Module Name: src
Committed By: ryo
Date: Mon Jul 9 06:07:06 UTC 2018
Modified Files:
src/common/lib/libc/arch/aarch64/string: memcmp.S
Log Message:
avoid reading from out of range that may cause access fault.
To generate a diff of this commit:
cvs rdiff -u -r1.2 -r1.3 src/common/lib/libc/arch/aarch64/string/memcmp.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/common/lib/libc/arch/aarch64/string/memcmp.S
diff -u src/common/lib/libc/arch/aarch64/string/memcmp.S:1.2 src/common/lib/libc/arch/aarch64/string/memcmp.S:1.3
--- src/common/lib/libc/arch/aarch64/string/memcmp.S:1.2 Sun Feb 4 21:52:16 2018
+++ src/common/lib/libc/arch/aarch64/string/memcmp.S Mon Jul 9 06:07:06 2018
@@ -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 */
