diff options
Diffstat (limited to 'arch/x86/include/asm/linkage.h')
| -rw-r--r-- | arch/x86/include/asm/linkage.h | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h new file mode 100644 index 0000000000..571fe4d2d2 --- /dev/null +++ b/arch/x86/include/asm/linkage.h @@ -0,0 +1,151 @@ +/* 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 */ + |