libiberty/pex-unix.c

   1 /* Utilities to execute a program in a subprocess (possibly linked by pipes
   2    with other subprocesses), and wait for it.  Generic Unix version
   3    (also used for UWIN and VMS).
   4    Copyright (C) 1996-2017 Free Software Foundation, Inc.
   5
   6 This file is part of the libiberty library.
   7 Libiberty is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU Library General Public
   9 License as published by the Free Software Foundation; either
  10 version 2 of the License, or (at your option) any later version.
  11
  12 Libiberty is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 Library General Public License for more details.
  16
  17 You should have received a copy of the GNU Library General Public
  18 License along with libiberty; see the file COPYING.LIB.  If not,
  19 write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22 #include "config.h"
  23 #include "libiberty.h"
  24 #include "pex-common.h"
  25 #include "environ.h"
  26
  27 #include <stdio.h>
  28 #include <signal.h>
  29 #include <errno.h>
  30 #ifdef NEED_DECLARATION_ERRNO
  31 extern int errno;
  32 #endif
  33 #ifdef HAVE_STDLIB_H
  34 #include <stdlib.h>
  35 #endif
  36 #ifdef HAVE_STRING_H
  37 #include <string.h>
  38 #endif
  39 #ifdef HAVE_UNISTD_H
  40 #include <unistd.h>
  41 #endif
  42
  43 #include <sys/types.h>
  44
  45 #ifdef HAVE_FCNTL_H
  46 #include <fcntl.h>
  47 #endif
  48 #ifdef HAVE_SYS_WAIT_H
  49 #include <sys/wait.h>
  50 #endif
  51 #ifdef HAVE_GETRUSAGE
  52 #include <sys/time.h>
  53 #include <sys/resource.h>
  54 #endif
  55 #ifdef HAVE_SYS_STAT_H
  56 #include <sys/stat.h>
  57 #endif
  58 #ifdef HAVE_PROCESS_H
  59 #include <process.h>
  60 #endif
  61
  62 #ifdef vfork /* Autoconf may define this to fork for us. */
  63 # define VFORK_STRING "fork"
  64 #else
  65 # define VFORK_STRING "vfork"
  66 #endif
  67 #ifdef HAVE_VFORK_H
  68 #include <vfork.h>
  69 #endif
  70 #if defined(VMS) && defined (__LONG_POINTERS)
  71 #ifndef __CHAR_PTR32
  72 typedef char * __char_ptr32
  73 __attribute__ ((mode (SI)));
  74 #endif
  75
  76 typedef __char_ptr32 *__char_ptr_char_ptr32
  77 __attribute__ ((mode (SI)));
  78
  79 /* Return a 32 bit pointer to an array of 32 bit pointers
  80    given a 64 bit pointer to an array of 64 bit pointers.  */
  81
  82 static __char_ptr_char_ptr32
  83 to_ptr32 (char **ptr64)
  84 {
  85   int argc;
  86   __char_ptr_char_ptr32 short_argv;
  87
  88   /* Count number of arguments.  */
  89   for (argc = 0; ptr64[argc] != NULL; argc++)
  90     ;
  91
  92   /* Reallocate argv with 32 bit pointers.  */
  93   short_argv = (__char_ptr_char_ptr32) decc$malloc
  94     (sizeof (__char_ptr32) * (argc + 1));
  95
  96   for (argc = 0; ptr64[argc] != NULL; argc++)
  97     short_argv[argc] = (__char_ptr32) decc$strdup (ptr64[argc]);
  98
  99   short_argv[argc] = (__char_ptr32) 0;
 100   return short_argv;
 101
 102 }
 103 #else
 104 #define to_ptr32(argv) argv
 105 #endif
 106
 107 /* File mode to use for private and world-readable files.  */
 108
 109 #if defined (S_IRUSR) && defined (S_IWUSR) && defined (S_IRGRP) && defined (S_IWGRP) && defined (S_IROTH) && defined (S_IWOTH)
 110 #define PUBLIC_MODE  \
 111     (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH)
 112 #else
 113 #define PUBLIC_MODE 0666
 114 #endif
 115
 116 /* Get the exit status of a particular process, and optionally get the
 117    time that it took.  This is simple if we have wait4, slightly
