4
0
mirror of git://sourceware.org/git/newlib-cygwin.git synced 2025-01-22 23:17:28 +08:00
Takashi Yano 3d94e07c49 newlib: libc: Fix crash on fprintf to a wide-oriented stream.
Previously, fprintf() on a wide-oriented stream crashes or outputs
garbage. This is because a narrow char string which can be odd bytes
in length is cast into a wide char string which should be even
bytes in length in __sprint_r/__sfputs_r based on the __SWID flag.
As a result, if the length is odd bytes, the reading buffer runs over
the buffer length, which causes a crash. If the length is even bytes,
garbage is printed.

With this patch, any output to the stream which is set to different
orientation fails with error just like glibc. Note that it behaves
differently from other libc implementations such as BSD, musl and
Solaris.

Reviewed-by: Corinna Vinschen <corinna@vinschen.de>
Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
2023-11-10 00:36:41 +09:00

146 lines
3.8 KiB
C

/*
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* and/or other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
/*
FUNCTION
<<fputs>>, <<fputs_unlocked>>---write a character string in a file or stream
INDEX
fputs
INDEX
fputs_unlocked
INDEX
_fputs_r
INDEX
_fputs_unlocked_r
SYNOPSIS
#include <stdio.h>
int fputs(const char *restrict <[s]>, FILE *restrict <[fp]>);
#define _GNU_SOURCE
#include <stdio.h>
int fputs_unlocked(const char *restrict <[s]>, FILE *restrict <[fp]>);
#include <stdio.h>
int _fputs_r(struct _reent *<[ptr]>, const char *restrict <[s]>, FILE *restrict <[fp]>);
#include <stdio.h>
int _fputs_unlocked_r(struct _reent *<[ptr]>, const char *restrict <[s]>, FILE *restrict <[fp]>);
DESCRIPTION
<<fputs>> writes the string at <[s]> (but without the trailing null)
to the file or stream identified by <[fp]>.
<<fputs_unlocked>> is a non-thread-safe version of <<fputs>>.
<<fputs_unlocked>> may only safely be used within a scope
protected by flockfile() (or ftrylockfile()) and funlockfile(). This
function may safely be used in a multi-threaded program if and only
if they are called while the invoking thread owns the (FILE *)
object, as is the case after a successful call to the flockfile() or
ftrylockfile() functions. If threads are disabled, then
<<fputs_unlocked>> is equivalent to <<fputs>>.
<<_fputs_r>> and <<_fputs_unlocked_r>> are simply reentrant versions of the
above that take an additional reentrant struct pointer argument: <[ptr]>.
RETURNS
If successful, the result is <<0>>; otherwise, the result is <<EOF>>.
PORTABILITY
ANSI C requires <<fputs>>, but does not specify that the result on
success must be <<0>>; any non-negative value is permitted.
<<fputs_unlocked>> is a GNU extension.
Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
*/
#include <_ansi.h>
#include <stdio.h>
#include <string.h>
#include "fvwrite.h"
#include "local.h"
#ifdef __IMPL_UNLOCKED__
#define _fputs_r _fputs_unlocked_r
#define fputs fputs_unlocked
#endif
/*
* Write the given string to the given file.
*/
int
_fputs_r (struct _reent * ptr,
char const *__restrict s,
FILE *__restrict fp)
{
#ifdef _FVWRITE_IN_STREAMIO
int result;
struct __suio uio;
struct __siov iov;
iov.iov_base = s;
iov.iov_len = uio.uio_resid = strlen (s);
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
CHECK_INIT(ptr, fp);
_newlib_flockfile_start (fp);
if (ORIENT (fp, -1) != -1)
result = EOF;
else
result = __sfvwrite_r (ptr, fp, &uio);
_newlib_flockfile_end (fp);
return result;
#else
const char *p = s;
CHECK_INIT(ptr, fp);
_newlib_flockfile_start (fp);
if (ORIENT (fp, -1) != -1)
goto error;
/* Make sure we can write. */
if (cantwrite (ptr, fp))
goto error;
while (*p)
{
if (__sputc_r (ptr, *p++, fp) == EOF)
goto error;
}
_newlib_flockfile_exit (fp);
return 0;
error:
_newlib_flockfile_end (fp);
return EOF;
#endif
}
#ifndef _REENT_ONLY
int
fputs (char const *__restrict s,
FILE *__restrict fp)
{
return _fputs_r (_REENT, s, fp);
}
#endif /* !_REENT_ONLY */