~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/export.h

Version: ~ [ linux-5.19-rc3 ] ~ [ linux-5.18.5 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.48 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.123 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.199 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.248 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.284 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.319 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.302 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /* SPDX-License-Identifier: GPL-2.0-only */
  2 #ifndef _LINUX_EXPORT_H
  3 #define _LINUX_EXPORT_H
  4 
  5 /*
  6  * Export symbols from the kernel to modules.  Forked from module.h
  7  * to reduce the amount of pointless cruft we feed to gcc when only
  8  * exporting a simple symbol or two.
  9  *
 10  * Try not to add #includes here.  It slows compilation and makes kernel
 11  * hackers place grumpy comments in header files.
 12  */
 13 
 14 #ifndef __ASSEMBLY__
 15 #ifdef MODULE
 16 extern struct module __this_module;
 17 #define THIS_MODULE (&__this_module)
 18 #else
 19 #define THIS_MODULE ((struct module *)0)
 20 #endif
 21 
 22 #ifdef CONFIG_MODVERSIONS
 23 /* Mark the CRC weak since genksyms apparently decides not to
 24  * generate a checksums for some symbols */
 25 #if defined(CONFIG_MODULE_REL_CRCS)
 26 #define __CRC_SYMBOL(sym, sec)                                          \
 27         asm("   .section \"___kcrctab" sec "+" #sym "\", \"a\"  \n"     \
 28             "   .weak   __crc_" #sym "                          \n"     \
 29             "   .long   __crc_" #sym " - .                      \n"     \
 30             "   .previous                                       \n")
 31 #else
 32 #define __CRC_SYMBOL(sym, sec)                                          \
 33         asm("   .section \"___kcrctab" sec "+" #sym "\", \"a\"  \n"     \
 34             "   .weak   __crc_" #sym "                          \n"     \
 35             "   .long   __crc_" #sym "                          \n"     \
 36             "   .previous                                       \n")
 37 #endif
 38 #else
 39 #define __CRC_SYMBOL(sym, sec)
 40 #endif
 41 
 42 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
 43 #include <linux/compiler.h>
 44 /*
 45  * Emit the ksymtab entry as a pair of relative references: this reduces
 46  * the size by half on 64-bit architectures, and eliminates the need for
 47  * absolute relocations that require runtime processing on relocatable
 48  * kernels.
 49  */
 50 #define __KSYMTAB_ENTRY(sym, sec)                                       \
 51         __ADDRESSABLE(sym)                                              \
 52         asm("   .section \"___ksymtab" sec "+" #sym "\", \"a\"  \n"     \
 53             "   .balign 4                                       \n"     \
 54             "__ksymtab_" #sym ":                                \n"     \
 55             "   .long   " #sym "- .                             \n"     \
 56             "   .long   __kstrtab_" #sym "- .                   \n"     \
 57             "   .long   __kstrtabns_" #sym "- .                 \n"     \
 58             "   .previous                                       \n")
 59 
 60 struct kernel_symbol {
 61         int value_offset;
 62         int name_offset;
 63         int namespace_offset;
 64 };
 65 #else
 66 #define __KSYMTAB_ENTRY(sym, sec)                                       \
 67         static const struct kernel_symbol __ksymtab_##sym               \
 68         __attribute__((section("___ksymtab" sec "+" #sym), used))       \
 69         __aligned(sizeof(void *))                                       \
 70         = { (unsigned long)&sym, __kstrtab_##sym, __kstrtabns_##sym }
 71 
 72 struct kernel_symbol {
 73         unsigned long value;
 74         const char *name;
 75         const char *namespace;
 76 };
 77 #endif
 78 
 79 #ifdef __GENKSYMS__
 80 
 81 #define ___EXPORT_SYMBOL(sym, sec, ns)  __GENKSYMS_EXPORT_SYMBOL(sym)
 82 
 83 #else
 84 
 85 /*
 86  * For every exported symbol, do the following:
 87  *
 88  * - If applicable, place a CRC entry in the __kcrctab section.
 89  * - Put the name of the symbol and namespace (empty string "" for none) in
 90  *   __ksymtab_strings.
 91  * - Place a struct kernel_symbol entry in the __ksymtab section.
 92  *
 93  * note on .section use: we specify progbits since usage of the "M" (SHF_MERGE)
 94  * section flag requires it. Use '%progbits' instead of '@progbits' since the
 95  * former apparently works on all arches according to the binutils source.
 96  */
 97 #define ___EXPORT_SYMBOL(sym, sec, ns)                                          \
 98         extern typeof(sym) sym;                                                 \
 99         extern const char __kstrtab_##sym[];                                    \
100         extern const char __kstrtabns_##sym[];                                  \
101         __CRC_SYMBOL(sym, sec);                                                 \
102         asm("   .section \"__ksymtab_strings\",\"aMS\",%progbits,1      \n"     \
103             "__kstrtab_" #sym ":                                        \n"     \
104             "   .asciz  \"" #sym "\"                                    \n"     \
105             "__kstrtabns_" #sym ":                                      \n"     \
106             "   .asciz  \"" ns "\"                                      \n"     \
107             "   .previous                                               \n");   \
108         __KSYMTAB_ENTRY(sym, sec)
109 
110 #endif
111 
112 #if !defined(CONFIG_MODULES) || defined(__DISABLE_EXPORTS)
113 
114 /*
115  * Allow symbol exports to be disabled completely so that C code may
116  * be reused in other execution contexts such as the UEFI stub or the
117  * decompressor.
118  */
119 #define __EXPORT_SYMBOL(sym, sec, ns)
120 
121 #elif defined(CONFIG_TRIM_UNUSED_KSYMS)
122 
123 #include <generated/autoksyms.h>
124 
125 /*
126  * For fine grained build dependencies, we want to tell the build system
127  * about each possible exported symbol even if they're not actually exported.
128  * We use a symbol pattern __ksym_marker_<symbol> that the build system filters
129  * from the $(NM) output (see scripts/gen_ksymdeps.sh). These symbols are
130  * discarded in the final link stage.
131  */
132 #define __ksym_marker(sym)      \
133         static int __ksym_marker_##sym[0] __section(".discard.ksym") __used
134 
135 #define __EXPORT_SYMBOL(sym, sec, ns)                                   \
136         __ksym_marker(sym);                                             \
137         __cond_export_sym(sym, sec, ns, __is_defined(__KSYM_##sym))
138 #define __cond_export_sym(sym, sec, ns, conf)                           \
139         ___cond_export_sym(sym, sec, ns, conf)
140 #define ___cond_export_sym(sym, sec, ns, enabled)                       \
141         __cond_export_sym_##enabled(sym, sec, ns)
142 #define __cond_export_sym_1(sym, sec, ns) ___EXPORT_SYMBOL(sym, sec, ns)
143 #define __cond_export_sym_0(sym, sec, ns) /* nothing */
144 
145 #else
146 
147 #define __EXPORT_SYMBOL(sym, sec, ns)   ___EXPORT_SYMBOL(sym, sec, ns)
148 
149 #endif /* CONFIG_MODULES */
150 
151 #ifdef DEFAULT_SYMBOL_NAMESPACE
152 #include <linux/stringify.h>
153 #define _EXPORT_SYMBOL(sym, sec)        __EXPORT_SYMBOL(sym, sec, __stringify(DEFAULT_SYMBOL_NAMESPACE))
154 #else
155 #define _EXPORT_SYMBOL(sym, sec)        __EXPORT_SYMBOL(sym, sec, "")
156 #endif
157 
158 #define EXPORT_SYMBOL(sym)              _EXPORT_SYMBOL(sym, "")
159 #define EXPORT_SYMBOL_GPL(sym)          _EXPORT_SYMBOL(sym, "_gpl")
160 #define EXPORT_SYMBOL_NS(sym, ns)       __EXPORT_SYMBOL(sym, "", #ns)
161 #define EXPORT_SYMBOL_NS_GPL(sym, ns)   __EXPORT_SYMBOL(sym, "_gpl", #ns)
162 
163 #endif /* !__ASSEMBLY__ */
164 
165 #endif /* _LINUX_EXPORT_H */
166 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp