u64 addr, void *buf, 186 size_t len) 187 { 188 char cmd[PATH_MAX * 2]; 189 const char *fmt; 190 FILE *f; 191 int ret; 192 193 fmt = "%s -z -d --start-address=0x%"PRIx64" --stop-address=0x%"PRIx64" %s"; 194 ret = snprintf(cmd, sizeof(cmd), fmt, "objdump", addr, addr + len, 195 filename); 196 if (ret <= 0 || (size_t)ret >= sizeof(cmd)) 197 return -1; 198 199 pr_debug("Objdump command is: %s\n", cmd); 200 201 /* Ignore objdump errors */ 202 strcat(cmd, " 2>/dev/null"); 203 204 f = popen(cmd, "r"); 205 if (!f) { 206 pr_debug("popen failed\n"); 207 return -1; 208 } 209 210 ret = read_objdump_output(f, buf, &len, addr); 211 if (len) { 212 pr_debug("objdump read too few bytes: %zd\n", len); 213 if (!ret) 214 ret = len; 215 } 216 217 pclose(f); 218 219 return ret; 220 } 221 222 static void dump_buf(unsigned char *buf, size_t len) 223 { 224 size_t i; 225 226 for (i = 0; i < len; i++) { 227 pr_debug("0x%02x ", buf[i]); 228 if (i % 16 == 15) 229 pr_debug("\n"); 230 } 231 pr_debug("\n"); 232 } 233 234 static int read_object_code(u64 addr, size_t len, u8 cpumode, 235 struct thread *thread, struct state *state) 236 { 237 struct addr_location al; 238 unsigned char buf1[BUFSZ]; 239 unsigned char buf2[BUFSZ]; 240 size_t ret_len; 241 u64 objdump_addr; 242 const char *objdump_name; 243 char decomp_name[KMOD_DECOMP_LEN]; 244 bool decomp = false; 245 int ret; 246 247 pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr); 248 249 if (!thread__find_map(thread, cpumode, addr, &al) || !al.map->dso) { 250 if (cpumode == PERF_RECORD_MISC_HYPERVISOR) { 251 pr_debug("Hypervisor address can not be resolved - skipping\n"); 252 return 0; 253 } 254 255 pr_debug("thread__find_map failed\n"); 256 return -1; 257 } 258 259 pr_debug("File is: %s\n", al.map->dso->long_name); 260 261 if (al.map->dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS && 262 !dso__is_kcore(al.map->dso)) { 263 pr_debug("Unexpected kernel address - skipping\n"); 264 return 0; 265 } 266 267 pr_debug("On file address is: %#"PRIx64"\n", al.addr); 268 269 if (len > BUFSZ) 270 len = BUFSZ; 271 272 /* Do not go off the map */ 273 if (addr + len > al.map->end) 274 len = al.map->end - addr; 275 276 /* Read the object code using perf */ 277 ret_len = dso__data_read_offset(al.map->dso, thread->mg->machine, 278 al.addr, buf1, len); 279 if (ret_len != len) { 280 pr_debug("dso__data_read_offset failed\n"); 281 return -1; 282 } 283 284 /* 285 * Converting addresses for use by objdump requires more information. 286 * map__load() does that. See map__rip_2objdump() for details. 287 */ 288 if (map__load(al.map)) 289 return -1; 290 291 /* objdump struggles with kcore - try each map only once */ 292 if (dso__is_kcore(al.map->dso)) { 293 size_t d; 294 295 for (d = 0; d < state->done_cnt; d++) { 296 if (state->done[d] == al.map->start) { 297 pr_debug("kcore map tested already"); 298 pr_debug(" - skipping\n"); 299 return 0; 300 } 301 } 302 if (state->done_cnt >= ARRAY_SIZE(state->done)) { 303 pr_debug("Too many kcore maps - skipping\n"); 304 return 0; 305 } 306 state->done[state->done_cnt++] = al.map->start; 307 } 308 309 objdump_name = al.map->dso->long_name; 310 if (dso__needs_decompress(al.map->dso)) { 311 if (dso__decompress_kmodule_path(al.map->dso, objdump_name, 312 decomp_name, 313 sizeof(decomp_name)) < 0) { 314 pr_debug("decompression failed\n"); 315 return -1; 316 } 317 318 decomp = true; 319 objdump_name = decomp_name; 320 } 321 322 /* Read the object