 118    harder if we have waitpid, and is a pain if we only have wait.  */
 119
 120 static pid_t pex_wait (struct pex_obj *, pid_t, int *, struct pex_time *);
 121
 122 #ifdef HAVE_WAIT4
 123
 124 static pid_t
 125 pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status,
 126           struct pex_time *time)
 127 {
 128   pid_t ret;
 129   struct rusage r;
 130
 131 #ifdef HAVE_WAITPID
 132   if (time == NULL)
 133     return waitpid (pid, status, 0);
 134 #endif
 135
 136   ret = wait4 (pid, status, 0, &r);
 137
 138   if (time != NULL)
 139     {
 140       time->user_seconds = r.ru_utime.tv_sec;
 141       time->user_microseconds= r.ru_utime.tv_usec;
 142       time->system_seconds = r.ru_stime.tv_sec;
 143       time->system_microseconds= r.ru_stime.tv_usec;
 144     }
 145
 146   return ret;
 147 }
 148
 149 #else /* ! defined (HAVE_WAIT4) */
 150
 151 #ifdef HAVE_WAITPID
 152
 153 #ifndef HAVE_GETRUSAGE
 154
 155 static pid_t
 156 pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status,
 157           struct pex_time *time)
 158 {
 159   if (time != NULL)
 160     memset (time, 0, sizeof (struct pex_time));
 161   return waitpid (pid, status, 0);
 162 }
 163
 164 #else /* defined (HAVE_GETRUSAGE) */
 165
 166 static pid_t
 167 pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status,
 168           struct pex_time *time)
 169 {
 170   struct rusage r1, r2;
 171   pid_t ret;
 172
 173   if (time == NULL)
 174     return waitpid (pid, status, 0);
 175
 176   getrusage (RUSAGE_CHILDREN, &r1);
 177
 178   ret = waitpid (pid, status, 0);
 179   if (ret < 0)
 180     return ret;
 181
 182   getrusage (RUSAGE_CHILDREN, &r2);
 183
 184   time->user_seconds = r2.ru_utime.tv_sec - r1.ru_utime.tv_sec;
 185   time->user_microseconds = r2.ru_utime.tv_usec - r1.ru_utime.tv_usec;
 186   if (r2.ru_utime.tv_usec < r1.ru_utime.tv_usec)
 187     {
 188       --time->user_seconds;
 189       time->user_microseconds += 1000000;
 190     }
 191
 192   time->system_seconds = r2.ru_stime.tv_sec - r1.ru_stime.tv_sec;
 193   time->system_microseconds = r2.ru_stime.tv_usec - r1.ru_stime.tv_usec;
 194   if (r2.ru_stime.tv_usec < r1.ru_stime.tv_usec)
 195     {
 196       --time->system_seconds;
 197       time->system_microseconds += 1000000;
 198     }
 199
 200   return ret;
 201 }
 202
 203 #endif /* defined (HAVE_GETRUSAGE) */
 204
 205 #else /* ! defined (HAVE_WAITPID) */
 206
 207 struct status_list
 208 {
 209   struct status_list *next;
 210   pid_t pid;
 211   int status;
 212   struct pex_time time;
 213 };
 214
 215 static pid_t
 216 pex_wait (struct pex_obj *obj, pid_t pid, int *status, struct pex_time *time)
 217 {
 218   struct status_list **pp;
 219
 220   for (pp = (struct status_list **) &obj->sysdep;
 221        *pp != NULL;
 222        pp = &(*pp)->next)
 223     {
 224       if ((*pp)->pid == pid)
 225         {
 226           struct status_list *p;
 227
 228           p = *pp;
 229           *status = p->status;
 230           if (time != NULL)
 231             *time = p->time;
 232           *pp = p->next;
 233           free (p);
 234           return pid;
 235         }
 236     }
 237
 238   while (1)
 239     {
 240       pid_t cpid;
 241       struct status_list *psl;
 242       struct pex_time pt;
 243 #ifdef HAVE_GETRUSAGE
 244       struct rusage r1, r2;
 245 #endif
 246
 247       if (time != NULL)
 248         {
 249 #ifdef HAVE_GETRUSAGE
 250           getrusage (RUSAGE_CHILDREN, &r1);
 251 #else
 252           memset (&pt, 0, sizeof (struct pex_time));
 253 #endif
 254         }
 255
 256       cpid = wait (status);
 257
 258 #ifdef HAVE_GETRUSAGE
 259       if (time != NULL && cpid >= 0)
 260         {
 261           getrusage (RUSAGE_CHILDREN, &r2);
 262
 263           pt.user_seconds = r2.ru_utime.tv_sec - r1.ru_utime.tv_sec;
 264           pt.user_microseconds = r2.ru_utime.tv_usec - r1.ru_utime.tv_usec;
 265           if (pt.user_microseconds < 0)
 266             {
 267               --pt.user_seconds;
 268               pt.user_microseconds += 1000000;
 269             }
 270
 271           pt.system_seconds = r2.ru_stime.tv_sec - r1.ru_stime.tv_sec;
 272           pt.system_microseconds = r2.ru_stime.tv_usec - r1.ru_stime.tv_usec;
 273           if (pt.system_microseconds < 0)
 274             {
 275               --pt.system_seconds;
 276               pt.system_microseconds += 1000000;
 277             }
 278         }
 279 #endif
 280
 281       if (cpid < 0 || cpid == pid)
 282         {
 283           if (time != NULL)
 284             *time = pt;
 285           return cpid;
 286         }
 287
 288       psl = XNEW (struct status_list);
 289       psl->pid = cpid;
 290       psl->status = *status;
 291       if (time != NULL)
 292         psl->time = pt;
 293       psl->next = (struct status_list *) obj->sysdep;
 294       obj->sysdep = (void *) psl;
 295     }
 296 }
 297
 298 #endif /* ! defined (HAVE_WAITPID) */
 299 #endif /* ! defined (HAVE_WAIT4) */
 300
 301 static void pex_child_error (struct pex_obj *, const char *, const char *, int)
 302      ATTRIBUTE_NORETURN;
 303 static int pex_unix_open_read (struct pex_obj *, const char *, int);
 304 static int pex_unix_open_write (struct pex_obj *, const char *, int, int);
 305 static pid_t pex_unix_exec_child (struct pex_obj *, int, const char *,
 306                                  char * const *, char * const *,
 307                                  int, int, int, int,
 308                                  const char **, int *);
 309 static int pex_unix_close (struct pex_obj *, int);
 310 static int pex_unix_wait (struct pex_obj *, pid_t, int *, struct pex_time *,
 311                           int, const char **, int *);
 312 static int pex_unix_pipe (struct pex_obj *, int *, int);
 313 static FILE *pex_unix_fdopenr (struct pex_obj *, int, int);
 314 static FILE *pex_unix_fdopenw (struct pex_obj *, int, int);
 315 static void pex_unix_cleanup (struct pex_obj *);
 316
 317 /* The list of functions we pass to the common routines.  */
 318
 319 const struct pex_funcs funcs =
 320 {
 321   pex_unix_open_read,
 322   pex_unix_open_write,
 323   pex_unix_exec_child,
 324   pex_unix_close,
 325   pex_unix_wait,
 326   pex_unix_pipe,
 327   pex_unix_fdopenr,
 328   pex_unix_fdopenw,
 329   pex_unix_cleanup
 330 };
 331
 332 /* Return a newly initialized pex_obj structure.  */
 333
 334 struct pex_obj *
 335 pex_init (int flags, const char *pname, const char *tempbase)
 336 {
 337   return pex_init_common (flags, pname, tempbase, &funcs);
 338 }
 339
 340 /* Open a file for reading.  */
 341
 342 static int
 343 pex_unix_open_read (struct pex_obj *obj ATTRIBUTE_UNUSED, const char *name,
 344                     int binary ATTRIBUTE_UNUSED)
 345 {
 346   return open (name, O_RDONLY);
 347 }
 348
 349 /* Open a file for writing.  */
 350
 351 static int
 352 pex_unix_open_write (struct pex_obj *obj ATTRIBUTE_UNUSED, const char *name,
 353                      int binary ATTRIBUTE_UNUSED, int append)
 354 {
 355   /* Note that we can't use O_EXCL here because gcc may have already
