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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 | #ifndef _LINUX_EXPORT_H #define _LINUX_EXPORT_H /* * Export symbols from the kernel to modules. Forked from module.h * to reduce the amount of pointless cruft we feed to gcc when only * exporting a simple symbol or two. * * Try not to add #includes here. It slows compilation and makes kernel * hackers place grumpy comments in header files. */ #ifndef __ASSEMBLY__ #ifdef MODULE extern struct module __this_module; #define THIS_MODULE (&__this_module) #else #define THIS_MODULE ((struct module *)0) #endif #ifdef CONFIG_MODULES #if defined(__KERNEL__) && !defined(__GENKSYMS__) #ifdef CONFIG_MODVERSIONS /* Mark the CRC weak since genksyms apparently decides not to * generate a checksums for some symbols */ #if defined(CONFIG_MODULE_REL_CRCS) #define __CRC_SYMBOL(sym, sec) \ asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \ " .weak __crc_" #sym " \n" \ " .long __crc_" #sym " - . \n" \ " .previous \n"); #else #define __CRC_SYMBOL(sym, sec) \ asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \ " .weak __crc_" #sym " \n" \ " .long __crc_" #sym " \n" \ " .previous \n"); #endif #else #define __CRC_SYMBOL(sym, sec) #endif #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS #include <linux/compiler.h> /* * Emit the ksymtab entry as a pair of relative references: this reduces * the size by half on 64-bit architectures, and eliminates the need for * absolute relocations that require runtime processing on relocatable * kernels. */ #define __KSYMTAB_ENTRY(sym, sec) \ __ADDRESSABLE(sym) \ asm(" .section \"___ksymtab" sec "+" #sym "\", \"a\" \n" \ " .balign 8 \n" \ "__ksymtab_" #sym ": \n" \ " .long " #sym "- . \n" \ " .long __kstrtab_" #sym "- . \n" \ " .previous \n") struct kernel_symbol { int value_offset; int name_offset; }; #else #define __KSYMTAB_ENTRY(sym, sec) \ static const struct kernel_symbol __ksymtab_##sym \ __attribute__((section("___ksymtab" sec "+" #sym), used)) \ = { (unsigned long)&sym, __kstrtab_##sym } struct kernel_symbol { unsigned long value; const char *name; }; #endif /* For every exported symbol, place a struct in the __ksymtab section */ #define ___EXPORT_SYMBOL(sym, sec) \ extern typeof(sym) sym; \ __CRC_SYMBOL(sym, sec) \ static const char __kstrtab_##sym[] \ __attribute__((section("__ksymtab_strings"), used, aligned(1))) \ = #sym; \ __KSYMTAB_ENTRY(sym, sec) #if defined(__DISABLE_EXPORTS) /* * Allow symbol exports to be disabled completely so that C code may * be reused in other execution contexts such as the UEFI stub or the * decompressor. */ #define __EXPORT_SYMBOL(sym, sec) #elif defined(__KSYM_DEPS__) /* * For fine grained build dependencies, we want to tell the build system * about each possible exported symbol even if they're not actually exported. * We use a string pattern that is unlikely to be valid code that the build * system filters out from the preprocessor output (see ksym_dep_filter * in scripts/Kbuild.include). */ #define __EXPORT_SYMBOL(sym, sec) === __KSYM_##sym === #elif defined(CONFIG_TRIM_UNUSED_KSYMS) #include <generated/autoksyms.h> #define __EXPORT_SYMBOL(sym, sec) \ __cond_export_sym(sym, sec, __is_defined(__KSYM_##sym)) #define __cond_export_sym(sym, sec, conf) \ ___cond_export_sym(sym, sec, conf) #define ___cond_export_sym(sym, sec, enabled) \ __cond_export_sym_##enabled(sym, sec) #define __cond_export_sym_1(sym, sec) ___EXPORT_SYMBOL(sym, sec) #define __cond_export_sym_0(sym, sec) /* nothing */ #else #define __EXPORT_SYMBOL ___EXPORT_SYMBOL #endif #define EXPORT_SYMBOL(sym) \ __EXPORT_SYMBOL(sym, "") #define EXPORT_SYMBOL_GPL(sym) \ __EXPORT_SYMBOL(sym, "_gpl") #define EXPORT_SYMBOL_GPL_FUTURE(sym) \ __EXPORT_SYMBOL(sym, "_gpl_future") #ifdef CONFIG_UNUSED_SYMBOLS #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused") #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl") #else #define EXPORT_UNUSED_SYMBOL(sym) #define EXPORT_UNUSED_SYMBOL_GPL(sym) #endif #endif /* __GENKSYMS__ */ #else /* !CONFIG_MODULES... */ #define EXPORT_SYMBOL(sym) #define EXPORT_SYMBOL_GPL(sym) #define EXPORT_SYMBOL_GPL_FUTURE(sym) #define EXPORT_UNUSED_SYMBOL(sym) #define EXPORT_UNUSED_SYMBOL_GPL(sym) #endif /* CONFIG_MODULES */ #endif /* !__ASSEMBLY__ */ #endif /* _LINUX_EXPORT_H */ |