Re: [PATCH v2 07/12] kbuild: Only run objtool if there is at least one command
From: Nicolas Schier
Date: Mon Mar 30 2026 - 16:27:43 EST
On Wed, Mar 18, 2026 at 05:49:27PM -0700, Josh Poimboeuf wrote:
> On Wed, Mar 18, 2026 at 08:54:31PM +0100, Nicolas Schier wrote:
> > On Tue, Mar 17, 2026 at 03:51:07PM -0700, Josh Poimboeuf wrote:
> > > Split the objtool args into commands and options, such that if no
> > > commands have been enabled, objtool doesn't run.
> > >
> > > This is in preparation in enabling objtool and klp-build for arm64.
> > >
> > > Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> > > Tested-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> > > Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> > > ---
> > > arch/x86/boot/startup/Makefile | 2 +-
> > > scripts/Makefile.build | 4 +--
> > > scripts/Makefile.lib | 46 ++++++++++++++++++----------------
> > > scripts/Makefile.vmlinux_o | 15 ++++-------
> > > 4 files changed, 33 insertions(+), 34 deletions(-)
> > >
> > [...]
> > > diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> > > index 3652b85be545..8a1bdfdb2fdb 100644
> > > --- a/scripts/Makefile.build
> > > +++ b/scripts/Makefile.build
> > > @@ -277,7 +277,7 @@ endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
> > > is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(target-stem).o)$(OBJECT_FILES_NON_STANDARD)n),$(is-kernel-object))
> > >
> > > ifdef CONFIG_OBJTOOL
> > > -$(obj)/%.o: private objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
> > > +$(obj)/%.o: private objtool-enabled = $(if $(is-standard-object),$(if $(objtool-cmds-y),$(if $(delay-objtool),$(is-single-obj-m),y)))
> >
> > Please use $(and a,b,c) instead of multiple nested $(if $(a),$(if
> > $(b),$(c)); as the last variable (is-single-obj-m) is 'y' or empty, the final 'y' can be
> > left-out:
> >
> > $(obj)/%.o: private objtool-enabled = $(and $(is-standard-object),$(objtool-cmds-y),$(delay-objtool),$(is-single-obj-m))
>
> I believe that would break the !delay-objtool case. The logic needs to
> be something like:
>
> if (is-standard-object && objtool-cmds-y) {
> if (delay-objtool) {
> // for delay-objtool, only enable objtool for single-object modules
> $(is-single-obj-m)
> } else {
> // for !delay-objtool, always enable objtool
> y
> }
> }
>
> so maybe something like this?
>
> $(obj)/%.o: private objtool-enabled = $(and $(is-standard-object),$(objtool-cmds-y),$(if $(delay-objtool),$(is-single-obj-m),y))
sorry for the delay! Yes, I overlooked the !delay-objtool. That line
looks good to me, thanks!
--
Nicolas