1 #ifndef _LINUX_EXPORT_H 2 #define _LINUX_EXPORT_H 3 /* 4 * Export symbols from the kernel to modules. Forked from module.h 5 * to reduce the amount of pointless cruft we feed to gcc when only 6 * exporting a simple symbol or two. 7 * 8 * If you feel the need to add #include <linux/foo.h> to this file 9 * then you are doing something wrong and should go away silently. 10 */ 11 12 /* Some toolchains use a `_' prefix for all user symbols. */ 13 #ifdef CONFIG_SYMBOL_PREFIX 14 #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX 15 #else 16 #define MODULE_SYMBOL_PREFIX "" 17 #endif 18 19 struct kernel_symbol 20 { 21 unsigned long value; 22 const char *name; 23 }; 24 25 #ifdef MODULE 26 extern struct module __this_module; 27 #define THIS_MODULE (&__this_module) 28 #else 29 #define THIS_MODULE ((struct module *)0) 30 #endif 31 32 #ifdef CONFIG_MODULES 33 34 #ifndef __GENKSYMS__ 35 #ifdef CONFIG_MODVERSIONS 36 /* Mark the CRC weak since genksyms apparently decides not to 37 * generate a checksums for some symbols */ 38 #define __CRC_SYMBOL(sym, sec) \ 39 extern void *__crc_##sym __attribute__((weak)); \ 40 static const unsigned long __kcrctab_##sym \ 41 __used \ 42 __attribute__((section("___kcrctab" sec "+" #sym), unused)) \ 43 = (unsigned long) &__crc_##sym; 44 #else 45 #define __CRC_SYMBOL(sym, sec) 46 #endif 47 48 /* For every exported symbol, place a struct in the __ksymtab section */ 49 #define __EXPORT_SYMBOL(sym, sec) \ 50 extern typeof(sym) sym; \ 51 __CRC_SYMBOL(sym, sec) \ 52 static const char __kstrtab_##sym[] \ 53 __attribute__((section("__ksymtab_strings"), aligned(1))) \ 54 = MODULE_SYMBOL_PREFIX #sym; \ 55 static const struct kernel_symbol __ksymtab_##sym \ 56 __used \ 57 __attribute__((section("___ksymtab" sec "+" #sym), unused)) \ 58 = { (unsigned long)&sym, __kstrtab_##sym } 59 60 #define EXPORT_SYMBOL(sym) \ 61 __EXPORT_SYMBOL(sym, "") 62 63 #define EXPORT_SYMBOL_GPL(sym) \ 64 __EXPORT_SYMBOL(sym, "_gpl") 65 66 #define EXPORT_SYMBOL_GPL_FUTURE(sym) \ 67 __EXPORT_SYMBOL(sym, "_gpl_future") 68 69 #ifdef CONFIG_UNUSED_SYMBOLS 70 #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused") 71 #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl") 72 #else 73 #define EXPORT_UNUSED_SYMBOL(sym) 74 #define EXPORT_UNUSED_SYMBOL_GPL(sym) 75 #endif 76 77 #endif /* __GENKSYMS__ */ 78 79 #else /* !CONFIG_MODULES... */ 80 81 #define EXPORT_SYMBOL(sym) 82 #define EXPORT_SYMBOL_GPL(sym) 83 #define EXPORT_SYMBOL_GPL_FUTURE(sym) 84 #define EXPORT_UNUSED_SYMBOL(sym) 85 #define EXPORT_UNUSED_SYMBOL_GPL(sym) 86 87 #endif /* CONFIG_MODULES */ 88 89 #endif /* _LINUX_EXPORT_H */ 90