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 #include <string.h>
31 #include <stdlib.h>
32 #include "private/libc_logging.h"
33
34 /*
35 * Runtime implementation of __memcpy_chk.
36 *
37 * See
38 * http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
39 * http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html
40 * for details.
41 *
42 * This memcpy check is called if _FORTIFY_SOURCE is defined and
43 * greater than 0.
44 */
__memcpy_chk(void * dest,const void * src,size_t copy_amount,size_t dest_len)45 extern "C" void* __memcpy_chk(void* dest, const void* src,
46 size_t copy_amount, size_t dest_len) {
47 if (__predict_false(copy_amount > dest_len)) {
48 __fortify_chk_fail("memcpy: prevented write past end of buffer",
49 BIONIC_EVENT_MEMCPY_BUFFER_OVERFLOW);
50 }
51
52 return memcpy(dest, src, copy_amount);
53 }
54