tools/perf/util/jitdump.c

   1 #include <sys/types.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <fcntl.h>
   6 #include <unistd.h>
   7 #include <inttypes.h>
   8 #include <byteswap.h>
   9 #include <sys/stat.h>
  10 #include <sys/mman.h>
  11
  12 #include "util.h"
  13 #include "event.h"
  14 #include "debug.h"
  15 #include "evlist.h"
  16 #include "symbol.h"
  17 #include "strlist.h"
  18 #include <elf.h>
  19
  20 #include "session.h"
  21 #include "jit.h"
  22 #include "jitdump.h"
  23 #include "genelf.h"
  24 #include "../builtin.h"
  25
  26 struct jit_buf_desc {
  27         struct perf_data_file *output;
  28         struct perf_session *session;
  29         struct machine *machine;
  30         union jr_entry   *entry;
  31         void             *buf;
  32         uint64_t         sample_type;
  33         size_t           bufsize;
  34         FILE             *in;
  35         bool             needs_bswap; /* handles cross-endianess */
  36         void             *debug_data;
  37         size_t           nr_debug_entries;
  38         uint32_t         code_load_count;
  39         u64              bytes_written;
  40         struct rb_root   code_root;
  41         char             dir[PATH_MAX];
  42 };
  43
  44 struct debug_line_info {
  45         unsigned long vma;
  46         unsigned int lineno;
  47         /* The filename format is unspecified, absolute path, relative etc. */
  48         char const filename[0];
  49 };
  50
  51 struct jit_tool {
  52         struct perf_tool tool;
  53         struct perf_data_file   output;
  54         struct perf_data_file   input;
  55         u64 bytes_written;
  56 };
  57
  58 #define hmax(a, b) ((a) > (b) ? (a) : (b))
  59 #define get_jit_tool(t) (container_of(tool, struct jit_tool, tool))
  60
  61 static int
  62 jit_emit_elf(char *filename,
  63              const char *sym,
  64              uint64_t code_addr,
  65              const void *code,
  66              int csize,
  67              void *debug,
  68              int nr_debug_entries)
  69 {
  70         int ret, fd;
  71
  72         if (verbose > 0)
  73                 fprintf(stderr, "write ELF image %s\n", filename);
  74
  75         fd = open(filename, O_CREAT|O_TRUNC|O_WRONLY, 0644);
  76         if (fd == -1) {
  77                 pr_warning("cannot create jit ELF %s: %s\n", filename, strerror(errno));
  78                 return -1;
  79         }
  80
  81         ret = jit_write_elf(fd, code_addr, sym, (const void *)code, csize, debug, nr_debug_entries);
  82
  83         close(fd);
  84
  85         if (ret)
  86                 unlink(filename);
  87
  88         return ret;
  89 }
  90
  91 static void
  92 jit_close(struct jit_buf_desc *jd)
  93 {
  94         if (!(jd && jd->in))
  95                 return;
  96         funlockfile(jd->in);
  97         fclose(jd->in);
  98         jd->in = NULL;
  99 }
 100
 101 static int
 102 jit_validate_events(struct perf_session *session)
 103 {
 104         struct perf_evsel *evsel;
 105
 106         /*
 107          * check that all events use CLOCK_MONOTONIC
 108          */
 109         evlist__for_each(session->evlist, evsel) {
 110                 if (evsel->attr.use_clockid == 0 || evsel->attr.clockid != CLOCK_MONOTONIC)
 111                         return -1;
 112         }
 113         return 0;
 114 }
 115
 116 static int
 117 jit_open(struct jit_buf_desc *jd, const char *name)
 118 {
 119         struct jitheader header;
 120         struct jr_prefix *prefix;
 121         ssize_t bs, bsz = 0;
 122         void *n, *buf = NULL;
 123         int ret, retval = -1;
 124
 125         jd->in = fopen(name, "r");
 126         if (!jd->in)
 127                 return -1;
 128
 129         bsz = hmax(sizeof(header), sizeof(*prefix));
 130
 131         buf = malloc(bsz);
 132         if (!buf)
 133                 goto error;
 134
 135         /*
 136          * protect from writer modifying the file while we are reading it
 137          */
 138         flockfile(jd->in);
 139
 140         ret = fread(buf, sizeof(header), 1, jd->in);
 141         if (ret != 1)
 142                 goto error;
 143
 144         memcpy(&header, buf, sizeof(header));
 145
 146         if (header.magic != JITHEADER_MAGIC) {
 147                 if (header.magic != JITHEADER_MAGIC_SW)
 148                         goto error;
 149                 jd->needs_bswap = true;
 150         }
 151
 152         if (jd->needs_bswap) {
 153                 header.version    = bswap_32(header.version);
 154                 header.total_size = bswap_32(header.total_size);
 155                 header.pid        = bswap_32(header.pid);
 156                 header.elf_mach   = bswap_32(header.elf_mach);
 157                 header.timestamp  = bswap_64(header.timestamp);
 158                 header.flags      = bswap_64(header.flags);
 159         }
 160
 161         if (verbose > 2)
 162                 pr_debug("version=%u\nhdr.size=%u\nts=0x%llx\npid=%d\nelf_mach=%d\n",
 163                         header.version,
 164                         header.total_size,
 165                         (unsigned long long)header.timestamp,
 166                         header.pid,
 167                         header.elf_mach);
 168
 169         if (header.flags & JITDUMP_FLAGS_RESERVED) {
 170                 pr_err("jitdump file contains invalid or unsupported flags 0x%llx\n",
 171                        (unsigned long long)header.flags & JITDUMP_FLAGS_RESERVED);
 172                 goto error;
 173         }
 174
 175         /*
 176          * validate event is using the correct clockid
 177          */
 178         if (jit_validate_events(jd->session)) {
 179                 pr_err("error, jitted code must be sampled with perf record -k 1\n");
 180                 goto error;
 181         }
 182
 183         bs = header.total_size - sizeof(header);
 184
 185         if (bs > bsz) {
 186                 n = realloc(buf, bs);
 187                 if (!n)
 188                         goto error;
 189                 bsz = bs;
 190                 buf = n;
 191                 /* read extra we do not know about */
 192                 ret = fread(buf, bs - bsz, 1, jd->in);
 193                 if (ret != 1)
 194                         goto error;
 195         }
 196         /*
 197          * keep dirname for generating files and mmap records
 198          */
 199         strcpy(jd->dir, name);
 200         dirname(jd->dir);
 201
 202         return 0;
 203 error:
 204         funlockfile(jd->in);
 205         fclose(jd->in);
 206         return retval;
 207 }
 208
 209 static union jr_entry *
 210 jit_get_next_entry(struct jit_buf_desc *jd)
 211 {
 212         struct jr_prefix *prefix;
 213         union jr_entry *jr;
 214         void *addr;
 215         size_t bs, size;
 216         int id, ret;
 217
 218         if (!(jd && jd->in))
 219                 return NULL;
 220
 221         if (jd->buf == NULL) {
 222                 size_t sz = getpagesize();
 223                 if (sz < sizeof(*prefix))
 224                         sz = sizeof(*prefix);
 225
 226                 jd->buf = malloc(sz);
 227                 if (jd->buf == NULL)
 228                         return NULL;
 229
 230                 jd->bufsize = sz;
 231         }
 232
 233         prefix = jd->buf;
 234
 235         /*
 236          * file is still locked at this point
 237          */
 238         ret = fread(prefix, sizeof(*prefix), 1, jd->in);
 239         if (ret  != 1)
 240                 return NULL;
 241
 242         if (jd->needs_bswap) {
 243                 prefix->id         = bswap_32(prefix->id);
 244                 prefix->total_size = bswap_32(prefix->total_size);