 356      created the temporary file via make_temp_file.  */
 357   return open (name, O_WRONLY | O_CREAT
 358                      | (append ? O_APPEND : O_TRUNC), PUBLIC_MODE);
 359 }
 360
 361 /* Close a file.  */
 362
 363 static int
 364 pex_unix_close (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd)
 365 {
 366   return close (fd);
 367 }
 368
 369 /* Report an error from a child process.  We don't use stdio routines,
 370    because we might be here due to a vfork call.  */
 371
 372 static void
 373 pex_child_error (struct pex_obj *obj, const char *executable,
 374                  const char *errmsg, int err)
 375 {
 376   int retval = 0;
 377 #define writeerr(s) retval |= (write (STDERR_FILE_NO, s, strlen (s)) < 0)
 378   writeerr (obj->pname);
 379   writeerr (": error trying to exec '");
 380   writeerr (executable);
 381   writeerr ("': ");
 382   writeerr (errmsg);
 383   writeerr (": ");
 384   writeerr (xstrerror (err));
 385   writeerr ("\n");
 386 #undef writeerr
 387   /* Exit with -2 if the error output failed, too.  */
 388   _exit (retval == 0 ? -1 : -2);
 389 }
 390
 391 /* Execute a child.  */
 392
 393 #if defined(HAVE_SPAWNVE) && defined(HAVE_SPAWNVPE)
 394 /* Implementation of pex->exec_child using the Cygwin spawn operation.  */
 395
 396 /* Subroutine of pex_unix_exec_child.  Move OLD_FD to a new file descriptor
 397    to be stored in *PNEW_FD, save the flags in *PFLAGS, and arrange for the
 398    saved copy to be close-on-exec.  Move CHILD_FD into OLD_FD.  If CHILD_FD
 399    is -1, OLD_FD is to be closed.  Return -1 on error.  */
 400
 401 static int
 402 save_and_install_fd(int *pnew_fd, int *pflags, int old_fd, int child_fd)
 403 {
 404   int new_fd, flags;
 405
 406   flags = fcntl (old_fd, F_GETFD);
 407
 408   /* If we could not retrieve the flags, then OLD_FD was not open.  */
 409   if (flags < 0)
 410     {
 411       new_fd = -1, flags = 0;
 412       if (child_fd >= 0 && dup2 (child_fd, old_fd) < 0)
 413         return -1;
 414     }
 415   /* If we wish to close OLD_FD, just mark it CLOEXEC.  */
 416   else if (child_fd == -1)
 417     {
 418       new_fd = old_fd;
 419       if ((flags & FD_CLOEXEC) == 0 && fcntl (old_fd, F_SETFD, FD_CLOEXEC) < 0)
 420         return -1;
 421     }
 422   /* Otherwise we need to save a copy of OLD_FD before installing CHILD_FD.  */
 423   else
 424     {
 425 #ifdef F_DUPFD_CLOEXEC
 426       new_fd = fcntl (old_fd, F_DUPFD_CLOEXEC, 3);
 427       if (new_fd < 0)
 428         return -1;
 429 #else
 430       /* Prefer F_DUPFD over dup in order to avoid getting a new fd
 431          in the range 0-2, right where a new stderr fd might get put.  */
 432       new_fd = fcntl (old_fd, F_DUPFD, 3);
 433       if (new_fd < 0)
 434         return -1;
 435       if (fcntl (new_fd, F_SETFD, FD_CLOEXEC) < 0)
 436         return -1;
 437 #endif
 438       if (dup2 (child_fd, old_fd) < 0)
 439         return -1;
 440     }
 441
 442   *pflags = flags;
 443   if (pnew_fd)
 444     *pnew_fd = new_fd;
 445   else if (new_fd != old_fd)
 446     abort ();
 447
 448   return 0;
 449 }
 450
 451 /* Subroutine of pex_unix_exec_child.  Move SAVE_FD back to OLD_FD
 452    restoring FLAGS.  If SAVE_FD < 0, OLD_FD is to be closed.  */
 453
 454 static int
 455 restore_fd(int old_fd, int save_fd, int flags)
 456 {
 457   /* For SAVE_FD < 0, all we have to do is restore the
 458      "closed-ness" of the original.  */
 459   if (save_fd < 0)
 460     return close (old_fd);
