libbb/xfuncs_printf.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6  * Copyright (C) 2006 Rob Landley
   7  * Copyright (C) 2006 Denys Vlasenko
   8  *
   9  * Licensed under GPLv2, see file LICENSE in this source tree.
  10  */
  11 /* We need to have separate xfuncs.c and xfuncs_printf.c because
  12  * with current linkers, even with section garbage collection,
  13  * if *.o module references any of XXXprintf functions, you pull in
  14  * entire printf machinery. Even if you do not use the function
  15  * which uses XXXprintf.
  16  *
  17  * xfuncs.c contains functions (not necessarily xfuncs)
  18  * which do not pull in printf, directly or indirectly.
  19  * xfunc_printf.c contains those which do.
  20  */
  21 #include "libbb.h"
  22
  23
  24 /* All the functions starting with "x" call bb_error_msg_and_die() if they
  25  * fail, so callers never need to check for errors.  If it returned, it
  26  * succeeded. */
  27
  28 void FAST_FUNC bb_die_memory_exhausted(void)
  29 {
  30         bb_simple_error_msg_and_die(bb_msg_memory_exhausted);
  31 }
  32
  33 #ifndef DMALLOC
  34 /* dmalloc provides variants of these that do abort() on failure.
  35  * Since dmalloc's prototypes overwrite the impls here as they are
  36  * included after these prototypes in libbb.h, all is well.
  37  */
  38 // Warn if we can't allocate size bytes of memory.
  39 void* FAST_FUNC malloc_or_warn(size_t size)
  40 {
  41         void *ptr = malloc(size);
  42         if (ptr == NULL && size != 0)
  43                 bb_simple_error_msg(bb_msg_memory_exhausted);
  44         return ptr;
  45 }
  46
  47 // Die if we can't allocate size bytes of memory.
  48 void* FAST_FUNC xmalloc(size_t size)
  49 {
  50         void *ptr = malloc(size);
  51         if (ptr == NULL && size != 0)
  52                 bb_die_memory_exhausted();
  53         return ptr;
  54 }
  55
  56 // Die if we can't resize previously allocated memory.  (This returns a pointer
  57 // to the new memory, which may or may not be the same as the old memory.
  58 // It'll copy the contents to a new chunk and free the old one if necessary.)
  59 void* FAST_FUNC xrealloc(void *ptr, size_t size)
  60 {
  61         ptr = realloc(ptr, size);
  62         if (ptr == NULL && size != 0)
  63                 bb_die_memory_exhausted();
  64         return ptr;
  65 }
  66 #endif /* DMALLOC */
  67
  68 // Die if we can't allocate and zero size bytes of memory.
  69 void* FAST_FUNC xzalloc(size_t size)
  70 {
  71         void *ptr = xmalloc(size);
  72         memset(ptr, 0, size);
  73         return ptr;
  74 }
  75
  76 // Die if we can't copy a string to freshly allocated memory.
  77 char* FAST_FUNC xstrdup(const char *s)
  78 {
  79         char *t;
  80
  81         if (s == NULL)
  82                 return NULL;
  83
  84         t = strdup(s);
  85
  86         if (t == NULL)
  87                 bb_die_memory_exhausted();
  88
  89         return t;
  90 }
  91
  92 // Die if we can't allocate n+1 bytes (space for the null terminator) and copy
  93 // the (possibly truncated to length n) string into it.
  94 char* FAST_FUNC xstrndup(const char *s, size_t n)
  95 {
  96         char *t;
  97
  98         t = strndup(s, n);
  99
 100         if (t == NULL)
 101                 bb_die_memory_exhausted();
 102
 103         return t;
 104 }
 105
 106 void* FAST_FUNC xmemdup(const void *s, size_t n)
 107 {
 108         return memcpy(xmalloc(n), s, n);
 109 }
 110
 111 void* FAST_FUNC mmap_read(int fd, size_t size)
 112 {
 113         return mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
 114 }
 115
 116 void* FAST_FUNC mmap_anon(size_t size)
 117 {
 118         return mmap(NULL, size,
 119                         PROT_READ | PROT_WRITE,
 120                         MAP_PRIVATE | MAP_ANONYMOUS,
 121                         /* ignored: */ -1, 0);
 122 }
 123
 124 void* FAST_FUNC xmmap_anon(size_t size)
 125 {
 126         void *p = mmap_anon(size);
 127         if (p == MAP_FAILED)
 128                 bb_die_memory_exhausted();
 129         return p;
 130 }
 131
 132 // Die if we can't open a file and return a FILE* to it.
