Re: [PATCH 1/3] kbuild: add -fno-PIE

From: Ingo Molnar
Date: Wed Nov 09 2016 - 01:10:51 EST



* Michal Marek <mmarek@xxxxxxxx> wrote:

> On Fri, Nov 04, 2016 at 07:39:38PM +0100, Sebastian Andrzej Siewior wrote:
> > Debian started to build the gcc with -fPIE by default so the kernel
> > build ends before it starts properly with:
> > |kernel/bounds.c:1:0: error: code model kernel does not support PIC mode
> >
> > Also add to KBUILD_AFLAGS due to:
> >
> > |gcc -Wp,-MD,arch/x86/entry/vdso/vdso32/.note.o.d â -mfentry -DCC_USING_FENTRY â vdso/vdso32/note.S
> > |arch/x86/entry/vdso/vdso32/note.S:1:0: sorry, unimplemented: -mfentry isnât supported for 32-bit in combination with -fpic
> >
> > Tagging it stable so it is possible to compile recent stable kernels as
> > well.
> >
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> > ---
> > Makefile | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/Makefile b/Makefile
> > index a2650f9c6a25..d61145ebf498 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -622,6 +622,8 @@ include arch/$(SRCARCH)/Makefile
> > KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
> > KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
> > KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
> > +KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
> > +KBUILD_AFLAGS += $(call cc-option,-fno-PIE)
>
> Bad compiler. No pie for you.
>
> I applied this one to kbuild.git. How about 2/3 and 3/3. Will these be
> merged via tip.git or shall I apply them as well?

I'd suggest applying them to the kbuild tree, as they are related.

Thanks,

Ingo