| /* Utilities to execute a program in a subprocess (possibly linked by pipes |
| with other subprocesses), and wait for it. Generic Unix version |
| (also used for UWIN and VMS). |
| Copyright (C) 1996-2024 Free Software Foundation, Inc. |
| |
| This file is part of the libiberty library. |
| Libiberty is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Library General Public |
| License as published by the Free Software Foundation; either |
| version 2 of the License, or (at your option) any later version. |
| |
| Libiberty is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Library General Public License for more details. |
| |
| You should have received a copy of the GNU Library General Public |
| License along with libiberty; see the file COPYING.LIB. If not, |
| write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, |
| Boston, MA 02110-1301, USA. */ |
| |
| #include "config.h" |
| #include "libiberty.h" |
| #include "pex-common.h" |
| #include "environ.h" |
| |
| #include <stdio.h> |
| #include <signal.h> |
| #include <errno.h> |
| #ifdef NEED_DECLARATION_ERRNO |
| extern int errno; |
| #endif |
| #ifdef HAVE_STDLIB_H |
| #include <stdlib.h> |
| #endif |
| #ifdef HAVE_STRING_H |
| #include <string.h> |
| #endif |
| #ifdef HAVE_UNISTD_H |
| #include <unistd.h> |
| #endif |
| |
| #include <sys/types.h> |
| |
| #ifdef HAVE_FCNTL_H |
| #include <fcntl.h> |
| #endif |
| #ifdef HAVE_SYS_WAIT_H |
| #include <sys/wait.h> |
| #endif |
| #ifdef HAVE_GETRUSAGE |
| #include <sys/time.h> |
| #include <sys/resource.h> |
| #endif |
| #ifdef HAVE_SYS_STAT_H |
| #include <sys/stat.h> |
| #endif |
| #ifdef HAVE_PROCESS_H |
| #include <process.h> |
| #endif |
| #ifdef HAVE_SPAWN_H |
| #include <spawn.h> |
| #endif |
| |
| #ifdef vfork /* Autoconf may define this to fork for us. */ |
| # define VFORK_STRING "fork" |
| #else |
| # define VFORK_STRING "vfork" |
| #endif |
| #ifdef HAVE_VFORK_H |
| #include <vfork.h> |
| #endif |
| #if defined(VMS) && defined (__LONG_POINTERS) |
| #ifndef __CHAR_PTR32 |
| typedef char * __char_ptr32 |
| __attribute__ ((mode (SI))); |
| #endif |
| |
| typedef __char_ptr32 *__char_ptr_char_ptr32 |
| __attribute__ ((mode (SI))); |
| |
| /* Return a 32 bit pointer to an array of 32 bit pointers |
| given a 64 bit pointer to an array of 64 bit pointers. */ |
| |
| static __char_ptr_char_ptr32 |
| to_ptr32 (char **ptr64) |
| { |
| int argc; |
| __char_ptr_char_ptr32 short_argv; |
| |
| /* Count number of arguments. */ |
| for (argc = 0; ptr64[argc] != NULL; argc++) |
| ; |
| |
| /* Reallocate argv with 32 bit pointers. */ |
| short_argv = (__char_ptr_char_ptr32) decc$malloc |
| (sizeof (__char_ptr32) * (argc + 1)); |
| |
| for (argc = 0; ptr64[argc] != NULL; argc++) |
| short_argv[argc] = (__char_ptr32) decc$strdup (ptr64[argc]); |
| |
| short_argv[argc] = (__char_ptr32) 0; |
| return short_argv; |
| |
| } |
| #else |
| #define to_ptr32(argv) argv |
| #endif |
| |
| /* File mode to use for private and world-readable files. */ |
| |
| #if defined (S_IRUSR) && defined (S_IWUSR) && defined (S_IRGRP) && defined (S_IWGRP) && defined (S_IROTH) && defined (S_IWOTH) |
| #define PUBLIC_MODE \ |
| (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH) |
| #else |
| #define PUBLIC_MODE 0666 |