 245                 prefix->timestamp  = bswap_64(prefix->timestamp);
 246         }
 247         id   = prefix->id;
 248         size = prefix->total_size;
 249
 250         bs = (size_t)size;
 251         if (bs < sizeof(*prefix))
 252                 return NULL;
 253
 254         if (id >= JIT_CODE_MAX) {
 255                 pr_warning("next_entry: unknown prefix %d, skipping\n", id);
 256                 return NULL;
 257         }
 258         if (bs > jd->bufsize) {
 259                 void *n;
 260                 n = realloc(jd->buf, bs);
 261                 if (!n)
 262                         return NULL;
 263                 jd->buf = n;
 264                 jd->bufsize = bs;
 265         }
 266
 267         addr = ((void *)jd->buf) + sizeof(*prefix);
 268
 269         ret = fread(addr, bs - sizeof(*prefix), 1, jd->in);
 270         if (ret != 1)
 271                 return NULL;
 272
 273         jr = (union jr_entry *)jd->buf;
 274
 275         switch(id) {
 276         case JIT_CODE_DEBUG_INFO:
 277                 if (jd->needs_bswap) {
 278                         uint64_t n;
 279                         jr->info.code_addr = bswap_64(jr->info.code_addr);
 280                         jr->info.nr_entry  = bswap_64(jr->info.nr_entry);
 281                         for (n = 0 ; n < jr->info.nr_entry; n++) {
 282                                 jr->info.entries[n].addr    = bswap_64(jr->info.entries[n].addr);
 283                                 jr->info.entries[n].lineno  = bswap_32(jr->info.entries[n].lineno);
 284                                 jr->info.entries[n].discrim = bswap_32(jr->info.entries[n].discrim);
 285                         }
 286                 }
 287                 break;
 288         case JIT_CODE_CLOSE:
 289                 break;
 290         case JIT_CODE_LOAD:
 291                 if (jd->needs_bswap) {
 292                         jr->load.pid       = bswap_32(jr->load.pid);
 293                         jr->load.tid       = bswap_32(jr->load.tid);
 294                         jr->load.vma       = bswap_64(jr->load.vma);
 295                         jr->load.code_addr = bswap_64(jr->load.code_addr);
 296                         jr->load.code_size = bswap_64(jr->load.code_size);
 297                         jr->load.code_index= bswap_64(jr->load.code_index);
 298                 }
 299                 jd->code_load_count++;
 300                 break;
 301         case JIT_CODE_MOVE:
 302                 if (jd->needs_bswap) {
 303                         jr->move.pid           = bswap_32(jr->move.pid);
 304                         jr->move.tid           = bswap_32(jr->move.tid);
 305                         jr->move.vma           = bswap_64(jr->move.vma);
 306                         jr->move.old_code_addr = bswap_64(jr->move.old_code_addr);
 307                         jr->move.new_code_addr = bswap_64(jr->move.new_code_addr);
 308                         jr->move.code_size     = bswap_64(jr->move.code_size);
 309                         jr->move.code_index    = bswap_64(jr->move.code_index);
 310                 }
 311                 break;
 312         case JIT_CODE_MAX:
 313         default:
 314                 return NULL;
 315         }
 316         return jr;
 317 }
 318
 319 static int
 320 jit_inject_event(struct jit_buf_desc *jd, union perf_event *event)
 321 {
 322         ssize_t size;
 323
 324         size = perf_data_file__write(jd->output, event, event->header.size);
 325         if (size < 0)
 326                 return -1;
 327
 328         jd->bytes_written += size;
 329         return 0;
 330 }
 331
 332 static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr)
 333 {
 334         struct perf_sample sample;
 335         union perf_event *event;
 336         struct perf_tool *tool = jd->session->tool;
 337         uint64_t code, addr;
