Commit 8eb5d34e authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Peter Zijlstra
Browse files

x86/asm: Differentiate between code and function alignment 



Create SYM_F_ALIGN to differentiate alignment requirements between
SYM_CODE and SYM_FUNC.

This distinction is useful later when adding padding in front of
functions; IOW this allows following the compiler's
patchable-function-entry option.

[peterz: Changelog]

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111143.824822743@infradead.org
parent d49a0626

arch/x86/include/asm/linkage.h

+9 −5
Original line number Diff line number Diff line
@@ -12,11 +12,15 @@ 
#define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0)))

#endif /* CONFIG_X86_32 */



#ifdef __ASSEMBLY__



#define __ALIGN		.balign CONFIG_FUNCTION_ALIGNMENT, 0x90;

#define __ALIGN_STR	__stringify(__ALIGN)



#define ASM_FUNC_ALIGN		__ALIGN_STR

#define __FUNC_ALIGN		__ALIGN

#define SYM_F_ALIGN		__FUNC_ALIGN



#ifdef __ASSEMBLY__



#if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)

#define RET	jmp __x86_return_thunk

#else /* CONFIG_RETPOLINE */
@@ -55,7 +59,7 @@ 


/* SYM_FUNC_START -- use for global functions */

#define SYM_FUNC_START(name)				\

	SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)	\

	SYM_START(name, SYM_L_GLOBAL, SYM_F_ALIGN)	\

	ENDBR



/* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */
@@ -65,7 +69,7 @@ 


/* SYM_FUNC_START_LOCAL -- use for local functions */

#define SYM_FUNC_START_LOCAL(name)			\

	SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN)	\

	SYM_START(name, SYM_L_LOCAL, SYM_F_ALIGN)	\

	ENDBR



/* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */
@@ -75,7 +79,7 @@ 


/* SYM_FUNC_START_WEAK -- use for weak functions */

#define SYM_FUNC_START_WEAK(name)			\

	SYM_START(name, SYM_L_WEAK, SYM_A_ALIGN)	\

	SYM_START(name, SYM_L_WEAK, SYM_F_ALIGN)	\

	ENDBR



/* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */