arch/arm64/include/asm/compiler.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_COMPILER_H
#define __ASM_COMPILER_H

#ifdef ARM64_ASM_ARCH
#define ARM64_ASM_PREAMBLE ".arch " ARM64_ASM_ARCH "\n"
#else
#define ARM64_ASM_PREAMBLE
#endif

/*
 * The EL0/EL1 pointer bits used by a pointer authentication code.
 * This is dependent on TBI0/TBI1 being enabled, or bits 63:56 would also apply.
 */
#define ptrauth_user_pac_mask()		GENMASK_ULL(54, vabits_actual)
#define ptrauth_kernel_pac_mask()	GENMASK_ULL(63, vabits_actual)

/* Valid for EL0 TTBR0 and EL1 TTBR1 instruction pointers */
#define ptrauth_clear_pac(ptr)						\
	((ptr & BIT_ULL(55)) ? (ptr | ptrauth_kernel_pac_mask()) :	\
			       (ptr & ~ptrauth_user_pac_mask()))

#define __builtin_return_address(val)					\
	(void *)(ptrauth_clear_pac((unsigned long)__builtin_return_address(val)))

#ifdef CONFIG_CFI_CLANG
/*
 * With CONFIG_CFI_CLANG, the compiler replaces function address
 * references with the address of the function's CFI jump table
 * entry. The function_nocfi macro always returns the address of the
 * actual function instead.
 */
#define function_nocfi(x) ({						\
	void *addr;							\
	asm("adrp %0, " __stringify(x) "\n\t"				\
	    "add  %0, %0, :lo12:" __stringify(x)			\
	    : "=r" (addr));						\
	addr;								\
})
#endif

#endif /* __ASM_COMPILER_H */