 133 // Notice we haven't got xfread(), This is for use with fscanf() and friends.
 134 FILE* FAST_FUNC xfopen(const char *path, const char *mode)
 135 {
 136         FILE *fp = fopen(path, mode);
 137         if (fp == NULL)
 138                 bb_perror_msg_and_die("can't open '%s'", path);
 139         return fp;
 140 }
 141
 142 // Die if we can't open a file and return a fd.
 143 int FAST_FUNC xopen3(const char *pathname, int flags, int mode)
 144 {
 145         int ret;
 146
 147         ret = open(pathname, flags, mode);
 148         if (ret < 0) {
 149                 bb_perror_msg_and_die("can't open '%s'", pathname);
 150         }
 151         return ret;
 152 }
 153
 154 // Die if we can't open a file and return a fd.
 155 int FAST_FUNC xopen(const char *pathname, int flags)
 156 {
 157         return xopen3(pathname, flags, 0666);
 158 }
 159
 160 // Warn if we can't open a file and return a fd.
 161 int FAST_FUNC open3_or_warn(const char *pathname, int flags, int mode)
 162 {
 163         int ret;
 164
 165         ret = open(pathname, flags, mode);
 166         if (ret < 0) {
 167                 bb_perror_msg("can't open '%s'", pathname);
 168         }
 169         return ret;
 170 }
 171
 172 // Warn if we can't open a file and return a fd.
 173 int FAST_FUNC open_or_warn(const char *pathname, int flags)
 174 {
 175         return open3_or_warn(pathname, flags, 0666);
 176 }
 177
 178 /* Die if we can't open an existing file readonly with O_NONBLOCK
 179  * and return the fd.
 180  * Note that for ioctl O_RDONLY is sufficient.
 181  */
 182 int FAST_FUNC xopen_nonblocking(const char *pathname)
 183 {
 184         return xopen(pathname, O_RDONLY | O_NONBLOCK);
 185 }
 186
 187 int FAST_FUNC xopen_as_uid_gid(const char *pathname, int flags, uid_t u, gid_t g)
 188 {
 189         int fd;
 190         uid_t old_euid = geteuid();
 191         gid_t old_egid = getegid();
 192
 193         xsetegid(g);
 194         xseteuid(u);
 195
 196         fd = xopen(pathname, flags);
 197
 198         xseteuid(old_euid);
 199         xsetegid(old_egid);
 200
 201         return fd;
 202 }
 203
 204 void FAST_FUNC xunlink(const char *pathname)
 205 {
 206         if (unlink(pathname))
 207                 bb_perror_msg_and_die("can't remove file '%s'", pathname);
 208 }
 209
 210 void FAST_FUNC xrename(const char *oldpath, const char *newpath)
 211 {
 212         if (rename(oldpath, newpath))
 213                 bb_perror_msg_and_die("can't move '%s' to '%s'", oldpath, newpath);
 214 }
 215
 216 int FAST_FUNC rename_or_warn(const char *oldpath, const char *newpath)
 217 {
 218         int n = rename(oldpath, newpath);
 219         if (n)
 220                 bb_perror_msg("can't move '%s' to '%s'", oldpath, newpath);
 221         return n;
 222 }
 223
 224 void FAST_FUNC xpipe(int *filedes)
 225 {
 226         if (pipe(filedes))
 227                 bb_simple_perror_msg_and_die("can't create pipe");
 228 }
 229
 230 void FAST_FUNC xdup2(int from, int to)
 231 {
 232         if (dup2(from, to) != to)
 233                 bb_simple_perror_msg_and_die("can't duplicate file descriptor");
 234                 //              " %d to %d", from, to);
 235 }
 236
 237 // "Renumber" opened fd
 238 void FAST_FUNC xmove_fd(int from, int to)
 239 {
 240         if (from == to)
 241                 return;
 242         xdup2(from, to);
 243         close(from);
 244 }
 245
 246 // Die with an error message if we can't write the entire buffer.
 247 void FAST_FUNC xwrite(int fd, const void *buf, size_t count)
 248 {
 249         if (count) {
 250                 ssize_t size = full_write(fd, buf, count);
 251                 if ((size_t)size != count) {
 252                         /*
 253                          * Two cases: write error immediately;
 254                          * or some writes succeeded, then we hit an error.
 255                          * In either case, errno is set.
 256                          */
 257                         bb_simple_perror_msg_and_die(
 258                                 size >= 0 ? "short write" : "write error"
 259                         );
 260                 }
 261         }
 262 }
 263 void FAST_FUNC xwrite_str(int fd, const char *str)
 264 {
 265         xwrite(fd, str, strlen(str));
 266 }
 267
 268 void FAST_FUNC xclose(int fd)
 269 {
 270         if (close(fd))
 271                 bb_simple_perror_msg_and_die("close failed");
 272 }
 273
 274 // Die with an error message if we can't lseek to the right spot.
 275 off_t FAST_FUNC xlseek(int fd, off_t offset, int whence)
 276 {
 277         off_t off = lseek(fd, offset, whence);
 278         if (off == (off_t)-1) {
 279                 bb_perror_msg_and_die("lseek(%"OFF_FMT"u, %d)", offset, whence);
 280         }
 281         return off;
 282 }
 283
 284 int FAST_FUNC xmkstemp(char *template)
 285 {
 286         int fd = mkstemp(template);
 287         if (fd < 0)
 288                 bb_perror_msg_and_die("can't create temp file '%s'", template);
 289         return fd;
 290 }
 291
 292 // Die with supplied filename if this FILE* has ferror set.
 293 void FAST_FUNC die_if_ferror(FILE *fp, const char *fn)
 294 {
 295         if (ferror(fp)) {
 296                 /* ferror doesn't set useful errno */
 297                 bb_error_msg_and_die("%s: I/O error", fn);
 298         }
 299 }
 300
 301 // Die with an error message if stdout has ferror set.
 302 void FAST_FUNC die_if_ferror_stdout(void)
 303 {
 304         die_if_ferror(stdout, bb_msg_standard_output);
 305 }
 306
 307 int FAST_FUNC fflush_all(void)
 308 {
 309         return fflush(NULL);
 310 }
 311
 312
 313 int FAST_FUNC bb_putchar(int ch)
 314 {
 315         return putchar(ch);
 316 }
 317
 318 int FAST_FUNC fputs_stdout(const char *s)
 319 {
 320         return fputs(s, stdout);
 321 }
 322
 323 /* Die with an error message if we can't copy an entire FILE* to stdout,
 324  * then close that file. */
 325 void FAST_FUNC xprint_and_close_file(FILE *file)
 326 {
 327         fflush_all();
 328         // copyfd outputs error messages for us.
 329         if (bb_copyfd_eof(fileno(file), STDOUT_FILENO) == -1)
 330                 xfunc_die();
 331
 332         fclose(file);
 333 }
 334
 335 // Die with an error message if we can't malloc() enough space and do an
 336 // sprintf() into that space.
 337 char* FAST_FUNC xasprintf(const char *format, ...)
 338 {
 339         va_list p;
 340         int r;
 341         char *string_ptr;
 342
 343         va_start(p, format);
 344         r = vasprintf(&string_ptr, format, p);
 345         va_end(p);
 346
 347         if (r < 0)
 348                 bb_die_memory_exhausted();
 349         return string_ptr;
 350 }
 351
 352 void FAST_FUNC xsetenv(const char *key, const char *value)
 353 {
 354         if (setenv(key, value, 1))
 355                 bb_die_memory_exhausted();
 356 }
 357
 358 /* Handles "VAR=VAL" strings, even those which are part of environ
 359  * _right now_
 360  */
 361 void FAST_FUNC bb_unsetenv(const char *var)
 362 {
 363         char onstack[128 - 16]; /* smaller stack setup code on x86 */
 364         char *tp;
 365
 366         tp = strchr(var, '=');
 367         if (tp) {
 368                 /* In case var was putenv'ed, we can't replace '='
 369                  * with NUL and unsetenv(var) - it won't work,
 370                  * env is modified by the replacement, unsetenv
 371                  * sees "VAR" instead of "VAR=VAL" and does not remove it!
 372                  * Horror :(
 373                  */
 374                 unsigned sz = tp - var;
 375                 if (sz < sizeof(onstack)) {
 376                         ((char*)mempcpy(onstack, var, sz))[0] = '\0';
 377                         tp = NULL;
 378                         var = onstack;
 379                 } else {
 380                         /* unlikely: very long var name */
 381                         var = tp = xstrndup(var, sz);
 382                 }
 383         }
 384         unsetenv(var);
 385         free(tp);
 386 }
 387
 388 void FAST_FUNC bb_unsetenv_and_free(char *var)
 389 {
 390         bb_unsetenv(var);
 391         free(var);
 392 }
 393
 394 // Die with an error message if we can't set gid.  (Because resource limits may
 395 // limit this user to a given number of processes, and if that fills up the
 396 // setgid() will fail and we'll _still_be_root_, which is bad.)
 397 void FAST_FUNC xsetgid(gid_t gid)
 398 {
 399         if (setgid(gid)) bb_simple_perror_msg_and_die("setgid");
 400 }
 401
 402 // Die with an error message if we can't set uid.  (See xsetgid() for why.)
 403 void FAST_FUNC xsetuid(uid_t uid)
 404 {
 405         if (setuid(uid)) bb_simple_perror_msg_and_die("setuid");
 406 }
 407
 408 void FAST_FUNC xsetegid(gid_t egid)
 409 {
 410         if (setegid(egid)) bb_simple_perror_msg_and_die("setegid");
 411 }
 412
 413 void FAST_FUNC xseteuid(uid_t euid)
 414 {
 415         if (seteuid(euid)) bb_simple_perror_msg_and_die("seteuid");
 416 }
 417
 418 int FAST_FUNC chdir_or_warn(const char *path)
 419 {
 420         int r = chdir(path);
 421         if (r != 0)
 422                 bb_perror_msg("can't change directory to '%s'", path);
 423         return r;
 424 }
 425 // Die if we can't chdir to a new path.
 426 void FAST_FUNC xchdir(const char *path)
 427 {
 428         if (chdir_or_warn(path) != 0)
 429                 xfunc_die();
 430 }
 431
 432 void FAST_FUNC xfchdir(int fd)
 433 {
 434         if (fchdir(fd))
 435                 bb_simple_perror_msg_and_die("fchdir");
 436 }
 437
 438 void FAST_FUNC xchroot(const char *path)
 439 {
 440         if (chroot(path))
 441                 bb_perror_msg_and_die("can't change root directory to '%s'", path);
 442         xchdir("/");
 443 }
 444
 445 // Print a warning message if opendir() fails, but don't die.
 446 DIR* FAST_FUNC warn_opendir(const char *path)
 447 {
 448         DIR *dp;
 449
 450         dp = opendir(path);
 451         if (!dp)
 452                 bb_perror_msg("can't open '%s'", path);
 453         return dp;
 454 }
 455
 456 // Die with an error message if opendir() fails.
 457 DIR* FAST_FUNC xopendir(const char *path)
 458 {
 459         DIR *dp;
 460
 461         dp = opendir(path);
 462         if (!dp)
 463                 bb_perror_msg_and_die("can't open '%s'", path);
 464         return dp;
 465 }
 466
 467 // Die with an error message if we can't open a new socket.
 468 int FAST_FUNC xsocket(int domain, int type, int protocol)
 469 {
 470         int r = socket(domain, type, protocol);
 471
 472         if (r < 0) {
 473                 /* Hijack vaguely related config option */
 474 #if ENABLE_VERBOSE_RESOLUTION_ERRORS
 475                 const char *s = "INET";
 476 # ifdef AF_PACKET
 477                 if (domain == AF_PACKET) s = "PACKET";
 478 # endif
 479 # ifdef AF_NETLINK
 480                 if (domain == AF_NETLINK) s = "NETLINK";
 481 # endif
 482 IF_FEATURE_IPV6(if (domain == AF_INET6) s = "INET6";)
 483                 bb_perror_msg_and_die("socket(AF_%s,%d,%d)", s, type, protocol);
 484 #else
 485                 bb_simple_perror_msg_and_die("socket");
 486 #endif
 487         }
 488
 489         return r;
 490 }
 491
 492 // Die with an error message if we can't bind a socket to an address.
 493 void FAST_FUNC xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen)
 494 {
 495         if (bind(sockfd, my_addr, addrlen)) bb_simple_perror_msg_and_die("bind");
 496 }
 497
 498 // Die with an error message if we can't listen for connections on a socket.
 499 void FAST_FUNC xlisten(int s, int backlog)
 500 {
 501         if (listen(s, backlog)) bb_simple_perror_msg_and_die("listen");
 502 }
 503
 504 /* Die with an error message if sendto failed.
