1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _ASM_X86_LINKAGE_H 3#define _ASM_X86_LINKAGE_H 4 5#include <linux/stringify.h> 6#include <asm/ibt.h> 7 8#undef notrace 9#define notrace __attribute__((no_instrument_function)) 10 11#ifdef CONFIG_64BIT 12/* 13 * The generic version tends to create spurious ENDBR instructions under 14 * certain conditions. 15 */ 16#define _THIS_IP_ ({ unsigned long __here; asm ("lea 0(%%rip), %0" : "=r" (__here)); __here; }) 17#endif 18 19#ifdef CONFIG_X86_32 20#define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0))) 21#endif /* CONFIG_X86_32 */ 22 23#define __ALIGN .balign CONFIG_FUNCTION_ALIGNMENT, 0x90; 24#define __ALIGN_STR __stringify(__ALIGN) 25 26#if defined(CONFIG_CALL_PADDING) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO) 27#define FUNCTION_PADDING .skip CONFIG_FUNCTION_ALIGNMENT, 0x90; 28#else 29#define FUNCTION_PADDING 30#endif 31 32#if (CONFIG_FUNCTION_ALIGNMENT > 8) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO) 33# define __FUNC_ALIGN __ALIGN; FUNCTION_PADDING 34#else 35# define __FUNC_ALIGN __ALIGN 36#endif 37 38#define ASM_FUNC_ALIGN __stringify(__FUNC_ALIGN) 39#define SYM_F_ALIGN __FUNC_ALIGN 40 41#ifdef __ASSEMBLY__ 42 43#if defined(CONFIG_MITIGATION_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO) 44#define RET jmp __x86_return_thunk 45#else /* CONFIG_MITIGATION_RETPOLINE */ 46#ifdef CONFIG_MITIGATION_SLS 47#define RET ret; int3 48#else 49#define RET ret 50#endif 51#endif /* CONFIG_MITIGATION_RETPOLINE */ 52 53#else /* __ASSEMBLY__ */ 54 55#if defined(CONFIG_MITIGATION_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO) 56#define ASM_RET "jmp __x86_return_thunk\n\t" 57#else /* CONFIG_MITIGATION_RETPOLINE */ 58#ifdef CONFIG_MITIGATION_SLS 59#define ASM_RET "ret; int3\n\t" 60#else 61#define ASM_RET "ret\n\t" 62#endif 63#endif /* CONFIG_MITIGATION_RETPOLINE */ 64 65#endif /* __ASSEMBLY__ */ 66 67/* 68 * Depending on -fpatchable-function-entry=N,N usage (CONFIG_CALL_PADDING) the 69 * CFI symbol layout changes. 70 * 71 * Without CALL_THUNKS: 72 * 73 * .align FUNCTION_ALIGNMENT 74 * __cfi_##name: 75 * .skip FUNCTION_PADDING, 0x90 76 * .byte 0xb8 77 * .long __kcfi_typeid_##name 78 * name: 79 * 80 * With CALL_THUNKS: 81 * 82 * .align FUNCTION_ALIGNMENT 83 * __cfi_##name: 84 * .byte 0xb8 85 * .long __kcfi_typeid_##name 86 * .skip FUNCTION_PADDING, 0x90 87 * name: 88 * 89 * In both cases the whole thing is FUNCTION_ALIGNMENT aligned and sized. 90 */ 91 92#ifdef CONFIG_CALL_PADDING 93#define CFI_PRE_PADDING 94#define CFI_POST_PADDING .skip CONFIG_FUNCTION_PADDING_BYTES, 0x90; 95#else 96#define CFI_PRE_PADDING .skip CONFIG_FUNCTION_PADDING_BYTES, 0x90; 97#define CFI_POST_PADDING 98#endif 99 100#define __CFI_TYPE(name) \ 101 SYM_START(__cfi_##name, SYM_L_LOCAL, SYM_A_NONE) \ 102 CFI_PRE_PADDING \ 103 .byte 0xb8 ASM_NL \ 104 .long __kcfi_typeid_##name ASM_NL \ 105 CFI_POST_PADDING \ 106 SYM_FUNC_END(__cfi_##name) 107 108/* UML needs to be able to override memcpy() and friends for KASAN. */ 109#ifdef CONFIG_UML 110# define SYM_FUNC_ALIAS_MEMFUNC SYM_FUNC_ALIAS_WEAK 111#else 112# define SYM_FUNC_ALIAS_MEMFUNC SYM_FUNC_ALIAS 113#endif 114 115/* SYM_TYPED_FUNC_START -- use for indirectly called globals, w/ CFI type */ 116#define SYM_TYPED_FUNC_START(name) \ 117 SYM_TYPED_START(name, SYM_L_GLOBAL, SYM_F_ALIGN) \ 118 ENDBR 119 120/* SYM_FUNC_START -- use for global functions */ 121#define SYM_FUNC_START(name) \ 122 SYM_START(name, SYM_L_GLOBAL, SYM_F_ALIGN) \ 123 ENDBR 124 125/* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */ 126#define SYM_FUNC_START_NOALIGN(name) \ 127 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) \ 128 ENDBR 129 130/* SYM_FUNC_START_LOCAL -- use for local functions */ 131#define SYM_FUNC_START_LOCAL(name) \ 132 SYM_START(name, SYM_L_LOCAL, SYM_F_ALIGN) \ 133 ENDBR 134 135/* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */ 136#define SYM_FUNC_START_LOCAL_NOALIGN(name) \ 137 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) \ 138 ENDBR 139 140/* SYM_FUNC_START_WEAK -- use for weak functions */ 141#define SYM_FUNC_START_WEAK(name) \ 142 SYM_START(name, SYM_L_WEAK, SYM_F_ALIGN) \ 143 ENDBR 144 145/* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */ 146#define SYM_FUNC_START_WEAK_NOALIGN(name) \ 147 SYM_START(name, SYM_L_WEAK, SYM_A_NONE) \ 148 ENDBR 149 150#endif /* _ASM_X86_LINKAGE_H */ 151 152