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Christopher Ferrisacdde8c2013-02-26 01:30:00 -08001/*
Christopher Ferris4d8fe512013-04-19 14:01:50 -07002 * Copyright (C) 2013 The Android Open Source Project
Christopher Ferrisacdde8c2013-02-26 01:30:00 -08003 * 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/cpu-features.h>
32#include <machine/asm.h>
Christopher Ferris7c860db2013-08-01 13:13:33 -070033#include "libc_events.h"
Christopher Ferrisacdde8c2013-02-26 01:30:00 -080034
35/*
36 * This code assumes it is running on a processor that supports all arm v7
37 * instructions, that supports neon instructions, and that has a 32 byte
38 * cache line.
39 */
40
Christopher Ferris7c860db2013-08-01 13:13:33 -070041#define CACHE_LINE_SIZE 32
42
Christopher Ferrisacdde8c2013-02-26 01:30:00 -080043 .text
44 .fpu neon
45
Christopher Ferris7c860db2013-08-01 13:13:33 -070046ENTRY(__memcpy_chk)
47 cmp r2, r3
48 bgt fortify_check_failed
49
50 // Fall through to memcpy...
51END(__memcpy_chk)
Christopher Ferrisacdde8c2013-02-26 01:30:00 -080052
53ENTRY(memcpy)
54 .save {r0, lr}
55 /* start preloading as early as possible */
Christopher Ferris4d8fe512013-04-19 14:01:50 -070056 pld [r1, #(CACHE_LINE_SIZE*4)]
Christopher Ferrisacdde8c2013-02-26 01:30:00 -080057 stmfd sp!, {r0, lr}
Christopher Ferrisacdde8c2013-02-26 01:30:00 -080058
59 /* do we have at least 16-bytes to copy (needed for alignment below) */
60 cmp r2, #16
61 blo 5f
62
63 /* align destination to cache-line for the write-buffer */
64 rsb r3, r0, #0
65 ands r3, r3, #0xF
Christopher Ferris4d8fe512013-04-19 14:01:50 -070066 beq 2f
Christopher Ferrisacdde8c2013-02-26 01:30:00 -080067
68 /* copy up to 15-bytes (count in r3) */
69 sub r2, r2, r3
70 movs ip, r3, lsl #31
71 ldrmib lr, [r1], #1
72 strmib lr, [r0], #1
73 ldrcsb ip, [r1], #1
74 ldrcsb lr, [r1], #1
75 strcsb ip, [r0], #1
76 strcsb lr, [r0], #1
77 movs ip, r3, lsl #29
78 bge 1f
79 // copies 4 bytes, destination 32-bits aligned
80 vld4.8 {d0[0], d1[0], d2[0], d3[0]}, [r1]!
81 vst4.8 {d0[0], d1[0], d2[0], d3[0]}, [r0, :32]!
821: bcc 2f
83 // copies 8 bytes, destination 64-bits aligned
84 vld1.8 {d0}, [r1]!
85 vst1.8 {d0}, [r0, :64]!
Christopher Ferrisacdde8c2013-02-26 01:30:00 -080086
Christopher Ferris4d8fe512013-04-19 14:01:50 -0700872: /* make sure we have at least 64 bytes to copy */
Christopher Ferrisacdde8c2013-02-26 01:30:00 -080088 subs r2, r2, #64
89 blo 2f
90
Christopher Ferrisacdde8c2013-02-26 01:30:00 -0800911: /* The main loop copies 64 bytes at a time */
92 vld1.8 {d0 - d3}, [r1]!
93 vld1.8 {d4 - d7}, [r1]!
Christopher Ferris4d8fe512013-04-19 14:01:50 -070094 pld [r1, #(CACHE_LINE_SIZE*2)]
Christopher Ferrisacdde8c2013-02-26 01:30:00 -080095 subs r2, r2, #64
96 vst1.8 {d0 - d3}, [r0, :128]!
97 vst1.8 {d4 - d7}, [r0, :128]!
98 bhs 1b
99
1002: /* fix-up the remaining count and make sure we have >= 32 bytes left */
Christopher Ferris4d8fe512013-04-19 14:01:50 -0700101 adds r2, r2, #32
Christopher Ferrisacdde8c2013-02-26 01:30:00 -0800102 blo 4f
103
Christopher Ferris4d8fe512013-04-19 14:01:50 -0700104 /* Copy 32 bytes. These cache lines were already preloaded */
Christopher Ferrisacdde8c2013-02-26 01:30:00 -0800105 vld1.8 {d0 - d3}, [r1]!
Christopher Ferris4d8fe512013-04-19 14:01:50 -0700106 sub r2, r2, #32
Christopher Ferrisacdde8c2013-02-26 01:30:00 -0800107 vst1.8 {d0 - d3}, [r0, :128]!
Christopher Ferris4d8fe512013-04-19 14:01:50 -0700108
Christopher Ferrisacdde8c2013-02-26 01:30:00 -08001094: /* less than 32 left */
110 add r2, r2, #32
111 tst r2, #0x10
112 beq 5f
113 // copies 16 bytes, 128-bits aligned
114 vld1.8 {d0, d1}, [r1]!
115 vst1.8 {d0, d1}, [r0, :128]!
116
1175: /* copy up to 15-bytes (count in r2) */
118 movs ip, r2, lsl #29
119 bcc 1f
120 vld1.8 {d0}, [r1]!
121 vst1.8 {d0}, [r0]!
1221: bge 2f
123 vld4.8 {d0[0], d1[0], d2[0], d3[0]}, [r1]!
124 vst4.8 {d0[0], d1[0], d2[0], d3[0]}, [r0]!
1252: movs ip, r2, lsl #31
126 ldrmib r3, [r1], #1
127 ldrcsb ip, [r1], #1
128 ldrcsb lr, [r1], #1
129 strmib r3, [r0], #1
130 strcsb ip, [r0], #1
131 strcsb lr, [r0], #1
132
133 ldmfd sp!, {r0, lr}
134 bx lr
Christopher Ferris7c860db2013-08-01 13:13:33 -0700135
136 // Only reached when the __memcpy_chk check fails.
137fortify_check_failed:
138 ldr r0, error_message
139 ldr r1, error_code
1401:
141 add r0, pc
142 bl __fortify_chk_fail
143error_code:
144 .word BIONIC_EVENT_MEMCPY_BUFFER_OVERFLOW
145error_message:
146 .word error_string-(1b+8)
Christopher Ferrisacdde8c2013-02-26 01:30:00 -0800147END(memcpy)
Christopher Ferris7c860db2013-08-01 13:13:33 -0700148
149 .data
150error_string:
151 .string "memcpy buffer overflow"