| #endif |
| |
| /* Get the exit status of a particular process, and optionally get the |
| time that it took. This is simple if we have wait4, slightly |
| harder if we have waitpid, and is a pain if we only have wait. */ |
| |
| static pid_t pex_wait (struct pex_obj *, pid_t, int *, struct pex_time *); |
| |
| #ifdef HAVE_WAIT4 |
| |
| static pid_t |
| pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status, |
| struct pex_time *time) |
| { |
| pid_t ret; |
| struct rusage r; |
| |
| #ifdef HAVE_WAITPID |
| if (time == NULL) |
| return waitpid (pid, status, 0); |
| #endif |
| |
| ret = wait4 (pid, status, 0, &r); |
| |
| if (time != NULL) |
| { |
| time->user_seconds = r.ru_utime.tv_sec; |
| time->user_microseconds= r.ru_utime.tv_usec; |
| time->system_seconds = r.ru_stime.tv_sec; |
| time->system_microseconds= r.ru_stime.tv_usec; |
| } |
| |
| return ret; |
| } |
| |
| #else /* ! defined (HAVE_WAIT4) */ |
| |
| #ifdef HAVE_WAITPID |
| |
| #ifndef HAVE_GETRUSAGE |
| |
| static pid_t |
| pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status, |
| struct pex_time *time) |
| { |
| if (time != NULL) |
| memset (time, 0, sizeof (struct pex_time)); |
| return waitpid (pid, status, 0); |
| } |
| |
| #else /* defined (HAVE_GETRUSAGE) */ |
| |
| static pid_t |
| pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status, |
| struct pex_time *time) |
| { |
| struct rusage r1, r2; |
| pid_t ret; |
| |
| if (time == NULL) |
| return waitpid (pid, status, 0); |
| |
| getrusage (RUSAGE_CHILDREN, &r1); |
| |
| ret = waitpid (pid, status, 0); |
| if (ret < 0) |
| return ret; |
| |
| getrusage (RUSAGE_CHILDREN, &r2); |
| |
| time->user_seconds = r2.ru_utime.tv_sec - r1.ru_utime.tv_sec; |
| time->user_microseconds = r2.ru_utime.tv_usec - r1.ru_utime.tv_usec; |
| if (r2.ru_utime.tv_usec < r1.ru_utime.tv_usec) |
| { |
| --time->user_seconds; |
| time->user_microseconds += 1000000; |
| } |
| |
| time->system_seconds = r2.ru_stime.tv_sec - r1.ru_stime.tv_sec; |
| time->system_microseconds = r2.ru_stime.tv_usec - r1.ru_stime.tv_usec; |
| if (r2.ru_stime.tv_usec < r1.ru_stime.tv_usec) |
| { |
| --time->system_seconds; |
| time->system_microseconds += 1000000; |
| } |
| |
| return ret; |
| } |
| |
| #endif /* defined (HAVE_GETRUSAGE) */ |
| |
| #else /* ! defined (HAVE_WAITPID) */ |
| |
| struct status_list |
| { |
| struct status_list *next; |
| pid_t pid; |
| int status; |
| struct pex_time time; |
| }; |
| |
| static pid_t |
| pex_wait (struct pex_obj *obj, pid_t pid, int *status, struct pex_time *time) |
| { |
| struct status_list **pp; |
| |
| for (pp = (struct status_list **) &obj->sysdep; |
| *pp != NULL; |
| pp = &(*pp)->next) |
| { |
| if ((*pp)->pid == pid) |
| { |
| struct status_list *p; |
| |
| p = *pp; |
| *status = p->status; |
| if (time != NULL) |
| *time = p->time; |
| *pp = p->next; |
| free (p); |
| return pid; |
| } |
| } |
| |
| while (1) |
| { |
| pid_t cpid; |
| struct status_list *psl; |
| struct pex_time pt; |
| #ifdef HAVE_GETRUSAGE |
| struct rusage r1, r2; |
| #endif |
| |
| if (time != NULL) |
| { |
| #ifdef HAVE_GETRUSAGE |
| getrusage (RUSAGE_CHILDREN, &r1); |
| #else |
| memset (&pt, 0, sizeof (struct pex_time)); |
| #endif |
| } |
| |
| cpid = wait (status); |
| |
