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authorStefan Agner <stefan.agner@toradex.com>2017-09-26 16:04:08 +0200
committerStefan Agner <stefan.agner@toradex.com>2017-09-26 18:11:18 +0200
commit1f4d46cea2bc1886a13ae9adfcd9e4243eed6a4c (patch)
tree2001999c70f8e46b192fc552590810aab35710e3 /arch/x86/lib/copy_user_64.S
parentd152ae9d4704d8c7b3775e3b1a20e62aa3b1eed8 (diff)
parentb52c9082f2eb3a6f7fbbc86fad3eaa2a1725da66 (diff)
Merge tag 'v4.4.88' into toradex_vf_4.4-next
This is the 4.4.88 stable release
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 27f89c79a44b..423644c230e7 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -80,7 +80,7 @@ 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
@@ -101,7 +101,8 @@ 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
@@ -215,6 +216,8 @@ ENDPROC(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