/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_LINKAGE_H
#define _ASM_X86_LINKAGE_H

#include <linux/stringify.h>
#include <asm/ibt.h>

#undef notrace
#define notrace __attribute__((no_instrument_function))

#ifdef CONFIG_64BIT
/*
 * The generic version tends to create spurious ENDBR instructions under
 * certain conditions.
 */
#define _THIS_IP_ ({ unsigned long __here; asm ("lea 0(%%rip), %0" : "=r" (__here)); __here; })
#endif

#ifdef CONFIG_X86_32
#define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0)))
#endif /* CONFIG_X86_32 */

#define __ALIGN        .balign CONFIG_FUNCTION_ALIGNMENT, 0x90;
#define __ALIGN_STR    __stringify(__ALIGN)

#if defined(CONFIG_CALL_PADDING) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
#define FUNCTION_PADDING    .skip CONFIG_FUNCTION_ALIGNMENT, 0x90;
#else
#define FUNCTION_PADDING
#endif

#if (CONFIG_FUNCTION_ALIGNMENT > 8) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
# define __FUNC_ALIGN        __ALIGN; FUNCTION_PADDING
#else
# define __FUNC_ALIGN        __ALIGN
#endif

#define ASM_FUNC_ALIGN        __stringify(__FUNC_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 */
#ifdef CONFIG_SLS
#define RET    ret; int3
#else
#define RET    ret
#endif
#endif /* CONFIG_RETPOLINE */

#else /* __ASSEMBLY__ */

#if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
#define ASM_RET    "jmp __x86_return_thunk\n\t"
#else /* CONFIG_RETPOLINE */
#ifdef CONFIG_SLS
#define ASM_RET    "ret; int3\n\t"
#else
#define ASM_RET    "ret\n\t"
#endif
#endif /* CONFIG_RETPOLINE */

#endif /* __ASSEMBLY__ */

/*
 * Depending on -fpatchable-function-entry=N,N usage (CONFIG_CALL_PADDING) the
 * CFI symbol layout changes.
 *
 * Without CALL_THUNKS:
 *
 *     .align    FUNCTION_ALIGNMENT
 * __cfi_##name:
 *     .skip    FUNCTION_PADDING, 0x90
 *     .byte   0xb8
 *     .long    __kcfi_typeid_##name
 * name:
 *
 * With CALL_THUNKS:
 *
 *     .align FUNCTION_ALIGNMENT
 * __cfi_##name:
 *     .byte    0xb8
 *     .long    __kcfi_typeid_##name
 *     .skip    FUNCTION_PADDING, 0x90
 * name:
 *
 * In both cases the whole thing is FUNCTION_ALIGNMENT aligned and sized.
 */

#ifdef CONFIG_CALL_PADDING
#define CFI_PRE_PADDING
#define CFI_POST_PADDING    .skip    CONFIG_FUNCTION_PADDING_BYTES, 0x90;
#else
#define CFI_PRE_PADDING        .skip    CONFIG_FUNCTION_PADDING_BYTES, 0x90;
#define CFI_POST_PADDING
#endif

#define __CFI_TYPE(name)                    \
    SYM_START(__cfi_##name, SYM_L_LOCAL, SYM_A_NONE)    \
    CFI_PRE_PADDING                        \
    .byte 0xb8 ASM_NL                    \
    .long __kcfi_typeid_##name ASM_NL            \
    CFI_POST_PADDING                    \
    SYM_FUNC_END(__cfi_##name)

/* UML needs to be able to override memcpy() and friends for KASAN. */
#ifdef CONFIG_UML
# define SYM_FUNC_ALIAS_MEMFUNC    SYM_FUNC_ALIAS_WEAK
#else
# define SYM_FUNC_ALIAS_MEMFUNC    SYM_FUNC_ALIAS
#endif

/* SYM_TYPED_FUNC_START -- use for indirectly called globals, w/ CFI type */
#define SYM_TYPED_FUNC_START(name)                \
    SYM_TYPED_START(name, SYM_L_GLOBAL, SYM_F_ALIGN)    \
    ENDBR

/* SYM_FUNC_START -- use for global functions */
#define SYM_FUNC_START(name)                \
    SYM_START(name, SYM_L_GLOBAL, SYM_F_ALIGN)    \
    ENDBR

/* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */
#define SYM_FUNC_START_NOALIGN(name)            \
    SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE)    \
    ENDBR

/* SYM_FUNC_START_LOCAL -- use for local functions */
#define SYM_FUNC_START_LOCAL(name)            \
    SYM_START(name, SYM_L_LOCAL, SYM_F_ALIGN)    \
    ENDBR

/* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */
#define SYM_FUNC_START_LOCAL_NOALIGN(name)        \
    SYM_START(name, SYM_L_LOCAL, SYM_A_NONE)    \
    ENDBR

/* SYM_FUNC_START_WEAK -- use for weak functions */
#define SYM_FUNC_START_WEAK(name)            \
    SYM_START(name, SYM_L_WEAK, SYM_F_ALIGN)    \
    ENDBR

/* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */
#define SYM_FUNC_START_WEAK_NOALIGN(name)        \
    SYM_START(name, SYM_L_WEAK, SYM_A_NONE)        \
    ENDBR

#endif /* _ASM_X86_LINKAGE_H */