| #ifdef HAVE_GETRUSAGE |
| if (time != NULL && cpid >= 0) |
| { |
| getrusage (RUSAGE_CHILDREN, &r2); |
| |
| pt.user_seconds = r2.ru_utime.tv_sec - r1.ru_utime.tv_sec; |
| pt.user_microseconds = r2.ru_utime.tv_usec - r1.ru_utime.tv_usec; |
| if (pt.user_microseconds < 0) |
| { |
| --pt.user_seconds; |
| pt.user_microseconds += 1000000; |
| } |
| |
| pt.system_seconds = r2.ru_stime.tv_sec - r1.ru_stime.tv_sec; |
| pt.system_microseconds = r2.ru_stime.tv_usec - r1.ru_stime.tv_usec; |
| if (pt.system_microseconds < 0) |
| { |
| --pt.system_seconds; |
| pt.system_microseconds += 1000000; |
| } |
| } |
| #endif |
| |
| if (cpid < 0 || cpid == pid) |
| { |
| if (time != NULL) |
| *time = pt; |
| return cpid; |
| } |
| |
| psl = XNEW (struct status_list); |
| psl->pid = cpid; |
| psl->status = *status; |
| if (time != NULL) |
| psl->time = pt; |
| psl->next = (struct status_list *) obj->sysdep; |
| obj->sysdep = (void *) psl; |
| } |
| } |
| |
| #endif /* ! defined (HAVE_WAITPID) */ |
| #endif /* ! defined (HAVE_WAIT4) */ |
| |
| static int pex_unix_open_read (struct pex_obj *, const char *, int); |
| static int pex_unix_open_write (struct pex_obj *, const char *, int, int); |
| static pid_t pex_unix_exec_child (struct pex_obj *, int, const char *, |
| char * const *, char * const *, |
| int, int, int, int, |
| const char **, int *); |
| static int pex_unix_close (struct pex_obj *, int); |
| static pid_t pex_unix_wait (struct pex_obj *, pid_t, int *, struct pex_time *, |
| int, const char **, int *); |
| static int pex_unix_pipe (struct pex_obj *, int *, int); |
| static FILE *pex_unix_fdopenr (struct pex_obj *, int, int); |
| static FILE *pex_unix_fdopenw (struct pex_obj *, int, int); |
| static void pex_unix_cleanup (struct pex_obj *); |
| |
| /* The list of functions we pass to the common routines. */ |
| |
| const struct pex_funcs funcs = |
| { |
| pex_unix_open_read, |
| pex_unix_open_write, |
| pex_unix_exec_child, |
| pex_unix_close, |
| pex_unix_wait, |
| pex_unix_pipe, |
| pex_unix_fdopenr, |
| pex_unix_fdopenw, |
| pex_unix_cleanup |
| }; |
| |
| /* Return a newly initialized pex_obj structure. */ |
| |
| struct pex_obj * |
| pex_init (int flags, const char *pname, const char *tempbase) |
| { |
| return pex_init_common (flags, pname, tempbase, &funcs); |
| } |
| |
| /* Open a file for reading. */ |
| |
| static int |
| pex_unix_open_read (struct pex_obj *obj ATTRIBUTE_UNUSED, const char *name, |
| int binary ATTRIBUTE_UNUSED) |
| { |
| return open (name, O_RDONLY); |
| } |
| |
| /* Open a file for writing. */ |
| |
| static int |
| pex_unix_open_write (struct pex_obj *obj ATTRIBUTE_UNUSED, const char *name, |
| int binary ATTRIBUTE_UNUSED, int append) |
| { |
| /* Note that we can't use O_EXCL here because gcc may have already |
| created the temporary file via make_temp_file. */ |
| return open (name, O_WRONLY | O_CREAT |
| | (append ? O_APPEND : O_TRUNC), PUBLIC_MODE); |
| } |
| |
| /* Close a file. */ |
| |
| static int |
| pex_unix_close (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd) |
| { |
| return close (fd); |
| } |
| |
| /* Execute a child. */ |
| |
| #if defined(HAVE_SPAWNVE) && defined(HAVE_SPAWNVPE) |
| /* Implementation of pex->exec_child using the Cygwin spawn operation. */ |
