From 07a422bb213adb7ee1afbb2347ce6922c60a558a Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 16 Mar 2018 16:37:12 +0900 Subject: 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: $(vmlinux-dirs): prepare scripts Because there is no dependency between 'prepare' and 'scripts', the parallel building can execute them simultaneously. 'prepare' depends on 'prepare1', which touched autoksyms.h, while 'scripts' descends into script/, then scripts/mod/, which needs if CONFIG_TRIM_UNUSED_KSYMS. It was the reason of the race. I am not happy to have unrelated code in the Kconfig Makefile, so getting it back to the top Makefile. I removed the standalone test target because I want to use it to create an empty autoksyms.h file. Here is a little improvement; unnecessary autoksyms.h is not created when CONFIG_TRIM_UNUSED_KSYMS is disabled. [1] https://lkml.org/lkml/2016/11/30/734 [2] https://lkml.org/lkml/2016/11/30/531 Signed-off-by: Masahiro Yamada Acked-by: Nicolas Pitre --- Makefile | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 5aa07da..b65cfe3 100644 --- a/Makefile +++ b/Makefile @@ -1019,9 +1019,11 @@ ifdef CONFIG_TRIM_UNUSED_KSYMS "$(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) -- cgit v1.1