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f5016932 PG |
1 | #ifndef _LINUX_EXPORT_H |
2 | #define _LINUX_EXPORT_H | |
b67067f1 | 3 | |
f5016932 PG |
4 | /* |
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. | |
8 | * | |
b92021b0 RR |
9 | * Try not to add #includes here. It slows compilation and makes kernel |
10 | * hackers place grumpy comments in header files. | |
f5016932 PG |
11 | */ |
12 | ||
13 | /* Some toolchains use a `_' prefix for all user symbols. */ | |
b92021b0 RR |
14 | #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX |
15 | #define __VMLINUX_SYMBOL(x) _##x | |
16 | #define __VMLINUX_SYMBOL_STR(x) "_" #x | |
f5016932 | 17 | #else |
b92021b0 RR |
18 | #define __VMLINUX_SYMBOL(x) x |
19 | #define __VMLINUX_SYMBOL_STR(x) #x | |
f5016932 PG |
20 | #endif |
21 | ||
b92021b0 RR |
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) | |
25 | ||
26 | #ifndef __ASSEMBLY__ | |
f5016932 PG |
27 | struct kernel_symbol |
28 | { | |
29 | unsigned long value; | |
30 | const char *name; | |
31 | }; | |
32 | ||
33 | #ifdef MODULE | |
34 | extern struct module __this_module; | |
35 | #define THIS_MODULE (&__this_module) | |
36 | #else | |
37 | #define THIS_MODULE ((struct module *)0) | |
38 | #endif | |
39 | ||
40 | #ifdef CONFIG_MODULES | |
41 | ||
f2355416 | 42 | #if defined(__KERNEL__) && !defined(__GENKSYMS__) |
f5016932 PG |
43 | #ifdef CONFIG_MODVERSIONS |
44 | /* Mark the CRC weak since genksyms apparently decides not to | |
45 | * generate a checksums for some symbols */ | |
b67067f1 NP |
46 | #define __CRC_SYMBOL(sym, sec) \ |
47 | extern __visible void *__crc_##sym __attribute__((weak)); \ | |
48 | static const unsigned long __kcrctab_##sym \ | |
49 | __used \ | |
50 | __attribute__((section("___kcrctab" sec "+" #sym), used)) \ | |
f5016932 PG |
51 | = (unsigned long) &__crc_##sym; |
52 | #else | |
53 | #define __CRC_SYMBOL(sym, sec) | |
54 | #endif | |
55 | ||
56 | /* For every exported symbol, place a struct in the __ksymtab section */ | |
b67067f1 NP |
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 \ | |
64 | __used \ | |
65 | __attribute__((section("___ksymtab" sec "+" #sym), used)) \ | |
f5016932 PG |
66 | = { (unsigned long)&sym, __kstrtab_##sym } |
67 | ||
c1a95fda NP |
68 | #if defined(__KSYM_DEPS__) |
69 | ||
70 | /* | |
71 | * For fine grained build dependencies, we want to tell the build system | |
72 | * about each possible exported symbol even if they're not actually exported. | |
73 | * We use a string pattern that is unlikely to be valid code that the build | |
74 | * system filters out from the preprocessor output (see ksym_dep_filter | |
75 | * in scripts/Kbuild.include). | |
76 | */ | |
77 | #define __EXPORT_SYMBOL(sym, sec) === __KSYM_##sym === | |
78 | ||
79 | #elif defined(CONFIG_TRIM_UNUSED_KSYMS) | |
f2355416 | 80 | |
f2355416 NP |
81 | #include <generated/autoksyms.h> |
82 | ||
83 | #define __EXPORT_SYMBOL(sym, sec) \ | |
6023d236 | 84 | __cond_export_sym(sym, sec, __is_defined(__KSYM_##sym)) |
f2355416 NP |
85 | #define __cond_export_sym(sym, sec, conf) \ |
86 | ___cond_export_sym(sym, sec, conf) | |
87 | #define ___cond_export_sym(sym, sec, enabled) \ | |
88 | __cond_export_sym_##enabled(sym, sec) | |
89 | #define __cond_export_sym_1(sym, sec) ___EXPORT_SYMBOL(sym, sec) | |
90 | #define __cond_export_sym_0(sym, sec) /* nothing */ | |
91 | ||
92 | #else | |
93 | #define __EXPORT_SYMBOL ___EXPORT_SYMBOL | |
94 | #endif | |
95 | ||
f5016932 PG |
96 | #define EXPORT_SYMBOL(sym) \ |
97 | __EXPORT_SYMBOL(sym, "") | |
98 | ||
99 | #define EXPORT_SYMBOL_GPL(sym) \ | |
100 | __EXPORT_SYMBOL(sym, "_gpl") | |
101 | ||
102 | #define EXPORT_SYMBOL_GPL_FUTURE(sym) \ | |
103 | __EXPORT_SYMBOL(sym, "_gpl_future") | |
104 | ||
105 | #ifdef CONFIG_UNUSED_SYMBOLS | |
106 | #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused") | |
107 | #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl") | |
108 | #else | |
109 | #define EXPORT_UNUSED_SYMBOL(sym) | |
110 | #define EXPORT_UNUSED_SYMBOL_GPL(sym) | |
111 | #endif | |
112 | ||
113 | #endif /* __GENKSYMS__ */ | |
114 | ||
115 | #else /* !CONFIG_MODULES... */ | |
116 | ||
117 | #define EXPORT_SYMBOL(sym) | |
118 | #define EXPORT_SYMBOL_GPL(sym) | |
119 | #define EXPORT_SYMBOL_GPL_FUTURE(sym) | |
120 | #define EXPORT_UNUSED_SYMBOL(sym) | |
121 | #define EXPORT_UNUSED_SYMBOL_GPL(sym) | |
122 | ||
123 | #endif /* CONFIG_MODULES */ | |
b92021b0 | 124 | #endif /* !__ASSEMBLY__ */ |
f5016932 PG |
125 | |
126 | #endif /* _LINUX_EXPORT_H */ |