 505  * Return bytes sent otherwise  */
 506 ssize_t FAST_FUNC xsendto(int s, const void *buf, size_t len, const struct sockaddr *to,
 507                                 socklen_t tolen)
 508 {
 509         ssize_t ret = sendto(s, buf, len, 0, to, tolen);
 510         if (ret < 0) {
 511                 if (ENABLE_FEATURE_CLEAN_UP)
 512                         close(s);
 513                 bb_simple_perror_msg_and_die("sendto");
 514         }
 515         return ret;
 516 }
 517
 518 // xstat() - a stat() which dies on failure with meaningful error message
 519 void FAST_FUNC xstat(const char *name, struct stat *stat_buf)
 520 {
 521         if (stat(name, stat_buf))
 522                 bb_perror_msg_and_die("can't stat '%s'", name);
 523 }
 524
 525 void FAST_FUNC xfstat(int fd, struct stat *stat_buf, const char *errmsg)
 526 {
 527         /* errmsg is usually a file name, but not always:
 528          * xfstat may be called in a spot where file name is no longer
 529          * available, and caller may give e.g. "can't stat input file" string.
 530          */
 531         if (fstat(fd, stat_buf))
 532                 bb_simple_perror_msg_and_die(errmsg);
 533 }
 534
 535 #if ENABLE_SELINUX
 536 // selinux_or_die() - die if SELinux is disabled.
 537 void FAST_FUNC selinux_or_die(void)
 538 {
 539         int rc = is_selinux_enabled();
 540         if (rc == 0) {
 541                 bb_simple_error_msg_and_die("SELinux is disabled");
 542         } else if (rc < 0) {
 543                 bb_simple_error_msg_and_die("is_selinux_enabled() failed");
 544         }
 545 }
 546 #else
 547 /* not defined, other code must have no calls to it */
 548 #endif
 549
 550 int FAST_FUNC ioctl_or_perror_and_die(int fd, unsigned request, void *argp, const char *fmt,...)
 551 {
 552         int ret;
 553         va_list p;
 554
 555         ret = ioctl(fd, request, argp);
 556         if (ret < 0) {
 557                 va_start(p, fmt);
 558                 bb_verror_msg(fmt, p, strerror(errno));
 559                 /* xfunc_die can actually longjmp, so be nice */
 560                 va_end(p);
 561                 xfunc_die();
 562         }
 563         return ret;
 564 }
 565
 566 int FAST_FUNC ioctl_or_perror(int fd, unsigned request, void *argp, const char *fmt,...)
 567 {
 568         va_list p;
 569         int ret = ioctl(fd, request, argp);
 570
 571         if (ret < 0) {
 572                 va_start(p, fmt);
 573                 bb_verror_msg(fmt, p, strerror(errno));
 574                 va_end(p);
 575         }
 576         return ret;
 577 }
 578
 579 #if ENABLE_IOCTL_HEX2STR_ERROR
 580 int FAST_FUNC bb_ioctl_or_warn(int fd, unsigned request, void *argp, const char *ioctl_name)
 581 {
 582         int ret;
 583
 584         ret = ioctl(fd, request, argp);
 585         if (ret < 0)
 586                 bb_simple_perror_msg(ioctl_name);
 587         return ret;
 588 }
 589 int FAST_FUNC bb_xioctl(int fd, unsigned request, void *argp, const char *ioctl_name)
 590 {
 591         int ret;
 592
 593         ret = ioctl(fd, request, argp);
 594         if (ret < 0)
 595                 bb_simple_perror_msg_and_die(ioctl_name);
 596         return ret;
 597 }
 598 #else
 599 int FAST_FUNC bb_ioctl_or_warn(int fd, unsigned request, void *argp)
 600 {
 601         int ret;
 602
 603         ret = ioctl(fd, request, argp);
 604         if (ret < 0)
 605                 bb_perror_msg("ioctl %#x failed", request);
 606         return ret;
 607 }
 608 int FAST_FUNC bb_xioctl(int fd, unsigned request, void *argp)
 609 {
 610         int ret;
 611
 612         ret = ioctl(fd, request, argp);
 613         if (ret < 0)
 614                 bb_perror_msg_and_die("ioctl %#x failed", request);
 615         return ret;
 616 }
 617 #endif
 618
 619 char* FAST_FUNC xmalloc_ttyname(int fd)
 620 {
 621         char buf[128];
 622         int r = ttyname_r(fd, buf, sizeof(buf) - 1);
 623         if (r)
 624                 return NULL;
 625         return xstrdup(buf);
 626 }
 627
 628 void FAST_FUNC generate_uuid(uint8_t *buf)
 629 {
 630         /* http://www.ietf.org/rfc/rfc4122.txt
