memcpy.S revision 68b67113a44311b3568027af5893e316f63ec556 
1/*
2 * Copyright (C) 2008 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/* Assumes neon instructions and a cache line size of 32 bytes. */
30
31#include <machine/asm.h>
32#include "private/libc_events.h"
33
34/*
35 * This code assumes it is running on a processor that supports all arm v7
36 * instructions, that supports neon instructions, and that has a 32 byte
37 * cache line.
38 */
39
40        .text
41        .syntax unified
42        .fpu    neon
43        .thumb
44        .thumb_func
45
46ENTRY(__memcpy_chk)
47        .cfi_startproc
48        cmp         r2, r3
49        bhi         __memcpy_chk_fail
50
51        // Fall through to memcpy...
52        .cfi_endproc
53END(__memcpy_chk)
54
55ENTRY(memcpy)
56        .cfi_startproc
57        pld     [r1, #64]
58        stmfd   sp!, {r0, lr}
59        .save   {r0, lr}
60        .cfi_def_cfa_offset 8
61        .cfi_rel_offset r0, 0
62        .cfi_rel_offset lr, 4
63        .cfi_endproc
64END(memcpy)
65
66#define MEMCPY_BASE         __memcpy_base
67#define MEMCPY_BASE_ALIGNED __memcpy_base_aligned
68#include "memcpy_base.S"
69
70ENTRY_PRIVATE(__memcpy_chk_fail)
71        .cfi_startproc
72        // Preserve lr for backtrace.
73        push    {lr}
74        .save   {lr}
75        .cfi_def_cfa_offset 4
76        .cfi_rel_offset lr, 0
77
78        ldr     r0, error_message
79        ldr     r1, error_code
801:
81        add     r0, pc
82        bl      __fortify_chk_fail
83error_code:
84        .word   BIONIC_EVENT_MEMCPY_BUFFER_OVERFLOW
85error_message:
86        .word   error_string-(1b+4)
87        .cfi_endproc
88END(__memcpy_chk_fail)
89
90        .data
91error_string:
92        .string     "memcpy: prevented write past end of buffer"
93