[PATCH v3 1/8] kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o

Masahiro Yamada
2022-09-28T06:42:51Z

Do not build modules.builtin(.modinfo) as a side-effect of vmlinux.

There are no good reason to rebuild them just because any of vmlinux's
prerequistes (vmlinux.lds, .vmlinux.export.c, etc.) has been updated.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

Changes in v3:
- Move to the head of the series

Changes in v2:
- New patch

Makefile | 6 +++++-
scripts/Makefile.vmlinux_o | 26 +++++++++++++++++++++++++-
scripts/link-vmlinux.sh | 7 -------
3 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/Makefile b/Makefile
index 2b4980490ecb..83d8ff1d521a 100644
--- a/Makefile
+++ b/Makefile
@@ -1153,9 +1153,13 @@ targets += vmlinux.a
vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
$(call if_changed,ar_vmlinux.a)

-vmlinux.o: autoksyms_recursive vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE
+PHONY += vmlinux_o
+vmlinux_o: autoksyms_recursive vmlinux.a $(KBUILD_VMLINUX_LIBS)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o

+vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
+ @:
+
ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)

# Final link of vmlinux with optional arch pass after final link
diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o
index 68c22879bade..0edfdb40364b 100644
--- a/scripts/Makefile.vmlinux_o
+++ b/scripts/Makefile.vmlinux_o
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only

PHONY := __default
-__default: vmlinux.o
+__default: vmlinux.o modules.builtin.modinfo modules.builtin

include include/config/auto.conf
include $(srctree)/scripts/Kbuild.include
@@ -62,6 +62,30 @@ vmlinux.o: $(initcalls-lds) vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE

targets += vmlinux.o

+# module.builtin.modinfo
+# ---------------------------------------------------------------------------
+
+OBJCOPYFLAGS_modules.builtin.modinfo := -j .modinfo -O binary
+
+targets += modules.builtin.modinfo
+modules.builtin.modinfo: vmlinux.o FORCE
+ $(call if_changed,objcopy)
+
+# module.builtin
+# ---------------------------------------------------------------------------
+
+# The second line aids cases where multiple modules share the same object.
+
+quiet_cmd_modules_builtin = GEN $@
+ cmd_modules_builtin = \
+ tr '\0' '\n' < $< | \
+ sed -n 's/^[[:alnum:]:_]*\.file=//p' | \
+ tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$$/.ko/' > $@
+
+targets += modules.builtin
+modules.builtin: modules.builtin.modinfo FORCE
+ $(call if_changed,modules_builtin)
+
# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 2782c5d1518b..e3d42202e54c 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -214,13 +214,6 @@ if [ "$1" = "clean" ]; then
exit 0
fi

-info MODINFO modules.builtin.modinfo
-${OBJCOPY} -j .modinfo -O binary vmlinux.o modules.builtin.modinfo
-info GEN modules.builtin
-# The second line aids cases where multiple modules share the same object.
-tr '\0' '\n' < modules.builtin.modinfo | sed -n 's/^[[:alnum:]:_]*\.file=//p' |
- tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$/.ko/' > modules.builtin
-
if is_enabled CONFIG_MODULES; then
${MAKE} -f "${srctree}/scripts/Makefile.vmlinux" .vmlinux.export.o
fi
--
2.34.1