diff options
Diffstat (limited to 'kernel/include/linux/export.h')
-rw-r--r-- | kernel/include/linux/export.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/kernel/include/linux/export.h b/kernel/include/linux/export.h new file mode 100644 index 000000000..96e45ea46 --- /dev/null +++ b/kernel/include/linux/export.h @@ -0,0 +1,98 @@ +#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. + */ + +/* Some toolchains use a `_' prefix for all user symbols. */ +#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX +#define __VMLINUX_SYMBOL(x) _##x +#define __VMLINUX_SYMBOL_STR(x) "_" #x +#else +#define __VMLINUX_SYMBOL(x) x +#define __VMLINUX_SYMBOL_STR(x) #x +#endif + +/* Indirect, so macros are expanded before pasting. */ +#define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x) +#define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x) + +#ifndef __ASSEMBLY__ +struct kernel_symbol +{ + unsigned long value; + const char *name; +}; + +#ifdef MODULE +extern struct module __this_module; +#define THIS_MODULE (&__this_module) +#else +#define THIS_MODULE ((struct module *)0) +#endif + +#ifdef CONFIG_MODULES + +#ifndef __GENKSYMS__ +#ifdef CONFIG_MODVERSIONS +/* Mark the CRC weak since genksyms apparently decides not to + * generate a checksums for some symbols */ +#define __CRC_SYMBOL(sym, sec) \ + extern __visible void *__crc_##sym __attribute__((weak)); \ + static const unsigned long __kcrctab_##sym \ + __used \ + __attribute__((section("___kcrctab" sec "+" #sym), unused)) \ + = (unsigned long) &__crc_##sym; +#else +#define __CRC_SYMBOL(sym, sec) +#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"), aligned(1))) \ + = VMLINUX_SYMBOL_STR(sym); \ + extern const struct kernel_symbol __ksymtab_##sym; \ + __visible const struct kernel_symbol __ksymtab_##sym \ + __used \ + __attribute__((section("___ksymtab" sec "+" #sym), unused)) \ + = { (unsigned long)&sym, __kstrtab_##sym } + +#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 */ |