1 #ifndef _LINUX_EXPORT_H
2 #define _LINUX_EXPORT_H
5 * Export symbols from the kernel to modules. Forked from module.h
6 * to reduce the amount of pointless cruft we feed to gcc when only
7 * exporting a simple symbol or two.
9 * Try not to add #includes here. It slows compilation and makes kernel
10 * hackers place grumpy comments in header files.
13 /* Some toolchains use a `_' prefix for all user symbols. */
14 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
15 #define __VMLINUX_SYMBOL(x) _##x
16 #define __VMLINUX_SYMBOL_STR(x) "_" #x
18 #define __VMLINUX_SYMBOL(x) x
19 #define __VMLINUX_SYMBOL_STR(x) #x
22 /* Indirect, so macros are expanded before pasting. */
23 #define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x)
24 #define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x)
34 extern struct module __this_module;
35 #define THIS_MODULE (&__this_module)
37 #define THIS_MODULE ((struct module *)0)
43 #ifdef CONFIG_MODVERSIONS
44 /* Mark the CRC weak since genksyms apparently decides not to
45 * generate a checksums for some symbols */
46 #define __CRC_SYMBOL(sym, sec) \
47 extern __visible void *__crc_##sym __attribute__((weak)); \
48 static const unsigned long __kcrctab_##sym \
50 __attribute__((section("___kcrctab" sec "+" #sym), used)) \
51 = (unsigned long) &__crc_##sym;
53 #define __CRC_SYMBOL(sym, sec)
56 /* For every exported symbol, place a struct in the __ksymtab section */
57 #define __EXPORT_SYMBOL(sym, sec) \
58 extern typeof(sym) sym; \
59 __CRC_SYMBOL(sym, sec) \
60 static const char __kstrtab_##sym[] \
61 __attribute__((section("__ksymtab_strings"), aligned(1))) \
62 = VMLINUX_SYMBOL_STR(sym); \
63 static const struct kernel_symbol __ksymtab_##sym \
65 __attribute__((section("___ksymtab" sec "+" #sym), used)) \
66 = { (unsigned long)&sym, __kstrtab_##sym }
68 #define EXPORT_SYMBOL(sym) \
69 __EXPORT_SYMBOL(sym, "")
71 #define EXPORT_SYMBOL_GPL(sym) \
72 __EXPORT_SYMBOL(sym, "_gpl")
74 #define EXPORT_SYMBOL_GPL_FUTURE(sym) \
75 __EXPORT_SYMBOL(sym, "_gpl_future")
77 #ifdef CONFIG_UNUSED_SYMBOLS
78 #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
79 #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
81 #define EXPORT_UNUSED_SYMBOL(sym)
82 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
85 #endif /* __GENKSYMS__ */
87 #else /* !CONFIG_MODULES... */
89 #define EXPORT_SYMBOL(sym)
90 #define EXPORT_SYMBOL_GPL(sym)
91 #define EXPORT_SYMBOL_GPL_FUTURE(sym)
92 #define EXPORT_UNUSED_SYMBOL(sym)
93 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
95 #endif /* CONFIG_MODULES */
96 #endif /* !__ASSEMBLY__ */
98 #endif /* _LINUX_EXPORT_H */