platform_bionic/libc/bionic/__strlcat_chk.cpp
Elliott Hughes d1eda33f01 Avoid confusing "read prevented write" log messages.
Moving to a "function: message" style avoids ambiguity.

Change-Id: If9d590e50265c61725d3673bd03796e65edd2d5e
2013-10-15 16:49:28 -07:00

52 lines
2.1 KiB
C++

/*
* Copyright (C) 2012 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <string.h>
#include <stdlib.h>
#include "private/libc_logging.h"
/*
* __strlcat_chk. Called in place of strlcat() when we know the
* size of the buffer we're writing into.
*
* See
* http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
* http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html
* for details.
*
* This strlcat check is called if _FORTIFY_SOURCE is defined and
* greater than 0.
*/
extern "C" size_t __strlcat_chk(char* dest, const char* src,
size_t supplied_size, size_t dest_len_from_compiler) {
if (__predict_false(supplied_size > dest_len_from_compiler)) {
__fortify_chk_fail("strlcat: prevented write past end of buffer", 0);
}
return strlcat(dest, src, supplied_size);
}