git.ozlabs.org Git - ccan/blob - ccan/failtest/failtest.c

   1 /* Licensed under LGPL - see LICENSE file for details */
   2 #include "config.h"
   3 #include <stdarg.h>
   4 #include <string.h>
   5 #include <stdio.h>
   6 #include <stdarg.h>
   7 #include <ctype.h>
   8 #include <err.h>
   9 #include <unistd.h>
  10 #include <poll.h>
  11 #include <errno.h>
  12 #include <sys/types.h>
  13 #include <sys/wait.h>
  14 #include <sys/stat.h>
  15 #include <sys/time.h>
  16 #include <signal.h>
  17 #include <assert.h>
  18 #include <ccan/read_write_all/read_write_all.h>
  19 #include <ccan/failtest/failtest_proto.h>
  20 #include <ccan/failtest/failtest.h>
  21 #include <ccan/build_assert/build_assert.h>
  22
  23 enum failtest_result (*failtest_hook)(struct failtest_call *, unsigned);
  24
  25 static int tracefd = -1;
  26
  27 unsigned int failtest_timeout_ms = 20000;
  28
  29 const char *failpath;
  30 const char *debugpath;
  31
  32 enum info_type {
  33         WRITE,
  34         RELEASE_LOCKS,
  35         FAILURE,
  36         SUCCESS,
  37         UNEXPECTED
  38 };
  39
  40 struct lock_info {
  41         int fd;
  42         /* end is inclusive: you can't have a 0-byte lock. */
  43         off_t start, end;
  44         int type;
  45 };
  46
  47 bool (*failtest_exit_check)(struct failtest_call *history, unsigned num);
  48
  49 static struct failtest_call *history = NULL;
  50 static unsigned int history_num = 0;
  51 static int control_fd = -1;
  52 static struct timeval start;
  53 static unsigned int probe_count = 0;
  54
  55 static struct write_call *child_writes = NULL;
  56 static unsigned int child_writes_num = 0;
  57
  58 static pid_t lock_owner;
  59 static struct lock_info *locks = NULL;
  60 static unsigned int lock_num = 0;
  61
  62 static pid_t orig_pid;
  63
  64 static const char info_to_arg[] = "mceoxprwf";
  65
  66 /* Dummy call used for failtest_undo wrappers. */
  67 static struct failtest_call unrecorded_call;
  68
  69 static struct failtest_call *add_history_(enum failtest_call_type type,
  70                                           const char *file,
  71                                           unsigned int line,
  72                                           const void *elem,
  73                                           size_t elem_size)
  74 {
  75         /* NULL file is how we suppress failure. */
  76         if (!file)
  77                 return &unrecorded_call;
  78
  79         history = realloc(history, (history_num + 1) * sizeof(*history));
  80         history[history_num].type = type;
  81         history[history_num].file = file;
  82         history[history_num].line = line;
  83         history[history_num].cleanup = NULL;
  84         memcpy(&history[history_num].u, elem, elem_size);
  85         return &history[history_num++];
  86 }
  87
  88 #define add_history(type, file, line, elem) \
  89         add_history_((type), (file), (line), (elem), sizeof(*(elem)))
  90
  91 /* We do a fake call inside a sizeof(), to check types. */
  92 #define set_cleanup(call, clean, type)                  \
  93         (call)->cleanup = (void *)((void)sizeof(clean((type *)NULL),1), (clean))
  94
  95 static bool read_write_info(int fd)
  96 {
  97         struct write_call *w;
  98         char *buf;
  99
 100         /* We don't need all of this, but it's simple. */
 101         child_writes = realloc(child_writes,
 102                                (child_writes_num+1) * sizeof(child_writes[0]));
 103         w = &child_writes[child_writes_num];
 104         if (!read_all(fd, w, sizeof(*w)))
 105                 return false;
 106
 107         w->buf = buf = malloc(w->count);
 108         if (!read_all(fd, buf, w->count))
 109                 return false;
 110
 111         child_writes_num++;
 112         return true;
 113 }
 114
 115 static char *failpath_string(void)
 116 {
 117         unsigned int i;
 118         char *ret = malloc(history_num + 1);
 119
 120         for (i = 0; i < history_num; i++) {
 121                 ret[i] = info_to_arg[history[i].type];
 122                 if (history[i].fail)
 123                         ret[i] = toupper(ret[i]);
 124         }
 125         ret[i] = '\0';
 126         return ret;
 127 }
 128
 129 static void tell_parent(enum info_type type)
 130 {
 131         if (control_fd != -1)
 132                 write_all(control_fd, &type, sizeof(type));
 133 }
 134
 135 static void child_fail(const char *out, size_t outlen, const char *fmt, ...)
