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bbda5ec671
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
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#define __ASM_GENERIC_EXPORT_H
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#ifndef KSYM_FUNC
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#define KSYM_FUNC(x) x
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#endif
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#ifdef CONFIG_64BIT
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#ifndef KSYM_ALIGN
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#define KSYM_ALIGN 8
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#endif
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#else
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#ifndef KSYM_ALIGN
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#define KSYM_ALIGN 4
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#endif
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#endif
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#ifndef KCRC_ALIGN
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#define KCRC_ALIGN 4
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#endif
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.macro __put, val, name
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#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
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.long \val - ., \name - .
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#elif defined(CONFIG_64BIT)
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.quad \val, \name
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#else
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.long \val, \name
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#endif
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.endm
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/*
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* note on .section use: @progbits vs %progbits nastiness doesn't matter,
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* since we immediately emit into those sections anyway.
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*/
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.macro ___EXPORT_SYMBOL name,val,sec
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#ifdef CONFIG_MODULES
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.globl __ksymtab_\name
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.section ___ksymtab\sec+\name,"a"
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.balign KSYM_ALIGN
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__ksymtab_\name:
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__put \val, __kstrtab_\name
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.previous
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.section __ksymtab_strings,"a"
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__kstrtab_\name:
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.asciz "\name"
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.previous
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#ifdef CONFIG_MODVERSIONS
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.section ___kcrctab\sec+\name,"a"
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.balign KCRC_ALIGN
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__kcrctab_\name:
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#if defined(CONFIG_MODULE_REL_CRCS)
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.long __crc_\name - .
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#else
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.long __crc_\name
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#endif
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.weak __crc_\name
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.previous
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#endif
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#endif
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.endm
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#undef __put
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#if defined(CONFIG_TRIM_UNUSED_KSYMS)
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#include <linux/kconfig.h>
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#include <generated/autoksyms.h>
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.macro __ksym_marker sym
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.section ".discard.ksym","a"
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__ksym_marker_\sym:
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.previous
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.endm
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#define __EXPORT_SYMBOL(sym, val, sec) \
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__ksym_marker sym; \
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__cond_export_sym(sym, val, sec, __is_defined(__KSYM_##sym))
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#define __cond_export_sym(sym, val, sec, conf) \
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___cond_export_sym(sym, val, sec, conf)
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#define ___cond_export_sym(sym, val, sec, enabled) \
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__cond_export_sym_##enabled(sym, val, sec)
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#define __cond_export_sym_1(sym, val, sec) ___EXPORT_SYMBOL sym, val, sec
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#define __cond_export_sym_0(sym, val, sec) /* nothing */
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#else
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#define __EXPORT_SYMBOL(sym, val, sec) ___EXPORT_SYMBOL sym, val, sec
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#endif
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#define EXPORT_SYMBOL(name) \
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__EXPORT_SYMBOL(name, KSYM_FUNC(name),)
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#define EXPORT_SYMBOL_GPL(name) \
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__EXPORT_SYMBOL(name, KSYM_FUNC(name), _gpl)
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#define EXPORT_DATA_SYMBOL(name) \
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__EXPORT_SYMBOL(name, name,)
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#define EXPORT_DATA_SYMBOL_GPL(name) \
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__EXPORT_SYMBOL(name, name,_gpl)
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#endif
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