code using objdump */ 323 objdump_addr = map__rip_2objdump(al.map, al.addr); 324 ret = read_via_objdump(objdump_name, objdump_addr, buf2, len); 325 326 if (decomp) 327 unlink(objdump_name); 328 329 if (ret > 0) { 330 /* 331 * The kernel maps are inaccurate - assume objdump is right in 332 * that case. 333 */ 334 if (cpumode == PERF_RECORD_MISC_KERNEL || 335 cpumode == PERF_RECORD_MISC_GUEST_KERNEL) { 336 len -= ret; 337 if (len) { 338 pr_debug("Reducing len to %zu\n", len); 339 } else if (dso__is_kcore(al.map->dso)) { 340 /* 341 * objdump cannot handle very large segments 342 * that may be found in kcore. 343 */ 344 pr_debug("objdump failed for kcore"); 345 pr_debug(" - skipping\n"); 346 return 0; 347 } else { 348 return -1; 349 } 350 } 351 } 352 if (ret < 0) { 353 pr_debug("read_via_objdump failed\n"); 354 return -1; 355 } 356 357 /* The results should be identical */ 358 if (memcmp(buf1, buf2, len)) { 359 pr_debug("Bytes read differ from those read by objdump\n"); 360 pr_debug("buf1 (dso):\n"); 361 dump_buf(buf1, len); 362 pr_debug("buf2 (objdump):\n"); 363 dump_buf(buf2, len); 364 return -1; 365 } 366 pr_debug("Bytes read match those read by objdump\n"); 367 368 return 0; 369 } 370 371 static int process_sample_event(struct machine *machine, 372 struct evlist *evlist, 373 union perf_event *event, struct state *state) 374 { 375 struct perf_sample sample; 376 struct thread *thread; 377 int ret; 378 379 if (perf_evlist__parse_sample(evlist, event, &sample)) { 380 pr_debug("perf_evlist__parse_sample failed\n"); 381 return -1; 382 } 383 384 thread = machine__findnew_thread(machine, sample.pid, sample.tid); 385 if (!thread) { 386 pr_debug("machine__findnew_thread failed\n"); 387 return -1; 388 } 389 390 ret = read_object_code(sample.ip, READLEN, sample.cpumode, thread, state); 391 thread__put(thread); 392 return ret; 393 } 394 395 static int process_event(struct machine *machine, struct evlist *evlist, 396 union perf_event *event, struct state *state) 397 { 398 if (event->header.type == PERF_RECORD_SAMPLE) 399 return process_sample_event(machine, evlist, event, state); 400 401 if (event->header.type == PERF_RECORD_THROTTLE || 402 event->header.type == PERF_RECORD_UNTHROTTLE) 403 return 0; 404 405 if (event->header.type < PERF_RECORD_MAX) { 406 int ret; 407 408 ret = machine__process_event(machine, event, NULL); 409 if (ret < 0) 410 pr_debug("machine__process_event failed, event type %u\n", 411 event->header.type); 412 return ret; 413 } 414 415 return 0; 416 } 417 418 static int process_events(struct machine *machine, struct evlist *evlist, 419 struct state *state) 420 { 421 union perf_event *event; 422 struct perf_mmap *md; 423 int i, ret; 424 425 for (i = 0; i < evlist->nr_mmaps; i++) { 426 md = &evlist->mmap[i]; 427 if (perf_mmap__read_init(md) < 0) 428 continue; 429 430 while ((event = perf_mmap__read_event(md)) != NULL) { 431 ret = process_event(machine, evlist, event, state); 432 perf_mmap__consume(md); 433 if (ret < 0) 434 return ret; 435 } 436 perf_mmap__read_done(md); 437 } 438 return 0; 439 } 440 441 static int comp(const void *a, const void *b) 442 { 443 return *(int *)a - *(int *)b; 444 } 445 446 static void do_sort_something(void) 447 { 448 int buf[40960], i; 449 450 for (i = 0; i < (int)ARRAY_SIZE(buf); i++) 451 buf[i] = ARRAY_SIZE(buf) - i - 1; 452 453 qsort(buf, ARRAY_SIZE(buf), sizeof(int), comp); 454 455 for (i = 0; i < (int)ARRAY_SIZE(buf); i++) { 456 if (buf[i] != i) { 457 