 136 {
 137         va_list ap;
 138         char *path = failpath_string();
 139
 140         va_start(ap, fmt);
 141         vfprintf(stderr, fmt, ap);
 142         va_end(ap);
 143
 144         fprintf(stderr, "%.*s", (int)outlen, out);
 145         printf("To reproduce: --failpath=%s\n", path);
 146         free(path);
 147         tell_parent(FAILURE);
 148         exit(1);
 149 }
 150
 151 static void trace(const char *fmt, ...)
 152 {
 153         va_list ap;
 154
 155         if (tracefd == -1)
 156                 return;
 157
 158         va_start(ap, fmt);
 159         vdprintf(tracefd, fmt, ap);
 160         va_end(ap);
 161 }
 162
 163 static pid_t child;
 164
 165 static void hand_down(int signum)
 166 {
 167         kill(child, signum);
 168 }
 169
 170 static void release_locks(void)
 171 {
 172         /* Locks were never acquired/reacquired? */
 173         if (lock_owner == 0)
 174                 return;
 175
 176         /* We own them?  Release them all. */
 177         if (lock_owner == getpid()) {
 178                 unsigned int i;
 179                 struct flock fl;
 180                 fl.l_type = F_UNLCK;
 181                 fl.l_whence = SEEK_SET;
 182                 fl.l_start = 0;
 183                 fl.l_len = 0;
 184
 185                 for (i = 0; i < lock_num; i++)
 186                         fcntl(locks[i].fd, F_SETLK, &fl);
 187         } else {
 188                 /* Our parent must have them; pass request up. */
 189                 enum info_type type = RELEASE_LOCKS;
 190                 assert(control_fd != -1);
 191                 write_all(control_fd, &type, sizeof(type));
 192         }
 193         lock_owner = 0;
 194 }
 195
 196 /* off_t is a signed type.  Getting its max is non-trivial. */
 197 static off_t off_max(void)
 198 {
 199         BUILD_ASSERT(sizeof(off_t) == 4 || sizeof(off_t) == 8);
 200         if (sizeof(off_t) == 4)
 201                 return (off_t)0x7FFFFFF;
 202         else
 203                 return (off_t)0x7FFFFFFFFFFFFFFULL;
 204 }
 205
 206 static void get_locks(void)
 207 {
 208         unsigned int i;
 209         struct flock fl;
 210
 211         if (lock_owner == getpid())
 212                 return;
 213
 214         if (lock_owner != 0) {
 215                 enum info_type type = RELEASE_LOCKS;
 216                 assert(control_fd != -1);
 217                 write_all(control_fd, &type, sizeof(type));
 218         }
 219
 220         fl.l_whence = SEEK_SET;
 221
 222         for (i = 0; i < lock_num; i++) {
 223                 fl.l_type = locks[i].type;
 224                 fl.l_start = locks[i].start;
 225                 if (locks[i].end == off_max())
 226                         fl.l_len = 0;
 227                 else
 228                         fl.l_len = locks[i].end - locks[i].start + 1;
 229
 230                 if (fcntl(locks[i].fd, F_SETLKW, &fl) != 0)
 231                         abort();
 232         }
 233         lock_owner = getpid();
 234 }
 235
 236 struct saved_file {
 237         struct saved_file *next;
 238         int fd;
 239         void *contents;
 240         off_t off, len;
 241 };
 242
 243 static struct saved_file *save_file(struct saved_file *next, int fd)
 244 {
 245         struct saved_file *s = malloc(sizeof(*s));
 246
 247         s->next = next;
 248         s->fd = fd;
 249         s->off = lseek(fd, 0, SEEK_CUR);
 250         /* Special file?  Erk... */
 251         assert(s->off != -1);
 252         s->len = lseek(fd, 0, SEEK_END);
 253         lseek(fd, 0, SEEK_SET);
 254         s->contents = malloc(s->len);
 255         if (read(fd, s->contents, s->len) != s->len)
 256                 err(1, "Failed to save %zu bytes", (size_t)s->len);
 257         lseek(fd, s->off, SEEK_SET);
 258         return s;
 259 }
 260
 261 /* We have little choice but to save and restore open files: mmap means we
 262  * can really intercept changes in the child.
