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 * Export symbols from the kernel to modules. Forked from module.h 11 * to reduce the amount of pointless cruft we feed to gcc when only 12 * exporting a simple symbol or two. 13 * 14 * Try not to add #includes here. It slows compilation and makes kernel 15 * hackers place grumpy comments in header files. 16 */ 17 18 /* 19 * This comment block is used by fixdep. Please do not remove. 20 * 21 * When CONFIG_MODVERSIONS is changed from n to y, all source files having 22 * EXPORT_SYMBOL variants must be re-compiled because genksyms is run as a 23 * side effect of the *.o build rule. 24 */ 25 26 #ifndef __ASSEMBLY__ 27 #ifdef MODULE 28 extern struct module __this_module; 29 #define THIS_MODULE (&__this_module) 30 #else 31 #define THIS_MODULE ((struct module *)0) 32 #endif 33 #endif /* __ASSEMBLY__ */ 34 35 #ifdef CONFIG_64BIT 36 #define __EXPORT_SYMBOL_REF(sym) \ 37 .balign 8 ASM_NL \ 38 .quad sym 39 #else 40 #define __EXPORT_SYMBOL_REF(sym) \ 41 .balign 4 ASM_NL \ 42 .long sym 43 #endif 44 45 #define ___EXPORT_SYMBOL(sym, license, ns) \ 46 .section ".export_symbol","a" ASM_NL \ 47 __export_symbol_##sym: ASM_NL \ 48 .asciz license ASM_NL \ 49 .asciz ns ASM_NL \ 50 __EXPORT_SYMBOL_REF(sym) ASM_NL \ 51 .previous 52 53 #if defined(__DISABLE_EXPORTS) 54 55 /* 56 * Allow symbol exports to be disabled completely so that C code may 57 * be reused in other execution contexts such as the UEFI stub or the 58 * decompressor. 59 */ 60 #define __EXPORT_SYMBOL(sym, license, ns) 61 62 #elif defined(__GENKSYMS__) 63 64 #define __EXPORT_SYMBOL(sym, license, ns) __GENKSYMS_EXPORT_SYMBOL(sym) 65 66 #elif defined(__ASSEMBLY__) 67 68 #define __EXPORT_SYMBOL(sym, license, ns) \ 69 ___EXPORT_SYMBOL(sym, license, ns) 70 71 #else 72 73 #define __EXPORT_SYMBOL(sym, license, ns) \ 74 extern typeof(sym) sym; \ 75 __ADDRESSABLE(sym) \ 76 asm(__stringify(___EXPORT_SYMBOL(sym, license, ns))) 77 78 #endif 79 80 #ifdef DEFAULT_SYMBOL_NAMESPACE 81 #define _EXPORT_SYMBOL(sym, license) __EXPORT_SYMBOL(sym, license, __stringify(DEFAULT_SYMBOL_NAMESPACE)) 82 #else 83 #define _EXPORT_SYMBOL(sym, license) __EXPORT_SYMBOL(sym, license, "") 84 #endif 85 86 #define EXPORT_SYMBOL(sym) _EXPORT_SYMBOL(sym, "") 87 #define EXPORT_SYMBOL_GPL(sym) _EXPORT_SYMBOL(sym, "GPL") 88 #define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", __stringify(ns)) 89 #define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "GPL", __stringify(ns)) 90 91 #endif /* _LINUX_EXPORT_H */ 92