Hi Masahiro, On 9 October 2017 at 18:25, Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> wrote: > 2017-10-02 19:50 GMT+09:00 Jonas Gorski <jonas.gorski@xxxxxxxxx>: >> By passing appropriate values in KBUILD_EXTRA_SYMBOLS it is possible to >> make modpost be able to resolve all symbols for external modules, even >> between to other external modules. >> >> Because of this, it might be desirable to make unresolved symbols an >> error on external module builds as well, to catch missing exports there >> as well. >> >> So add a new flag KBUILD_MODPOST_ERROR which can be set to enable this >> behaviour. It has no effect on non external module builds. >> >> Signed-off-by: Jonas Gorski <jonas.gorski@xxxxxxxxx> >> --- >> The main target is to allow distributions (like LEDE) that make use of >> kernel backports and other out of tree drivers to be able to catch >> errors like missing EXPORT_SYMBOLs in the kernel early. >> >> scripts/Makefile.modpost | 6 +++++- >> 1 file changed, 5 insertions(+), 1 deletion(-) >> >> diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost >> index 16923ba4b5b1..29f787bf8c3a 100644 >> --- a/scripts/Makefile.modpost >> +++ b/scripts/Makefile.modpost >> @@ -34,6 +34,8 @@ >> >> # KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined >> # symbols in the final module linking stage >> +# KBUILD_MODPOST_ERROR can be set to error out in case of undefined >> +# symbols in the final module linking stage for external modules >> # KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. >> # This is solely useful to speed up test compiles >> PHONY := _modpost >> @@ -49,6 +51,8 @@ ifneq ($(KBUILD_EXTMOD),) >> obj := $(KBUILD_EXTMOD) >> src := $(obj) >> >> +KBUILD_MODPOST_WARN = $(if $(KBUILD_MODPOST_ERROR),,1) >> + >> # Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS >> include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ >> $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) >> @@ -78,7 +82,7 @@ modpost = scripts/mod/modpost \ >> $(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \ >> $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S) \ >> $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ >> - $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) >> + $(if $(KBUILD_MODPOST_WARN),-w) >> >> MODPOST_OPT=$(subst -i,-n,$(filter -i,$(MAKEFLAGS))) >> > > > The motivation looks reasonable to me, > but having both KBUILD_MODPOST_WARN and KBUILD_MODPOST_ERROR > is a bit confusing, I think. > > (Some people may wonder what would happen if both are set...) > > > So, here is my suggestion. > > > We have only KBUILD_MODPOST_WARN. > > The default value is 1 for external module building. > 0 for kernel building. > > > If you want to change the default behavior, > you can specify KBUILD_MODPOST_WARN=1 when building kernel, > or KBUILD_MODPOST_WARN=0 when building external module > from the command line. Makes sense, I was thinking too complicated. > > Also, you need to update Documentation/kbuild/kbuild.txt Indeed, I missed that. Will fix in v2. Regards Jonas -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