 263  *
 264  * We could do non-mmap'ed files on demand, however. */
 265 static struct saved_file *save_files(void)
 266 {
 267         struct saved_file *files = NULL;
 268         int i;
 269
 270         /* Figure out the set of live fds. */
 271         for (i = history_num - 2; i >= 0; i--) {
 272                 if (history[i].type == FAILTEST_OPEN) {
 273                         int fd = history[i].u.open.ret;
 274                         /* Only do successful, writable fds. */
 275                         if (fd < 0)
 276                                 continue;
 277
 278                         /* If it was closed, cleanup == NULL. */
 279                         if (!history[i].cleanup)
 280                                 continue;
 281
 282                         if ((history[i].u.open.flags & O_RDWR) == O_RDWR) {
 283                                 files = save_file(files, fd);
 284                         } else if ((history[i].u.open.flags & O_WRONLY)
 285                                    == O_WRONLY) {
 286                                 /* FIXME: Handle O_WRONLY.  Open with O_RDWR? */
 287                                 abort();
 288                         }
 289                 }
 290         }
 291
 292         return files;
 293 }
 294
 295 static void restore_files(struct saved_file *s)
 296 {
 297         while (s) {
 298                 struct saved_file *next = s->next;
 299
 300                 lseek(s->fd, 0, SEEK_SET);
 301                 if (write(s->fd, s->contents, s->len) != s->len)
 302                         err(1, "Failed to restore %zu bytes", (size_t)s->len);
 303                 if (ftruncate(s->fd, s->len) != 0)
 304                         err(1, "Failed to trim file to length %zu",
 305                             (size_t)s->len);
 306                 free(s->contents);
 307                 lseek(s->fd, s->off, SEEK_SET);
 308                 free(s);
 309                 s = next;
 310         }
 311 }
 312
 313 static void free_files(struct saved_file *s)
 314 {
 315         while (s) {
 316                 struct saved_file *next = s->next;
 317                 free(s->contents);
 318                 free(s);
 319                 s = next;
 320         }
 321 }
 322
 323 /* Free up memory, so valgrind doesn't report leaks. */
 324 static void free_everything(void)
 325 {
 326         unsigned int i;
 327
 328         /* We don't do this in cleanup: needed even for failed opens. */
 329         for (i = 0; i < history_num; i++) {
 330                 if (history[i].type == FAILTEST_OPEN)
 331                         free((char *)history[i].u.open.pathname);
 332         }
 333         free(history);
 334 }
 335
 336 static NORETURN void failtest_cleanup(bool forced_cleanup, int status)
 337 {
 338         int i;
 339
 340         /* For children, we don't care if they "failed" the testing. */
 341         if (control_fd != -1)
 342                 status = 0;
 343
 344         if (forced_cleanup)
 345                 history_num--;
 346
 347         /* Cleanup everything, in reverse order. */
 348         for (i = history_num - 1; i >= 0; i--) {
 349                 if (!history[i].cleanup)
 350                         continue;
 351                 if (!forced_cleanup) {
 352                         printf("Leak at %s:%u: --failpath=%s\n",
 353                                history[i].file, history[i].line,
 354                                failpath_string());
 355                         status = 1;
 356                 }
 357                 history[i].cleanup(&history[i].u);
 358         }
 359
 360         free_everything();
 361         tell_parent(SUCCESS);
 362         exit(status);
 363 }
 364
 365 static bool should_fail(struct failtest_call *call)
 366 {
 367         int status;
 368         int control[2], output[2];
 369         enum info_type type = UNEXPECTED;
 370         char *out = NULL;
 371         size_t outlen = 0;
 372         struct saved_file *files;
 373
 374         /* Are we probing? */
 375         if (probe_count && --probe_count == 0 && control_fd != -1)
 376                 failtest_cleanup(true, 0);
 377
 378         if (call == &unrecorded_call)
 379                 return false;
 380
 381         if (failpath) {
 382                 /* + means continue after end, like normal. */
 383                 if (*failpath == '+')
 384                         failpath = NULL;
 385                 else if (*failpath == '\0') {
 386                         /* Continue, but don't inject errors. */
 387                         return call->fail = false;
 388                 } else {
 389                         if (tolower((unsigned char)*failpath)
 390                             != info_to_arg[call->type])
 391                                 errx(1, "Failpath expected '%c' got '%c'\n",
 392                                      info_to_arg[call->type], *failpath);
 393                         call->fail = isupper((unsigned char)*(failpath++));
 394                         return call->fail;
 395                 }
 396         }
 397
 398         /* Attach debugger if they asked for it. */
 399         if (debugpath && history_num == strlen(debugpath)) {
 400                 unsigned int i;
 401
 402                 for (i = 0; i < history_num; i++) {
 403                         unsigned char c = info_to_arg[history[i].type];
 404                         if (history[i].fail)
 405                                 c = toupper(c);
 406                         if (c != debugpath[i])
 407                                 break;
