usr/lib/posix/exec/execve.c

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This source file includes following definitions.
execve
   1 /*
   2  * Copyright (c) 2005-2006, Kohsuke Ohtani
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the author nor the names of any co-contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29 
  30 #include <sys/prex.h>
  31 #include <ipc/exec.h>
  32 #include <ipc/ipc.h>
  33 
  34 #include <unistd.h>
  35 #include <limits.h>
  36 #include <string.h>
  37 #include <errno.h>
  38 #include <stdlib.h>
  39 
  40 /*
  41  * Note:
  42  *
  43  * The state after exec() are as follows:
  44  * - Opened file descriptors remain open except FD_CLOEXEC flag is set.
  45  * - Opened directory streams are closed
  46  * - Signals set to the default action.
  47  * - Any asynchronous I/O operations are cancelled.
  48  */
  49 int
  50 execve(const char *path, char * const *argv, char * const *envp)
  51 {
  52         object_t execobj;
  53         struct exec_msg msg;
  54         int error, i, argc, envc;
  55         size_t bufsz;
  56         char *dest, *src;
  57 
  58         if ((error = object_lookup("!exec", &execobj)) != 0)
  59                 return ENOSYS;
  60 
  61         if (path == NULL)
  62                 return EFAULT;
  63 /*
  64     if (strlen(path) >= PATH_MAX)
  65         return ENAMETOOLONG;
  66 */
  67 
  68         /* Get arg/env buffer size */
  69         bufsz = 0;
  70         argc = 0;
  71         if (argv) {
  72                 while (argv[argc]) {
  73                         bufsz += (strlen(argv[argc]) + 1);
  74                         argc++;
  75                 }
  76         }
  77         envc = 0;
  78         if (envp) {
  79                 while (envp[envc]) {
  80                         bufsz += (strlen(envp[envc]) + 1);
  81                         envc++;
  82                 }
  83         }
  84         if (bufsz >= ARG_MAX)
  85                 return E2BIG;
  86 
  87         dest = msg.buf;
  88         for (i = 0; i < argc; i++) {
  89                 src = argv[i];
  90                 while ((*dest++ = *src++) != 0);
  91         }
  92         for (i = 0; i < envc; i++) {
  93                 src = envp[i];
  94                 while ((*dest++ = *src++) != 0);
  95         }
  96 
  97         /* Request to exec server */
  98         msg.hdr.code = EXEC_EXECVE;
  99         msg.argc = argc;
 100         msg.envc = envc;
 101         msg.bufsz = bufsz;
 102         getcwd(msg.cwd, PATH_MAX);
 103         strlcpy(msg.path, path, PATH_MAX);
 104         do {
 105                 error = msg_send(execobj, &msg, sizeof(msg));
 106         } while (error == EINTR);
 107 
 108         /*
 109          * If exec() request is done successfully, control never comes here.
 110          */
 111         errno = 0;
 112         if (error)
 113                 errno = EIO;
 114         else if (msg.hdr.status)
 115                 errno = msg.hdr.status;
 116 
 117         return -1;
 118 }
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root/usr/lib/posix/exec/execve.c

DEFINITIONS
