[RFC 1/3] add support for exporting symbols from .S files

Arnd Bergmann
2008-08-11T14:39:34Z

This makes it possible to export symbols from assembly files, instead
of having to export them through an extra ksyms.c file.

I found this nicer to implement using a gas macro than a cpp macro.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -1,5 +1,7 @@
#ifndef _LINUX_MODULE_H
#define _LINUX_MODULE_H
+
+#ifndef __ASSEMBLY__
/*
* Dynamic loading of modules into the kernel.
*
@@ -605,4 +607,54 @@ static inline void module_remove_modinfo_attrs(struct module *mod)

#define __MODULE_STRING(x) __stringify(x)

+#else /* __ASSEMBLY__ */
+#include <asm/types.h>
+
+#ifdef CONFIG_MODULES
+.macro __EXPORT_SYMBOL sym section symtab strtab
+ .section \section,"a",@progbits
+ .type \symtab, @object
+ .ifeq BITS_PER_LONG-32
+ .align 3
+\symtab:
+ .long \sym
+ .long \strtab
+ .else
+ .align 4
+\symtab:
+ .quad \sym
+ .quad \strtab
+ .endif
+ .size \symtab,.-\symtab
+ .previous
+
+ .section __ksymtab_strings,"a",@progbits
+ .type \strtab, @object
+\strtab:
+ .string "\sym"
+ .size \strtab,.-\strtab
+ .previous
+ .endm
+
+#define EXPORT_SYMBOL(sym) \
+ __EXPORT_SYMBOL sym,__ksymtab,__ksymtab_ ## sym,__kstrtab_ ## sym
+#define EXPORT_SYMBOL_GPL(sym) \
+ __EXPORT_SYMBOL sym,__ksymtab_gpl,__ksymtab_ ## sym,__kstrtab_ ## sym
+#define EXPORT_SYMBOL_GPL_FUTURE(sym) \
+ __EXPORT_SYMBOL sym,__ksymtab_gpl_future,__ksymtab_ ## sym,__kstrtab_ ## sym
+#define EXPORT_UNUSED_SYMBOL(sym) \
+ __EXPORT_SYMBOL sym,__ksymtab_unused,__ksymtab_ ## sym,__kstrtab_ ## sym
+#define EXPORT_UNUSED_SYMBOL_GPL(sym) \
+ __EXPORT_SYMBOL sym,__ksymtab_unused_gpl,__ksymtab_ ## sym,__kstrtab_ ## sym
+
+#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_MODULE_H */