 461
 462   /* For SAVE_FD == OLD_FD, all we have to do is restore the
 463      original setting of the CLOEXEC flag.  */
 464   if (save_fd == old_fd)
 465     {
 466       if (flags & FD_CLOEXEC)
 467         return 0;
 468       return fcntl (old_fd, F_SETFD, flags);
 469     }
 470
 471   /* Otherwise we have to move the descriptor back, restore the flags,
 472      and close the saved copy.  */
 473 #ifdef HAVE_DUP3
 474   if (flags == FD_CLOEXEC)
 475     {
 476       if (dup3 (save_fd, old_fd, O_CLOEXEC) < 0)
 477         return -1;
 478     }
 479   else
 480 #endif
 481     {
 482       if (dup2 (save_fd, old_fd) < 0)
 483         return -1;
 484       if (flags != 0 && fcntl (old_fd, F_SETFD, flags) < 0)
 485         return -1;
 486     }
 487   return close (save_fd);
 488 }
 489
 490 static pid_t
 491 pex_unix_exec_child (struct pex_obj *obj ATTRIBUTE_UNUSED,
 492                      int flags, const char *executable,
 493                      char * const * argv, char * const * env,
 494                      int in, int out, int errdes, int toclose,
 495                      const char **errmsg, int *err)
 496 {
 497   int fl_in = 0, fl_out = 0, fl_err = 0, fl_tc = 0;
 498   int save_in = -1, save_out = -1, save_err = -1;
 499   int max, retries;
 500   pid_t pid;
 501
 502   if (flags & PEX_STDERR_TO_STDOUT)
 503     errdes = out;
 504
 505   /* We need the three standard file descriptors to be set up as for
 506      the child before we perform the spawn.  The file descriptors for
 507      the parent need to be moved and marked for close-on-exec.  */
 508   if (in != STDIN_FILE_NO
 509       && save_and_install_fd (&save_in, &fl_in, STDIN_FILE_NO, in) < 0)
 510     goto error_dup2;
 511   if (out != STDOUT_FILE_NO
 512       && save_and_install_fd (&save_out, &fl_out, STDOUT_FILE_NO, out) < 0)
 513     goto error_dup2;
 514   if (errdes != STDERR_FILE_NO
 515       && save_and_install_fd (&save_err, &fl_err, STDERR_FILE_NO, errdes) < 0)
 516     goto error_dup2;
 517   if (toclose >= 0
 518       && save_and_install_fd (NULL, &fl_tc, toclose, -1) < 0)
 519     goto error_dup2;
 520
 521   /* Now that we've moved the file descriptors for the child into place,
 522      close the originals.  Be careful not to close any of the standard
 523      file descriptors that we just set up.  */
 524   max = -1;
 525   if (errdes >= 0)
 526     max = STDERR_FILE_NO;
 527   else if (out >= 0)
 528     max = STDOUT_FILE_NO;
 529   else if (in >= 0)
 530     max = STDIN_FILE_NO;
 531   if (in > max)
 532     close (in);
 533   if (out > max)
 534     close (out);
 535   if (errdes > max && errdes != out)
 536     close (errdes);
 537
 538   /* If we were not given an environment, use the global environment.  */
 539   if (env == NULL)
 540     env = environ;
 541
 542   /* Launch the program.  If we get EAGAIN (normally out of pid's), try
 543      again a few times with increasing backoff times.  */
 544   retries = 0;
 545   while (1)
 546     {
 547       typedef const char * const *cc_cp;
 548
 549       if (flags & PEX_SEARCH)
 550         pid = spawnvpe (_P_NOWAITO, executable, (cc_cp)argv, (cc_cp)env);
 551       else
 552         pid = spawnve (_P_NOWAITO, executable, (cc_cp)argv, (cc_cp)env);
 553
 554       if (pid > 0)
 555         break;
 556
 557       *err = errno;
 558       *errmsg = "spawn";
 559       if (errno != EAGAIN || ++retries == 4)
 560         return (pid_t) -1;
 561       sleep (1 << retries);
 562     }
 563
 564   /* Success.  Restore the parent's file descriptors that we saved above.  */
 565   if (toclose >= 0
 566       && restore_fd (toclose, toclose, fl_tc) < 0)
 567     goto error_dup2;
 568   if (in != STDIN_FILE_NO
 569       && restore_fd (STDIN_FILE_NO, save_in, fl_in) < 0)
 570     goto error_dup2;
 571   if (out != STDOUT_FILE_NO
 572       && restore_fd (STDOUT_FILE_NO, save_out, fl_out) < 0)
 573     goto error_dup2;
 574   if (errdes != STDERR_FILE_NO
 575       && restore_fd (STDERR_FILE_NO, save_err, fl_err) < 0)
 576     goto error_dup2;
 577
 578   return pid;
 579
 580  error_dup2:
 581   *err = errno;
 582   *errmsg = "dup2";
 583   return (pid_t) -1;
 584 }
 585
 586 #else
 587 /* Implementation of pex->exec_child using standard vfork + exec.  */
 588
 589 static pid_t
 590 pex_unix_exec_child (struct pex_obj *obj, int flags, const char *executable,
 591                      char * const * argv, char * const * env,
 592                      int in, int out, int errdes,
 593                      int toclose, const char **errmsg, int *err)
 594 {
 595   pid_t pid;
 596
 597   /* We declare these to be volatile to avoid warnings from gcc about
 598      them being clobbered by vfork.  */
 599   volatile int sleep_interval;
 600   volatile int retries;
 601
 602   /* We vfork and then set environ in the child before calling execvp.
 603      This clobbers the parent's environ so we need to restore it.
 604      It would be nice to use one of the exec* functions that takes an
 605      environment as a parameter, but that may have portability issues.  */
 606   char **save_environ = environ;
 607
 608   sleep_interval = 1;
 609   pid = -1;
 610   for (retries = 0; retries < 4; ++retries)
 611     {
 612       pid = vfork ();
 613       if (pid >= 0)
 614         break;
 615       sleep (sleep_interval);
 616       sleep_interval *= 2;
 617     }
 618
 619   switch (pid)
 620     {
 621     case -1:
 622       *err = errno;
 623       *errmsg = VFORK_STRING;
 624       return (pid_t) -1;
 625
 626     case 0:
 627       /* Child process.  */
 628       if (in != STDIN_FILE_NO)
 629         {
 630           if (dup2 (in, STDIN_FILE_NO) < 0)
 631             pex_child_error (obj, executable, "dup2", errno);
 632           if (close (in) < 0)
 633             pex_child_error (obj, executable, "close", errno);
 634         }
 635       if (out != STDOUT_FILE_NO)
 636         {
 637           if (dup2 (out, STDOUT_FILE_NO) < 0)
 638             pex_child_error (obj, executable, "dup2", errno);
 639           if (close (out) < 0)
 640             pex_child_error (obj, executable, "close", errno);
 641         }
 642       if (errdes != STDERR_FILE_NO)
 643         {
 644           if (dup2 (errdes, STDERR_FILE_NO) < 0)
 645             pex_child_error (obj, executable, "dup2", errno);
 646           if (close (errdes) < 0)
 647             pex_child_error (obj, executable, "close", errno);
 648         }
 649       if (toclose >= 0)
 650         {
 651           if (close (toclose) < 0)
 652             pex_child_error (obj, executable, "close", errno);
 653         }
 654       if ((flags & PEX_STDERR_TO_STDOUT) != 0)
 655         {
 656           if (dup2 (STDOUT_FILE_NO, STDERR_FILE_NO) < 0)
 657             pex_child_error (obj, executable, "dup2", errno);
 658         }
 659
 660       if (env)
 661         {
 662           /* NOTE: In a standard vfork implementation this clobbers the
 663              parent's copy of environ "too" (in reality there's only one copy).
