/* 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 */