| 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, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005 |
| 5 | Free Software Foundation, Inc. |
| 6 | |
| 7 | This file is part of the libiberty library. |
| 8 | Libiberty is free software; you can redistribute it and/or |
| 9 | modify it under the terms of the GNU Library General Public |
| 10 | License as published by the Free Software Foundation; either |
| 11 | version 2 of the License, or (at your option) any later version. |
| 12 | |
| 13 | Libiberty is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | Library General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU Library General Public |
| 19 | License along with libiberty; see the file COPYING.LIB. If not, |
| 20 | write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, |
| 21 | Boston, MA 02110-1301, USA. */ |
| 22 | |
| 23 | #include "config.h" |
| 24 | #include "libiberty.h" |
| 25 | #include "pex-common.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 | |
| 59 | |
| 60 | #ifdef vfork /* Autoconf may define this to fork for us. */ |
| 61 | # define VFORK_STRING "fork" |
| 62 | #else |
| 63 | # define VFORK_STRING "vfork" |
| 64 | #endif |
| 65 | #ifdef HAVE_VFORK_H |
| 66 | #include <vfork.h> |
| 67 | #endif |
| 68 | #ifdef VMS |
| 69 | #define vfork() (decc$$alloc_vfork_blocks() >= 0 ? \ |
| 70 | lib$get_current_invo_context(decc$$get_vfork_jmpbuf()) : -1) |
| 71 | #endif /* VMS */ |
| 72 | |
| 73 | |
| 74 | /* File mode to use for private and world-readable files. */ |
| 75 | |
| 76 | #if defined (S_IRUSR) && defined (S_IWUSR) && defined (S_IRGRP) && defined (S_IWGRP) && defined (S_IROTH) && defined (S_IWOTH) |
| 77 | #define PUBLIC_MODE \ |
| 78 | (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH) |
| 79 | #else |
| 80 | #define PUBLIC_MODE 0666 |
| 81 | #endif |
| 82 | |
| 83 | /* Get the exit status of a particular process, and optionally get the |
| 84 | time that it took. This is simple if we have wait4, slightly |
| 85 | harder if we have waitpid, and is a pain if we only have wait. */ |
| 86 | |
| 87 | static pid_t pex_wait (struct pex_obj *, pid_t, int *, struct pex_time *); |
| 88 | |
| 89 | #ifdef HAVE_WAIT4 |
| 90 | |
| 91 | static pid_t |
| 92 | pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status, |
| 93 | struct pex_time *time) |
| 94 | { |
| 95 | pid_t ret; |
| 96 | struct rusage r; |
| 97 | |
| 98 | #ifdef HAVE_WAITPID |
| 99 | if (time == NULL) |
| 100 | return waitpid (pid, status, 0); |
| 101 | #endif |
| 102 | |
| 103 | ret = wait4 (pid, status, 0, &r); |
| 104 | |
| 105 | if (time != NULL) |
| 106 | { |
| 107 | time->user_seconds = r.ru_utime.tv_sec; |
| 108 | time->user_microseconds= r.ru_utime.tv_usec; |
| 109 | time->system_seconds = r.ru_stime.tv_sec; |
| 110 | time->system_microseconds= r.ru_stime.tv_usec; |
| 111 | } |
| 112 | |
| 113 | return ret; |
| 114 | } |
| 115 | |
| 116 | #else /* ! defined (HAVE_WAIT4) */ |
| 117 | |
| 118 | #ifdef HAVE_WAITPID |
| 119 | |
| 120 | #ifndef HAVE_GETRUSAGE |
| 121 | |
| 122 | static pid_t |
| 123 | pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status, |
| 124 | struct pex_time *time) |
| 125 | { |
| 126 | if (time != NULL) |
| 127 | memset (time, 0, sizeof (struct pex_time)); |
| 128 | return waitpid (pid, status, 0); |
| 129 | } |
| 130 | |
| 131 | #else /* defined (HAVE_GETRUSAGE) */ |
| 132 | |
| 133 | static pid_t |
| 134 | pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status, |
| 135 | struct pex_time *time) |
| 136 | { |
| 137 | struct rusage r1, r2; |
| 138 | pid_t ret; |
| 139 | |
| 140 | if (time == NULL) |
| 141 | return waitpid (pid, status, 0); |
| 142 | |
| 143 | getrusage (RUSAGE_CHILDREN, &r1); |
| 144 | |
| 145 | ret = waitpid (pid, status, 0); |
| 146 | if (ret < 0) |
| 147 | return ret; |
| 148 | |
| 149 | getrusage (RUSAGE_CHILDREN, &r2); |
| 150 | |
| 151 | time->user_seconds = r2.ru_utime.tv_sec - r1.ru_utime.tv_sec; |
| 152 | time->user_microseconds = r2.ru_utime.tv_usec - r1.ru_utime.tv_usec; |
| 153 | if (r2.ru_utime.tv_usec < r1.ru_utime.tv_usec) |
| 154 | { |
| 155 | --time->user_seconds; |
| 156 | time->user_microseconds += 1000000; |
| 157 | } |
| 158 | |
| 159 | time->system_seconds = r2.ru_stime.tv_sec - r1.ru_stime.tv_sec; |
| 160 | time->system_microseconds = r2.ru_stime.tv_usec - r1.ru_stime.tv_usec; |
| 161 | if (r2.ru_stime.tv_usec < r1.ru_stime.tv_usec) |
| 162 | { |
| 163 | --time->system_seconds; |
| 164 | time->system_microseconds += 1000000; |
| 165 | } |
| 166 | |
| 167 | return ret; |
| 168 | } |
| 169 | |
| 170 | #endif /* defined (HAVE_GETRUSAGE) */ |
| 171 | |
| 172 | #else /* ! defined (HAVE_WAITPID) */ |
| 173 | |
| 174 | struct status_list |
| 175 | { |
| 176 | struct status_list *next; |
| 177 | pid_t pid; |
| 178 | int status; |
| 179 | struct pex_time time; |
| 180 | }; |
| 181 | |
| 182 | static pid_t |
| 183 | pex_wait (struct pex_obj *obj, pid_t pid, int *status, struct pex_time *time) |
| 184 | { |
| 185 | struct status_list **pp; |
| 186 | |
| 187 | for (pp = (struct status_list **) &obj->sysdep; |
| 188 | *pp != NULL; |
| 189 | pp = &(*pp)->next) |
| 190 | { |
| 191 | if ((*pp)->pid == pid) |
| 192 | { |
| 193 | struct status_list *p; |
| 194 | |
| 195 | p = *pp; |
| 196 | *status = p->status; |
| 197 | if (time != NULL) |
| 198 | *time = p->time; |
| 199 | *pp = p->next; |
| 200 | free (p); |
| 201 | return pid; |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | while (1) |
| 206 | { |
| 207 | pid_t cpid; |
| 208 | struct status_list *psl; |
| 209 | struct pex_time pt; |
| 210 | #ifdef HAVE_GETRUSAGE |
| 211 | struct rusage r1, r2; |
| 212 | #endif |
| 213 | |
| 214 | if (time != NULL) |
| 215 | { |
| 216 | #ifdef HAVE_GETRUSAGE |
| 217 | getrusage (RUSAGE_CHILDREN, &r1); |
| 218 | #else |
| 219 | memset (&pt, 0, sizeof (struct pex_time)); |
| 220 | #endif |
| 221 | } |
| 222 | |
| 223 | cpid = wait (status); |
| 224 | |
| 225 | #ifdef HAVE_GETRUSAGE |
| 226 | if (time != NULL && cpid >= 0) |
| 227 | { |
| 228 | getrusage (RUSAGE_CHILDREN, &r2); |
| 229 | |
| 230 | pt.user_seconds = r2.ru_utime.tv_sec - r1.ru_utime.tv_sec; |
| 231 | pt.user_microseconds = r2.ru_utime.tv_usec - r1.ru_utime.tv_usec; |
| 232 | if (pt.user_microseconds < 0) |
| 233 | { |
| 234 | --pt.user_seconds; |
| 235 | pt.user_microseconds += 1000000; |
| 236 | } |
| 237 | |
| 238 | pt.system_seconds = r2.ru_stime.tv_sec - r1.ru_stime.tv_sec; |
| 239 | pt.system_microseconds = r2.ru_stime.tv_usec - r1.ru_stime.tv_usec; |
| 240 | if (pt.system_microseconds < 0) |
| 241 | { |
| 242 | --pt.system_seconds; |
| 243 | pt.system_microseconds += 1000000; |
| 244 | } |
| 245 | } |
| 246 | #endif |
| 247 | |
| 248 | if (cpid < 0 || cpid == pid) |
| 249 | { |
| 250 | if (time != NULL) |
| 251 | *time = pt; |
| 252 | return cpid; |
| 253 | } |
| 254 | |
| 255 | psl = XNEW (struct status_list); |
| 256 | psl->pid = cpid; |
| 257 | psl->status = *status; |
| 258 | if (time != NULL) |
| 259 | psl->time = pt; |
| 260 | psl->next = (struct status_list *) obj->sysdep; |
| 261 | obj->sysdep = (void *) psl; |
| 262 | } |
| 263 | } |
| 264 | |
| 265 | #endif /* ! defined (HAVE_WAITPID) */ |
| 266 | #endif /* ! defined (HAVE_WAIT4) */ |
| 267 | |
| 268 | static void pex_child_error (struct pex_obj *, const char *, const char *, int) |
| 269 | ATTRIBUTE_NORETURN; |
| 270 | static int pex_unix_open_read (struct pex_obj *, const char *, int); |
| 271 | static int pex_unix_open_write (struct pex_obj *, const char *, int); |
| 272 | static long pex_unix_exec_child (struct pex_obj *, int, const char *, |
| 273 | char * const *, char * const *, |
| 274 | int, int, int, int, |
| 275 | const char **, int *); |
| 276 | static int pex_unix_close (struct pex_obj *, int); |
| 277 | static int pex_unix_wait (struct pex_obj *, long, int *, struct pex_time *, |
| 278 | int, const char **, int *); |
| 279 | static int pex_unix_pipe (struct pex_obj *, int *, int); |
| 280 | static FILE *pex_unix_fdopenr (struct pex_obj *, int, int); |
| 281 | static FILE *pex_unix_fdopenw (struct pex_obj *, int, int); |
| 282 | static void pex_unix_cleanup (struct pex_obj *); |
| 283 | |
| 284 | /* The list of functions we pass to the common routines. */ |
| 285 | |
| 286 | const struct pex_funcs funcs = |
| 287 | { |
| 288 | pex_unix_open_read, |
| 289 | pex_unix_open_write, |
| 290 | pex_unix_exec_child, |
| 291 | pex_unix_close, |
| 292 | pex_unix_wait, |
| 293 | pex_unix_pipe, |
| 294 | pex_unix_fdopenr, |
| 295 | pex_unix_fdopenw, |
| 296 | pex_unix_cleanup |
| 297 | }; |
| 298 | |
| 299 | /* Return a newly initialized pex_obj structure. */ |
| 300 | |
| 301 | struct pex_obj * |
| 302 | pex_init (int flags, const char *pname, const char *tempbase) |
| 303 | { |
| 304 | return pex_init_common (flags, pname, tempbase, &funcs); |
| 305 | } |
| 306 | |
| 307 | /* Open a file for reading. */ |
| 308 | |
| 309 | static int |
| 310 | pex_unix_open_read (struct pex_obj *obj ATTRIBUTE_UNUSED, const char *name, |
| 311 | int binary ATTRIBUTE_UNUSED) |
| 312 | { |
| 313 | return open (name, O_RDONLY); |
| 314 | } |
| 315 | |
| 316 | /* Open a file for writing. */ |
| 317 | |
| 318 | static int |
| 319 | pex_unix_open_write (struct pex_obj *obj ATTRIBUTE_UNUSED, const char *name, |
| 320 | int binary ATTRIBUTE_UNUSED) |
| 321 | { |
| 322 | /* Note that we can't use O_EXCL here because gcc may have already |
