linux/init
Masahiro Yamada 7b4537199a 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)
2022-05-24 16:33:20 +09:00
..
calibrate.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
do_mounts.c block: remove genhd.h 2022-02-02 07:49:59 -07:00
do_mounts.h init: add an init_mknod helper 2020-07-31 08:17:54 +02:00
do_mounts_initrd.c Merge branch 'hch.init_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 09:40:34 -07:00
do_mounts_rd.c init: add an init_unlink helper 2020-07-31 08:17:52 +02:00
init_task.c kcsan: Remove redundant zero-initialization of globals 2021-12-09 16:42:26 -08:00
initramfs.c memblock: use memblock_free for freeing virtual pointers 2021-11-06 13:30:41 -07:00
Kconfig kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS 2022-05-24 16:33:20 +09:00
main.c Merge branch 'akpm' (patches from Andrew) 2022-03-24 14:14:07 -07:00
Makefile sched/preempt: Tell about PREEMPT_DYNAMIC on kernel headers 2022-03-11 15:36:35 +01:00
noinitramfs.c init: move usermodehelper_enable() to populate_rootfs() 2021-09-08 11:50:27 -07:00
version.c kbuild: add an elfnote for whether vmlinux is built with lto 2021-04-25 05:25:42 +09:00