On Fri, Apr 8, 2022 at 6:39 AM David Laight <David.Laight@xxxxxxxxxx> wrote:
>
> From: Nick Desaulniers
> > Sent: 07 April 2022 18:59
> >
> > On Wed, Apr 6, 2022 at 8:31 AM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
> > >
> > > The dependency
> > >
> > > $(obj)/%.mod: $(obj)/%$(mod-prelink-ext).o
> > >
> > > ... exists because *.mod files previously contained undefined symbols,
> > > which are computed from *.o files when CONFIG_TRIM_UNUSED_KSYMS=y.
> > >
> > > Now that the undefined symbols are put into separate *.usyms files,
> > > there is no reason to make *.mod depend on *.o files.
> > >
> > > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> > > ---
> > >
> > > Makefile | 3 ++-
> > > scripts/Makefile.build | 5 ++---
> > > 2 files changed, 4 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/Makefile b/Makefile
> > > index 82ee893909e9..e915aacd02b0 100644
> > > --- a/Makefile
> > > +++ b/Makefile
> > > @@ -1792,7 +1792,8 @@ ifdef single-build
> > >
> > > # .ko is special because modpost is needed
> > > single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
> > > -single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
> > > +single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
> > > + $(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
> >
> > I'm on board with this patch, and the overall goal with the series. My
> > brain is having a hard time parsing `o mod` though. Can you walk me
> > through that? Are those targets for .o and .mod files, respectively?
Yes.
Kbuild can build a module individually.
make foo/bar/baz.ko
(but modpost check does not work well)
To do this, Kbuild needs to descend to
the directory and generate
foo/bar/baz.o and foo/bar/baz.mod.
Previously, foo/bar/baz.o was generated as a
prerequisite of foo/bar/baz.mod, but now we
need to request Kbuild to generate both of them.
> I think I'd do:
> single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS))
> single-no-ko += $(patsubst %.ko, %.o, $(single-ko))
> single-no-ko += $(patsubst %.ko, %.mod, $(single-ko))
>
> Although you can use the simpler SYSV make suffix substitution syntax:
> single-no-ko += $(single-ko:.ko=.o) $(single-ko:.ko=.mod)
Right. I tend to use $(patsubst ), but
in some places, shorter SYSV syntax is used.
I admit inconsistency.
>
> David
>
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)
--
Best Regards
Masahiro Yamada
