1cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich/* 2cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * Copyright (C) 2012 The Android Open Source Project 3cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * All rights reserved. 4cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * 5cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * Redistribution and use in source and binary forms, with or without 6cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * modification, are permitted provided that the following conditions 7cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * are met: 8cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * * Redistributions of source code must retain the above copyright 9cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * notice, this list of conditions and the following disclaimer. 10cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * * Redistributions in binary form must reproduce the above copyright 11cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * notice, this list of conditions and the following disclaimer in 12cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * the documentation and/or other materials provided with the 13cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * distribution. 14cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * 15cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * SUCH DAMAGE. 27cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich */ 28cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich 29e4c6b08c4e81f640afc502804d1226a3e79dc26dNick Kralevich#undef _FORTIFY_SOURCE 30e4c6b08c4e81f640afc502804d1226a3e79dc26dNick Kralevich 31cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich#include <stdio.h> 32cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich#include <stdlib.h> 33cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich#include <stdarg.h> 34eb847bc8666842a3cfc9c06e8458ad1abebebaf0Elliott Hughes#include "private/libc_logging.h" 35cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich 36cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich/* 37cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * Runtime implementation of __builtin____vsnprintf_chk. 38cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * 39cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * See 40cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html 41cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html 42cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * for details. 43cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * 44cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * This vsnprintf check is called if _FORTIFY_SOURCE is defined and 45cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich * greater than 0. 46cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich */ 47d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughesextern "C" int __vsnprintf_chk(char* dest, size_t supplied_size, int /*flags*/, 48d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes size_t dest_len_from_compiler, const char* format, va_list va) { 49d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes if (__predict_false(supplied_size > dest_len_from_compiler)) { 50d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes __fortify_chk_fail("vsnprintf: prevented write past end of buffer", 0); 51d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes } 52cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich 53d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes return vsnprintf(dest, supplied_size, format, va); 54cffdf6693ffb50d2a1258d955a162bca83038f25Nick Kralevich} 554035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes 564035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes/* 574035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes * Runtime implementation of __builtin____snprintf_chk. 584035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes * 594035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes * See 604035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes * http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html 614035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes * http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html 624035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes * for details. 634035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes * 644035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes * This snprintf check is called if _FORTIFY_SOURCE is defined and 654035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes * greater than 0. 664035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes */ 67d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughesextern "C" int __snprintf_chk(char* dest, size_t supplied_size, int flags, 6868b67113a44311b3568027af5893e316f63ec556Elliott Hughes size_t dest_len_from_compiler, const char* format, ...) { 69d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes va_list va; 70d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes va_start(va, format); 71d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes int result = __vsnprintf_chk(dest, supplied_size, flags, dest_len_from_compiler, format, va); 72d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes va_end(va); 73d1eda33f012e46083b91e087fb79d14a5ce70f0eElliott Hughes return result; 744035b7a32155eac46f3f3782774deb5967ea2b54Elliott Hughes} 75