| |
| /* Subroutine of pex_unix_exec_child. Move OLD_FD to a new file descriptor |
| to be stored in *PNEW_FD, save the flags in *PFLAGS, and arrange for the |
| saved copy to be close-on-exec. Move CHILD_FD into OLD_FD. If CHILD_FD |
| is -1, OLD_FD is to be closed. Return -1 on error. */ |
| |
| static int |
| save_and_install_fd(int *pnew_fd, int *pflags, int old_fd, int child_fd) |
| { |
| int new_fd, flags; |
| |
| flags = fcntl (old_fd, F_GETFD); |
| |
| /* If we could not retrieve the flags, then OLD_FD was not open. */ |
| if (flags < 0) |
| { |
| new_fd = -1, flags = 0; |
| if (child_fd >= 0 && dup2 (child_fd, old_fd) < 0) |
| return -1; |
| } |
| /* If we wish to close OLD_FD, just mark it CLOEXEC. */ |
| else if (child_fd == -1) |
| { |
| new_fd = old_fd; |
| if ((flags & FD_CLOEXEC) == 0 && fcntl (old_fd, F_SETFD, FD_CLOEXEC) < 0) |
| return -1; |
| } |
| /* Otherwise we need to save a copy of OLD_FD before installing CHILD_FD. */ |
| else |
| { |
| #ifdef F_DUPFD_CLOEXEC |
| new_fd = fcntl (old_fd, F_DUPFD_CLOEXEC, 3); |
| if (new_fd < 0) |
| return -1; |
| #else |
| /* Prefer F_DUPFD over dup in order to avoid getting a new fd |
| in the range 0-2, right where a new stderr fd might get put. */ |
| new_fd = fcntl (old_fd, F_DUPFD, 3); |
| if (new_fd < 0) |
| return -1; |
| if (fcntl (new_fd, F_SETFD, FD_CLOEXEC) < 0) |
| return -1; |
| #endif |
| if (dup2 (child_fd, old_fd) < 0) |
| return -1; |
| } |
| |
| *pflags = flags; |
| if (pnew_fd) |
| *pnew_fd = new_fd; |
| else if (new_fd != old_fd) |
| abort (); |
| |
| return 0; |
| } |
| |
| /* Subroutine of pex_unix_exec_child. Move SAVE_FD back to OLD_FD |
| restoring FLAGS. If SAVE_FD < 0, OLD_FD is to be closed. */ |
| |
| static int |
| restore_fd(int old_fd, int save_fd, int flags) |
| { |
| /* For SAVE_FD < 0, all we have to do is restore the |
| "closed-ness" of the original. */ |
| if (save_fd < 0) |
| return close (old_fd); |
| |
| /* For SAVE_FD == OLD_FD, all we have to do is restore the |
| original setting of the CLOEXEC flag. */ |
| if (save_fd == old_fd) |
| { |
| if (flags & FD_CLOEXEC) |
| return 0; |
| return fcntl (old_fd, F_SETFD, flags); |
| } |
| |
| /* Otherwise we have to move the descriptor back, restore the flags, |
| and close the saved copy. */ |
| #ifdef HAVE_DUP3 |
| if (flags == FD_CLOEXEC) |
| { |
| if (dup3 (save_fd, old_fd, O_CLOEXEC) < 0) |
| return -1; |
| } |
| else |
| #endif |
| { |
| if (dup2 (save_fd, old_fd) < 0) |
| return -1; |
| if (flags != 0 && fcntl (old_fd, F_SETFD, flags) < 0) |
| return -1; |
| } |
| return close (save_fd); |
| } |
| |
| static pid_t |
| pex_unix_exec_child (struct pex_obj *obj ATTRIBUTE_UNUSED, |
| int flags, const char *executable, |
| char * const * argv, char * const * env, |
| int in, int out, int errdes, int toclose, |
| const char **errmsg, int *err) |
| { |
| int fl_in = 0, fl_out = 0, fl_err = 0, fl_tc = 0; |
| int save_in = -1, save_out = -1, save_err = -1; |
| int max, retries; |
| pid_t pid; |
| |
| if (flags & PEX_STDERR_TO_STDOUT) |
| errdes = out; |
| |
| /* We need the three standard file descriptors to be set up as for |
| the child before we perform the spawn. The file descriptors for |
| the parent need to be moved and marked for close-on-exec. */ |