 338         uintptr_t uaddr;
 339         char *filename;
 340         struct stat st;
 341         size_t size;
 342         u16 idr_size;
 343         const char *sym;
 344         uint32_t count;
 345         int ret, csize;
 346         pid_t pid, tid;
 347         struct {
 348                 u32 pid, tid;
 349                 u64 time;
 350         } *id;
 351
 352         pid   = jr->load.pid;
 353         tid   = jr->load.tid;
 354         csize = jr->load.code_size;
 355         addr  = jr->load.code_addr;
 356         sym   = (void *)((unsigned long)jr + sizeof(jr->load));
 357         code  = (unsigned long)jr + jr->load.p.total_size - csize;
 358         count = jr->load.code_index;
 359         idr_size = jd->machine->id_hdr_size;
 360
 361         event = calloc(1, sizeof(*event) + idr_size);
 362         if (!event)
 363                 return -1;
 364
 365         filename = event->mmap2.filename;
 366         size = snprintf(filename, PATH_MAX, "%s/jitted-%d-%u.so",
 367                         jd->dir,
 368                         pid,
 369                         count);
 370
 371         size++; /* for \0 */
 372
 373         size = PERF_ALIGN(size, sizeof(u64));
 374         uaddr = (uintptr_t)code;
 375         ret = jit_emit_elf(filename, sym, addr, (const void *)uaddr, csize, jd->debug_data, jd->nr_debug_entries);
 376
 377         if (jd->debug_data && jd->nr_debug_entries) {
 378                 free(jd->debug_data);
 379                 jd->debug_data = NULL;
 380                 jd->nr_debug_entries = 0;
 381         }
 382
 383         if (ret) {
 384                 free(event);
 385                 return -1;
 386         }
 387         if (stat(filename, &st))
 388                 memset(&st, 0, sizeof(stat));
 389
 390         event->mmap2.header.type = PERF_RECORD_MMAP2;
 391         event->mmap2.header.misc = PERF_RECORD_MISC_USER;
 392         event->mmap2.header.size = (sizeof(event->mmap2) -
 393                         (sizeof(event->mmap2.filename) - size) + idr_size);
 394
 395         event->mmap2.pgoff = GEN_ELF_TEXT_OFFSET;
 396         event->mmap2.start = addr;
 397         event->mmap2.len   = csize;
 398         event->mmap2.pid   = pid;
 399         event->mmap2.tid   = tid;
 400         event->mmap2.ino   = st.st_ino;
 401         event->mmap2.maj   = major(st.st_dev);
 402         event->mmap2.min   = minor(st.st_dev);
 403         event->mmap2.prot  = st.st_mode;
 404         event->mmap2.flags = MAP_SHARED;
 405         event->mmap2.ino_generation = 1;
 406
 407         id = (void *)((unsigned long)event + event->mmap.header.size - idr_size);
 408         if (jd->sample_type & PERF_SAMPLE_TID) {
 409                 id->pid  = pid;
 410                 id->tid  = tid;
 411         }
 412         if (jd->sample_type & PERF_SAMPLE_TIME)
 413                 id->time = jr->load.p.timestamp;
 414
 415         /*
 416          * create pseudo sample to induce dso hit increment
 417          * use first address as sample address
 418          */
 419         memset(&sample, 0, sizeof(sample));
 420         sample.pid  = pid;
 421         sample.tid  = tid;
 422         sample.time = id->time;
 423         sample.ip   = addr;
 424
 425         ret = perf_event__process_mmap2(tool, event, &sample, jd->machine);
 426         if (ret)
 427                 return ret;
 428
 429         ret = jit_inject_event(jd, event);
 430         /*
 431          * mark dso as use to generate buildid in the header
 432          */
 433         if (!ret)
 434                 build_id__mark_dso_hit(tool, event, &sample, NULL, jd->machine);
 435
 436         return ret;
 437 }
 438
 439 static int jit_repipe_code_move(struct jit_buf_desc *jd, union jr_entry *jr)
 440 {
 441         struct perf_sample sample;
 442         union perf_event *event;
