mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 01:41:39 +00:00
![Masahiro Yamada](/assets/img/avatar_default.png)
My main motivation of this commit is to clean up scripts/Kbuild.include and scripts/Makefile.build. Currently, CONFIG_TRIM_UNUSED_KSYMS works with a tricky gimmick; possibly exported symbols are detected by letting $(CPP) replace EXPORT_SYMBOL* with a special string '=== __KSYM_*===', which is post-processed by sed, and passed to fixdep. The extra preprocessing is costly, and hacking cmd_and_fixdep is ugly. I came up with a new way to find exported symbols; insert a dummy symbol __ksym_marker_* to each potentially exported symbol. Those dummy symbols are picked up by $(NM), post-processed by sed, then appended to .*.cmd files. I collected the post-process part to a new shell script scripts/gen_ksymdeps.sh for readability. The dummy symbols are put into the .discard.* section so that the linker script rips them off the final vmlinux or modules. A nice side-effect is building with CONFIG_TRIM_UNUSED_KSYMS will be much faster. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nicolas Pitre <nico@linaro.org>
96 lines
2.1 KiB
C
96 lines
2.1 KiB
C
#ifndef __ASM_GENERIC_EXPORT_H
|
|
#define __ASM_GENERIC_EXPORT_H
|
|
|
|
#ifndef KSYM_FUNC
|
|
#define KSYM_FUNC(x) x
|
|
#endif
|
|
#ifdef CONFIG_64BIT
|
|
#ifndef KSYM_ALIGN
|
|
#define KSYM_ALIGN 8
|
|
#endif
|
|
#else
|
|
#ifndef KSYM_ALIGN
|
|
#define KSYM_ALIGN 4
|
|
#endif
|
|
#endif
|
|
#ifndef KCRC_ALIGN
|
|
#define KCRC_ALIGN 4
|
|
#endif
|
|
|
|
.macro __put, val, name
|
|
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
|
|
.long \val - ., \name - .
|
|
#elif defined(CONFIG_64BIT)
|
|
.quad \val, \name
|
|
#else
|
|
.long \val, \name
|
|
#endif
|
|
.endm
|
|
|
|
/*
|
|
* note on .section use: @progbits vs %progbits nastiness doesn't matter,
|
|
* since we immediately emit into those sections anyway.
|
|
*/
|
|
.macro ___EXPORT_SYMBOL name,val,sec
|
|
#ifdef CONFIG_MODULES
|
|
.globl __ksymtab_\name
|
|
.section ___ksymtab\sec+\name,"a"
|
|
.balign KSYM_ALIGN
|
|
__ksymtab_\name:
|
|
__put \val, __kstrtab_\name
|
|
.previous
|
|
.section __ksymtab_strings,"a"
|
|
__kstrtab_\name:
|
|
.asciz "\name"
|
|
.previous
|
|
#ifdef CONFIG_MODVERSIONS
|
|
.section ___kcrctab\sec+\name,"a"
|
|
.balign KCRC_ALIGN
|
|
__kcrctab_\name:
|
|
#if defined(CONFIG_MODULE_REL_CRCS)
|
|
.long __crc_\name - .
|
|
#else
|
|
.long __crc_\name
|
|
#endif
|
|
.weak __crc_\name
|
|
.previous
|
|
#endif
|
|
#endif
|
|
.endm
|
|
#undef __put
|
|
|
|
#if defined(CONFIG_TRIM_UNUSED_KSYMS)
|
|
|
|
#include <linux/kconfig.h>
|
|
#include <generated/autoksyms.h>
|
|
|
|
.macro __ksym_marker sym
|
|
.section ".discard.ksym","a"
|
|
__ksym_marker_\sym:
|
|
.previous
|
|
.endm
|
|
|
|
#define __EXPORT_SYMBOL(sym, val, sec) \
|
|
__ksym_marker sym; \
|
|
__cond_export_sym(sym, val, sec, __is_defined(__KSYM_##sym))
|
|
#define __cond_export_sym(sym, val, sec, conf) \
|
|
___cond_export_sym(sym, val, sec, conf)
|
|
#define ___cond_export_sym(sym, val, sec, enabled) \
|
|
__cond_export_sym_##enabled(sym, val, sec)
|
|
#define __cond_export_sym_1(sym, val, sec) ___EXPORT_SYMBOL sym, val, sec
|
|
#define __cond_export_sym_0(sym, val, sec) /* nothing */
|
|
|
|
#else
|
|
#define __EXPORT_SYMBOL(sym, val, sec) ___EXPORT_SYMBOL sym, val, sec
|
|
#endif
|
|
|
|
#define EXPORT_SYMBOL(name) \
|
|
__EXPORT_SYMBOL(name, KSYM_FUNC(name),)
|
|
#define EXPORT_SYMBOL_GPL(name) \
|
|
__EXPORT_SYMBOL(name, KSYM_FUNC(name), _gpl)
|
|
#define EXPORT_DATA_SYMBOL(name) \
|
|
__EXPORT_SYMBOL(name, name,)
|
|
#define EXPORT_DATA_SYMBOL_GPL(name) \
|
|
__EXPORT_SYMBOL(name, name,_gpl)
|
|
|
|
#endif
|