| 323 | created the temporary file via make_temp_file. */ |
| 324 | return open (name, O_WRONLY | O_CREAT | O_TRUNC, PUBLIC_MODE); |
| 325 | } |
| 326 | |
| 327 | /* Close a file. */ |
| 328 | |
| 329 | static int |
| 330 | pex_unix_close (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd) |
| 331 | { |
| 332 | return close (fd); |
| 333 | } |
| 334 | |
| 335 | /* Report an error from a child process. We don't use stdio routines, |
| 336 | because we might be here due to a vfork call. */ |
| 337 | |
| 338 | static void |
| 339 | pex_child_error (struct pex_obj *obj, const char *executable, |
| 340 | const char *errmsg, int err) |
| 341 | { |
| 342 | #define writeerr(s) (void) write (STDERR_FILE_NO, s, strlen (s)) |
| 343 | writeerr (obj->pname); |
| 344 | writeerr (": error trying to exec '"); |
| 345 | writeerr (executable); |
| 346 | writeerr ("': "); |
| 347 | writeerr (errmsg); |
| 348 | writeerr (": "); |
| 349 | writeerr (xstrerror (err)); |
| 350 | writeerr ("\n"); |
| 351 | _exit (-1); |
| 352 | } |
| 353 | |
| 354 | /* Execute a child. */ |
| 355 | |
| 356 | extern char **environ; |
| 357 | |
| 358 | static long |
| 359 | pex_unix_exec_child (struct pex_obj *obj, int flags, const char *executable, |
| 360 | char * const * argv, char * const * env, |
| 361 | int in, int out, int errdes, |
| 362 | int toclose, const char **errmsg, int *err) |
| 363 | { |
| 364 | pid_t pid; |
| 365 | |
| 366 | /* We declare these to be volatile to avoid warnings from gcc about |
| 367 | them being clobbered by vfork. */ |
| 368 | volatile int sleep_interval; |
| 369 | volatile int retries; |
| 370 | |
| 371 | sleep_interval = 1; |
| 372 | pid = -1; |
| 373 | for (retries = 0; retries < 4; ++retries) |
| 374 | { |
| 375 | pid = vfork (); |
| 376 | if (pid >= 0) |
| 377 | break; |
| 378 | sleep (sleep_interval); |
| 379 | sleep_interval *= 2; |
| 380 | } |
| 381 | |
| 382 | switch (pid) |
| 383 | { |
| 384 | case -1: |
| 385 | *err = errno; |
| 386 | *errmsg = VFORK_STRING; |
| 387 | return -1; |
| 388 | |
| 389 | case 0: |
| 390 | /* Child process. */ |
| 391 | if (in != STDIN_FILE_NO) |
| 392 | { |
| 393 | if (dup2 (in, STDIN_FILE_NO) < 0) |
| 394 | pex_child_error (obj, executable, "dup2", errno); |
| 395 | if (close (in) < 0) |
| 396 | pex_child_error (obj, executable, "close", errno); |
| 397 | } |
| 398 | if (out != STDOUT_FILE_NO) |
| 399 | { |
| 400 | if (dup2 (out, STDOUT_FILE_NO) < 0) |
| 401 | pex_child_error (obj, executable, "dup2", errno); |
| 402 | if (close (out) < 0) |
| 403 | pex_child_error (obj, executable, "close", errno); |
| 404 | } |
| 405 | if (errdes != STDERR_FILE_NO) |
| 406 | { |
| 407 | if (dup2 (errdes, STDERR_FILE_NO) < 0) |
| 408 | pex_child_error (obj, executable, "dup2", errno); |
| 409 | if (close (errdes) < 0) |
| 410 | pex_child_error (obj, executable, "close", errno); |
| 411 | } |
| 412 | if (toclose >= 0) |
| 413 | { |
| 414 | if (close (toclose) < 0) |
| 415 | pex_child_error (obj, executable, "close", errno); |
| 416 | } |
| 417 | if ((flags & PEX_STDERR_TO_STDOUT) != 0) |
| 418 | { |
| 419 | if (dup2 (STDOUT_FILE_NO, STDERR_FILE_NO) < 0) |
