Re: [PATCH V2] LoongArch: Fix module relocation error with binutils 2.41

[Huacai Chen]

Hi, Ruoyao,

On Thu, Aug 10, 2023 at 11:21 AM Xi Ruoyao <xry111@xxxxxxxxxxx> wrote:
>
> On Thu, 2023-08-10 at 11:20 +0800, Xi Ruoyao wrote:
> > Can we backport this patch into stable?  It fixes a build error with
> > binutils >= 2.41.
>
> Correction: not a build error, but all modules won't load if built with
> binutils >= 2.41 without the patch.
Generally we can backport, but I don't think there are users who use
the old kernels. :)

Huacai
>
> > On Mon, 2023-07-10 at 13:00 +0800, Huacai Chen wrote:
> > > Binutils 2.41 enables linker relaxation by default, but the kernel
> > > module loader doesn't support that, so just disable it. Otherwise we
> > > get such an error when loading modules:
> > >
> > > "Unknown relocation type 102"
> > >
> > > As an alternative, we could add linker relaxation support in the kernel
> > > module loader. But it is relatively large complexity that may or may not
> > > bring a similar gain, and we don't really want to include this linker
> > > pass in the kernel.
> > >
> > > Reviewed-by: WANG Xuerui <git@xxxxxxxxxx>
> > > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > > ---
> > >  arch/loongarch/Makefile | 2 ++
> > >  1 file changed, 2 insertions(+)
> > >
> > > diff --git a/arch/loongarch/Makefile b/arch/loongarch/Makefile
> > > index 09ba338a64de..7466d3b15db8 100644
> > > --- a/arch/loongarch/Makefile
> > > +++ b/arch/loongarch/Makefile
> > > @@ -68,6 +68,8 @@ LDFLAGS_vmlinux                       += -static -n -nostdlib
> > >  ifdef CONFIG_AS_HAS_EXPLICIT_RELOCS
> > >  cflags-y                       += $(call cc-option,-mexplicit-relocs)
> > >  KBUILD_CFLAGS_KERNEL           += $(call cc-option,-mdirect-extern-access)
> > > +KBUILD_AFLAGS_MODULE           += $(call cc-option,-mno-relax) $(call cc-option,-Wa$(comma)-mno-relax)
> > > +KBUILD_CFLAGS_MODULE           += $(call cc-option,-mno-relax) $(call cc-option,-Wa$(comma)-mno-relax)
> > >  else
> > >  cflags-y                       += $(call cc-option,-mno-explicit-relocs)
> > >  KBUILD_AFLAGS_KERNEL           += -Wa,-mla-global-with-pcrel
> >
>
> --
> Xi Ruoyao <xry111@xxxxxxxxxxx>
> School of Aerospace Science and Technology, Xidian University