| if (in != STDIN_FILE_NO |
| && save_and_install_fd (&save_in, &fl_in, STDIN_FILE_NO, in) < 0) |
| goto error_dup2; |
| if (out != STDOUT_FILE_NO |
| && save_and_install_fd (&save_out, &fl_out, STDOUT_FILE_NO, out) < 0) |
| goto error_dup2; |
| if (errdes != STDERR_FILE_NO |
| && save_and_install_fd (&save_err, &fl_err, STDERR_FILE_NO, errdes) < 0) |
| goto error_dup2; |
| if (toclose >= 0 |
| && save_and_install_fd (NULL, &fl_tc, toclose, -1) < 0) |
| goto error_dup2; |
| |
| /* Now that we've moved the file descriptors for the child into place, |
| close the originals. Be careful not to close any of the standard |
| file descriptors that we just set up. */ |
| max = -1; |
| if (errdes >= 0) |
| max = STDERR_FILE_NO; |
| else if (out >= 0) |
| max = STDOUT_FILE_NO; |
| else if (in >= 0) |
| max = STDIN_FILE_NO; |
| if (in > max) |
| close (in); |
| if (out > max) |
| close (out); |
| if (errdes > max && errdes != out) |
| close (errdes); |
| |
| /* If we were not given an environment, use the global environment. */ |
| if (env == NULL) |
| env = environ; |
| |
| /* Launch the program. If we get EAGAIN (normally out of pid's), try |
| again a few times with increasing backoff times. */ |
| retries = 0; |
| while (1) |
| { |
| typedef const char * const *cc_cp; |
| |
| if (flags & PEX_SEARCH) |
| pid = spawnvpe (_P_NOWAITO, executable, (cc_cp)argv, (cc_cp)env); |
| else |
| pid = spawnve (_P_NOWAITO, executable, (cc_cp)argv, (cc_cp)env); |
| |
| if (pid > 0) |
| break; |
| |
| *err = errno; |
| *errmsg = "spawn"; |
| if (errno != EAGAIN || ++retries == 4) |
| return (pid_t) -1; |
| sleep (1 << retries); |
| } |
| |
| /* Success. Restore the parent's file descriptors that we saved above. */ |
| if (toclose >= 0 |
| && restore_fd (toclose, toclose, fl_tc) < 0) |
| goto error_dup2; |
| if (in != STDIN_FILE_NO |
| && restore_fd (STDIN_FILE_NO, save_in, fl_in) < 0) |
| goto error_dup2; |
| if (out != STDOUT_FILE_NO |
| && restore_fd (STDOUT_FILE_NO, save_out, fl_out) < 0) |
| goto error_dup2; |
| if (errdes != STDERR_FILE_NO |
| && restore_fd (STDERR_FILE_NO, save_err, fl_err) < 0) |
| goto error_dup2; |
| |
| return pid; |
| |
| error_dup2: |
| *err = errno; |
| *errmsg = "dup2"; |
| return (pid_t) -1; |
| } |
| |
| #elif defined(HAVE_POSIX_SPAWN) && defined(HAVE_POSIX_SPAWNP) |
| /* Implementation of pex->exec_child using posix_spawn. */ |
| |
| static pid_t |
| pex_unix_exec_child (struct pex_obj *obj ATTRIBUTE_UNUSED, |
| int flags, const char *executable, |
| char * const * argv, char * const * env, |
| int in, int out, int errdes, |
| int toclose, const char **errmsg, int *err) |
| { |
| int ret; |
| pid_t pid = -1; |
| posix_spawnattr_t attr; |
| posix_spawn_file_actions_t actions; |
| int attr_initialized = 0, actions_initialized = 0; |
| |
| *err = 0; |
| |
| ret = posix_spawnattr_init (&attr); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawnattr_init"; |
| goto exit; |
| } |
| attr_initialized = 1; |
| |
| /* Use vfork() on glibc <=2.24. */ |
| #ifdef POSIX_SPAWN_USEVFORK |
| ret = posix_spawnattr_setflags (&attr, POSIX_SPAWN_USEVFORK); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawnattr_setflags"; |
| goto exit; |
| } |
| #endif |
| |
