RE: [PATCH] ARM: fix linker call for ARM_MODULE_PLTS
From: Wiebe, Wladislav (Nokia - DE/Ulm)
Date: Fri Sep 02 2016 - 12:36:46 EST
> From: Russell King - ARM Linux [mailto:linux@xxxxxxxxxxxxxxx]
> Sent: Friday, September 02, 2016 11:25 AM
>
> On Fri, Sep 02, 2016 at 09:17:58AM +0000, Wiebe, Wladislav (Nokia - DE/Ulm)
> wrote:
> > module.lds script doesn't get called when
> > CONFIG_ARM_MODULE_PLTS is enabled.
> > Use KBUILD_LDFLAGS_MODULE to fix it.
>
> For those of us who haven't encountered this problem, could you include
> some commentry in the commit message describing the failure mechanism
> and why you think this is the correct solution?
>
> The final link for modules is:
>
> quiet_cmd_ld_ko_o = LD [M] $@
> cmd_ld_ko_o = $(LD) -r $(LDFLAGS) \
> $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
> -o $@ $(filter-out FORCE,$^)
>
> which seems to always include both flags. Why is it ignored when it's
> in LDFLAGS_MODULE? What about the other flags we pass in
> LDFLAGS_MODULE?
aah -- just found an issue in my environment where LDFLAGS_MODULE gets overwritten
due to a none upstream patch on scripts/Makefile.modpost.
It worked only for me when using the KBUILD_LDFLAGS_MODULE
and I did not get deep inside after I saw in
https://www.kernel.org/doc/Documentation/kbuild/makefiles.txt
+++++
KBUILD_LDFLAGS_MODULE Options for $(LD) when linking modules
$(KBUILD_LDFLAGS_MODULE) is used to add arch-specific options
used when linking modules. This is often a linker script.
From commandline LDFLAGS_MODULE shall be used (see kbuild.txt).
+++++
and found that all other architectures are also users of KBUILD_LDFLAGS_MODULE for that purpose
$ git grep LDFLAGS_MODULE arch/
arch/arm/Makefile:LDFLAGS_MODULE += --be8
arch/arm/Makefile:LDFLAGS_MODULE += -T $(srctree)/arch/arm/kernel/module.lds
arch/arm64/Makefile:KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/arm64/kernel/module.lds
arch/hexagon/Makefile:# LDFLAGS_MODULE += -shared
arch/ia64/Makefile:KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/ia64/module.lds
arch/m68k/Makefile:KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/m68k/kernel/module.lds
arch/powerpc/Makefile:KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
arch/powerpc/Makefile: KBUILD_LDFLAGS_MODULE += --ppc476-workaround \
Anyway, feel free to ignore this patch and thanks a lot for the fast feedback.
>
> Thanks.
>
> >
> > Signed-off-by: Wladislav Wiebe <wladislav.wiebe@xxxxxxxxx>
> > ---
> > arch/arm/Makefile | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> > index 61f6ccc..01c6025 100644
> > --- a/arch/arm/Makefile
> > +++ b/arch/arm/Makefile
> > @@ -20,7 +20,7 @@ LDFLAGS_MODULE += --be8
> > endif
> >
> > ifeq ($(CONFIG_ARM_MODULE_PLTS),y)
> > -LDFLAGS_MODULE += -T $(srctree)/arch/arm/kernel/module.lds
> > +KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/arm/kernel/module.lds
> > endif
> >
> > OBJCOPYFLAGS :=-O binary -R .comment -S
> > --
> > 1.7.12.4
>
> --
> RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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