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| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-03-16 16:37:12 +0900 |
|---|---|---|
| committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-03-26 02:01:22 +0900 |
| commit | 07a422bb213adb7ee1afbb2347ce6922c60a558a (patch) | |
| tree | cdc621b641d4afba9b79316c28286324f676f204 /Makefile | |
| parent | d8821622c889d9dbc1a31b16e726717394954596 (diff) | |
| download | lwn-07a422bb213adb7ee1afbb2347ce6922c60a558a.tar.gz lwn-07a422bb213adb7ee1afbb2347ce6922c60a558a.zip | |
kbuild: restore autoksyms.h touch to the top Makefile
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:
$(vmlinux-dirs): prepare scripts
Because there is no dependency between 'prepare' and 'scripts', the
parallel building can execute them simultaneously.
'prepare' depends on 'prepare1', which touched autoksyms.h, while
'scripts' descends into script/, then scripts/mod/, which needs
<generated/autoksyms.h> if CONFIG_TRIM_UNUSED_KSYMS. It was the
reason of the race.
I am not happy to have unrelated code in the Kconfig Makefile, so
getting it back to the top Makefile.
I removed the standalone test target because I want to use it to
create an empty autoksyms.h file. Here is a little improvement;
unnecessary autoksyms.h is not created when CONFIG_TRIM_UNUSED_KSYMS
is disabled.
[1] https://lkml.org/lkml/2016/11/30/734
[2] https://lkml.org/lkml/2016/11/30/531
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 12 |
1 files changed, 7 insertions, 5 deletions
@@ -1019,9 +1019,11 @@ ifdef CONFIG_TRIM_UNUSED_KSYMS "$(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) @@ -1065,7 +1067,7 @@ 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 @@ -1095,7 +1097,7 @@ 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) |