diff options
Diffstat (limited to 'include/linux/export.h')
| -rw-r--r-- | include/linux/export.h | 147 |
1 files changed, 73 insertions, 74 deletions
diff --git a/include/linux/export.h b/include/linux/export.h index 412cd509effe..a686fd0ba406 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -1,97 +1,96 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ #ifndef _LINUX_EXPORT_H #define _LINUX_EXPORT_H + +#include <linux/compiler.h> +#include <linux/linkage.h> +#include <linux/stringify.h> + /* - * Export symbols from the kernel to modules. Forked from module.h - * to reduce the amount of pointless cruft we feed to gcc when only - * exporting a simple symbol or two. + * This comment block is used by fixdep. Please do not remove. * - * Try not to add #includes here. It slows compilation and makes kernel - * hackers place grumpy comments in header files. + * When CONFIG_MODVERSIONS is changed from n to y, all source files having + * EXPORT_SYMBOL variants must be re-compiled because genksyms is run as a + * side effect of the *.o build rule. */ -/* Some toolchains use a `_' prefix for all user symbols. */ -#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX -#define __VMLINUX_SYMBOL(x) _##x -#define __VMLINUX_SYMBOL_STR(x) "_" #x +#ifdef CONFIG_64BIT +#define __EXPORT_SYMBOL_REF(sym) \ + .balign 8 ASM_NL \ + .quad sym #else -#define __VMLINUX_SYMBOL(x) x -#define __VMLINUX_SYMBOL_STR(x) #x +#define __EXPORT_SYMBOL_REF(sym) \ + .balign 4 ASM_NL \ + .long sym #endif -/* Indirect, so macros are expanded before pasting. */ -#define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x) -#define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x) +/* + * LLVM integrated assembler cam merge adjacent string literals (like + * C and GNU-as) passed to '.ascii', but not to '.asciz' and chokes on: + * + * .asciz "MODULE_" "kvm" ; + */ +#define ___EXPORT_SYMBOL(sym, license, ns...) \ + .section ".export_symbol","a" ASM_NL \ + __export_symbol_##sym: ASM_NL \ + .asciz license ASM_NL \ + .ascii ns "\0" ASM_NL \ + __EXPORT_SYMBOL_REF(sym) ASM_NL \ + .previous + +#if defined(__DISABLE_EXPORTS) + +/* + * Allow symbol exports to be disabled completely so that C code may + * be reused in other execution contexts such as the UEFI stub or the + * decompressor. + */ +#define __EXPORT_SYMBOL(sym, license, ns) + +#elif defined(__GENKSYMS__) -#ifndef __ASSEMBLY__ -struct kernel_symbol -{ - unsigned long value; - const char *name; -}; +#define __EXPORT_SYMBOL(sym, license, ns) __GENKSYMS_EXPORT_SYMBOL(sym) + +#elif defined(__ASSEMBLY__) + +#define __EXPORT_SYMBOL(sym, license, ns) \ + ___EXPORT_SYMBOL(sym, license, ns) -#ifdef MODULE -extern struct module __this_module; -#define THIS_MODULE (&__this_module) #else -#define THIS_MODULE ((struct module *)0) -#endif -#ifdef CONFIG_MODULES - -#ifndef __GENKSYMS__ -#ifdef CONFIG_MODVERSIONS -/* Mark the CRC weak since genksyms apparently decides not to - * generate a checksums for some symbols */ -#define __CRC_SYMBOL(sym, sec) \ - extern void *__crc_##sym __attribute__((weak)); \ - static const unsigned long __kcrctab_##sym \ - __used \ - __attribute__((section("___kcrctab" sec "+" #sym), unused)) \ - = (unsigned long) &__crc_##sym; +#ifdef CONFIG_GENDWARFKSYMS +/* + * With CONFIG_GENDWARFKSYMS, ensure the compiler emits debugging + * information for all exported symbols, including those defined in + * different TUs, by adding a __gendwarfksyms_ptr_<symbol> pointer + * that's discarded during the final link. + */ +#define __GENDWARFKSYMS_EXPORT(sym) \ + static typeof(sym) *__gendwarfksyms_ptr_##sym __used \ + __section(".discard.gendwarfksyms") = &sym; #else -#define __CRC_SYMBOL(sym, sec) +#define __GENDWARFKSYMS_EXPORT(sym) #endif -/* For every exported symbol, place a struct in the __ksymtab section */ -#define __EXPORT_SYMBOL(sym, sec) \ +#define __EXPORT_SYMBOL(sym, license, ns) \ extern typeof(sym) sym; \ - __CRC_SYMBOL(sym, sec) \ - static const char __kstrtab_##sym[] \ - __attribute__((section("__ksymtab_strings"), aligned(1))) \ - = VMLINUX_SYMBOL_STR(sym); \ - static const struct kernel_symbol __ksymtab_##sym \ - __used \ - __attribute__((section("___ksymtab" sec "+" #sym), unused)) \ - = { (unsigned long)&sym, __kstrtab_##sym } - -#define EXPORT_SYMBOL(sym) \ - __EXPORT_SYMBOL(sym, "") - -#define EXPORT_SYMBOL_GPL(sym) \ - __EXPORT_SYMBOL(sym, "_gpl") - -#define EXPORT_SYMBOL_GPL_FUTURE(sym) \ - __EXPORT_SYMBOL(sym, "_gpl_future") - -#ifdef CONFIG_UNUSED_SYMBOLS -#define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused") -#define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl") -#else -#define EXPORT_UNUSED_SYMBOL(sym) -#define EXPORT_UNUSED_SYMBOL_GPL(sym) -#endif + __ADDRESSABLE(sym) \ + __GENDWARFKSYMS_EXPORT(sym) \ + asm(__stringify(___EXPORT_SYMBOL(sym, license, ns))) -#endif /* __GENKSYMS__ */ +#endif -#else /* !CONFIG_MODULES... */ +#ifdef DEFAULT_SYMBOL_NAMESPACE +#define _EXPORT_SYMBOL(sym, license) __EXPORT_SYMBOL(sym, license, DEFAULT_SYMBOL_NAMESPACE) +#else +#define _EXPORT_SYMBOL(sym, license) __EXPORT_SYMBOL(sym, license, "") +#endif -#define EXPORT_SYMBOL(sym) -#define EXPORT_SYMBOL_GPL(sym) -#define EXPORT_SYMBOL_GPL_FUTURE(sym) -#define EXPORT_UNUSED_SYMBOL(sym) -#define EXPORT_UNUSED_SYMBOL_GPL(sym) +#define EXPORT_SYMBOL(sym) _EXPORT_SYMBOL(sym, "") +#define EXPORT_SYMBOL_GPL(sym) _EXPORT_SYMBOL(sym, "GPL") +#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", ns) +#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "GPL", ns) -#endif /* CONFIG_MODULES */ -#endif /* !__ASSEMBLY__ */ +#define EXPORT_SYMBOL_FOR_MODULES(sym, mods) __EXPORT_SYMBOL(sym, "GPL", "module:" mods) #endif /* _LINUX_EXPORT_H */ |