Commit f02e8a65 authored by Alessio Igor Bogani's avatar Alessio Igor Bogani Committed by Rusty Russell
Browse files

module: Sort exported symbols 



This patch places every exported symbol in its own section
(i.e. "___ksymtab+printk").  Thus the linker will use its SORT() directive
to sort and finally merge all symbol in the right and final section
(i.e. "__ksymtab").

The symbol prefixed archs use an underscore as prefix for symbols.
To avoid collision we use a different character to create the temporary
section names.

This work was supported by a hardware donation from the CE Linux Forum.

Signed-off-by: default avatarAlessio Igor Bogani <abogani@kernel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (folded in '+' fixup)
Tested-by: default avatarDirk Behme <dirk.behme@googlemail.com>
parent de4d8d53

include/asm-generic/vmlinux.lds.h

+10 −10
Original line number Diff line number Diff line
@@ -274,70 +274,70 @@ 
	/* Kernel symbol table: Normal symbols */			\

	__ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {		\

		VMLINUX_SYMBOL(__start___ksymtab) = .;			\

		*(__ksymtab)						\

		*(SORT(___ksymtab+*))					\

		VMLINUX_SYMBOL(__stop___ksymtab) = .;			\

	}								\

									\

	/* Kernel symbol table: GPL-only symbols */			\

	__ksymtab_gpl     : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) {	\

		VMLINUX_SYMBOL(__start___ksymtab_gpl) = .;		\

		*(__ksymtab_gpl)					\

		*(SORT(___ksymtab_gpl+*))				\

		VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .;		\

	}								\

									\

	/* Kernel symbol table: Normal unused symbols */		\

	__ksymtab_unused  : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) {	\

		VMLINUX_SYMBOL(__start___ksymtab_unused) = .;		\

		*(__ksymtab_unused)					\

		*(SORT(___ksymtab_unused+*))				\

		VMLINUX_SYMBOL(__stop___ksymtab_unused) = .;		\

	}								\

									\

	/* Kernel symbol table: GPL-only unused symbols */		\

	__ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \

		VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .;	\

		*(__ksymtab_unused_gpl)					\

		*(SORT(___ksymtab_unused_gpl+*))			\

		VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .;	\

	}								\

									\

	/* Kernel symbol table: GPL-future-only symbols */		\

	__ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \

		VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .;	\

		*(__ksymtab_gpl_future)					\

		*(SORT(___ksymtab_gpl_future+*))			\

		VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .;	\

	}								\

									\

	/* Kernel symbol table: Normal symbols */			\

	__kcrctab         : AT(ADDR(__kcrctab) - LOAD_OFFSET) {		\

		VMLINUX_SYMBOL(__start___kcrctab) = .;			\

		*(__kcrctab)						\

		*(SORT(___kcrctab+*))					\

		VMLINUX_SYMBOL(__stop___kcrctab) = .;			\

	}								\

									\

	/* Kernel symbol table: GPL-only symbols */			\

	__kcrctab_gpl     : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) {	\

		VMLINUX_SYMBOL(__start___kcrctab_gpl) = .;		\

		*(__kcrctab_gpl)					\

		*(SORT(___kcrctab_gpl+*))				\

		VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .;		\

	}								\

									\

	/* Kernel symbol table: Normal unused symbols */		\

	__kcrctab_unused  : AT(ADDR(__kcrctab_unused) - LOAD_OFFSET) {	\

		VMLINUX_SYMBOL(__start___kcrctab_unused) = .;		\

		*(__kcrctab_unused)					\

		*(SORT(___kcrctab_unused+*))				\

		VMLINUX_SYMBOL(__stop___kcrctab_unused) = .;		\

	}								\

									\

	/* Kernel symbol table: GPL-only unused symbols */		\

	__kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \

		VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .;	\

		*(__kcrctab_unused_gpl)					\

		*(SORT(___kcrctab_unused_gpl+*))			\

		VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .;	\

	}								\

									\

	/* Kernel symbol table: GPL-future-only symbols */		\

	__kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \

		VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .;	\

		*(__kcrctab_gpl_future)					\

		*(SORT(___kcrctab_gpl_future+*))			\

		VMLINUX_SYMBOL(__stop___kcrctab_gpl_future) = .;	\

	}								\

									\

include/linux/module.h

+2 −2
Original line number Diff line number Diff line
@@ -224,7 +224,7 @@ struct module_use { 
	extern void *__crc_##sym __attribute__((weak));		\

	static const unsigned long __kcrctab_##sym		\

	__used							\

	__attribute__((section("__kcrctab" sec), unused))	\

	__attribute__((section("___kcrctab" sec "+" #sym), unused))	\

	= (unsigned long) &__crc_##sym;

#else

#define __CRC_SYMBOL(sym, sec)
@@ -239,7 +239,7 @@ struct module_use { 
	= MODULE_SYMBOL_PREFIX #sym;                    	\

	static const struct kernel_symbol __ksymtab_##sym	\

	__used							\

	__attribute__((section("__ksymtab" sec), unused))	\

	__attribute__((section("___ksymtab" sec "+" #sym), unused))	\

	= { (unsigned long)&sym, __kstrtab_##sym }



#define EXPORT_SYMBOL(sym)					\

scripts/module-common.lds

+11 −0
Original line number Diff line number Diff line
@@ -5,4 +5,15 @@ 
 */

SECTIONS {

	/DISCARD/ : { *(.discard) }



	__ksymtab		: { *(SORT(___ksymtab+*)) }

	__ksymtab_gpl		: { *(SORT(___ksymtab_gpl+*)) }

	__ksymtab_unused	: { *(SORT(___ksymtab_unused+*)) }

	__ksymtab_unused_gpl	: { *(SORT(___ksymtab_unused_gpl+*)) }

	__ksymtab_gpl_future	: { *(SORT(___ksymtab_gpl_future+*)) }

	__kcrctab		: { *(SORT(___kcrctab+*)) }

	__kcrctab_gpl		: { *(SORT(___kcrctab_gpl+*)) }

	__kcrctab_unused	: { *(SORT(___kcrctab_unused+*)) }

	__kcrctab_unused_gpl	: { *(SORT(___kcrctab_unused_gpl+*)) }

	__kcrctab_gpl_future	: { *(SORT(___kcrctab_gpl_future+*)) }

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE