From 0a16d2e8cb7e6310debc208d42ff725361ae1911 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 20 Jul 2018 16:46:32 +0900 Subject: kbuild: use 'include' directive to load auto.conf from top Makefile When you build targets that require the kernel configuration, dot-config is set to 1, then the top-level Makefile includes auto.conf. However, Make considers its inclusion is optional because the '-include' directive is used here. If a necessary configuration file is missing for the external module building, the following error message is displayed: ERROR: Kernel configuration is invalid. include/generated/autoconf.h or include/config/auto.conf are missing. Run 'make oldconfig && make prepare' on kernel src to fix it. However, Make still continues building; /bin/false let the creation of 'include/config/auto.config' fail, but Make can ignore the error since it is included by the '-include' directive. I guess the reason of using '-include' directive was to suppress the warning when you build the kernel from a pristine source tree: Makefile:605: include/config/auto.conf: No such file or directory The previous commit made sure include/config/auto.conf exists after the 'make *config' stage. Now, we can use the 'include' directive without showing the warning. Signed-off-by: Masahiro Yamada --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index a89d8a0d3ee1..6a222e21ca6d 100644 --- a/Makefile +++ b/Makefile @@ -584,7 +584,7 @@ virt-y := virt/ endif # KBUILD_EXTMOD ifeq ($(dot-config),1) --include include/config/auto.conf +include include/config/auto.conf endif # The all: target is the default when no target is given on the -- cgit v1.2.3 From d79424137a7312d381d131d707a462440c0e8df9 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 20 Jul 2018 16:46:34 +0900 Subject: kbuild: do not update config when running install targets "make syncconfig" is automatically invoked when any of the following happens: - .config is updated - any of Kconfig files is updated - any of environment variables referenced in Kconfig is changed Then, it updates configuration files such as include/config/auto.conf include/generated/autoconf.h, etc. Even install targets (install, modules_install, etc.) are no exception. However, they should never ever modify the source tree. Install targets are often run with root privileges. Once those configuration files are owned by root, "make mrproper" would end up with permission error. Install targets should just copy things blindly. They should not care whether the configuration is up-to-date or not. This makes more sense because we are interested in the configuration that was used in the previous kernel building. This issue has existed since before, but rarely happened. I expect more chance where people are hit by this; with the new Kconfig syntax extension, the .config now contains the compiler information. If you cross-compile the kernel with CROSS_COMPILE, but forget to pass it for "make install", you meet "any of environment variables referenced in Kconfig is changed" because $(CC) is referenced in Kconfig. Another scenario is the compiler upgrade before the installation. Install targets need the configuration. "make modules_install" refer to CONFIG_MODULES etc. "make dtbs_install" also needs CONFIG_ARCH_* to decide which dtb files to install. However, the auto-update of the configuration files should be avoided. We already do this for external modules. Now, Make targets are categorized into 3 groups: [1] Do not need the kernel configuration at all help, coccicheck, headers_install etc. [2] Need the latest kernel configuration If new config options are added, Kconfig will show prompt to ask user's selection. Build targets such as vmlinux, in-kernel modules are the cases. [3] Need the kernel configuration, but do not want to update it Install targets except headers_install, and external modules are the cases. Signed-off-by: Masahiro Yamada --- Makefile | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 6a222e21ca6d..8ca9e0b114f1 100644 --- a/Makefile +++ b/Makefile @@ -225,10 +225,12 @@ no-dot-config-targets := $(clean-targets) \ cscope gtags TAGS tags help% %docs check% coccicheck \ $(version_h) headers_% archheaders archscripts \ kernelversion %src-pkg +no-sync-config-targets := $(no-dot-config-targets) install %install -config-targets := 0 -mixed-targets := 0 -dot-config := 1 +config-targets := 0 +mixed-targets := 0 +dot-config := 1 +may-sync-config := 1 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),) ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),) @@ -236,6 +238,16 @@ ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),) endif endif +ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),) + ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),) + may-sync-config := 0 + endif +endif + +ifneq ($(KBUILD_EXTMOD),) + may-sync-config := 0 +endif + ifeq ($(KBUILD_EXTMOD),) ifneq ($(filter config %config,$(MAKECMDGOALS)),) config-targets := 1 @@ -606,7 +618,7 @@ ARCH_CFLAGS := include arch/$(SRCARCH)/Makefile