-/* Copyright (C) 1993-2017 Free Software Foundation, Inc.
+/* Copyright (C) 1993-2019 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
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/>.
+ <https://www.gnu.org/licenses/>.
As a special exception, if you link the code in this file with
files compiled with a GNU compiler to produce an executable,
This exception applies to code released by its copyright holders
in files containing the exception. */
-#include "libioP.h"
-#include "stdio.h"
+#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
+#include <libioP.h>
#include <fd_to_filename.h>
-#include <kernel-features.h>
-
FILE *
freopen64 (const char *filename, const char *mode, FILE *fp)
{
- FILE *result;
+ FILE *result = NULL;
+ char fdfilename[FD_TO_FILENAME_SIZE];
+
CHECK_FILE (fp, NULL);
- if (!(fp->_flags & _IO_IS_FILEBUF))
- return NULL;
+
_IO_acquire_lock (fp);
+ /* First flush the stream (failure should be ignored). */
+ _IO_SYNC (fp);
+
+ if (!(fp->_flags & _IO_IS_FILEBUF))
+ goto end;
+
int fd = _IO_fileno (fp);
- const char *gfilename = (filename == NULL && fd >= 0
- ? fd_to_filename (fd) : filename);
+ const char *gfilename
+ = filename != NULL ? filename : fd_to_filename (fd, fdfilename);
+
fp->_flags2 |= _IO_FLAGS2_NOCLOSE;
_IO_file_close_it (fp);
_IO_JUMPS_FILE_plus (fp) = &_IO_file_jumps;
/* unbound stream orientation */
result->_mode = 0;
- if (fd != -1)
+ if (fd != -1 && _IO_fileno (result) != fd)
{
- __dup3 (_IO_fileno (result), fd,
- (result->_flags2 & _IO_FLAGS2_CLOEXEC) != 0
- ? O_CLOEXEC : 0);
+ /* At this point we have both file descriptors already allocated,
+ so __dup3 will not fail with EBADF, EINVAL, or EMFILE. But
+ we still need to check for EINVAL and, due Linux internal
+ implementation, EBUSY. It is because on how it internally opens
+ the file by splitting the buffer allocation operation and VFS
+ opening (a dup operation may run when a file is still pending
+ 'install' on VFS). */
+ if (__dup3 (_IO_fileno (result), fd,
+ (result->_flags2 & _IO_FLAGS2_CLOEXEC) != 0
+ ? O_CLOEXEC : 0) == -1)
+ {
+ _IO_file_close_it (result);
+ result = NULL;
+ goto end;
+ }
__close (_IO_fileno (result));
_IO_fileno (result) = fd;
}
}
else if (fd != -1)
__close (fd);
- if (filename == NULL)
- free ((char *) gfilename);
+
+end:
_IO_release_lock (fp);
return result;
}