1 | /* Copyright (C) 1994-2017 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <http://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <errno.h> |
19 | #include <stddef.h> |
20 | #include <stdio.h> |
21 | #include <unistd.h> |
22 | #include <sys/stat.h> |
23 | |
24 | |
25 | /* Execute the file FD refers to, overlaying the running program image. |
26 | ARGV and ENVP are passed to the new program, as for `execve'. */ |
27 | int |
28 | fexecve (int fd, char *const argv[], char *const envp[]) |
29 | { |
30 | if (fd < 0 || argv == NULL || envp == NULL) |
31 | { |
32 | __set_errno (EINVAL); |
33 | return -1; |
34 | } |
35 | |
36 | /* We use the /proc filesystem to get the information. If it is not |
37 | mounted we fail. */ |
38 | char buf[sizeof "/proc/self/fd/" + sizeof (int) * 3]; |
39 | __snprintf (buf, sizeof (buf), "/proc/self/fd/%d" , fd); |
40 | |
41 | /* We do not need the return value. */ |
42 | __execve (buf, argv, envp); |
43 | |
44 | int save = errno; |
45 | |
46 | /* We come here only if the 'execve' call fails. Determine whether |
47 | /proc is mounted. If not we return ENOSYS. */ |
48 | struct stat st; |
49 | if (stat ("/proc/self/fd" , &st) != 0 && errno == ENOENT) |
50 | save = ENOSYS; |
51 | |
52 | __set_errno (save); |
53 | |
54 | return -1; |
55 | } |
56 | |