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#include <machine/cpu-features.h> 30#include <private/bionic_asm.h> 31#include <private/libc_events.h> 32 33/* 34 * This code assumes it is running on a processor that supports all arm v7 35 * instructions, that supports neon instructions, and that supports 36 * unaligned neon instruction accesses to memory. 37 */ 38 39 .fpu neon 40 .syntax unified 41 42ENTRY(__memset_chk) 43 cmp r2, r3 44 bls .L_done 45 46 // Preserve lr for backtrace. 47 push {lr} 48 .cfi_def_cfa_offset 4 49 .cfi_rel_offset lr, 0 50 51 ldr r0, error_message 52 ldr r1, error_code 531: 54 add r0, pc 55 bl __fortify_chk_fail 56error_code: 57 .word BIONIC_EVENT_MEMSET_BUFFER_OVERFLOW 58error_message: 59 .word error_string-(1b+8) 60END(__memset_chk) 61 62ENTRY(bzero) 63 mov r2, r1 64 mov r1, #0 65 66.L_done: 67 // Fall through to memset... 68END(bzero) 69 70/* memset() returns its first argument. */ 71ENTRY(memset) 72 mov r3, r0 73 vdup.8 q0, r1 74 75 /* make sure we have at least 32 bytes to write */ 76 subs r2, r2, #32 77 blo 2f 78 vmov q1, q0 79 801: /* The main loop writes 32 bytes at a time */ 81 subs r2, r2, #32 82 vst1.8 {d0 - d3}, [r3]! 83 bhs 1b 84 852: /* less than 32 left */ 86 add r2, r2, #32 87 tst r2, #0x10 88 beq 3f 89 90 // writes 16 bytes, 128-bits aligned 91 vst1.8 {d0, d1}, [r3]! 923: /* write up to 15-bytes (count in r2) */ 93 movs ip, r2, lsl #29 94 bcc 1f 95 vst1.8 {d0}, [r3]! 961: bge 2f 97 vst1.32 {d0[0]}, [r3]! 982: movs ip, r2, lsl #31 99 strbmi r1, [r3], #1 100 strbcs r1, [r3], #1 101 strbcs r1, [r3], #1 102 bx lr 103END(memset) 104 105 .data 106error_string: 107 .string "memset: prevented write past end of buffer" 108