From: "H. Peter Anvin (Intel)" <hpa@xxxxxxxxx> commit f87bc8dc7a7c438c70f97b4e51c76a183313272e upstream. 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. [ pawan: resolved merged conflict for __ASM_REGPFX ] Signed-off-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20210910195910.2542662-3-hpa@xxxxxxxxx --- arch/x86/include/asm/asm.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h index 6dd47c9ec788..fbcfec4dc4cc 100644 --- a/arch/x86/include/asm/asm.h +++ b/arch/x86/include/asm/asm.h @@ -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 */ -- 2.34.1
