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| author | Masahiro Yamada <masahiroy@kernel.org> | 2022-05-13 20:39:22 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2022-05-24 16:33:20 +0900 |
| commit | 7b4537199a4a8480b8c3ba37a2d44765ce76cd9b (patch) | |
| tree | 0690afa62208ca15fd36069afcbdac85908d0676 /init | |
| parent | f292d875d0dc700b3af0bef04c5abc1dc7b3b62c (diff) | |
| download | lwn-7b4537199a4a8480b8c3ba37a2d44765ce76cd9b.tar.gz lwn-7b4537199a4a8480b8c3ba37a2d44765ce76cd9b.zip | |
kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS
include/{linux,asm-generic}/export.h defines a weak symbol, __crc_*
as a placeholder.
Genksyms writes the version CRCs into the linker script, which will be
used for filling the __crc_* symbols. The linker script format depends
on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset
to the reference of CRC.
It is time to get rid of this complexity.
Now that modpost parses text files (.*.cmd) to collect all the CRCs,
it can generate C code that will be linked to the vmlinux or modules.
Generate a new C file, .vmlinux.export.c, which contains the CRCs of
symbols exported by vmlinux. It is compiled and linked to vmlinux in
scripts/link-vmlinux.sh.
Put the CRCs of symbols exported by modules into the existing *.mod.c
files. No additional build step is needed for modules. As before,
*.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal.
No linker magic is used here. The new C implementation works in the
same way, whether CONFIG_RELOCATABLE is enabled or not.
CONFIG_MODULE_REL_CRCS is no longer needed.
Previously, Kbuild invoked additional $(LD) to update the CRCs in
objects, but this step is unneeded too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/init/Kconfig b/init/Kconfig index ddcbefe535e9..f5b14318dfcb 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2136,10 +2136,6 @@ config ASM_MODVERSIONS assembly. This can be enabled only when the target architecture supports it. -config MODULE_REL_CRCS - bool - depends on MODVERSIONS - config MODULE_SRCVERSION_ALL bool "Source checksum for all modules" help |