bionic/libc/stdio/__vsnprintf_chk.c
Nick Kralevich cffdf6693f FORTIFY_SOURCE: add snprintf, vsnprintf
Add _FORTIFY_SOURCE support for snprintf, vsnprintf

At this time, we opt out of these protections for clang, as clang
does not implement __builtin_va_arg_pack().

http://clang.llvm.org/docs/UsersManual.html#c_unimpl_gcc

Change-Id: I73ebe5ec8dad1dca8898a76d6afb693a25f75375
2012-06-11 16:46:16 -07:00

61 lines
2.2 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 <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <private/logd.h>
/*
* Runtime implementation of __builtin____vsnprintf_chk.
*
* 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 vsnprintf check is called if _FORTIFY_SOURCE is defined and
* greater than 0.
*/
int __vsnprintf_chk(
char *dest,
size_t supplied_size,
int flags,
size_t dest_len_from_compiler,
const char *format,
va_list va)
{
if (supplied_size > dest_len_from_compiler) {
__libc_android_log_print(ANDROID_LOG_FATAL, "libc",
"*** vsnprintf buffer overflow detected ***\n");
abort();
}
return vsnprintf(dest, supplied_size, format, va);
}