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 * Try not to add #includes here.  It slows compilation and makes kernel
9 * hackers place grumpy comments in header files.
10 */
11
12/* Some toolchains use a `_' prefix for all user symbols. */
13#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
14#define __VMLINUX_SYMBOL(x) _##x
15#define __VMLINUX_SYMBOL_STR(x) "_" #x
16#else
17#define __VMLINUX_SYMBOL(x) x
18#define __VMLINUX_SYMBOL_STR(x) #x
19#endif
20
21/* Indirect, so macros are expanded before pasting. */
22#define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x)
23#define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x)
24
25#ifndef __ASSEMBLY__
26struct kernel_symbol
27{
28	unsigned long value;
29	const char *name;
30};
31
32#ifdef MODULE
33extern struct module __this_module;
34#define THIS_MODULE (&__this_module)
35#else
36#define THIS_MODULE ((struct module *)0)
37#endif
38
39#ifdef CONFIG_MODULES
40
41#ifndef __GENKSYMS__
42#ifdef CONFIG_MODVERSIONS
43/* Mark the CRC weak since genksyms apparently decides not to
44 * generate a checksums for some symbols */
45#define __CRC_SYMBOL(sym, sec)					\
46	extern __visible void *__crc_##sym __attribute__((weak));		\
47	static const unsigned long __kcrctab_##sym		\
48	__used							\
49	__attribute__((section("___kcrctab" sec "+" #sym), unused))	\
50	= (unsigned long) &__crc_##sym;
51#else
52#define __CRC_SYMBOL(sym, sec)
53#endif
54
55/* For every exported symbol, place a struct in the __ksymtab section */
56#define __EXPORT_SYMBOL(sym, sec)				\
57	extern typeof(sym) sym;					\
58	__CRC_SYMBOL(sym, sec)					\
59	static const char __kstrtab_##sym[]			\
60	__attribute__((section("__ksymtab_strings"), aligned(1))) \
61	= VMLINUX_SYMBOL_STR(sym);				\
62	extern const struct kernel_symbol __ksymtab_##sym;	\
63	__visible const struct kernel_symbol __ksymtab_##sym	\
64	__used							\
65	__attribute__((section("___ksymtab" sec "+" #sym), unused))	\
66	= { (unsigned long)&sym, __kstrtab_##sym }
67
68#define EXPORT_SYMBOL(sym)					\
69	__EXPORT_SYMBOL(sym, "")
70
71#define EXPORT_SYMBOL_GPL(sym)					\
72	__EXPORT_SYMBOL(sym, "_gpl")
73
74#define EXPORT_SYMBOL_GPL_FUTURE(sym)				\
75	__EXPORT_SYMBOL(sym, "_gpl_future")
76
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")
80#else
81#define EXPORT_UNUSED_SYMBOL(sym)
82#define EXPORT_UNUSED_SYMBOL_GPL(sym)
83#endif
84
85#endif	/* __GENKSYMS__ */
86
87#else /* !CONFIG_MODULES... */
88
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)
94
95#endif /* CONFIG_MODULES */
96#endif /* !__ASSEMBLY__ */
97
98#endif /* _LINUX_EXPORT_H */
99