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Commit de2ff888 authored by Borislav Petkov's avatar Borislav Petkov
Browse files

x86/lib/copy_user_64.S: Convert to ALTERNATIVE_2 



Use the asm macro and drop the locally grown version.

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
parent 090a3f61

arch/x86/lib/copy_user_64.S

+10 −30
Original line number Diff line number Diff line
@@ -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)