1 /* 2 * Copyright (C) 2013 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 #include <private/bionic_asm.h> 30 31 .syntax unified 32 33 .thumb 34 .thumb_func 35 36 // To avoid warning about deprecated instructions, add an explicit 37 // arch. The code generated is exactly the same. 38 .arch armv7-a 39 40 // Get the length of the source string first, then do a memcpy of the data 41 // instead of a strcpy. 42 ENTRY(__strcpy_chk) 43 pld [r0, #0] 44 push {r0, lr} 45 .cfi_def_cfa_offset 8 46 .cfi_rel_offset r0, 0 47 .cfi_rel_offset lr, 4 48 49 mov lr, r2 50 mov r0, r1 51 52 ands r3, r1, #7 53 beq .L_mainloop 54 55 // Align to a double word (64 bits). 56 rsb r3, r3, #8 57 lsls ip, r3, #31 58 beq .L_align_to_32 59 60 ldrb r2, [r0], #1 61 cbz r2, .L_update_count_and_finish 62 63 .L_align_to_32: 64 bcc .L_align_to_64 65 ands ip, r3, #2 66 beq .L_align_to_64 67 68 ldrb r2, [r0], #1 69 cbz r2, .L_update_count_and_finish 70 ldrb r2, [r0], #1 71 cbz r2, .L_update_count_and_finish 72 73 .L_align_to_64: 74 tst r3, #4 75 beq .L_mainloop 76 ldr r3, [r0], #4 77 78 sub ip, r3, #0x01010101 79 bic ip, ip, r3 80 ands ip, ip, #0x80808080 81 bne .L_zero_in_second_register 82 83 .p2align 2 84 .L_mainloop: 85 ldrd r2, r3, [r0], #8 86 87 pld [r0, #64] 88 89 sub ip, r2, #0x01010101 90 bic ip, ip, r2 91 ands ip, ip, #0x80808080 92 bne .L_zero_in_first_register 93 94 sub ip, r3, #0x01010101 95 bic ip, ip, r3 96 ands ip, ip, #0x80808080 97 bne .L_zero_in_second_register 98 b .L_mainloop 99 100 .L_update_count_and_finish: 101 sub r3, r0, r1 102 sub r3, r3, #1 103 b .L_check_size 104 105 .L_zero_in_first_register: 106 sub r3, r0, r1 107 lsls r2, ip, #17 108 bne .L_sub8_and_finish 109 bcs .L_sub7_and_finish 110 lsls ip, ip, #1 111 bne .L_sub6_and_finish 112 113 sub r3, r3, #5 114 b .L_check_size 115 116 .L_sub8_and_finish: 117 sub r3, r3, #8 118 b .L_check_size 119 120 .L_sub7_and_finish: 121 sub r3, r3, #7 122 b .L_check_size 123 124 .L_sub6_and_finish: 125 sub r3, r3, #6 126 b .L_check_size 127 128 .L_zero_in_second_register: 129 sub r3, r0, r1 130 lsls r2, ip, #17 131 bne .L_sub4_and_finish 132 bcs .L_sub3_and_finish 133 lsls ip, ip, #1 134 bne .L_sub2_and_finish 135 136 sub r3, r3, #1 137 b .L_check_size 138 139 .L_sub4_and_finish: 140 sub r3, r3, #4 141 b .L_check_size 142 143 .L_sub3_and_finish: 144 sub r3, r3, #3 145 b .L_check_size 146 147 .L_sub2_and_finish: 148 sub r3, r3, #2 149 150 .L_check_size: 151 pld [r1, #0] 152 pld [r1, #64] 153 ldr r0, [sp] 154 155 // Add 1 for copy length to get the string terminator. 156 add r2, r3, #1 157 158 cmp r2, lr 159 itt hi 160 movhi r0, r2 161 bhi __strcpy_chk_fail 162 163 #include "memcpy_base.S" 164 165 END(__strcpy_chk) 166