 408                 }
 409                 if (i == history_num) {
 410                         char str[80];
 411
 412                         /* Don't timeout. */
 413                         signal(SIGUSR1, SIG_IGN);
 414                         sprintf(str, "xterm -e gdb /proc/%d/exe %d &",
 415                                 getpid(), getpid());
 416                         if (system(str) == 0)
 417                                 sleep(5);
 418                 }
 419         }
 420
 421         if (failtest_hook) {
 422                 switch (failtest_hook(history, history_num)) {
 423                 case FAIL_OK:
 424                         break;
 425                 case FAIL_PROBE:
 426                         /* Already down probe path?  Stop now. */
 427                         if (!probe_count) {
 428                                 /* FIXME: We should run *parent* and
 429                                  * run probe until calls match up again. */
 430                                 probe_count = 3;
 431                                 break;
 432                         } else {
 433                                 /* Child should give up now. */
 434                                 if (control_fd != -1)
 435                                         failtest_cleanup(true, 0);
 436                                 /* Parent, don't fail again. */
 437                         }
 438                 case FAIL_DONT_FAIL:
 439                         call->fail = false;
 440                         return false;
 441                 default:
 442                         abort();
 443                 }
 444         }
 445
 446         files = save_files();
 447
 448         /* We're going to fail in the child. */
 449         call->fail = true;
 450         if (pipe(control) != 0 || pipe(output) != 0)
 451                 err(1, "opening pipe");
 452
 453         /* Prevent double-printing (in child and parent) */
 454         fflush(stdout);
 455         child = fork();
 456         if (child == -1)
 457                 err(1, "forking failed");
 458
 459         if (child == 0) {
 460                 if (tracefd != -1) {
 461                         struct timeval now;
 462                         const char *p;
 463                         gettimeofday(&now, NULL);
 464                         if (now.tv_usec < start.tv_usec) {
 465                                 now.tv_sec--;
 466                                 now.tv_usec += 1000000;
 467                         }
 468                         now.tv_usec -= start.tv_usec;
 469                         now.tv_sec -= start.tv_sec;
 470                         p = failpath_string();
 471                         trace("%u->%u (%u.%02u): %s (", getppid(), getpid(),
 472                               (int)now.tv_sec, (int)now.tv_usec / 10000, p);
 473                         free((char *)p);
 474                         p = strrchr(history[history_num-1].file, '/');
 475                         if (p)
 476                                 trace("%s", p+1);
 477                         else
 478                                 trace("%s", history[history_num-1].file);
 479                         trace(":%u)\n", history[history_num-1].line);
 480                 }
 481                 close(control[0]);
 482                 close(output[0]);
 483                 dup2(output[1], STDOUT_FILENO);
 484                 dup2(output[1], STDERR_FILENO);
 485                 if (output[1] != STDOUT_FILENO && output[1] != STDERR_FILENO)
 486                         close(output[1]);
 487                 control_fd = control[1];
 488                 /* Valgrind spots the leak if we don't free these. */
 489                 free_files(files);
 490                 return true;
 491         }
 492
 493         signal(SIGUSR1, hand_down);
 494
 495         close(control[1]);
 496         close(output[1]);
 497
 498         /* We grab output so we can display it; we grab writes so we
 499          * can compare. */
 500         do {
 501                 struct pollfd pfd[2];
 502                 int ret;
 503
 504                 pfd[0].fd = output[0];
 505                 pfd[0].events = POLLIN|POLLHUP;
 506                 pfd[1].fd = control[0];
 507                 pfd[1].events = POLLIN|POLLHUP;
 508
 509                 if (type == SUCCESS)
 510                         ret = poll(pfd, 1, failtest_timeout_ms);
 511                 else
 512                         ret = poll(pfd, 2, failtest_timeout_ms);
 513
 514                 if (ret == 0)
 515                         hand_down(SIGUSR1);
 516                 if (ret < 0) {
 517                         if (errno == EINTR)
 518                                 continue;
 519                         err(1, "Poll returned %i", ret);
 520                 }
 521
 522                 if (pfd[0].revents & POLLIN) {
 523                         ssize_t len;
 524
 525                         out = realloc(out, outlen + 8192);
 526                         len = read(output[0], out + outlen, 8192);
 527                         outlen += len;
 528                 } else if (type != SUCCESS && (pfd[1].revents & POLLIN)) {
 529                         if (read_all(control[0], &type, sizeof(type))) {
 530                                 if (type == WRITE) {
 531                                         if (!read_write_info(control[0]))
 532                                                 break;
 533                                 } else if (type == RELEASE_LOCKS) {
