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x86/lib/copy_user_64.S: Convert to ALTERNATIVE_2

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Use the asm macro and drop the locally grown version.

Signed-off-by: Borislav Petkov <bp@suse.de>
This commit is contained in:
Borislav Petkov 2015-01-13 01:38:17 +01:00
parent 090a3f6155
commit de2ff88884
1 changed files with 10 additions and 30 deletions
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40
arch/x86/lib/copy_user_64.S
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@ -16,30 +16,6 @@
#include <asm/asm.h>
#include <asm/smap.h>
/*
* By placing feature2 after feature1 in altinstructions section, we logically
* implement:
* If CPU has feature2, jmp to alt2 is used
* else if CPU has feature1, jmp to alt1 is used
* else jmp to orig is used.
*/
.macro ALTERNATIVE_JUMP feature1,feature2,orig,alt1,alt2
0:
jmp \orig
1:
.section .altinstr_replacement,"ax"
2:
jmp \alt1
3:
jmp \alt2
.previous
.section .altinstructions,"a"
altinstruction_entry 0b,2b,\feature1,5,5,0
altinstruction_entry 0b,3b,\feature2,5,5,0
.previous
.endm
.macro ALIGN_DESTINATION
/* check for bad alignment of destination */
movl %edi,%ecx
@ -73,9 +49,11 @@ ENTRY(_copy_to_user)
jc bad_to_user
cmpq TI_addr_limit(%rax),%rcx
ja bad_to_user
ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,X86_FEATURE_ERMS, \
copy_user_generic_unrolled,copy_user_generic_string, \
copy_user_enhanced_fast_string
ALTERNATIVE_2 "jmp copy_user_generic_unrolled", \
"jmp copy_user_generic_string", \
X86_FEATURE_REP_GOOD, \
"jmp copy_user_enhanced_fast_string", \
X86_FEATURE_ERMS
CFI_ENDPROC
ENDPROC(_copy_to_user)
@ -88,9 +66,11 @@ ENTRY(_copy_from_user)
jc bad_from_user
cmpq TI_addr_limit(%rax),%rcx
ja bad_from_user
ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,X86_FEATURE_ERMS, \
copy_user_generic_unrolled,copy_user_generic_string, \
copy_user_enhanced_fast_string
ALTERNATIVE_2 "jmp copy_user_generic_unrolled", \
"jmp copy_user_generic_string", \
X86_FEATURE_REP_GOOD, \
"jmp copy_user_enhanced_fast_string", \
X86_FEATURE_ERMS
CFI_ENDPROC
ENDPROC(_copy_from_user)