 631          *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 632          * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 633          * |                          time_low                             |
 634          * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 635          * |       time_mid                |         time_hi_and_version   |
 636          * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 637          * |clk_seq_and_variant            |         node (0-1)            |
 638          * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 639          * |                         node (2-5)                            |
 640          * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 641          * IOW, uuid has this layout:
 642          * uint32_t time_low (big endian)
 643          * uint16_t time_mid (big endian)
 644          * uint16_t time_hi_and_version (big endian)
 645          *  version is a 4-bit field:
 646          *   1 Time-based
 647          *   2 DCE Security, with embedded POSIX UIDs
 648          *   3 Name-based (MD5)
 649          *   4 Randomly generated
 650          *   5 Name-based (SHA-1)
 651          * uint16_t clk_seq_and_variant (big endian)
 652          *  variant is a 3-bit field:
 653          *   0xx Reserved, NCS backward compatibility
 654          *   10x The variant specified in rfc4122
 655          *   110 Reserved, Microsoft backward compatibility
 656          *   111 Reserved for future definition
 657          * uint8_t node[6]
 658          *
 659          * For version 4, these bits are set/cleared:
 660          * time_hi_and_version & 0x0fff | 0x4000
 661          * clk_seq_and_variant & 0x3fff | 0x8000
 662          */
 663         pid_t pid;
 664         int i;
 665
 666         open_read_close("/dev/urandom", buf, 16);
 667         /* Paranoia. /dev/urandom may be missing.
 668          * rand() is guaranteed to generate at least [0, 2^15) range,
 669          * but lowest bits in some libc are not so "random".
 670          */
 671         srand(monotonic_us()); /* pulls in printf */
 672         pid = getpid();
 673         while (1) {
 674                 for (i = 0; i < 16; i++)
 675                         buf[i] ^= rand() >> 5;
 676                 if (pid == 0)
 677                         break;
 678                 srand(pid);
 679                 pid = 0;
 680         }
 681
 682         /* version = 4 */
 683         buf[4 + 2    ] = (buf[4 + 2    ] & 0x0f) | 0x40;
 684         /* variant = 10x */
 685         buf[4 + 2 + 2] = (buf[4 + 2 + 2] & 0x3f) | 0x80;
 686 }
 687
 688 #if BB_MMU
 689 pid_t FAST_FUNC xfork(void)
 690 {
 691         pid_t pid;
 692         pid = fork();
 693         if (pid < 0) /* wtf? */
 694                 bb_simple_perror_msg_and_die("vfork"+1);
 695         return pid;
 696 }
 697 #endif
 698
 699 void FAST_FUNC xvfork_parent_waits_and_exits(void)
 700 {
 701         pid_t pid;
 702
 703         fflush_all();
 704         pid = xvfork();
 705         if (pid > 0) {
 706                 /* Parent */
 707                 int exit_status = wait_for_exitstatus(pid);
 708                 if (WIFSIGNALED(exit_status))
 709                         kill_myself_with_sig(WTERMSIG(exit_status));
 710                 _exit(WEXITSTATUS(exit_status));
 711         }
 712         /* Child continues */
 713 }
 714
 715 // Useful when we do know that pid is valid, and we just want to wait
 716 // for it to exit. Not existing pid is fatal. waitpid() status is not returned.
 717 int FAST_FUNC wait_for_exitstatus(pid_t pid)
 718 {
 719         int exit_status, n;
 720
 721         n = safe_waitpid(pid, &exit_status, 0);
 722         if (n < 0)
 723                 bb_simple_perror_msg_and_die("waitpid");
 724         return exit_status;
 725 }
 726
 727 void FAST_FUNC xsettimeofday(const struct timeval *tv)
 728 {
 729         if (settimeofday(tv, NULL))
 730                 bb_simple_perror_msg_and_die("settimeofday");
 731 }
 732
 733 void FAST_FUNC xgettimeofday(struct timeval *tv)
 734 {
 735 #if 0
 736         if (gettimeofday(tv, NULL))
 737                 bb_simple_perror_msg_and_die("gettimeofday");
 738 #else
 739         /* Never fails on Linux */
 740         gettimeofday(tv, NULL);
 741 #endif
 742 }