 534                                         release_locks();
 535                                         /* FIXME: Tell them we're done... */
 536                                 }
 537                         }
 538                 } else if (pfd[0].revents & POLLHUP) {
 539                         break;
 540                 }
 541         } while (type != FAILURE);
 542
 543         close(output[0]);
 544         close(control[0]);
 545         waitpid(child, &status, 0);
 546         if (!WIFEXITED(status)) {
 547                 if (WTERMSIG(status) == SIGUSR1)
 548                         child_fail(out, outlen, "Timed out");
 549                 else
 550                         child_fail(out, outlen, "Killed by signal %u: ",
 551                                    WTERMSIG(status));
 552         }
 553         /* Child printed failure already, just pass up exit code. */
 554         if (type == FAILURE) {
 555                 fprintf(stderr, "%.*s", (int)outlen, out);
 556                 tell_parent(type);
 557                 exit(WEXITSTATUS(status) ? WEXITSTATUS(status) : 1);
 558         }
 559         if (WEXITSTATUS(status) != 0)
 560                 child_fail(out, outlen, "Exited with status %i: ",
 561                            WEXITSTATUS(status));
 562
 563         free(out);
 564         signal(SIGUSR1, SIG_DFL);
 565
 566         restore_files(files);
 567
 568         /* We continue onwards without failing. */
 569         call->fail = false;
 570         return false;
 571 }
 572
 573 static void cleanup_calloc(struct calloc_call *call)
 574 {
 575         free(call->ret);
 576 }
 577
 578 void *failtest_calloc(size_t nmemb, size_t size,
 579                       const char *file, unsigned line)
 580 {
 581         struct failtest_call *p;
 582         struct calloc_call call;
 583         call.nmemb = nmemb;
 584         call.size = size;
 585         p = add_history(FAILTEST_CALLOC, file, line, &call);
 586
 587         if (should_fail(p)) {
 588                 p->u.calloc.ret = NULL;
 589                 p->error = ENOMEM;
 590         } else {
 591                 p->u.calloc.ret = calloc(nmemb, size);
 592                 set_cleanup(p, cleanup_calloc, struct calloc_call);
 593         }
 594         errno = p->error;
 595         return p->u.calloc.ret;
 596 }
 597
 598 static void cleanup_malloc(struct malloc_call *call)
 599 {
 600         free(call->ret);
 601 }
 602
 603 void *failtest_malloc(size_t size, const char *file, unsigned line)
 604 {
 605         struct failtest_call *p;
 606         struct malloc_call call;
 607         call.size = size;
 608
 609         p = add_history(FAILTEST_MALLOC, file, line, &call);
 610         if (should_fail(p)) {
 611                 p->u.calloc.ret = NULL;
 612                 p->error = ENOMEM;
 613         } else {
 614                 p->u.calloc.ret = malloc(size);
 615                 set_cleanup(p, cleanup_malloc, struct malloc_call);
 616         }
 617         errno = p->error;
 618         return p->u.calloc.ret;
 619 }
 620
 621 static void cleanup_realloc(struct realloc_call *call)
 622 {
 623         free(call->ret);
 624 }
 625
 626 /* Walk back and find out if we got this ptr from a previous routine. */
 627 static void fixup_ptr_history(void *ptr, unsigned int last)
 628 {
 629         int i;
 630
 631         /* Start at end of history, work back. */
 632         for (i = last - 1; i >= 0; i--) {
 633                 switch (history[i].type) {
 634                 case FAILTEST_REALLOC:
 635                         if (history[i].u.realloc.ret == ptr) {
 636                                 history[i].cleanup = NULL;
 637                                 return;
 638                         }
 639                         break;
 640                 case FAILTEST_MALLOC:
 641                         if (history[i].u.malloc.ret == ptr) {
 642                                 history[i].cleanup = NULL;
 643                                 return;
 644                         }
 645                         break;
 646                 case FAILTEST_CALLOC:
 647                         if (history[i].u.calloc.ret == ptr) {
 648                                 history[i].cleanup = NULL;
 649                                 return;
 650                         }
 651                         break;
 652                 default:
 653                         break;
 654                 }
 655         }
 656 }
 657
 658 void *failtest_realloc(void *ptr, size_t size, const char *file, unsigned line)
 659 {
 660         struct failtest_call *p;
 661         struct realloc_call call;
 662         call.size = size;
 663         p = add_history(FAILTEST_REALLOC, file, line, &call);
 664
 665         /* FIXME: Try one child moving allocation, one not. */
 666         if (should_fail(p)) {
 667                 p->u.realloc.ret = NULL;
 668                 p->error = ENOMEM;
 669         } else {
 670                 fixup_ptr_history(ptr, history_num-1);
 671                 p->u.realloc.ret = realloc(ptr, size);
 672                 set_cleanup(p, cleanup_realloc, struct realloc_call);
 673         }
 674         errno = p->error;
 675         return p->u.realloc.ret;
 676 }
 677
 678 void failtest_free(void *ptr)
 679 {
 680         fixup_ptr_history(ptr, history_num);
 681         free(ptr);
 682 }
 683
 684 static void cleanup_open(struct open_call *call)
 685 {
 686         close(call->ret);
 687 }
 688
 689 int failtest_open(const char *pathname,
 690                   const char *file, unsigned line, ...)
