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authorXie Xiaobo <xiaobo.xie@nxp.com>2017-12-12 08:12:33 (GMT)
committerXie Xiaobo <xiaobo.xie@nxp.com>2017-12-12 08:12:33 (GMT)
commitc0246a9ec4d461ef4dd7647f94005380bb9e7f0b (patch)
tree7588601aa6ce98f5e9fd083a1b351d9023c0b295 /arch/x86/lib/copy_user_64.S
parent50fd1a6d79d48a7c35890aecce5a5d6b872a461d (diff)
parent56f4a560c6d6318b5a8e18a1b3e44909a5158d1e (diff)
downloadlinux-c0246a9ec4d461ef4dd7647f94005380bb9e7f0b.tar.xz
Merge Linaro linux 4.9.62 into linux-4.9
Signed-off-by: Xiaobo Xie <xiaobo.xie@nxp.com>
Diffstat (limited to 'arch/x86/lib/copy_user_64.S')
-rw-r--r--arch/x86/lib/copy_user_64.S7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index d376e4b..04c067b 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -84,7 +84,7 @@ ENTRY(copy_user_generic_unrolled)
movl %edx,%ecx
andl $63,%edx
shrl $6,%ecx
- jz 17f
+ jz .L_copy_short_string
1: movq (%rsi),%r8
2: movq 1*8(%rsi),%r9
3: movq 2*8(%rsi),%r10
@@ -105,7 +105,8 @@ ENTRY(copy_user_generic_unrolled)
leaq 64(%rdi),%rdi
decl %ecx
jnz 1b
-17: movl %edx,%ecx
+.L_copy_short_string:
+ movl %edx,%ecx
andl $7,%edx
shrl $3,%ecx
jz 20f
@@ -221,6 +222,8 @@ EXPORT_SYMBOL(copy_user_generic_string)
*/
ENTRY(copy_user_enhanced_fast_string)
ASM_STAC
+ cmpl $64,%edx
+ jb .L_copy_short_string /* less then 64 bytes, avoid the costly 'rep' */
movl %edx,%ecx
1: rep
movsb