1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 #ifndef _LINUX_EXPORT_H 3 #define _LINUX_EXPORT_H 4 5 #include <linux/compiler.h> 6 #include <linux/linkage.h> 7 #include <linux/stringify.h> 8 9 /* 10 * This comment block is used by fixdep. Please do not remove. 11 * 12 * When CONFIG_MODVERSIONS is changed from n to y, all source files having 13 * EXPORT_SYMBOL variants must be re-compiled because genksyms is run as a 14 * side effect of the *.o build rule. 15 */ 16 17 #ifdef CONFIG_64BIT 18 #define __EXPORT_SYMBOL_REF(sym) \ 19 .balign 8 ASM_NL \ 20 .quad sym 21 #else 22 #define __EXPORT_SYMBOL_REF(sym) \ 23 .balign 4 ASM_NL \ 24 .long sym 25 #endif 26 27 #define ___EXPORT_SYMBOL(sym, license, ns) \ 28 .section ".export_symbol","a" ASM_NL \ 29 __export_symbol_##sym: ASM_NL \ 30 .asciz license ASM_NL \ 31 .asciz ns ASM_NL \ 32 __EXPORT_SYMBOL_REF(sym) ASM_NL \ 33 .previous 34 35 #if defined(__DISABLE_EXPORTS) 36 37 /* 38 * Allow symbol exports to be disabled completely so that C code may 39 * be reused in other execution contexts such as the UEFI stub or the 40 * decompressor. 41 */ 42 #define __EXPORT_SYMBOL(sym, license, ns) 43 44 #elif defined(__GENKSYMS__) 45 46 #define __EXPORT_SYMBOL(sym, license, ns) __GENKSYMS_EXPORT_SYMBOL(sym) 47 48 #elif defined(__ASSEMBLY__) 49 50 #define __EXPORT_SYMBOL(sym, license, ns) \ 51 ___EXPORT_SYMBOL(sym, license, ns) 52 53 #else 54 55 #ifdef CONFIG_GENDWARFKSYMS 56 /* 57 * With CONFIG_GENDWARFKSYMS, ensure the compiler emits debugging 58 * information for all exported symbols, including those defined in 59 * different TUs, by adding a __gendwarfksyms_ptr_<symbol> pointer 60 * that's discarded during the final link. 61 */ 62 #define __GENDWARFKSYMS_EXPORT(sym) \ 63 static typeof(sym) *__gendwarfksyms_ptr_##sym __used \ 64 __section(".discard.gendwarfksyms") = &sym; 65 #else 66 #define __GENDWARFKSYMS_EXPORT(sym) 67 #endif 68 69 #define __EXPORT_SYMBOL(sym, license, ns) \ 70 extern typeof(sym) sym; \ 71 __ADDRESSABLE(sym) \ 72 __GENDWARFKSYMS_EXPORT(sym) \ 73 asm(__stringify(___EXPORT_SYMBOL(sym, license, ns))) 74 75 #endif 76 77 #ifdef DEFAULT_SYMBOL_NAMESPACE 78 #define _EXPORT_SYMBOL(sym, license) __EXPORT_SYMBOL(sym, license, DEFAULT_SYMBOL_NAMESPACE) 79 #else 80 #define _EXPORT_SYMBOL(sym, license) __EXPORT_SYMBOL(sym, license, "") 81 #endif 82 83 #define EXPORT_SYMBOL(sym) _EXPORT_SYMBOL(sym, "") 84 #define EXPORT_SYMBOL_GPL(sym) _EXPORT_SYMBOL(sym, "GPL") 85 #define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", ns) 86 #define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "GPL", ns) 87 88 #endif /* _LINUX_EXPORT_H */ 89