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Message-ID: <292e6aa6b9399c8dd53562f51237090bcd6d19c5.camel@xry111.site>
Subject: Re: [PATCH V2] LoongArch: Fix module relocation error with binutils
 2.41
From:   Xi Ruoyao <xry111@xry111.site>
To:     Huacai Chen <chenhuacai@loongson.cn>,
        Arnd Bergmann <arnd@arndb.de>,
        Huacai Chen <chenhuacai@kernel.org>
Cc:     loongarch@lists.linux.dev, linux-arch@vger.kernel.org,
        Xuefeng Li <lixuefeng@loongson.cn>,
        Guo Ren <guoren@kernel.org>, Xuerui Wang <kernel@xen0n.name>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        linux-kernel@vger.kernel.org, loongson-kernel@lists.loongnix.cn,
        WANG Xuerui <git@xen0n.name>, stable@vger.kernel.org
Date:   Thu, 10 Aug 2023 11:21:40 +0800
In-Reply-To: <ce4cee2d76340d1776560c124c1894080ded13bb.camel@xry111.site>
References: <20230710050024.2519893-1-chenhuacai@loongson.cn>
         <ce4cee2d76340d1776560c124c1894080ded13bb.camel@xry111.site>
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On Thu, 2023-08-10 at 11:20 +0800, Xi Ruoyao wrote:
> Can we backport this patch into stable?=C2=A0 It fixes a build error with
> binutils >=3D 2.41.

Correction: not a build error, but all modules won't load if built with
binutils >=3D 2.41 without the patch.

> 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:
> >=20
> > "Unknown relocation type 102"
> >=20
> > As an alternative, we could add linker relaxation support in the kernel
> > module loader. But it is relatively large complexity that may or may no=
t
> > bring a similar gain, and we don't really want to include this linker
> > pass in the kernel.
> >=20
> > Reviewed-by: WANG Xuerui <git@xen0n.name>
> > Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> > ---
> > =C2=A0arch/loongarch/Makefile | 2 ++
> > =C2=A01 file changed, 2 insertions(+)
> >=20
> > 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=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0+=3D -static -n -nostdlib
> > =C2=A0ifdef CONFIG_AS_HAS_EXPLICIT_RELOCS
> > =C2=A0cflags-y=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0+=3D $(call cc-option,-mexplicit-relocs)
> > =C2=A0KBUILD_CFLAGS_KERNEL=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0+=3D $(call cc-option,-mdirect-extern-access)
> > +KBUILD_AFLAGS_MODULE=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0+=3D $(call cc-option,-mno-relax) $(call cc-option,-Wa$(c=
omma)-mno-relax)
> > +KBUILD_CFLAGS_MODULE=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0+=3D $(call cc-option,-mno-relax) $(call cc-option,-Wa$(c=
omma)-mno-relax)
> > =C2=A0else
> > =C2=A0cflags-y=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0+=3D $(call cc-option,-mno-explicit-relocs)
> > =C2=A0KBUILD_AFLAGS_KERNEL=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0+=3D -Wa,-mla-global-with-pcrel
>=20

--=20
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University