| ret = posix_spawn_file_actions_init (&actions); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawn_file_actions_init"; |
| goto exit; |
| } |
| actions_initialized = 1; |
| |
| if (in != STDIN_FILE_NO) |
| { |
| ret = posix_spawn_file_actions_adddup2 (&actions, in, STDIN_FILE_NO); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawn_file_actions_adddup2"; |
| goto exit; |
| } |
| |
| ret = posix_spawn_file_actions_addclose (&actions, in); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawn_file_actions_addclose"; |
| goto exit; |
| } |
| } |
| |
| if (out != STDOUT_FILE_NO) |
| { |
| ret = posix_spawn_file_actions_adddup2 (&actions, out, STDOUT_FILE_NO); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawn_file_actions_adddup2"; |
| goto exit; |
| } |
| |
| ret = posix_spawn_file_actions_addclose (&actions, out); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawn_file_actions_addclose"; |
| goto exit; |
| } |
| } |
| |
| if (errdes != STDERR_FILE_NO) |
| { |
| ret = posix_spawn_file_actions_adddup2 (&actions, errdes, STDERR_FILE_NO); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawn_file_actions_adddup2"; |
| goto exit; |
| } |
| |
| ret = posix_spawn_file_actions_addclose (&actions, errdes); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawn_file_actions_addclose"; |
| goto exit; |
| } |
| } |
| |
| if (toclose >= 0) |
| { |
| ret = posix_spawn_file_actions_addclose (&actions, toclose); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawn_file_actions_addclose"; |
| goto exit; |
| } |
| } |
| |
| if ((flags & PEX_STDERR_TO_STDOUT) != 0) |
| { |
| ret = posix_spawn_file_actions_adddup2 (&actions, STDOUT_FILE_NO, STDERR_FILE_NO); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawn_file_actions_adddup2"; |
| goto exit; |
| } |
| } |
| |
| if ((flags & PEX_SEARCH) != 0) |
| { |
| ret = posix_spawnp (&pid, executable, &actions, &attr, argv, env ? env : environ); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawnp"; |
| pid = -1; /* The value of pid is unspecified on failure. */ |
| goto exit; |
| } |
| } |
| else |
| { |
| ret = posix_spawn (&pid, executable, &actions, &attr, argv, env ? env : environ); |
| if (ret) |
| { |
| *err = ret; |
| *errmsg = "posix_spawn"; |
| pid = -1; |
| goto exit; |
| } |
| } |
| |
| exit: |
| if (actions_initialized) |
| posix_spawn_file_actions_destroy (&actions); |
| if (attr_initialized) |
| posix_spawnattr_destroy (&attr); |
| |
| if (!*err && in != STDIN_FILE_NO) |
| if (close (in)) |
| *errmsg = "close", *err = errno, pid = -1; |
| if (!*err && out != STDOUT_FILE_NO) |
| if (close (out)) |
| *errmsg = "close", *err = errno, pid = -1; |
| if (!*err && errdes != STDERR_FILE_NO) |
| if (close (errdes)) |
| *errmsg = "close", *err = errno, pid = -1; |
| |
| return pid; |
| } |
| #else |
| /* Implementation of pex->exec_child using standard vfork + exec. */ |
| |
| static pid_t |
| pex_unix_exec_child (struct pex_obj *obj, int flags, const char *executable, |
| char * const * argv, char * const * env, |
| int in, int out, int errdes, |
| int toclose, const char **errmsg, int *err) |
| { |
| pid_t pid = -1; |
| /* Tuple to communicate error from child to parent. We can safely |
| transfer string literal pointers as both run with identical |
| address mappings. */ |
| struct fn_err |
