mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 01:41:39 +00:00
![Rusty Russell](/assets/img/avatar_default.png)
We have CONFIG_SYMBOL_PREFIX, which three archs define to the string "_". But Al Viro broke this in "consolidate cond_syscall and SYSCALL_ALIAS declarations" (in linux-next), and he's not the first to do so. Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to prefix it so something. So various places define helpers which are defined to nothing if CONFIG_SYMBOL_PREFIX isn't set: 1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX. 2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym) 3) include/linux/export.h defines MODULE_SYMBOL_PREFIX. 4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7) 5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym) 6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX 7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version for pasting. (arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too). Let's solve this properly: 1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX. 2) Make linux/export.h usable from asm. 3) Define VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR(). 4) Make everyone use them. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: James Hogan <james.hogan@imgtec.com> Tested-by: James Hogan <james.hogan@imgtec.com> (metag)
97 lines
2.7 KiB
C
97 lines
2.7 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
|
|
|
|
#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;
|
|
#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), 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
|
|
|
|
#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 */
|