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Diffstat (limited to 'include/linux/linkage.h')
| -rw-r--r-- | include/linux/linkage.h | 360 |
1 files changed, 360 insertions, 0 deletions
diff --git a/include/linux/linkage.h b/include/linux/linkage.h new file mode 100644 index 000000000..5c8865bb5 --- /dev/null +++ b/include/linux/linkage.h @@ -0,0 +1,360 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_LINKAGE_H +#define _LINUX_LINKAGE_H + +#include <linux/compiler_types.h> +#include <linux/stringify.h> +#include <linux/export.h> +#include <asm/linkage.h> + +/* Some toolchains use other characters (e.g. '`') to mark new line in macro */ +#ifndef ASM_NL +#define ASM_NL ; +#endif + +#ifdef __cplusplus +#define CPP_ASMLINKAGE extern "C" +#else +#define CPP_ASMLINKAGE +#endif + +#ifndef asmlinkage +#define asmlinkage CPP_ASMLINKAGE +#endif + +#ifndef cond_syscall +#define cond_syscall(x) asm( \ + ".weak " __stringify(x) "\n\t" \ + ".set " __stringify(x) "," \ + __stringify(sys_ni_syscall)) +#endif + +#ifndef SYSCALL_ALIAS +#define SYSCALL_ALIAS(alias, name) asm( \ + ".globl " __stringify(alias) "\n\t" \ + ".set " __stringify(alias) "," \ + __stringify(name)) +#endif + +#define __page_aligned_data __section(".data..page_aligned") __aligned(PAGE_SIZE) +#define __page_aligned_bss __section(".bss..page_aligned") __aligned(PAGE_SIZE) + +/* + * For assembly routines. + * + * Note when using these that you must specify the appropriate + * alignment directives yourself + */ +#define __PAGE_ALIGNED_DATA .section ".data..page_aligned", "aw" +#define __PAGE_ALIGNED_BSS .section ".bss..page_aligned", "aw" + +/* + * This is used by architectures to keep arguments on the stack + * untouched by the compiler by keeping them live until the end. + * The argument stack may be owned by the assembly-language + * caller, not the callee, and gcc doesn't always understand + * that. + * + * We have the return value, and a maximum of six arguments. + * + * This should always be followed by a "return ret" for the + * protection to work (ie no more work that the compiler might + * end up needing stack temporaries for). + */ +/* Assembly files may be compiled with -traditional .. */ +#ifndef __ASSEMBLY__ +#ifndef asmlinkage_protect +# define asmlinkage_protect(n, ret, args...) do { } while (0) +#endif +#endif + +#ifndef __ALIGN +#define __ALIGN .balign CONFIG_FUNCTION_ALIGNMENT +#define __ALIGN_STR __stringify(__ALIGN) +#endif + +#ifdef __ASSEMBLY__ + +/* SYM_T_FUNC -- type used by assembler to mark functions */ +#ifndef SYM_T_FUNC +#define SYM_T_FUNC STT_FUNC +#endif + +/* SYM_T_OBJECT -- type used by assembler to mark data */ +#ifndef SYM_T_OBJECT +#define SYM_T_OBJECT STT_OBJECT +#endif + +/* SYM_T_NONE -- type used by assembler to mark entries of unknown type */ +#ifndef SYM_T_NONE +#define SYM_T_NONE STT_NOTYPE +#endif + +/* SYM_A_* -- align the symbol? */ +#define SYM_A_ALIGN ALIGN +#define SYM_A_NONE /* nothing */ + +/* SYM_L_* -- linkage of symbols */ +#define SYM_L_GLOBAL(name) .globl name +#define SYM_L_WEAK(name) .weak name +#define SYM_L_LOCAL(name) /* nothing */ + +#ifndef LINKER_SCRIPT +#define ALIGN __ALIGN +#define ALIGN_STR __ALIGN_STR + +/* === DEPRECATED annotations === */ + +#ifndef CONFIG_ARCH_USE_SYM_ANNOTATIONS +#ifndef GLOBAL +/* deprecated, use SYM_DATA*, SYM_ENTRY, or similar */ +#define GLOBAL(name) \ + .globl name ASM_NL \ + name: +#endif + +#ifndef ENTRY +/* deprecated, use SYM_FUNC_START */ +#define ENTRY(name) \ + SYM_FUNC_START(name) +#endif +#endif /* CONFIG_ARCH_USE_SYM_ANNOTATIONS */ +#endif /* LINKER_SCRIPT */ + +#ifndef CONFIG_ARCH_USE_SYM_ANNOTATIONS +#ifndef WEAK +/* deprecated, use SYM_FUNC_START_WEAK* */ +#define WEAK(name) \ + SYM_FUNC_START_WEAK(name) +#endif + +#ifndef END +/* deprecated, use SYM_FUNC_END, SYM_DATA_END, or SYM_END */ +#define END(name) \ + .size name, .-name +#endif + +/* If symbol 'name' is treated as a subroutine (gets called, and returns) + * then please use ENDPROC to mark 'name' as STT_FUNC for the benefit of + * static analysis tools such as stack depth analyzer. + */ +#ifndef ENDPROC +/* deprecated, use SYM_FUNC_END */ +#define ENDPROC(name) \ + SYM_FUNC_END(name) +#endif +#endif /* CONFIG_ARCH_USE_SYM_ANNOTATIONS */ + +/* === generic annotations === */ + +/* SYM_ENTRY -- use only if you have to for non-paired symbols */ +#ifndef SYM_ENTRY +#define SYM_ENTRY(name, linkage, align...) \ + linkage(name) ASM_NL \ + align ASM_NL \ + name: +#endif + +/* SYM_START -- use only if you have to */ +#ifndef SYM_START +#define SYM_START(name, linkage, align...) \ + SYM_ENTRY(name, linkage, align) +#endif + +/* SYM_END -- use only if you have to */ +#ifndef SYM_END +#define SYM_END(name, sym_type) \ + .type name sym_type ASM_NL \ + .set .L__sym_size_##name, .-name ASM_NL \ + .size name, .L__sym_size_##name +#endif + +/* SYM_ALIAS -- use only if you have to */ +#ifndef SYM_ALIAS +#define SYM_ALIAS(alias, name, linkage) \ + linkage(alias) ASM_NL \ + .set alias, name ASM_NL +#endif + +/* === code annotations === */ + +/* + * FUNC -- C-like functions (proper stack frame etc.) + * CODE -- non-C code (e.g. irq handlers with different, special stack etc.) + * + * Objtool validates stack for FUNC, but not for CODE. + * Objtool generates debug info for both FUNC & CODE, but needs special + * annotations for each CODE's start (to describe the actual stack frame). + * + * Objtool requires that all code must be contained in an ELF symbol. Symbol + * names that have a .L prefix do not emit symbol table entries. .L + * prefixed symbols can be used within a code region, but should be avoided for + * denoting a range of code via ``SYM_*_START/END`` annotations. + * + * ALIAS -- does not generate debug info -- the aliased function will + */ + +/* SYM_INNER_LABEL_ALIGN -- only for labels in the middle of code */ +#ifndef SYM_INNER_LABEL_ALIGN +#define SYM_INNER_LABEL_ALIGN(name, linkage) \ + .type name SYM_T_NONE ASM_NL \ + SYM_ENTRY(name, linkage, SYM_A_ALIGN) +#endif + +/* SYM_INNER_LABEL -- only for labels in the middle of code */ +#ifndef SYM_INNER_LABEL +#define SYM_INNER_LABEL(name, linkage) \ + .type name SYM_T_NONE ASM_NL \ + SYM_ENTRY(name, linkage, SYM_A_NONE) +#endif + +/* SYM_FUNC_START -- use for global functions */ +#ifndef SYM_FUNC_START +#define SYM_FUNC_START(name) \ + SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) +#endif + +/* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */ +#ifndef SYM_FUNC_START_NOALIGN +#define SYM_FUNC_START_NOALIGN(name) \ + SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) +#endif + +/* SYM_FUNC_START_LOCAL -- use for local functions */ +#ifndef SYM_FUNC_START_LOCAL +#define SYM_FUNC_START_LOCAL(name) \ + SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) +#endif + +/* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */ +#ifndef SYM_FUNC_START_LOCAL_NOALIGN +#define SYM_FUNC_START_LOCAL_NOALIGN(name) \ + SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) +#endif + +/* SYM_FUNC_START_WEAK -- use for weak functions */ +#ifndef SYM_FUNC_START_WEAK +#define SYM_FUNC_START_WEAK(name) \ + SYM_START(name, SYM_L_WEAK, SYM_A_ALIGN) +#endif + +/* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */ +#ifndef SYM_FUNC_START_WEAK_NOALIGN +#define SYM_FUNC_START_WEAK_NOALIGN(name) \ + SYM_START(name, SYM_L_WEAK, SYM_A_NONE) +#endif + +/* + * SYM_FUNC_END -- the end of SYM_FUNC_START_LOCAL, SYM_FUNC_START, + * SYM_FUNC_START_WEAK, ... + */ +#ifndef SYM_FUNC_END +#define SYM_FUNC_END(name) \ + SYM_END(name, SYM_T_FUNC) +#endif + +/* + * SYM_FUNC_ALIAS -- define a global alias for an existing function + */ +#ifndef SYM_FUNC_ALIAS +#define SYM_FUNC_ALIAS(alias, name) \ + SYM_ALIAS(alias, name, SYM_L_GLOBAL) +#endif + +/* + * SYM_FUNC_ALIAS_LOCAL -- define a local alias for an existing function + */ +#ifndef SYM_FUNC_ALIAS_LOCAL +#define SYM_FUNC_ALIAS_LOCAL(alias, name) \ + SYM_ALIAS(alias, name, SYM_L_LOCAL) +#endif + +/* + * SYM_FUNC_ALIAS_WEAK -- define a weak global alias for an existing function + */ +#ifndef SYM_FUNC_ALIAS_WEAK +#define SYM_FUNC_ALIAS_WEAK(alias, name) \ + SYM_ALIAS(alias, name, SYM_L_WEAK) +#endif + +/* SYM_CODE_START -- use for non-C (special) functions */ +#ifndef SYM_CODE_START +#define SYM_CODE_START(name) \ + SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) +#endif + +/* SYM_CODE_START_NOALIGN -- use for non-C (special) functions, w/o alignment */ +#ifndef SYM_CODE_START_NOALIGN +#define SYM_CODE_START_NOALIGN(name) \ + SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) +#endif + +/* SYM_CODE_START_LOCAL -- use for local non-C (special) functions */ +#ifndef SYM_CODE_START_LOCAL +#define SYM_CODE_START_LOCAL(name) \ + SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) +#endif + +/* + * SYM_CODE_START_LOCAL_NOALIGN -- use for local non-C (special) functions, + * w/o alignment + */ +#ifndef SYM_CODE_START_LOCAL_NOALIGN +#define SYM_CODE_START_LOCAL_NOALIGN(name) \ + SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) +#endif + +/* SYM_CODE_END -- the end of SYM_CODE_START_LOCAL, SYM_CODE_START, ... */ +#ifndef SYM_CODE_END +#define SYM_CODE_END(name) \ + SYM_END(name, SYM_T_NONE) +#endif + +/* === data annotations === */ + +/* SYM_DATA_START -- global data symbol */ +#ifndef SYM_DATA_START +#define SYM_DATA_START(name) \ + SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) +#endif + +/* SYM_DATA_START -- local data symbol */ +#ifndef SYM_DATA_START_LOCAL +#define SYM_DATA_START_LOCAL(name) \ + SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) +#endif + +/* SYM_DATA_END -- the end of SYM_DATA_START symbol */ +#ifndef SYM_DATA_END +#define SYM_DATA_END(name) \ + SYM_END(name, SYM_T_OBJECT) +#endif + +/* SYM_DATA_END_LABEL -- the labeled end of SYM_DATA_START symbol */ +#ifndef SYM_DATA_END_LABEL +#define SYM_DATA_END_LABEL(name, linkage, label) \ + linkage(label) ASM_NL \ + .type label SYM_T_OBJECT ASM_NL \ + label: \ + SYM_END(name, SYM_T_OBJECT) +#endif + +/* SYM_DATA -- start+end wrapper around simple global data */ +#ifndef SYM_DATA +#define SYM_DATA(name, data...) \ + SYM_DATA_START(name) ASM_NL \ + data ASM_NL \ + SYM_DATA_END(name) +#endif + +/* SYM_DATA_LOCAL -- start+end wrapper around simple local data */ +#ifndef SYM_DATA_LOCAL +#define SYM_DATA_LOCAL(name, data...) \ + SYM_DATA_START_LOCAL(name) ASM_NL \ + data ASM_NL \ + SYM_DATA_END(name) +#endif + +#endif /* __ASSEMBLY__ */ + +#endif /* _LINUX_LINKAGE_H */ |