#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(CONFIG_TRIM_UNUSED_KSYMS) #include <generated/autoksyms.h> /* * 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 symbol pattern __ksym_marker_<symbol> that the build system filters * from the $(NM) output (see scripts/gen_ksymdeps.sh). These symbols are * discarded in the final link stage. */ #define __ksym_marker(sym) \ static int __ksym_marker_##sym[0] __section(".discard.ksym") __used #define __EXPORT_SYMBOL(sym, sec) \ __ksym_marker(sym); \ __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 */