| /* Copyright (C) 1994-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <errno.h> |
| #include <stddef.h> |
| #include <stdio.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <sys/stat.h> |
| |
| #include <sysdep.h> |
| #include <sys/syscall.h> |
| #include <kernel-features.h> |
| |
| |
| /* Execute the file FD refers to, overlaying the running program image. |
| ARGV and ENVP are passed to the new program, as for `execve'. */ |
| int |
| fexecve (int fd, char *const argv[], char *const envp[]) |
| { |
| if (fd < 0 || argv == NULL || envp == NULL) |
| { |
| __set_errno (EINVAL); |
| return -1; |
| } |
| |
| #ifdef __NR_execveat |
| /* Avoid implicit array coercion in syscall macros. */ |
| INLINE_SYSCALL (execveat, 5, fd, "", &argv[0], &envp[0], AT_EMPTY_PATH); |
| # ifndef __ASSUME_EXECVEAT |
| if (errno != ENOSYS) |
| return -1; |
| # endif |
| #endif |
| |
| #ifndef __ASSUME_EXECVEAT |
| /* We use the /proc filesystem to get the information. If it is not |
| mounted we fail. */ |
| char buf[sizeof "/proc/self/fd/" + sizeof (int) * 3]; |
| __snprintf (buf, sizeof (buf), "/proc/self/fd/%d", fd); |
| |
| /* We do not need the return value. */ |
| __execve (buf, argv, envp); |
| |
| int save = errno; |
| |
| /* We come here only if the 'execve' call fails. Determine whether |
| /proc is mounted. If not we return ENOSYS. */ |
| struct stat st; |
| if (stat ("/proc/self/fd", &st) != 0 && errno == ENOENT) |
| save = ENOSYS; |
| |
| __set_errno (save); |
| #endif |
| |
| return -1; |
| } |