pr_debug("qsort failed\n"); 458 break; 459 } 460 } 461 } 462 463 static void sort_something(void) 464 { 465 int i; 466 467 for (i = 0; i < 10; i++) 468 do_sort_something(); 469 } 470 471 static void syscall_something(void) 472 { 473 int pipefd[2]; 474 int i; 475 476 for (i = 0; i < 1000; i++) { 477 if (pipe(pipefd) < 0) { 478 pr_debug("pipe failed\n"); 479 break; 480 } 481 close(pipefd[1]); 482 close(pipefd[0]); 483 } 484 } 485 486 static void fs_something(void) 487 { 488 const char *test_file_name = "temp-perf-code-reading-test-file--"; 489 FILE *f; 490 int i; 491 492 for (i = 0; i < 1000; i++) { 493 f = fopen(test_file_name, "w+"); 494 if (f) { 495 fclose(f); 496 unlink(test_file_name); 497 } 498 } 499 } 500 501 #ifdef __s390x__ 502 #include "header.h" // for get_cpuid() 503 #endif 504 505 static const char *do_determine_event(bool excl_kernel) 506 { 507 const char *event = excl_kernel ? "cycles:u" : "cycles"; 508 509 #ifdef __s390x__ 510 char cpuid[128], model[16], model_c[16], cpum_cf_v[16]; 511 unsigned int family; 512 int ret, cpum_cf_a; 513 514 if (get_cpuid(cpuid, sizeof(cpuid))) 515 goto out_clocks; 516 ret = sscanf(cpuid, "%*[^,],%u,%[^,],%[^,],%[^,],%x", &family, model_c, 517 model, cpum_cf_v, &cpum_cf_a); 518 if (ret != 5) /* Not available */ 519 goto out_clocks; 520 if (excl_kernel && (cpum_cf_a & 4)) 521 return event; 522 if (!excl_kernel && (cpum_cf_a & 2)) 523 return event; 524 525 /* Fall through: missing authorization */ 526 out_clocks: 527 event = excl_kernel ? "cpu-clock:u" : "cpu-clock"; 528 529 #endif 530 return event; 531 } 532 533 static void do_something(void) 534 { 535 fs_something(); 536 537 sort_something(); 538 539 syscall_something(); 540 } 541 542 enum { 543 TEST_CODE_READING_OK, 544 TEST_CODE_READING_NO_VMLINUX, 545 TEST_CODE_READING_NO_KCORE, 546 TEST_CODE_READING_NO_ACCESS, 547 TEST_CODE_READING_NO_KERNEL_OBJ, 548 }; 549 550 static int do_test_code_reading(bool try_kcore) 551 { 552 struct machine *machine; 553 struct thread *thread; 554 struct record_opts opts = { 555 .mmap_pages = UINT_MAX, 556 .user_freq = UINT_MAX, 557 .user_interval = ULLONG_MAX, 558 .freq = 500, 559 .target = { 560 .uses_mmap = true, 561 }, 562 }; 563 struct state state = { 564 .done_cnt = 0, 565 }; 566 struct perf_thread_map *threads = NULL; 567 struct perf_cpu_map *cpus = NULL; 568 struct evlist *evlist = NULL; 569 struct evsel *evsel = NULL; 570 int err = -1, ret; 571 pid_t pid; 572 struct map *map; 573 bool have_vmlinux, have_kcore, excl_kernel = false; 574 575 pid = getpid(); 576 577 machine = machine__new_host(); 578 machine->env = &perf_env; 579 580 ret = machine__create_kernel_maps(machine); 581 if (ret < 0) { 582 pr_debug("machine__create_kernel_maps failed\n"); 583 goto out_err; 584 } 585 586 /* Force the use of kallsyms instead of vmlinux to try kcore */ 587 if (try_kcore) 588 symbol_conf.kallsyms_name = "/proc/kallsyms"; 589 590 /* Load kernel map */ 591 map = machine__kernel_map(machine); 592 ret = map__load(map); 593 if (ret < 0) { 594 pr_debug("map__load failed\n"); 595 goto out_err; 596 } 597 have_vmlinux = dso__is_vmlinux(map->dso); 598 have_kcore = dso__is_kcore(map->dso); 599 600 /* 2nd time through we just try kcore */ 601 if (try_kcore && !have_kcore) 602 return TEST_CODE_READING_NO_KCORE; 603 604 /* No point getting kernel events if there is no kernel object */ 605 if (!have_vmlinux && !have_kcore) 606 excl_kernel = true; 607 608 threads = thread_map__new_by_tid(pid); 