Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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 * If you feel the need to add #include <linux/foo.h> to this file
9 * then you are doing something wrong and should go away silently.
10 */
11
12/* Some toolchains use a `_' prefix for all user symbols. */
13#ifdef CONFIG_SYMBOL_PREFIX
14#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
15#else
16#define MODULE_SYMBOL_PREFIX ""
17#endif
18
19struct kernel_symbol
20{
21 unsigned long value;
22 const char *name;
23};
24
25#ifdef MODULE
26extern struct module __this_module;
27#define THIS_MODULE (&__this_module)
28#else
29#define THIS_MODULE ((struct module *)0)
30#endif
31
32#ifdef CONFIG_MODULES
33
34#ifndef __GENKSYMS__
35#ifdef CONFIG_MODVERSIONS
36/* Mark the CRC weak since genksyms apparently decides not to
37 * generate a checksums for some symbols */
38#define __CRC_SYMBOL(sym, sec) \
39 extern void *__crc_##sym __attribute__((weak)); \
40 static const unsigned long __kcrctab_##sym \
41 __used \
42 __attribute__((section("___kcrctab" sec "+" #sym), unused)) \
43 = (unsigned long) &__crc_##sym;
44#else
45#define __CRC_SYMBOL(sym, sec)
46#endif
47
48/* For every exported symbol, place a struct in the __ksymtab section */
49#define __EXPORT_SYMBOL(sym, sec) \
50 extern typeof(sym) sym; \
51 __CRC_SYMBOL(sym, sec) \
52 static const char __kstrtab_##sym[] \
53 __attribute__((section("__ksymtab_strings"), aligned(1))) \
54 = MODULE_SYMBOL_PREFIX #sym; \
55 static const struct kernel_symbol __ksymtab_##sym \
56 __used \
57 __attribute__((section("___ksymtab" sec "+" #sym), unused)) \
58 = { (unsigned long)&sym, __kstrtab_##sym }
59
60#define EXPORT_SYMBOL(sym) \
61 __EXPORT_SYMBOL(sym, "")
62
63#define EXPORT_SYMBOL_GPL(sym) \
64 __EXPORT_SYMBOL(sym, "_gpl")
65
66#define EXPORT_SYMBOL_GPL_FUTURE(sym) \
67 __EXPORT_SYMBOL(sym, "_gpl_future")
68
69#ifdef CONFIG_UNUSED_SYMBOLS
70#define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
71#define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
72#else
73#define EXPORT_UNUSED_SYMBOL(sym)
74#define EXPORT_UNUSED_SYMBOL_GPL(sym)
75#endif
76
77#endif /* __GENKSYMS__ */
78
79#else /* !CONFIG_MODULES... */
80
81#define EXPORT_SYMBOL(sym)
82#define EXPORT_SYMBOL_GPL(sym)
83#define EXPORT_SYMBOL_GPL_FUTURE(sym)
84#define EXPORT_UNUSED_SYMBOL(sym)
85#define EXPORT_UNUSED_SYMBOL_GPL(sym)
86
87#endif /* CONFIG_MODULES */
88
89#endif /* _LINUX_EXPORT_H */