| /* Copyright (C) 2005-2014 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 <fcntl.h> |
| #include <stdarg.h> |
| #include <stddef.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <sys/stat.h> |
| #include <kernel-features.h> |
| #include <sysdep-cancel.h> |
| #include <not-cancel.h> |
| |
| |
| #ifndef OPENAT |
| # define OPENAT openat |
| |
| # ifndef __ASSUME_ATFCTS |
| /* Set errno after a failed call. If BUF is not null, |
| it is a /proc/self/fd/ path name we just tried to use. */ |
| void |
| attribute_hidden |
| __atfct_seterrno (int errval, int fd, const char *buf) |
| { |
| if (buf != NULL) |
| { |
| struct stat64 st; |
| |
| if (errval == ENOTDIR || errval == ENOENT) |
| { |
| /* This can mean either the file descriptor is invalid or |
| /proc is not mounted. */ |
| if (__fxstat64 (_STAT_VER, fd, &st) != 0) |
| /* errno is already set correctly. */ |
| return; |
| |
| /* If /proc is not mounted there is nothing we can do. */ |
| if ((errval != ENOTDIR || S_ISDIR (st.st_mode)) |
| && (__xstat64 (_STAT_VER, "/proc/self/fd", &st) != 0 |
| || !S_ISDIR (st.st_mode))) |
| errval = ENOSYS; |
| } |
| } |
| |
| __set_errno (errval); |
| } |
| |
| int __have_atfcts; |
| # endif |
| #endif |
| |
| |
| #define OPENAT_NOT_CANCEL CONCAT (OPENAT) |
| #define CONCAT(name) CONCAT2 (name) |
| #define CONCAT2(name) __##name##_nocancel |
| |
| |
| int |
| OPENAT_NOT_CANCEL (fd, file, oflag, mode) |
| int fd; |
| const char *file; |
| int oflag; |
| mode_t mode; |
| { |
| |
| /* We have to add the O_LARGEFILE flag for openat64. */ |
| #ifdef MORE_OFLAGS |
| oflag |= MORE_OFLAGS; |
| #endif |
| |
| int res; |
| |
| #ifdef __NR_openat |
| # ifndef __ASSUME_ATFCTS |
| if (__have_atfcts >= 0) |
| # endif |
| { |
| res = INLINE_SYSCALL (openat, 4, fd, file, oflag, mode); |
| |
| # ifndef __ASSUME_ATFCTS |
| if (res == -1 && errno == ENOSYS) |
| __have_atfcts = -1; |
| else |
| # endif |
| return res; |
| } |
| #endif |
| |
| #ifndef __ASSUME_ATFCTS |
| INTERNAL_SYSCALL_DECL (err); |
| char *buf = NULL; |
| |
| if (fd != AT_FDCWD && file[0] != '/') |
| { |
| size_t filelen = strlen (file); |
| if (__builtin_expect (filelen == 0, 0)) |
| { |
| __set_errno (ENOENT); |
| return -1; |
| } |
| |
| static const char procfd[] = "/proc/self/fd/%d/%s"; |
| /* Buffer for the path name we are going to use. It consists of |
| - the string /proc/self/fd/ |
| - the file descriptor number |
| - the file name provided. |
| The final NUL is included in the sizeof. A bit of overhead |
| due to the format elements compensates for possible negative |
| numbers. */ |
| size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen; |
| buf = alloca (buflen); |
| |
| /* Note: snprintf cannot be canceled. */ |
| __snprintf (buf, buflen, procfd, fd, file); |
| file = buf; |
| } |
| |
| res = INTERNAL_SYSCALL (open, err, 3, file, oflag, mode); |
| |
| if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (res, err), 0)) |
| { |
| __atfct_seterrno (INTERNAL_SYSCALL_ERRNO (res, err), fd, buf); |
| res = -1; |
| } |
| |
| return res; |
| #endif |
| } |
| |
| #define UNDERIZE(name) UNDERIZE_1 (name) |
| #define UNDERIZE_1(name) __##name |
| #define __OPENAT UNDERIZE (OPENAT) |
| |
| |
| /* Open FILE with access OFLAG. Interpret relative paths relative to |
| the directory associated with FD. If OFLAG includes O_CREAT, a |
| third argument is the file protection. */ |
| int |
| __OPENAT (fd, file, oflag) |
| int fd; |
| const char *file; |
| int oflag; |
| { |
| mode_t mode = 0; |
| if (oflag & O_CREAT) |
| { |
| va_list arg; |
| va_start (arg, oflag); |
| mode = va_arg (arg, mode_t); |
| va_end (arg); |
| } |
| |
| if (SINGLE_THREAD_P) |
| return OPENAT_NOT_CANCEL (fd, file, oflag, mode); |
| |
| int oldtype = LIBC_CANCEL_ASYNC (); |
| |
| int res = OPENAT_NOT_CANCEL (fd, file, oflag, mode); |
| |
| LIBC_CANCEL_RESET (oldtype); |
| |
| return res; |
| } |
| libc_hidden_def (__OPENAT) |
| weak_alias (__OPENAT, OPENAT) |