1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #undef _FORTIFY_SOURCE 30 31 #include <stdio.h> 32 #include <stdlib.h> 33 #include <stdarg.h> 34 #include "private/libc_logging.h" 35 36 /* 37 * Runtime implementation of __builtin____vsnprintf_chk. 38 * 39 * See 40 * http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html 41 * http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html 42 * for details. 43 * 44 * This vsnprintf check is called if _FORTIFY_SOURCE is defined and 45 * greater than 0. 46 */ 47 extern "C" int __vsnprintf_chk(char* dest, size_t supplied_size, int /*flags*/, 48 size_t dest_len_from_compiler, const char* format, va_list va) { 49 if (__predict_false(supplied_size > dest_len_from_compiler)) { 50 __fortify_chk_fail("vsnprintf: prevented write past end of buffer", 0); 51 } 52 53 return vsnprintf(dest, supplied_size, format, va); 54 } 55 56 /* 57 * Runtime implementation of __builtin____snprintf_chk. 58 * 59 * See 60 * http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html 61 * http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html 62 * for details. 63 * 64 * This snprintf check is called if _FORTIFY_SOURCE is defined and 65 * greater than 0. 66 */ 67 extern "C" int __snprintf_chk(char* dest, size_t supplied_size, int flags, 68 size_t dest_len_from_compiler, const char* format, ...) { 69 va_list va; 70 va_start(va, format); 71 int result = __vsnprintf_chk(dest, supplied_size, flags, dest_len_from_compiler, format, va); 72 va_end(va); 73 return result; 74 } 75