| 420 | pex_child_error (obj, executable, "dup2", errno); |
| 421 | } |
| 422 | |
| 423 | if (env) |
| 424 | environ = (char**) env; |
| 425 | |
| 426 | if ((flags & PEX_SEARCH) != 0) |
| 427 | { |
| 428 | execvp (executable, argv); |
| 429 | pex_child_error (obj, executable, "execvp", errno); |
| 430 | } |
| 431 | else |
| 432 | { |
| 433 | execv (executable, argv); |
| 434 | pex_child_error (obj, executable, "execv", errno); |
| 435 | } |
| 436 | |
| 437 | /* NOTREACHED */ |
| 438 | return -1; |
| 439 | |
| 440 | default: |
| 441 | /* Parent process. */ |
| 442 | if (in != STDIN_FILE_NO) |
| 443 | { |
| 444 | if (close (in) < 0) |
| 445 | { |
| 446 | *err = errno; |
| 447 | *errmsg = "close"; |
| 448 | return -1; |
| 449 | } |
| 450 | } |
| 451 | if (out != STDOUT_FILE_NO) |
| 452 | { |
| 453 | if (close (out) < 0) |
| 454 | { |
| 455 | *err = errno; |
| 456 | *errmsg = "close"; |
| 457 | return -1; |
| 458 | } |
| 459 | } |
| 460 | if (errdes != STDERR_FILE_NO) |
| 461 | { |
| 462 | if (close (errdes) < 0) |
| 463 | { |
| 464 | *err = errno; |
| 465 | *errmsg = "close"; |
| 466 | return -1; |
| 467 | } |
| 468 | } |
| 469 | |
| 470 | return (long) pid; |
| 471 | } |
| 472 | } |
| 473 | |
| 474 | /* Wait for a child process to complete. */ |
| 475 | |
| 476 | static int |
| 477 | pex_unix_wait (struct pex_obj *obj, long pid, int *status, |
| 478 | struct pex_time *time, int done, const char **errmsg, |
| 479 | int *err) |
| 480 | { |
| 481 | /* If we are cleaning up when the caller didn't retrieve process |
| 482 | status for some reason, encourage the process to go away. */ |
| 483 | if (done) |
| 484 | kill (pid, SIGTERM); |
| 485 | |
| 486 | if (pex_wait (obj, pid, status, time) < 0) |
| 487 | { |
| 488 | *err = errno; |
| 489 | *errmsg = "wait"; |
| 490 | return -1; |
| 491 | } |
| 492 | |
| 493 | return 0; |
| 494 | } |
| 495 | |
| 496 | /* Create a pipe. */ |
| 497 | |
| 498 | static int |
| 499 | pex_unix_pipe (struct pex_obj *obj ATTRIBUTE_UNUSED, int *p, |
| 500 | int binary ATTRIBUTE_UNUSED) |
| 501 | { |
| 502 | return pipe (p); |
| 503 | } |
| 504 | |
| 505 | /* Get a FILE pointer to read from a file descriptor. */ |
| 506 | |
| 507 | static FILE * |
| 508 | pex_unix_fdopenr (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd, |
| 509 | int binary ATTRIBUTE_UNUSED) |
| 510 | { |
| 511 | return fdopen (fd, "r"); |
| 512 | } |
| 513 | |
| 514 | static FILE * |
| 515 | pex_unix_fdopenw (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd, |
| 516 | int binary ATTRIBUTE_UNUSED) |
| 517 | { |
| 518 | if (fcntl (fd, F_SETFD, FD_CLOEXEC) < 0) |
| 519 | return NULL; |
| 520 | return fdopen (fd, "w"); |
| 521 | } |
| 522 | |
| 523 | static void |
| 524 | pex_unix_cleanup (struct pex_obj *obj ATTRIBUTE_UNUSED) |
| 525 | { |
| 526 | #if !defined (HAVE_WAIT4) && !defined (HAVE_WAITPID) |
| 527 | while (obj->sysdep != NULL) |
| 528 | { |
| 529 | struct status_list *this; |
| 530 | struct status_list *next; |
| 531 | |
| 532 | this = (struct status_list *) obj->sysdep; |
| 533 | next = this->next; |
| 534 | free (this); |
| 535 | obj->sysdep = (void *) next; |
| 536 | } |
| 537 | #endif |
| 538 | } |