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

From: Michal Marek
Date: Tue Nov 08 2016 - 17:14:46 EST


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?

Thanks,
Michal