162 lines
4.9 KiB
C
162 lines
4.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
#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.
|
|
*/
|
|
|
|
#ifndef __ASSEMBLY__
|
|
#ifdef MODULE
|
|
extern struct module __this_module;
|
|
#define THIS_MODULE (&__this_module)
|
|
#else
|
|
#define THIS_MODULE ((struct module *)0)
|
|
#endif
|
|
|
|
#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 __crc_" #sym " \n" \
|
|
" .long __crc_" #sym " - . \n" \
|
|
" .previous \n")
|
|
#else
|
|
#define __CRC_SYMBOL(sym, sec) \
|
|
asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \
|
|
" .weak __crc_" #sym " \n" \
|
|
" .long __crc_" #sym " \n" \
|
|
" .previous \n")
|
|
#endif
|
|
#else
|
|
#define __CRC_SYMBOL(sym, sec)
|
|
#endif
|
|
|
|
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
|
|
#include <linux/compiler.h>
|
|
/*
|
|
* Emit the ksymtab entry as a pair of relative references: this reduces
|
|
* the size by half on 64-bit architectures, and eliminates the need for
|
|
* absolute relocations that require runtime processing on relocatable
|
|
* kernels.
|
|
*/
|
|
#define __KSYMTAB_ENTRY(sym, sec) \
|
|
__ADDRESSABLE(sym) \
|
|
asm(" .section \"___ksymtab" sec "+" #sym "\", \"a\" \n" \
|
|
" .balign 4 \n" \
|
|
"__ksymtab_" #sym ": \n" \
|
|
" .long " #sym "- . \n" \
|
|
" .long __kstrtab_" #sym "- . \n" \
|
|
" .long __kstrtabns_" #sym "- . \n" \
|
|
" .previous \n")
|
|
|
|
struct kernel_symbol {
|
|
int value_offset;
|
|
int name_offset;
|
|
int namespace_offset;
|
|
};
|
|
#else
|
|
#define __KSYMTAB_ENTRY(sym, sec) \
|
|
static const struct kernel_symbol __ksymtab_##sym \
|
|
__attribute__((section("___ksymtab" sec "+" #sym), used)) \
|
|
__aligned(sizeof(void *)) \
|
|
= { (unsigned long)&sym, __kstrtab_##sym, __kstrtabns_##sym }
|
|
|
|
struct kernel_symbol {
|
|
unsigned long value;
|
|
const char *name;
|
|
const char *namespace;
|
|
};
|
|
#endif
|
|
|
|
#ifdef __GENKSYMS__
|
|
|
|
#define ___EXPORT_SYMBOL(sym, sec, ns) __GENKSYMS_EXPORT_SYMBOL(sym)
|
|
|
|
#else
|
|
|
|
/* For every exported symbol, place a struct in the __ksymtab section */
|
|
#define ___EXPORT_SYMBOL(sym, sec, ns) \
|
|
extern typeof(sym) sym; \
|
|
__CRC_SYMBOL(sym, sec); \
|
|
static const char __kstrtab_##sym[] \
|
|
__attribute__((section("__ksymtab_strings"), used, aligned(1))) \
|
|
= #sym; \
|
|
static const char __kstrtabns_##sym[] \
|
|
__attribute__((section("__ksymtab_strings"), used, aligned(1))) \
|
|
= ns; \
|
|
__KSYMTAB_ENTRY(sym, sec)
|
|
|
|
#endif
|
|
|
|
#if !defined(CONFIG_MODULES) || 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, sec, ns)
|
|
|
|
#elif defined(CONFIG_TRIM_UNUSED_KSYMS)
|
|
|
|
#include <generated/autoksyms.h>
|
|
|
|
/*
|
|
* 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 symbol pattern __ksym_marker_<symbol> that the build system filters
|
|
* from the $(NM) output (see scripts/gen_ksymdeps.sh). These symbols are
|
|
* discarded in the final link stage.
|
|
*/
|
|
#define __ksym_marker(sym) \
|
|
static int __ksym_marker_##sym[0] __section(".discard.ksym") __used
|
|
|
|
#define __EXPORT_SYMBOL(sym, sec, ns) \
|
|
__ksym_marker(sym); \
|
|
__cond_export_sym(sym, sec, ns, __is_defined(__KSYM_##sym))
|
|
#define __cond_export_sym(sym, sec, ns, conf) \
|
|
___cond_export_sym(sym, sec, ns, conf)
|
|
#define ___cond_export_sym(sym, sec, ns, enabled) \
|
|
__cond_export_sym_##enabled(sym, sec, ns)
|
|
#define __cond_export_sym_1(sym, sec, ns) ___EXPORT_SYMBOL(sym, sec, ns)
|
|
#define __cond_export_sym_0(sym, sec, ns) /* nothing */
|
|
|
|
#else
|
|
|
|
#define __EXPORT_SYMBOL(sym, sec, ns) ___EXPORT_SYMBOL(sym, sec, ns)
|
|
|
|
#endif /* CONFIG_MODULES */
|
|
|
|
#ifdef DEFAULT_SYMBOL_NAMESPACE
|
|
#include <linux/stringify.h>
|
|
#define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, __stringify(DEFAULT_SYMBOL_NAMESPACE))
|
|
#else
|
|
#define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, "")
|
|
#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")
|
|
#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", #ns)
|
|
#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "_gpl", #ns)
|
|
|
|
#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 /* !__ASSEMBLY__ */
|
|
|
|
#endif /* _LINUX_EXPORT_H */
|