Messages in this thread Patch in this message | | | From | Masahiro Yamada <> | Subject | [PATCH v4 4/7] kbuild: restore touching autoksyms.h to the top Makefile | Date | Fri, 16 Mar 2018 16:37:12 +0900 |
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Commit d3fc425e819b ("kbuild: make sure autoksyms.h exists early") moved the code that touches autoksyms.h to scripts/kconfig/Makefile with obscure reason.
From Nicolas' comment [1], he did not seem to be sure about the root cause.
I guess I figured it out, so here is a fix-up I think is more correct. According to the error log in the original post [2], the build failed in scripts/mod/devicetable-offsets.c
scripts/mod/Makefile is descended from scripts/Makefile, which is invoked from the top-level Makefile by the 'scripts' target.
To build vmlinux and/or modules, Kbuild descend into $(vmlinux-dirs). This depends on 'prepare' and 'scripts' as follows:
$(vmlinux-dirs): prepare scripts
Because there is no dependency between 'prepare' and 'scripts', the parallel building can run them simultaneously.
'prepare' depends on 'prepare1', which touched autoksyms.h, whereas 'scripts' descends into script/, then scripts/mod/, which needs <generated/autoksyms.h> if CONFIG_TRIM_UNUSED_KSYMS. It was the reason of the race.
I am not happy to have unrelated code in the Kconfig Makefile, so getting it back to the top Makefile.
I removed the standalone test target because I want to use it to create an empty autoksyms.h file. Here is a little improvement; unnecessary autoksyms.h is not created when CONFIG_TRIM_UNUSED_KSYMS is disabled.
[1] https://lkml.org/lkml/2016/11/30/734 [2] https://lkml.org/lkml/2016/11/30/531
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Nicolas Pitre <nico@linaro.org> ---
Changes in v4: None Changes in v3: None Changes in v2: None
Makefile | 12 +++++++----- scripts/kconfig/Makefile | 2 -- 2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/Makefile b/Makefile index 9bf6697..0a3895c 100644 --- a/Makefile +++ b/Makefile @@ -1021,9 +1021,11 @@ ifdef CONFIG_TRIM_UNUSED_KSYMS "$(MAKE) -f $(srctree)/Makefile vmlinux" endif -# standalone target for easier testing -include/generated/autoksyms.h: FORCE - $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh true +autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h) + +$(autoksyms_h): + $(Q)mkdir -p $(dir $@) + $(Q)touch $@ ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink) @@ -1067,7 +1069,7 @@ include/config/kernel.release: include/config/auto.conf FORCE # in parallel PHONY += scripts scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \ - asm-generic gcc-plugins + asm-generic gcc-plugins $(autoksyms_h) $(Q)$(MAKE) $(build)=$(@) # Things we need to do before we recursively start building the kernel @@ -1097,7 +1099,7 @@ endif # that need to depend on updated CONFIG_* values can be checked here. prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic -prepare1: prepare2 $(version_h) include/generated/utsrelease.h \ +prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h \ include/config/auto.conf $(cmd_crmodverdir) diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile index 78c96aa..f9bdd02 100644 --- a/scripts/kconfig/Makefile +++ b/scripts/kconfig/Makefile @@ -38,8 +38,6 @@ nconfig: $(obj)/nconf # for external use. syncconfig: $(obj)/conf $(Q)mkdir -p include/config include/generated - $(Q)test -e include/generated/autoksyms.h || \ - touch include/generated/autoksyms.h $< $(silent) --$@ $(Kconfig) localyesconfig localmodconfig: $(obj)/conf -- 2.7.4
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