| { |
| const char *fn; |
| int err; |
| }; |
| volatile int do_pipe = 0; |
| volatile int pipes[2]; /* [0]:reader,[1]:writer. */ |
| #ifdef O_CLOEXEC |
| do_pipe = 1; |
| #endif |
| if (do_pipe) |
| { |
| #ifdef HAVE_PIPE2 |
| if (pipe2 ((int *)pipes, O_CLOEXEC)) |
| do_pipe = 0; |
| #else |
| if (pipe ((int *)pipes)) |
| do_pipe = 0; |
| else |
| { |
| if (fcntl (pipes[1], F_SETFD, FD_CLOEXEC) == -1) |
| { |
| close (pipes[0]); |
| close (pipes[1]); |
| do_pipe = 0; |
| } |
| } |
| #endif |
| } |
| |
| /* We declare these to be volatile to avoid warnings from gcc about |
| them being clobbered by vfork. */ |
| volatile int sleep_interval = 1; |
| volatile int retries; |
| |
| /* We vfork and then set environ in the child before calling execvp. |
| This clobbers the parent's environ so we need to restore it. |
| It would be nice to use one of the exec* functions that takes an |
| environment as a parameter, but that may have portability |
| issues. It is marked volatile so the child doesn't consider it a |
| dead variable and therefore clobber where ever it is stored. */ |
| char **volatile save_environ = environ; |
| |
| for (retries = 0; retries < 4; ++retries) |
| { |
| pid = vfork (); |
| if (pid >= 0) |
| break; |
| sleep (sleep_interval); |
| sleep_interval *= 2; |
| } |
| |
| switch (pid) |
| { |
| case -1: |
| if (do_pipe) |
| { |
| close (pipes[0]); |
| close (pipes[1]); |
| } |
| *err = errno; |
| *errmsg = VFORK_STRING; |
| return (pid_t) -1; |
| |
| case 0: |
| /* Child process. */ |
| { |
| struct fn_err failed; |
| failed.fn = NULL; |
| |
| if (do_pipe) |
| close (pipes[0]); |
| if (!failed.fn && in != STDIN_FILE_NO) |
| { |
| if (dup2 (in, STDIN_FILE_NO) < 0) |
| failed.fn = "dup2", failed.err = errno; |
| else if (close (in) < 0) |
| failed.fn = "close", failed.err = errno; |
| } |
| if (!failed.fn && out != STDOUT_FILE_NO) |
| { |
| if (dup2 (out, STDOUT_FILE_NO) < 0) |
| failed.fn = "dup2", failed.err = errno; |
| else if (close (out) < 0) |
| failed.fn = "close", failed.err = errno; |
| } |
| if (!failed.fn && errdes != STDERR_FILE_NO) |
| { |
| if (dup2 (errdes, STDERR_FILE_NO) < 0) |
| failed.fn = "dup2", failed.err = errno; |
| else if (close (errdes) < 0) |
| failed.fn = "close", failed.err = errno; |
| } |
| if (!failed.fn && toclose >= 0) |
| { |
| if (close (toclose) < 0) |
| failed.fn = "close", failed.err = errno; |
| } |
| if (!failed.fn && (flags & PEX_STDERR_TO_STDOUT) != 0) |
| { |
| if (dup2 (STDOUT_FILE_NO, STDERR_FILE_NO) < 0) |
| failed.fn = "dup2", failed.err = errno; |
| } |
| if (!failed.fn) |
| { |
| if (env) |
| /* NOTE: In a standard vfork implementation this clobbers |
| the parent's copy of environ "too" (in reality there's |
| only one copy). This is ok as we restore it below. */ |
| environ = (char**) env; |
| if ((flags & PEX_SEARCH) != 0) |
| { |
| execvp (executable, to_ptr32 (argv)); |
| failed.fn = "execvp", failed.err = errno; |
| } |
| else |
| { |
| execv (executable, to_ptr32 (argv)); |
| failed.fn = "execv", failed.err = errno; |
| } |
| } |
| |
| /* Something failed, report an error. We don't use stdio |
| routines, because we might be here due to a vfork call. */ |
| ssize_t retval = 0; |
| |
| if (!do_pipe |
