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authorRussell King <rmk+kernel@armlinux.org.uk>2017-09-09 16:34:41 +0100
committerRussell King <rmk+kernel@armlinux.org.uk>2017-09-09 16:34:41 +0100
commite558bdc21ae1f0db520eccd84015e17d8a589973 (patch)
treeb436123bd52f267b8c7f361618cded3e1e4421ea /arch/x86/lib/copy_user_64.S
parent746a272e44141af24a02f6c9b0f65f4c4598ed42 (diff)
parent9a3dc3186fc3795e076a4122da9e0258651a9631 (diff)
downloadop-kernel-dev-e558bdc21ae1f0db520eccd84015e17d8a589973.zip
op-kernel-dev-e558bdc21ae1f0db520eccd84015e17d8a589973.tar.gz
Merge branches 'fixes' and 'misc' into for-linus
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 c595957..020f75c 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -37,7 +37,7 @@ 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
@@ -58,7 +58,8 @@ 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
@@ -174,6 +175,8 @@ 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
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