Commit 669f8a90 authored by Borislav Petkov's avatar Borislav Petkov
Browse files

x86/smap: Use ALTERNATIVE macro 



... and drop unfolded version. No need for ASM_NOP3 anymore either as
the alternatives do the proper padding at build time and insert proper
NOPs at boot time.

There should be no apparent operational change from this patch.

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
parent de2ff888

arch/x86/include/asm/smap.h

+9 −21
Original line number Diff line number Diff line
@@ -28,22 +28,10 @@ 
#ifdef CONFIG_X86_SMAP



#define ASM_CLAC \

	661: ASM_NOP3 ;							\

	.pushsection .altinstr_replacement, "ax" ;			\

	662: __ASM_CLAC ;						\

	.popsection ;							\

	.pushsection .altinstructions, "a" ;				\

	altinstruction_entry 661b, 662b, X86_FEATURE_SMAP, 3, 3, 0 ;	\

	.popsection

	ALTERNATIVE "", __stringify(__ASM_CLAC), X86_FEATURE_SMAP



#define ASM_STAC \

	661: ASM_NOP3 ;							\

	.pushsection .altinstr_replacement, "ax" ;			\

	662: __ASM_STAC ;						\

	.popsection ;							\

	.pushsection .altinstructions, "a" ;				\

	altinstruction_entry 661b, 662b, X86_FEATURE_SMAP, 3, 3, 0 ;	\

	.popsection

	ALTERNATIVE "", __stringify(__ASM_STAC), X86_FEATURE_SMAP



#else /* CONFIG_X86_SMAP */
@@ -61,20 +49,20 @@ 
static __always_inline void clac(void)

{

	/* Note: a barrier is implicit in alternative() */

	alternative(ASM_NOP3, __stringify(__ASM_CLAC), X86_FEATURE_SMAP);

	alternative("", __stringify(__ASM_CLAC), X86_FEATURE_SMAP);

}



static __always_inline void stac(void)

{

	/* Note: a barrier is implicit in alternative() */

	alternative(ASM_NOP3, __stringify(__ASM_STAC), X86_FEATURE_SMAP);

	alternative("", __stringify(__ASM_STAC), X86_FEATURE_SMAP);

}



/* These macros can be used in asm() statements */

#define ASM_CLAC \

	ALTERNATIVE(ASM_NOP3, __stringify(__ASM_CLAC), X86_FEATURE_SMAP)

	ALTERNATIVE("", __stringify(__ASM_CLAC), X86_FEATURE_SMAP)

#define ASM_STAC \

	ALTERNATIVE(ASM_NOP3, __stringify(__ASM_STAC), X86_FEATURE_SMAP)

	ALTERNATIVE("", __stringify(__ASM_STAC), X86_FEATURE_SMAP)



#else /* CONFIG_X86_SMAP */

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