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As reported in bug 32134, freopen does not clear the flags set in fp->_flags2 by the "e", "m" or "c" mode characters. Clear these so that they can be set or not as appropriate from the mode string passed to freopen. The relevant test for "e" in tst-freopen2-main.c is enabled accordingly; "c" is expected to be covered in a separately written test (and while tst-freopen2-main.c does include transitions to and from "m", that's not really a semantic flag intended to result in behaving in an observably different way). Tested for x86_64.
98 lines
3.2 KiB
C
98 lines
3.2 KiB
C
/* Copyright (C) 1993-2024 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>.
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As a special exception, if you link the code in this file with
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files compiled with a GNU compiler to produce an executable,
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that does not cause the resulting executable to be covered by
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the GNU Lesser General Public License. This exception does not
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however invalidate any other reasons why the executable file
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might be covered by the GNU Lesser General Public License.
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This exception applies to code released by its copyright holders
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in files containing the exception. */
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#include <stdio.h>
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#include <fcntl.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <libioP.h>
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#include <fd_to_filename.h>
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FILE *
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freopen64 (const char *filename, const char *mode, FILE *fp)
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{
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FILE *result = NULL;
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struct fd_to_filename fdfilename;
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CHECK_FILE (fp, NULL);
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_IO_acquire_lock (fp);
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/* First flush the stream (failure should be ignored). */
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_IO_SYNC (fp);
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if (!(fp->_flags & _IO_IS_FILEBUF))
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goto end;
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int fd = _IO_fileno (fp);
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const char *gfilename
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= filename != NULL ? filename : __fd_to_filename (fd, &fdfilename);
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fp->_flags2 |= _IO_FLAGS2_NOCLOSE;
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_IO_file_close_it (fp);
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_IO_JUMPS_FILE_plus (fp) = &_IO_file_jumps;
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if (_IO_vtable_offset (fp) == 0 && fp->_wide_data != NULL)
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fp->_wide_data->_wide_vtable = &_IO_wfile_jumps;
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fp->_flags2 &= ~(_IO_FLAGS2_MMAP
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| _IO_FLAGS2_NOTCANCEL
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| _IO_FLAGS2_CLOEXEC);
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result = _IO_file_fopen (fp, gfilename, mode, 0);
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fp->_flags2 &= ~_IO_FLAGS2_NOCLOSE;
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if (result != NULL)
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result = __fopen_maybe_mmap (result);
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if (result != NULL)
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{
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/* unbound stream orientation */
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result->_mode = 0;
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if (fd != -1 && _IO_fileno (result) != fd)
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{
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/* At this point we have both file descriptors already allocated,
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so __dup3 will not fail with EBADF, EINVAL, or EMFILE. But
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we still need to check for EINVAL and, due Linux internal
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implementation, EBUSY. It is because on how it internally opens
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the file by splitting the buffer allocation operation and VFS
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opening (a dup operation may run when a file is still pending
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'install' on VFS). */
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if (__dup3 (_IO_fileno (result), fd,
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(result->_flags2 & _IO_FLAGS2_CLOEXEC) != 0
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? O_CLOEXEC : 0) == -1)
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{
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_IO_file_close_it (result);
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result = NULL;
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goto end;
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}
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__close (_IO_fileno (result));
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_IO_fileno (result) = fd;
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}
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}
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else if (fd != -1)
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__close (fd);
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end:
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_IO_release_lock (fp);
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return result;
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}
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