On Wed, Aug 12, 2015 at 04:24:49PM -0500, Chris J Arges wrote: > <snip> > > > > Thanks for trying it out. I couldn't figure out how to recreate this > > exact error, but I played around with "make mrproper" and saw some > > probably related errors. Does this fix it? > > > > ---8<--- > > > > Subject: [PATCH] stackvalidate: fix circular build dependencies > > > > After "make mrproper" with CONFIG_STACK_VALIDATION enabled, I get the > > following errors: > > > > make[2]: *** No rule to make target 'arch/x86/purgatory/purgatory.o', needed by 'arch/x86/purgatory/purgatory.ro'. Stop. > > make[3]: *** No rule to make target 'scripts/mod/empty.o', needed by 'scripts/mod/elfconfig.h'. Stop. > > > > These are caused by circular dependencies. The %.o pattern rules in > > scripts/Makefile.build have the stackvalidate binary listed as a > > dependency. But stackvalidate gets built *after* archprepare and > > scripts/mod, both of which build objects using the %.o pattern rules. > > > > The STACKVALIDATE and STACKVALIDATE_foo.o variables are already used to > > determine whether to validate a given object. Also use them to > > determine whether to create the pattern rule dependency. > > > > Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> > > --- > > scripts/Makefile.build | 7 +++++-- > > scripts/mod/Makefile | 2 ++ > > 2 files changed, 7 insertions(+), 2 deletions(-) > > > > diff --git a/scripts/Makefile.build b/scripts/Makefile.build > > index a1270d3..ec96c51 100644 > > --- a/scripts/Makefile.build > > +++ b/scripts/Makefile.build > > @@ -243,7 +243,7 @@ endif > > > > ifdef CONFIG_STACK_VALIDATION > > > > -stackvalidate = $(objtree)/scripts/stackvalidate/stackvalidate > > +__stackvalidate = $(objtree)/scripts/stackvalidate/stackvalidate > > > > ifndef CONFIG_FRAME_POINTER > > nofp = --no-frame-pointer > > @@ -251,9 +251,12 @@ endif > > > > # Set STACKVALIDATE_foo.o=n to skip stack validation for a file. > > # Set STACKVALIDATE=n to skip stack validation for a directory. > > +stackvalidate = $(if $(patsubst n%,, \ > > + $(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \ > > + $(__stackvalidate)) > > cmd_stackvalidate = $(if $(patsubst n%,, \ > > $(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \ > > - $(stackvalidate) $(nofp) "$(@)";) > > + $(__stackvalidate) $(nofp) "$(@)";) > > > > endif # CONFIG_STACK_VALIDATION > > > > diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile > > index c11212f..374c413 100644 > > --- a/scripts/mod/Makefile > > +++ b/scripts/mod/Makefile > > @@ -1,3 +1,5 @@ > > +STACKVALIDATE := n > > + > > hostprogs-y := modpost mk_elfconfig > > always := $(hostprogs-y) empty.o > > > > > > Josh, > > I still get build failures and I've pared it down to x86_64 defconfig plus: > CONFIG_MODVERSIONS=y > CONFIG_STACK_VALIDATION=y Are you still seeing the same error as before? I think the errors you saw were caused by stackvalidate choking on scripts/mod/empty.o. But I don't see how that's still possible with the above patch since I set STACKVALIDATE to 'n' in scripts/mod/Makefile which should tell it to skip the directory. > And it seems like some modules may get the .tmp_foo.o treatment while > others end up foo.o so something like the following will not work: > > cmd_stackvalidate = $(if $(patsubst n%,, \ > $(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \ > $(__stackvalidate) $(nofp) "$(@D)/.tmp_$(@F)";) > > In addition, I'm not sure if skipping modules like STACKVALIDATE_foo.o=n > will still function properly for modversioned modules. I'm not sure that's really a problem, since I don't think we'll need to skip validation of any module code. It's only used for skipping code which runs outside of the kernel's normal operation (e.g., boot, vdso, kexec). -- Josh -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