 691 {
 692         struct failtest_call *p;
 693         struct open_call call;
 694         va_list ap;
 695
 696         call.pathname = strdup(pathname);
 697         va_start(ap, line);
 698         call.flags = va_arg(ap, int);
 699         if (call.flags & O_CREAT) {
 700                 call.mode = va_arg(ap, int);
 701                 va_end(ap);
 702         }
 703         p = add_history(FAILTEST_OPEN, file, line, &call);
 704         /* Avoid memory leak! */
 705         if (p == &unrecorded_call)
 706                 free((char *)call.pathname);
 707         p->u.open.ret = open(pathname, call.flags, call.mode);
 708
 709         if (!failpath && p->u.open.ret == -1) {
 710                 p->fail = false;
 711                 p->error = errno;
 712         } else if (should_fail(p)) {
 713                 close(p->u.open.ret);
 714                 p->u.open.ret = -1;
 715                 /* FIXME: Play with error codes? */
 716                 p->error = EACCES;
 717         } else {
 718                 set_cleanup(p, cleanup_open, struct open_call);
 719         }
 720         errno = p->error;
 721         return p->u.open.ret;
 722 }
 723
 724 static void cleanup_pipe(struct pipe_call *call)
 725 {
 726         if (!call->closed[0])
 727                 close(call->fds[0]);
 728         if (!call->closed[1])
 729                 close(call->fds[1]);
 730 }
 731
 732 int failtest_pipe(int pipefd[2], const char *file, unsigned line)
 733 {
 734         struct failtest_call *p;
 735         struct pipe_call call;
 736
 737         p = add_history(FAILTEST_PIPE, file, line, &call);
 738         if (should_fail(p)) {
 739                 p->u.open.ret = -1;
 740                 /* FIXME: Play with error codes? */
 741                 p->error = EMFILE;
 742         } else {
 743                 p->u.pipe.ret = pipe(p->u.pipe.fds);
 744                 p->u.pipe.closed[0] = p->u.pipe.closed[1] = false;
 745                 set_cleanup(p, cleanup_pipe, struct pipe_call);
 746         }
 747         /* This causes valgrind to notice if they use pipefd[] after failure */
 748         memcpy(pipefd, p->u.pipe.fds, sizeof(p->u.pipe.fds));
 749         errno = p->error;
 750         return p->u.pipe.ret;
 751 }
 752
 753 ssize_t failtest_pread(int fd, void *buf, size_t count, off_t off,
 754                        const char *file, unsigned line)
 755 {
 756         struct failtest_call *p;
 757         struct read_call call;
 758         call.fd = fd;
 759         call.buf = buf;
 760         call.count = count;
 761         call.off = off;
 762         p = add_history(FAILTEST_READ, file, line, &call);
 763
 764         /* FIXME: Try partial read returns. */
 765         if (should_fail(p)) {
 766                 p->u.read.ret = -1;
 767                 p->error = EIO;
 768         } else {
 769                 p->u.read.ret = pread(fd, buf, count, off);
 770         }
 771         errno = p->error;
 772         return p->u.read.ret;
 773 }
 774
 775 ssize_t failtest_pwrite(int fd, const void *buf, size_t count, off_t off,
 776                         const char *file, unsigned line)
 777 {
 778         struct failtest_call *p;
 779         struct write_call call;
 780
 781         call.fd = fd;
 782         call.buf = buf;
 783         call.count = count;
 784         call.off = off;
 785         p = add_history(FAILTEST_WRITE, file, line, &call);
 786
 787         /* If we're a child, we need to make sure we write the same thing
 788          * to non-files as the parent does, so tell it. */
 789         if (control_fd != -1 && off == (off_t)-1) {
 790                 enum info_type type = WRITE;
 791
 792                 write_all(control_fd, &type, sizeof(type));
 793                 write_all(control_fd, &p->u.write, sizeof(p->u.write));
 794                 write_all(control_fd, buf, count);
 795         }
 796
 797         /* FIXME: Try partial write returns. */
 798         if (should_fail(p)) {
 799                 p->u.write.ret = -1;
 800                 p->error = EIO;
 801         } else {
 802                 /* FIXME: We assume same write order in parent and child */
 803                 if (off == (off_t)-1 && child_writes_num != 0) {
 804                         if (child_writes[0].fd != fd)
 805                                 errx(1, "Child wrote to fd %u, not %u?",
 806                                      child_writes[0].fd, fd);
 807                         if (child_writes[0].off != p->u.write.off)
 808                                 errx(1, "Child wrote to offset %zu, not %zu?",
 809                                      (size_t)child_writes[0].off,
 810                                      (size_t)p->u.write.off);
 811                         if (child_writes[0].count != count)
 812                                 errx(1, "Child wrote length %zu, not %zu?",
 813                                      child_writes[0].count, count);
 814                         if (memcmp(child_writes[0].buf, buf, count)) {
 815                                 child_fail(NULL, 0,
 816                                            "Child wrote differently to"
 817                                            " fd %u than we did!\n", fd);
 818                         }
 819                         free((char *)child_writes[0].buf);
 820                         child_writes_num--;
 821                         memmove(&child_writes[0], &child_writes[1],
 822                                 sizeof(child_writes[0]) * child_writes_num);
 823
 824                         /* Is this is a socket or pipe, child wrote it
 825                            already. */
 826                         if (p->u.write.off == (off_t)-1) {
 827                                 p->u.write.ret = count;
 828                                 errno = p->error;
 829                                 return p->u.write.ret;
 830                         }
 831                 }
 832                 p->u.write.ret = pwrite(fd, buf, count, off);
 833         }