609 if (!threads) { 610 pr_debug("thread_map__new_by_tid failed\n"); 611 goto out_err; 612 } 613 614 ret = perf_event__synthesize_thread_map(NULL, threads, 615 perf_event__process, machine, false); 616 if (ret < 0) { 617 pr_debug("perf_event__synthesize_thread_map failed\n"); 618 goto out_err; 619 } 620 621 thread = machine__findnew_thread(machine, pid, pid); 622 if (!thread) { 623 pr_debug("machine__findnew_thread failed\n"); 624 goto out_put; 625 } 626 627 cpus = perf_cpu_map__new(NULL); 628 if (!cpus) { 629 pr_debug("perf_cpu_map__new failed\n"); 630 goto out_put; 631 } 632 633 while (1) { 634 const char *str; 635 636 evlist = evlist__new(); 637 if (!evlist) { 638 pr_debug("perf_evlist__new failed\n"); 639 goto out_put; 640 } 641 642 perf_evlist__set_maps(&evlist->core, cpus, threads); 643 644 str = do_determine_event(excl_kernel); 645 pr_debug("Parsing event '%s'\n", str); 646 ret = parse_events(evlist, str, NULL); 647 if (ret < 0) { 648 pr_debug("parse_events failed\n"); 649 goto out_put; 650 } 651 652 perf_evlist__config(evlist, &opts, NULL); 653 654 evsel = perf_evlist__first(evlist); 655 656 evsel->core.attr.comm = 1; 657 evsel->core.attr.disabled = 1; 658 evsel->core.attr.enable_on_exec = 0; 659 660 ret = evlist__open(evlist); 661 if (ret < 0) { 662 if (!excl_kernel) { 663 excl_kernel = true; 664 /* 665 * Both cpus and threads are now owned by evlist 666 * and will be freed by following perf_evlist__set_maps 667 * call. Getting refference to keep them alive. 668 */ 669 perf_cpu_map__get(cpus); 670 perf_thread_map__get(threads); 671 perf_evlist__set_maps(&evlist->core, NULL, NULL); 672 evlist__delete(evlist); 673 evlist = NULL; 674 continue; 675 } 676 677 if (verbose > 0) { 678 char errbuf[512]; 679 perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf)); 680 pr_debug("perf_evlist__open() failed!\n%s\n", errbuf); 681 } 682 683 goto out_put; 684 } 685 break; 686 } 687 688 ret = perf_evlist__mmap(evlist, UINT_MAX); 689 if (ret < 0) { 690 pr_debug("perf_evlist__mmap failed\n"); 691 goto out_put; 692 } 693 694 evlist__enable(evlist); 695 696 do_something(); 697 698 evlist__disable(evlist); 699 700 ret = process_events(machine, evlist, &state); 701 if (ret < 0) 702 goto out_put; 703 704 if (!have_vmlinux && !have_kcore && !try_kcore) 705 err = TEST_CODE_READING_NO_KERNEL_OBJ; 706 else if (!have_vmlinux && !try_kcore) 707 err = TEST_CODE_READING_NO_VMLINUX; 708 else if (excl_kernel) 709 err = TEST_CODE_READING_NO_ACCESS; 710 else 711 err = TEST_CODE_READING_OK; 712 out_put: 713 thread__put(thread); 714 out_err: 715 716 if (evlist) { 717 evlist__delete(evlist); 718 } else { 719 perf_cpu_map__put(cpus); 720 perf_thread_map__put(threads); 721 } 722 machine__delete_threads(machine); 723 machine__delete(machine); 724 725 return err; 726 } 727 728 int test__code_reading(struct test *test __maybe_unused, int subtest __maybe_unused) 729 { 730 int ret; 731 732 ret = do_test_code_reading(false); 733 if (!ret) 734 ret = do_test_code_reading(true); 735 736 switch (ret) { 737 case TEST_CODE_READING_OK: 738 return 0; 739 case TEST_CODE_READING_NO_VMLINUX: 740 pr_debug("no vmlinux\n"); 741 return 0; 742 case TEST_CODE_READING_NO_KCORE: 743 pr_debug("no kcore\n"); 744 return 0; 745 case TEST_CODE_READING_NO_ACCESS: 746 pr_debug("no access\n"); 747 return 0; 748 case TEST_CODE_READING_NO_KERNEL_OBJ: 749 pr_debug("no kernel obj\n"); 750 return 0; 751 default: 752 return -1; 753 }; 754 } 755