ifeq ($(dot-config),1) -ifeq ($(KBUILD_EXTMOD),) +ifeq ($(may-sync-config),1) # Read in dependencies to all Kconfig* files, make sure to run syncconfig if # changes are detected. This should be included after arch/$(SRCARCH)/Makefile # because some architectures define CROSS_COMPILE there. @@ -621,8 +633,9 @@ $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ; include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig else -# external modules needs include/generated/autoconf.h and include/config/auto.conf -# but do not care if they are up-to-date. Use auto.conf to trigger the test +# External modules and some install targets need include/generated/autoconf.h +# and include/config/auto.conf but do not care if they are up-to-date. +# Use auto.conf to trigger the test PHONY += include/config/auto.conf include/config/auto.conf: @@ -634,7 +647,7 @@ include/config/auto.conf: echo >&2 ; \ /bin/false) -endif # KBUILD_EXTMOD +endif # may-sync-config else # Dummy target needed, because used as prerequisite -- cgit v1.2.3 From a29d4d8c5669a658b5a091b38205c13084967ce7 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 20 Jul 2018 16:46:35 +0900 Subject: kbuild: do not update config for 'make kernelrelease' 'make kernelrelease' depends on CONFIG_LOCALVERSION(_AUTO), but for the same reason as install targets, we do not want to update the configuration just for printing the kernelrelease string. This is likely to happen when you compiled the kernel with CROSS_COMPILE, but forget to pass it to 'make kernelrelease'. Signed-off-by: Masahiro Yamada --- Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 8ca9e0b114f1..060874d85e0d 100644 --- a/Makefile +++ b/Makefile @@ -225,7 +225,8 @@ no-dot-config-targets := $(clean-targets) \ cscope gtags TAGS tags help% %docs check% coccicheck \ $(version_h) headers_% archheaders archscripts \ kernelversion %src-pkg -no-sync-config-targets := $(no-dot-config-targets) install %install +no-sync-config-targets := $(no-dot-config-targets) install %install \ + kernelrelease config-targets := 0 mixed-targets := 0 -- cgit v1.2.3 From 2063945fdc3d4c0ac8f9319d942eda720d02aabe Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 20 Jul 2018 16:46:36 +0900 Subject: kbuild: remove auto.conf from prerequisite of phony targets The top-level Makefile adds include/config/auto.conf as prerequisites of 'scripts', 'prepare1', etc. They were needed to terminate the build when include/config/auto.conf is missing. Now that the inclusion of include/config/auto.conf is mandatory in the top-level Makefile if dot-config is 1 (Note 'include' directive is used instead of '-include'). Make terminates the build by itself if it fails to create or update include/config/auto.conf so we are sure that include/config/auto.conf exists in the very first stage of make. I am still keeping include/config/auto.conf as the prerequisite of %/modules.builtin because modules.builtin is a real file. According to commit a6c366324cac ("kbuild: Do not unnecessarily regenerate modules.builtin"), it is intentional to compare time-stamps between %/modules.builtin and include/config/auto.conf . I moved tristate.conf here because it is only included from scripts/Makefile.modbuiltin. Signed-off-by: Masahiro Yamada --- Makefile | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 060874d85e0d..f17dd994e01d 100644 --- a/Makefile +++ b/Makefile @@ -649,10 +649,6 @@ include/config/auto.conf: /bin/false) endif # may-sync-config - -else -# Dummy target needed, because used as prerequisite -include/config/auto.conf: ; endif # $(dot-config) KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,) @@ -1047,15 +1043,14 @@ define filechk_kernel.release endef # Store (new) KERNELRELEASE string in include/config/kernel.release -include/config/kernel.release: include/config/auto.conf FORCE +include/config/kernel.release: $(srctree)/Makefile FORCE $(call filechk,kernel.release) # Additional helpers built in scripts/ # Carefully list dependencies so we do not try to build scripts twice # in parallel PHONY += scripts -scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \ - asm-generic gcc-plugins $(autoksyms_h) +scripts: scripts_basic asm-generic gcc-plugins $(autoksyms_h) $(Q)$(MAKE) $(build)=$(@) # Things we need to do before we recursively start building the kernel @@ -1085,8 +1080,7 @@ endif # that need to depend on updated CONFIG_* values can be checked here. prepare2: prepare3 outputmakefile asm-generic -prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h \ - include/config/auto.conf +prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h $(cmd_crmodverdir) archprepare: archheaders archscripts prepare1 scripts_basic @@ -1224,7 +1218,7 @@ modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin modules.builtin: $(vmlinux-dirs:%=%/modules.builtin) $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin -%/modules.builtin: include/config/auto.conf +%/modules.builtin: include/config/auto.conf include/config/tristate.conf $(Q)$(MAKE) $(modbuiltin)=$* -- cgit v1.2.3