 443         struct perf_tool *tool = jd->session->tool;
 444         char *filename;
 445         size_t size;
 446         struct stat st;
 447         u16 idr_size;
 448         int ret;
 449         pid_t pid, tid;
 450         struct {
 451                 u32 pid, tid;
 452                 u64 time;
 453         } *id;
 454
 455         pid = jr->move.pid;
 456         tid =  jr->move.tid;
 457         idr_size = jd->machine->id_hdr_size;
 458
 459         /*
 460          * +16 to account for sample_id_all (hack)
 461          */
 462         event = calloc(1, sizeof(*event) + 16);
 463         if (!event)
 464                 return -1;
 465
 466         filename = event->mmap2.filename;
 467         size = snprintf(filename, PATH_MAX, "%s/jitted-%d-%"PRIu64,
 468                  jd->dir,
 469                  pid,
 470                  jr->move.code_index);
 471
 472         size++; /* for \0 */
 473
 474         if (stat(filename, &st))
 475                 memset(&st, 0, sizeof(stat));
 476
 477         size = PERF_ALIGN(size, sizeof(u64));
 478
 479         event->mmap2.header.type = PERF_RECORD_MMAP2;
 480         event->mmap2.header.misc = PERF_RECORD_MISC_USER;
 481         event->mmap2.header.size = (sizeof(event->mmap2) -
 482                         (sizeof(event->mmap2.filename) - size) + idr_size);
 483         event->mmap2.pgoff = GEN_ELF_TEXT_OFFSET;
 484         event->mmap2.start = jr->move.new_code_addr;
 485         event->mmap2.len   = jr->move.code_size;
 486         event->mmap2.pid   = pid;
 487         event->mmap2.tid   = tid;
 488         event->mmap2.ino   = st.st_ino;
 489         event->mmap2.maj   = major(st.st_dev);
 490         event->mmap2.min   = minor(st.st_dev);
 491         event->mmap2.prot  = st.st_mode;
 492         event->mmap2.flags = MAP_SHARED;
 493         event->mmap2.ino_generation = 1;
 494
 495         id = (void *)((unsigned long)event + event->mmap.header.size - idr_size);
 496         if (jd->sample_type & PERF_SAMPLE_TID) {
 497                 id->pid  = pid;
 498                 id->tid  = tid;
 499         }
 500         if (jd->sample_type & PERF_SAMPLE_TIME)
 501                 id->time = jr->load.p.timestamp;
 502
 503         /*
 504          * create pseudo sample to induce dso hit increment
 505          * use first address as sample address
 506          */
 507         memset(&sample, 0, sizeof(sample));
 508         sample.pid  = pid;
 509         sample.tid  = tid;
 510         sample.time = id->time;
 511         sample.ip   = jr->move.new_code_addr;
 512
 513         ret = perf_event__process_mmap2(tool, event, &sample, jd->machine);
 514         if (ret)
 515                 return ret;
 516
 517         ret = jit_inject_event(jd, event);
 518         if (!ret)
 519                 build_id__mark_dso_hit(tool, event, &sample, NULL, jd->machine);
 520
 521         return ret;
 522 }
 523
 524 static int jit_repipe_debug_info(struct jit_buf_desc *jd, union jr_entry *jr)
 525 {
 526         void *data;
 527         size_t sz;
 528
 529         if (!(jd && jr))
 530                 return -1;
 531
 532         sz  = jr->prefix.total_size - sizeof(jr->info);
 533         data = malloc(sz);
 534         if (!data)
 535                 return -1;
 536
 537         memcpy(data, &jr->info.entries, sz);
 538
 539         jd->debug_data       = data;
 540
 541         /*
 542          * we must use nr_entry instead of size here because
 543          * we cannot distinguish actual entry from padding otherwise
 544          */
 545         jd->nr_debug_entries = jr->info.nr_entry;
 546
 547         return 0;
 548 }
 549
 550 static int
 551 jit_process_dump(struct jit_buf_desc *jd)
 552 {
 553         union jr_entry *jr;
 554         int ret;
 555
 556         while ((jr = jit_get_next_entry(jd))) {
 557                 switch(jr->prefix.id) {
 558                 case JIT_CODE_LOAD:
 559                         ret = jit_repipe_code_load(jd, jr);
 560                         break;
 561                 case JIT_CODE_MOVE:
 562                         ret = jit_repipe_code_move(jd, jr);
 563                         break;
 564                 case JIT_CODE_DEBUG_INFO:
 565                         ret = jit_repipe_debug_info(jd, jr);
 566                         break;
 567                 default:
 568                         ret = 0;
 569                         continue;
 570                 }
 571         }
 572         return ret;
 573 }
 574
 575 static int
 576 jit_inject(struct jit_buf_desc *jd, char *path)
 577 {
 578         int ret;
 579
 580         if (verbose > 0)
 581                 fprintf(stderr, "injecting: %s\n", path);
 582
 583         ret = jit_open(jd, path);
 584         if (ret)
 585                 return -1;
 586
 587         ret = jit_process_dump(jd);
 588
 589         jit_close(jd);
 590
 591         if (verbose > 0)
 592                 fprintf(stderr, "injected: %s (%d)\n", path, ret);
 593
 594         return 0;
 595 }
 596
 597 /*
 598  * File must be with pattern .../jit-XXXX.dump
 599  * where XXXX is the PID of the process which did the mmap()
 600  * as captured in the RECORD_MMAP record
 601  */
 602 static int
 603 jit_detect(char *mmap_name, pid_t pid)
 604  {
 605         char *p;
 606         char *end = NULL;
 607         pid_t pid2;
 608
 609         if (verbose > 2)
 610                 fprintf(stderr, "jit marker trying : %s\n", mmap_name);
 611         /*
 612          * get file name
 613          */
 614         p = strrchr(mmap_name, '/');
 615         if (!p)
 616                 return -1;
 617
 618         /*
 619          * match prefix
 620          */
 621         if (strncmp(p, "/jit-", 5))
 622                 return -1;
 623
 624         /*
 625          * skip prefix
 626          */
 627         p += 5;
 628
 629         /*
 630          * must be followed by a pid
 631          */
 632         if (!isdigit(*p))
 633                 return -1;
 634
 635         pid2 = (int)strtol(p, &end, 10);
 636         if (!end)
 637                 return -1;
 638
 639         /*
 640          * pid does not match mmap pid
 641          * pid==0 in system-wide mode (synthesized)
 642          */
 643         if (pid && pid2 != pid)
 644                 return -1;
 645         /*
 646          * validate suffix
 647          */
 648         if (strcmp(end, ".dump"))
 649                 return -1;
 650
 651         if (verbose > 0)
 652                 fprintf(stderr, "jit marker found: %s\n", mmap_name);
 653
 654         return 0;
 655 }
 656
 657 int
 658 jit_process(struct perf_session *session,
 659             struct perf_data_file *output,
 660             struct machine *machine,
 661             char *filename,
 662             pid_t pid,
 663             u64 *nbytes)
 664 {
 665         struct perf_evsel *first;
 666         struct jit_buf_desc jd;
 667         int ret;
 668
 669         /*
 670          * first, detect marker mmap (i.e., the jitdump mmap)
 671          */
 672         if (jit_detect(filename, pid))
 673                 return 0;
 674
 675         memset(&jd, 0, sizeof(jd));
 676
 677         jd.session = session;
 678         jd.output  = output;
 679         jd.machine = machine;
 680
 681         /*
 682          * track sample_type to compute id_all layout
 683          * perf sets the same sample type to all events as of now
 684          */
 685         first = perf_evlist__first(session->evlist);
 686         jd.sample_type = first->attr.sample_type;
 687
 688         *nbytes = 0;
 689
 690         ret = jit_inject(&jd, filename);
 691         if (!ret) {
 692                 *nbytes = jd.bytes_written;
 693                 ret = 1;
 694         }
 695
 696         return ret;
 697 }