Aren/NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

avoid reading from out of range that may cause access fault.

Browse Source
This commit is contained in:
ryo 2018-07-09 06:07:06 +00:00
parent 9ab5372263
commit 6c83813761
1 changed files with 8 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
common/lib/libc/arch/aarch64/string/memcmp.S
View File

@ -1,4 +1,4 @@
/* $NetBSD: memcmp.S,v 1.2 2018/02/04 21:52:16 skrll Exp $ */
/* $NetBSD: memcmp.S,v 1.3 2018/07/09 06:07:06 ryo Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
@ -31,7 +31,7 @@
#include <machine/asm.h>
RCSID("$NetBSD: memcmp.S,v 1.2 2018/02/04 21:52:16 skrll Exp $")
RCSID("$NetBSD: memcmp.S,v 1.3 2018/07/09 06:07:06 ryo Exp $")
ENTRY(memcmp)
mov x9, x0
@ -55,17 +55,19 @@ ENTRY(memcmp)
sub x2, x2, #8 /* now subtract a dword */
sub x9, x9, x3 /* dword align src1 */
sub x10, x10, x3 /* adjust src2 */
ldr x6, [x10], #8 /* load dword from src2 */
sub x10, x10, x3 /* src2 -= x3 */
lsl x3, x3, #3 /* convert bytes to bits */
ldr x4, [x9], #8 /* load dword from src1 */
ldr x6, [x10], #8 /* load dword from src2 */
#ifdef __AARCH64EB__
lsl x4, x4, x3 /* discard leading bytes from data1 */
lsl x6, x6, x3 /* discard leading bytes from data2 */
lsr x6, x6, x3 /* discard leading bytes from data2 */
lsl x6, x6, x3 /* get back bit position */
#else
lsr x4, x4, x3 /* discard leading bytes from data1 */
lsr x6, x6, x3 /* discard leading bytes from data2 */
lsl x6, x6, x3 /* discard leading bytes from data2 */
lsr x6, x6, x3 /* get back bit position */
#endif
subs x0, x4, x6 /* compare data */
b.ne .Lmemcmp_last_compare /* difference. find it */