mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Ard Biesheuvel](/assets/img/avatar_default.png)
The previous patch introduced a separate inline asm version of the krcrctab declaration template for use with 64-bit architectures, which cannot refer to ELF symbols using 32-bit quantities. This declaration should be equivalent to the C one for 32-bit architectures, but just in case - unify them in a separate patch, which can simply be dropped if it turns out to break anything. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
133 lines
3.9 KiB
C
133 lines
3.9 KiB
C
#ifndef _LINUX_EXPORT_H
|
|
#define _LINUX_EXPORT_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.
|
|
*
|
|
* Try not to add #includes here. It slows compilation and makes kernel
|
|
* hackers place grumpy comments in header files.
|
|
*/
|
|
|
|
/* 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
|
|
#else
|
|
#define __VMLINUX_SYMBOL(x) x
|
|
#define __VMLINUX_SYMBOL_STR(x) #x
|
|
#endif
|
|
|
|
/* Indirect, so macros are expanded before pasting. */
|
|
#define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x)
|
|
#define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x)
|
|
|
|
#ifndef __ASSEMBLY__
|
|
struct kernel_symbol
|
|
{
|
|
unsigned long value;
|
|
const char *name;
|
|
};
|
|
|
|
#ifdef MODULE
|
|
extern struct module __this_module;
|
|
#define THIS_MODULE (&__this_module)
|
|
#else
|
|
#define THIS_MODULE ((struct module *)0)
|
|
#endif
|
|
|
|
#ifdef CONFIG_MODULES
|
|
|
|
#if defined(__KERNEL__) && !defined(__GENKSYMS__)
|
|
#ifdef CONFIG_MODVERSIONS
|
|
/* Mark the CRC weak since genksyms apparently decides not to
|
|
* generate a checksums for some symbols */
|
|
#if defined(CONFIG_MODULE_REL_CRCS)
|
|
#define __CRC_SYMBOL(sym, sec) \
|
|
asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \
|
|
" .weak " VMLINUX_SYMBOL_STR(__crc_##sym) " \n" \
|
|
" .long " VMLINUX_SYMBOL_STR(__crc_##sym) " - . \n" \
|
|
" .previous \n");
|
|
#else
|
|
#define __CRC_SYMBOL(sym, sec) \
|
|
asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \
|
|
" .weak " VMLINUX_SYMBOL_STR(__crc_##sym) " \n" \
|
|
" .long " VMLINUX_SYMBOL_STR(__crc_##sym) " \n" \
|
|
" .previous \n");
|
|
#endif
|
|
#else
|
|
#define __CRC_SYMBOL(sym, sec)
|
|
#endif
|
|
|
|
/* For every exported symbol, place a struct in the __ksymtab section */
|
|
#define ___EXPORT_SYMBOL(sym, sec) \
|
|
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), used)) \
|
|
= { (unsigned long)&sym, __kstrtab_##sym }
|
|
|
|
#if defined(__KSYM_DEPS__)
|
|
|
|
/*
|
|
* For fine grained build dependencies, we want to tell the build system
|
|
* about each possible exported symbol even if they're not actually exported.
|
|
* We use a string pattern that is unlikely to be valid code that the build
|
|
* system filters out from the preprocessor output (see ksym_dep_filter
|
|
* in scripts/Kbuild.include).
|
|
*/
|
|
#define __EXPORT_SYMBOL(sym, sec) === __KSYM_##sym ===
|
|
|
|
#elif defined(CONFIG_TRIM_UNUSED_KSYMS)
|
|
|
|
#include <generated/autoksyms.h>
|
|
|
|
#define __EXPORT_SYMBOL(sym, sec) \
|
|
__cond_export_sym(sym, sec, __is_defined(__KSYM_##sym))
|
|
#define __cond_export_sym(sym, sec, conf) \
|
|
___cond_export_sym(sym, sec, conf)
|
|
#define ___cond_export_sym(sym, sec, enabled) \
|
|
__cond_export_sym_##enabled(sym, sec)
|
|
#define __cond_export_sym_1(sym, sec) ___EXPORT_SYMBOL(sym, sec)
|
|
#define __cond_export_sym_0(sym, sec) /* nothing */
|
|
|
|
#else
|
|
#define __EXPORT_SYMBOL ___EXPORT_SYMBOL
|
|
#endif
|
|
|
|
#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
|
|
|
|
#endif /* __GENKSYMS__ */
|
|
|
|
#else /* !CONFIG_MODULES... */
|
|
|
|
#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)
|
|
|
|
#endif /* CONFIG_MODULES */
|
|
#endif /* !__ASSEMBLY__ */
|
|
|
|
#endif /* _LINUX_EXPORT_H */
|