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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 /scripts/link-vmlinux.sh | |
| parent | modpost: extract symbol versions from *.cmd files (diff) | |
| download | linux-dev-7b4537199a4a8480b8c3ba37a2d44765ce76cd9b.tar.xz linux-dev-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 $(LD) to update the CRCs in
objects, but this step is unneeded too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
Diffstat (limited to 'scripts/link-vmlinux.sh')
| -rwxr-xr-x | scripts/link-vmlinux.sh | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index eceb3ee7ec06..db34dc3163ae 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -90,7 +90,6 @@ modpost_link() if is_enabled CONFIG_MODVERSIONS; then gen_symversions - lds="${lds} -T .tmp_symversions.lds" fi # This might take a while, so indicate that we're doing @@ -183,6 +182,10 @@ vmlinux_link() libs="${KBUILD_VMLINUX_LIBS}" fi + if is_enabled CONFIG_MODULES; then + objs="${objs} .vmlinux.export.o" + fi + if [ "${SRCARCH}" = "um" ]; then wl=-Wl, ld="${CC}" @@ -312,6 +315,7 @@ cleanup() rm -f vmlinux.o rm -f .vmlinux.d rm -f .vmlinux.objs + rm -f .vmlinux.export.c } # Use "make V=1" to debug this script @@ -363,6 +367,10 @@ info GEN modules.builtin tr '\0' '\n' < modules.builtin.modinfo | sed -n 's/^[[:alnum:]:_]*\.file=//p' | tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$/.ko/' > modules.builtin +if is_enabled CONFIG_MODULES; then + ${MAKE} -f "${srctree}/scripts/Makefile.vmlinux" .vmlinux.export.o +fi + btf_vmlinux_bin_o="" if is_enabled CONFIG_DEBUG_INFO_BTF; then btf_vmlinux_bin_o=.btf.vmlinux.bin.o |