 834         errno = p->error;
 835         return p->u.write.ret;
 836 }
 837
 838 ssize_t failtest_read(int fd, void *buf, size_t count,
 839                       const char *file, unsigned line)
 840 {
 841         return failtest_pread(fd, buf, count, lseek(fd, 0, SEEK_CUR),
 842                               file, line);
 843 }
 844
 845 ssize_t failtest_write(int fd, const void *buf, size_t count,
 846                        const char *file, unsigned line)
 847 {
 848         return failtest_pwrite(fd, buf, count, lseek(fd, 0, SEEK_CUR),
 849                                file, line);
 850 }
 851
 852 static struct lock_info *WARN_UNUSED_RESULT
 853 add_lock(struct lock_info *locks, int fd, off_t start, off_t end, int type)
 854 {
 855         unsigned int i;
 856         struct lock_info *l;
 857
 858         for (i = 0; i < lock_num; i++) {
 859                 l = &locks[i];
 860
 861                 if (l->fd != fd)
 862                         continue;
 863                 /* Four cases we care about:
 864                  * Start overlap:
 865                  *      l =    |      |
 866                  *      new = |   |
 867                  * Mid overlap:
 868                  *      l =    |      |
 869                  *      new =    |  |
 870                  * End overlap:
 871                  *      l =    |      |
 872                  *      new =      |    |
 873                  * Total overlap:
 874                  *      l =    |      |
 875                  *      new = |         |
 876                  */
 877                 if (start > l->start && end < l->end) {
 878                         /* Mid overlap: trim entry, add new one. */
 879                         off_t new_start, new_end;
 880                         new_start = end + 1;
 881                         new_end = l->end;
 882                         l->end = start - 1;
 883                         locks = add_lock(locks,
 884                                          fd, new_start, new_end, l->type);
 885                         l = &locks[i];
 886                 } else if (start <= l->start && end >= l->end) {
 887                         /* Total overlap: eliminate entry. */
 888                         l->end = 0;
 889                         l->start = 1;
 890                 } else if (end >= l->start && end < l->end) {
 891                         /* Start overlap: trim entry. */
 892                         l->start = end + 1;
 893                 } else if (start > l->start && start <= l->end) {
 894                         /* End overlap: trim entry. */
 895                         l->end = start-1;
 896                 }
 897                 /* Nothing left?  Remove it. */
 898                 if (l->end < l->start) {
 899                         memmove(l, l + 1, (--lock_num - i) * sizeof(l[0]));
 900                         i--;
 901                 }
 902         }
 903
 904         if (type != F_UNLCK) {
 905                 locks = realloc(locks, (lock_num + 1) * sizeof(*locks));
 906                 l = &locks[lock_num++];
 907                 l->fd = fd;
 908                 l->start = start;
 909                 l->end = end;
 910                 l->type = type;
 911         }
 912         return locks;
 913 }
 914
 915 /* We trap this so we can record it: we don't fail it. */
 916 int failtest_close(int fd, const char *file, unsigned line)
 917 {
 918         int i;
 919         struct close_call call;
 920         struct failtest_call *p;
 921
 922         call.fd = fd;
 923         p = add_history(FAILTEST_CLOSE, file, line, &call);
 924         p->fail = false;
 925
 926         /* Consume close from failpath. */
 927         if (failpath)
 928                 if (should_fail(p))
 929                         abort();
 930
 931         if (fd < 0)
 932                 return close(fd);
 933
 934         /* Trace history to find source of fd. */
 935         for (i = history_num-1; i >= 0; i--) {
 936                 switch (history[i].type) {
 937                 case FAILTEST_PIPE:
 938                         /* From a pipe? */
 939                         if (history[i].u.pipe.fds[0] == fd) {
 940                                 assert(!history[i].u.pipe.closed[0]);
 941                                 history[i].u.pipe.closed[0] = true;
 942                                 if (history[i].u.pipe.closed[1])
 943                                         history[i].cleanup = NULL;
 944                                 goto out;
 945                         }
 946                         if (history[i].u.pipe.fds[1] == fd) {
 947                                 assert(!history[i].u.pipe.closed[1]);
 948                                 history[i].u.pipe.closed[1] = true;
 949                                 if (history[i].u.pipe.closed[0])
 950                                         history[i].cleanup = NULL;
 951                                 goto out;
 952                         }
 953                         break;
 954                 case FAILTEST_OPEN:
 955                         if (history[i].u.open.ret == fd) {
 956                                 assert((void *)history[i].cleanup
 957                                        == (void *)cleanup_open);
 958                                 history[i].cleanup = NULL;
 959                                 goto out;
 960                         }
 961                         break;
 962                 default:
 963                         break;
 964                 }
 965         }
 966
 967 out:
 968         locks = add_lock(locks, fd, 0, off_max(), F_UNLCK);
 969         return close(fd);
 970 }
 971
 972 /* Zero length means "to end of file" */
 973 static off_t end_of(off_t start, off_t len)
 974 {
 975         if (len == 0)
 976                 return off_max();
 977         return start + len - 1;
 978 }
 979
 980 /* FIXME: This only handles locks, really. */
 981 int failtest_fcntl(int fd, const char *file, unsigned line, int cmd, ...)
 982 {
 983         struct failtest_call *p;
 984         struct fcntl_call call;
 985         va_list ap;
 986
 987         call.fd = fd;
 988         call.cmd = cmd;
 989
 990         /* Argument extraction. */
 991         switch (cmd) {
 992         case F_SETFL:
 993         case F_SETFD:
 994                 va_start(ap, cmd);
 995                 call.arg.l = va_arg(ap, long);
 996                 va_end(ap);
 997                 return fcntl(fd, cmd, call.arg.l);
 998         case F_GETFD:
 999         case F_GETFL:
1000                 return fcntl(fd, cmd);
1001         case F_GETLK:
1002                 get_locks();
1003                 va_start(ap, cmd);
1004                 call.arg.fl = *va_arg(ap, struct flock *);
1005                 va_end(ap);
1006                 return fcntl(fd, cmd, &call.arg.fl);
1007         case F_SETLK:
1008         case F_SETLKW:
1009                 va_start(ap, cmd);
1010                 call.arg.fl = *va_arg(ap, struct flock *);
1011                 va_end(ap);
1012                 break;
1013         default:
1014                 /* This means you need to implement it here. */
1015                 err(1, "failtest: unknown fcntl %u", cmd);
1016         }
1017
1018         p = add_history(FAILTEST_FCNTL, file, line, &call);
1019
1020         if (should_fail(p)) {
1021                 p->u.fcntl.ret = -1;
1022                 if (p->u.fcntl.cmd == F_SETLK)
1023                         p->error = EAGAIN;
1024                 else
1025                         p->error = EDEADLK;
1026         } else {
1027                 get_locks();
1028                 p->u.fcntl.ret = fcntl(p->u.fcntl.fd, p->u.fcntl.cmd,
1029                                        &p->u.fcntl.arg.fl);
1030                 if (p->u.fcntl.ret == -1)
1031                         p->error = errno;
1032                 else {
1033                         /* We don't handle anything else yet. */
1034                         assert(p->u.fcntl.arg.fl.l_whence == SEEK_SET);
1035                         locks = add_lock(locks,
1036                                          p->u.fcntl.fd,
1037                                          p->u.fcntl.arg.fl.l_start,
1038                                          end_of(p->u.fcntl.arg.fl.l_start,
1039                                                 p->u.fcntl.arg.fl.l_len),
1040                                          p->u.fcntl.arg.fl.l_type);
1041                 }
1042         }
1043         errno = p->error;
1044         return p->u.fcntl.ret;
1045 }
1046
1047 pid_t failtest_getpid(const char *file, unsigned line)
1048 {
1049         /* You must call failtest_init first! */
1050         assert(orig_pid);
1051         return orig_pid;
1052 }
1053
1054 void failtest_init(int argc, char *argv[])
1055 {
1056         unsigned int i;
1057
1058         orig_pid = getpid();
1059
1060         for (i = 1; i < argc; i++) {
1061                 if (!strncmp(argv[i], "--failpath=", strlen("--failpath="))) {
1062                         failpath = argv[i] + strlen("--failpath=");
1063                 } else if (strcmp(argv[i], "--tracepath") == 0) {
1064                         tracefd = dup(STDERR_FILENO);
1065                         failtest_timeout_ms = -1;
1066                 } else if (!strncmp(argv[i], "--debugpath=",
1067                                     strlen("--debugpath="))) {
1068                         debugpath = argv[i] + strlen("--debugpath=");
1069                 }
1070         }
1071         gettimeofday(&start, NULL);
1072 }
1073
1074 bool failtest_has_failed(void)
1075 {
1076         return control_fd != -1;
1077 }
1078
1079 void failtest_exit(int status)
1080 {
1081         if (failtest_exit_check) {
1082                 if (!failtest_exit_check(history, history_num))
1083                         child_fail(NULL, 0, "failtest_exit_check failed\n");
1084         }
1085
1086         failtest_cleanup(false, status);
1087 }