| || write (pipes[1], &failed, sizeof (failed)) != sizeof (failed)) |
| { |
| /* The parent will not see our scream above, so write to |
| stdout. */ |
| #define writeerr(s) (retval |= write (STDERR_FILE_NO, s, strlen (s))) |
| writeerr (obj->pname); |
| writeerr (": error trying to exec '"); |
| writeerr (executable); |
| writeerr ("': "); |
| writeerr (failed.fn); |
| writeerr (": "); |
| writeerr (xstrerror (failed.err)); |
| writeerr ("\n"); |
| #undef writeerr |
| } |
| |
| /* Exit with -2 if the error output failed, too. */ |
| _exit (retval < 0 ? -2 : -1); |
| } |
| /* NOTREACHED */ |
| return (pid_t) -1; |
| |
| default: |
| /* Parent process. */ |
| { |
| /* Restore environ. Note that the parent either doesn't run |
| until the child execs/exits (standard vfork behaviour), or |
| if it does run then vfork is behaving more like fork. In |
| either case we needn't worry about clobbering the child's |
| copy of environ. */ |
| environ = save_environ; |
| |
| struct fn_err failed; |
| failed.fn = NULL; |
| if (do_pipe) |
| { |
| close (pipes[1]); |
| ssize_t len = read (pipes[0], &failed, sizeof (failed)); |
| if (len < 0) |
| failed.fn = NULL; |
| close (pipes[0]); |
| } |
| |
| if (!failed.fn && in != STDIN_FILE_NO) |
| if (close (in) < 0) |
| failed.fn = "close", failed.err = errno; |
| if (!failed.fn && out != STDOUT_FILE_NO) |
| if (close (out) < 0) |
| failed.fn = "close", failed.err = errno; |
| if (!failed.fn && errdes != STDERR_FILE_NO) |
| if (close (errdes) < 0) |
| failed.fn = "close", failed.err = errno; |
| |
| if (failed.fn) |
| { |
| *err = failed.err; |
| *errmsg = failed.fn; |
| return (pid_t) -1; |
| } |
| } |
| return pid; |
| } |
| } |
| #endif /* SPAWN */ |
| |
| /* Wait for a child process to complete. */ |
| |
| static pid_t |
| pex_unix_wait (struct pex_obj *obj, pid_t pid, int *status, |
| struct pex_time *time, int done, const char **errmsg, |
| int *err) |
| { |
| /* If we are cleaning up when the caller didn't retrieve process |
| status for some reason, encourage the process to go away. */ |
| if (done) |
| kill (pid, SIGTERM); |
| |
| if (pex_wait (obj, pid, status, time) < 0) |
| { |
| *err = errno; |
| *errmsg = "wait"; |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /* Create a pipe. */ |
| |
| static int |
| pex_unix_pipe (struct pex_obj *obj ATTRIBUTE_UNUSED, int *p, |
| int binary ATTRIBUTE_UNUSED) |
| { |
| return pipe (p); |
| } |
| |
| /* Get a FILE pointer to read from a file descriptor. */ |
| |
| static FILE * |
| pex_unix_fdopenr (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd, |
| int binary ATTRIBUTE_UNUSED) |
| { |
| return fdopen (fd, "r"); |
| } |
| |
| static FILE * |
| pex_unix_fdopenw (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd, |
| int binary ATTRIBUTE_UNUSED) |
| { |
| if (fcntl (fd, F_SETFD, FD_CLOEXEC) < 0) |
| return NULL; |
| return fdopen (fd, "w"); |
| } |
| |
| static void |
| pex_unix_cleanup (struct pex_obj *obj ATTRIBUTE_UNUSED) |
| { |
| #if !defined (HAVE_WAIT4) && !defined (HAVE_WAITPID) |
| while (obj->sysdep != NULL) |
| { |
| struct status_list *this; |
| struct status_list *next; |
| |
| this = (struct status_list *) obj->sysdep; |
| next = this->next; |
| free (this); |
| obj->sysdep = (void *) next; |
| } |
| #endif |
| } |