Commit f87bc8dc authored by H. Peter Anvin (Intel)'s avatar H. Peter Anvin (Intel) Committed by Borislav Petkov
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x86/asm: Add _ASM_RIP() macro for x86-64 (%rip) suffix 



Add a macro _ASM_RIP() to add a (%rip) suffix on 64 bits only. This is
useful for immediate memory references where one doesn't want gcc
to possibly use a register indirection as it may in the case of an "m"
constraint.

Signed-off-by: default avatarH. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210910195910.2542662-3-hpa@zytor.com
parent 6880fa6c

arch/x86/include/asm/asm.h

+5 −0
Original line number Diff line number Diff line
@@ -6,11 +6,13 @@ 
# define __ASM_FORM(x, ...)		x,## __VA_ARGS__

# define __ASM_FORM_RAW(x, ...)		x,## __VA_ARGS__

# define __ASM_FORM_COMMA(x, ...)	x,## __VA_ARGS__,

# define __ASM_REGPFX			%

#else

#include <linux/stringify.h>

# define __ASM_FORM(x, ...)		" " __stringify(x,##__VA_ARGS__) " "

# define __ASM_FORM_RAW(x, ...)		    __stringify(x,##__VA_ARGS__)

# define __ASM_FORM_COMMA(x, ...)	" " __stringify(x,##__VA_ARGS__) ","

# define __ASM_REGPFX			%%

#endif



#define _ASM_BYTES(x, ...)	__ASM_FORM(.byte x,##__VA_ARGS__ ;)
@@ -49,6 +51,9 @@ 
#define _ASM_SI		__ASM_REG(si)

#define _ASM_DI		__ASM_REG(di)



/* Adds a (%rip) suffix on 64 bits only; for immediate memory references */

#define _ASM_RIP(x)	__ASM_SEL_RAW(x, x (__ASM_REGPFX rip))



#ifndef __x86_64__

/* 32 bit */