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-rw-r--r--sysdeps/unix/sysv/linux/openat.c175
1 files changed, 175 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/openat.c b/sysdeps/unix/sysv/linux/openat.c
new file mode 100644
index 0000000000..df53b6cf2c
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/openat.c
@@ -0,0 +1,175 @@
+/* Copyright (C) 2005, 2006 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#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
+
+ INTERNAL_SYSCALL_DECL (err);
+ 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
+ char *buf = NULL;
+
+ if (fd != AT_FDCWD && file[0] != '/')
+ {
+ size_t filelen = strlen (file);
+ 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)