 664              This is ok as we restore it below.  */
 665           environ = (char**) env;
 666         }
 667
 668       if ((flags & PEX_SEARCH) != 0)
 669         {
 670           execvp (executable, to_ptr32 (argv));
 671           pex_child_error (obj, executable, "execvp", errno);
 672         }
 673       else
 674         {
 675           execv (executable, to_ptr32 (argv));
 676           pex_child_error (obj, executable, "execv", errno);
 677         }
 678
 679       /* NOTREACHED */
 680       return (pid_t) -1;
 681
 682     default:
 683       /* Parent process.  */
 684
 685       /* Restore environ.
 686          Note that the parent either doesn't run until the child execs/exits
 687          (standard vfork behaviour), or if it does run then vfork is behaving
 688          more like fork.  In either case we needn't worry about clobbering
 689          the child's copy of environ.  */
 690       environ = save_environ;
 691
 692       if (in != STDIN_FILE_NO)
 693         {
 694           if (close (in) < 0)
 695             {
 696               *err = errno;
 697               *errmsg = "close";
 698               return (pid_t) -1;
 699             }
 700         }
 701       if (out != STDOUT_FILE_NO)
 702         {
 703           if (close (out) < 0)
 704             {
 705               *err = errno;
 706               *errmsg = "close";
 707               return (pid_t) -1;
 708             }
 709         }
 710       if (errdes != STDERR_FILE_NO)
 711         {
 712           if (close (errdes) < 0)
 713             {
 714               *err = errno;
 715               *errmsg = "close";
 716               return (pid_t) -1;
 717             }
 718         }
 719
 720       return pid;
 721     }
 722 }
 723 #endif /* SPAWN */
 724
 725 /* Wait for a child process to complete.  */
 726
 727 static int
 728 pex_unix_wait (struct pex_obj *obj, pid_t pid, int *status,
 729                struct pex_time *time, int done, const char **errmsg,
 730                int *err)
 731 {
 732   /* If we are cleaning up when the caller didn't retrieve process
 733      status for some reason, encourage the process to go away.  */
 734   if (done)
 735     kill (pid, SIGTERM);
 736
 737   if (pex_wait (obj, pid, status, time) < 0)
 738     {
 739       *err = errno;
 740       *errmsg = "wait";
 741       return -1;
 742     }
 743
 744   return 0;
 745 }
 746
 747 /* Create a pipe.  */
 748
 749 static int
 750 pex_unix_pipe (struct pex_obj *obj ATTRIBUTE_UNUSED, int *p,
 751                int binary ATTRIBUTE_UNUSED)
 752 {
 753   return pipe (p);
 754 }
 755
 756 /* Get a FILE pointer to read from a file descriptor.  */
 757
 758 static FILE *
 759 pex_unix_fdopenr (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd,
 760                   int binary ATTRIBUTE_UNUSED)
 761 {
 762   return fdopen (fd, "r");
 763 }
 764
 765 static FILE *
 766 pex_unix_fdopenw (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd,
 767                   int binary ATTRIBUTE_UNUSED)
 768 {
 769   if (fcntl (fd, F_SETFD, FD_CLOEXEC) < 0)
 770     return NULL;
 771   return fdopen (fd, "w");
 772 }
 773
 774 static void
 775 pex_unix_cleanup (struct pex_obj *obj ATTRIBUTE_UNUSED)
 776 {
 777 #if !defined (HAVE_WAIT4) && !defined (HAVE_WAITPID)
 778   while (obj->sysdep != NULL)
 779     {
 780       struct status_list *this;
 781       struct status_list *next;
 782
 783       this = (struct status_list *) obj->sysdep;
 784       next = this->next;
 785       free (this);
 786       obj->sysdep = (void *) next;
 787     }
 788 #endif
 789 }