On Fri, Dec 29, 2017 at 01:18:30PM -0500, Paul Gortmaker wrote: > [Re: [Regression 4.15] Can't kill CONFIG_UNWINDER_ORC with fire or plague.] > On 29/12/2017 (Fri 10:47) Josh Poimboeuf wrote: > > > This seems to be related to a kconfig quirk where only silentoldconfig > > updates the include/config/auto.conf file. The other config targets > > (oldconfig, defconfig, etc) don't touch it. It seems intentional, but I > > have no idea why. > > > > That causes the Makefile to get stale data for 'CONFIG_*' variables when > > it includes auto.conf. So I don't think this is specific to the ORC > > check. It seems like it could also cause bugs elsewhere. > > OK, good - you agree with my initial diagnosis of stale auto.conf then. > Not sure what Randy was testing when he said he couldn't reproduce it. >
FWIW just to add another data point, I tripped over this repeatedly during a recent bisect of v4.14..v4.15-rc4. My ad-hoc solution was to just delete the stale auto.conf and reconfigure, IIRC. It was pretty annoying at the time, and I assumed everyone would be tripping over it so didn't bother making noise on lkml. Looks like I was mistaken... Cheers, Vito Caputo > > The below (ugly) patch fixes it, though I'm not sure this is the best > > way to do it. We probably need Masahiro or Michal to chime in here. > > Yep, that is why I intentionally put the kbuild folks on the To/Cc of > the original report (and ran away screaming at the prospect of debugging > Makefiles on xmas day). But with holidays and all, it might not be > until early January before they have a chance to reply. > > Paul. > -- > > > > > diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile > > index 297c1bf35140..3a0d92040a9c 100644 > > --- a/scripts/kconfig/Makefile > > +++ b/scripts/kconfig/Makefile > > @@ -21,18 +21,23 @@ unexport CONFIG_ > > > > xconfig: $(obj)/qconf > > $< $(silent) $(Kconfig) > > + $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig > > > > gconfig: $(obj)/gconf > > $< $(silent) $(Kconfig) > > + $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig > > > > menuconfig: $(obj)/mconf > > $< $(silent) $(Kconfig) > > + $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig > > > > config: $(obj)/conf > > $< $(silent) --oldaskconfig $(Kconfig) > > + $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig > > > > nconfig: $(obj)/nconf > > $< $(silent) $(Kconfig) > > + $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig > > > > silentoldconfig: $(obj)/conf > > $(Q)mkdir -p include/config include/generated > > @@ -85,6 +90,7 @@ PHONY += $(simple-targets) > > > > $(simple-targets): $(obj)/conf > > $< $(silent) --$@ $(Kconfig) > > + $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig > > > > PHONY += oldnoconfig savedefconfig defconfig > > > > @@ -108,9 +114,11 @@ else > > $(Q)$(MAKE) -f $(srctree)/Makefile $(KBUILD_DEFCONFIG) > > endif > > endif > > + $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig > > > > %_defconfig: $(obj)/conf > > $(Q)$< $(silent) --defconfig=arch/$(SRCARCH)/configs/$@ $(Kconfig) > > + $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig > > > > configfiles=$(wildcard $(srctree)/kernel/configs/$@ > > $(srctree)/arch/$(SRCARCH)/configs/$@) > > > > @@ -118,6 +126,7 @@ configfiles=$(wildcard $(srctree)/kernel/configs/$@ > > $(srctree)/arch/$(SRCARCH)/c > > $(if $(call configfiles),, $(error No configuration exists for this > > target on this architecture)) > > $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh -m > > .config $(configfiles) > > +$(Q)yes "" | $(MAKE) -f $(srctree)/Makefile oldconfig > > + $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig > > > > PHONY += kvmconfig > > kvmconfig: kvm_guest.config > > @@ -130,6 +139,7 @@ xenconfig: xen.config > > PHONY += tinyconfig > > tinyconfig: > > $(Q)$(MAKE) -f $(srctree)/Makefile allnoconfig tiny.config > > + $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig > > > > # Help text used by make help > > help:
