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Message-ID: <7cad6e78014168a8906e130e1cf3809077d2bda7.camel@xry111.site>
Subject: Re: [PATCH v4 0/4] LoongArch: Support new relocation types
From:   Xi Ruoyao <xry111@xry111.site>
To:     Youling Tang <tangyouling@loongson.cn>, loongarch@lists.linux.dev
Cc:     linux-kernel@vger.kernel.org, WANG Xuerui <kernel@xen0n.name>,
        Huacai Chen <chenhuacai@kernel.org>,
        Jinyang He <hejinyang@loongson.cn>,
        Lulu Cheng <chenglulu@loongson.cn>
Date:   Sat, 30 Jul 2022 01:55:29 +0800
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On Fri, 2022-07-29 at 20:19 +0800, Youling Tang wrote:

> On 07/29/2022 07:45 PM, Xi Ruoyao wrote:
> > Hmm... The problem is the "addresses" of per-cpu symbols are faked: the=
y
> > are actually offsets from $r21.=C2=A0 So we can't just load such an off=
set
> > with PCALA addressing.
> >=20
> > It looks like we'll need to introduce an attribute for GCC to make an
> > variable "must be addressed via GOT", and add the attribute into
> > PER_CPU_ATTRIBUTES.

> Yes, we need a GCC attribute to specify the per-cpu variable.

GCC patch adding "addr_global" attribute for LoongArch:
https://gcc.gnu.org/pipermail/gcc-patches/2022-July/599064.html

An experiment to use it:
https://github.com/xry111/linux/commit/c1d5d70

This fixes "modprobe x_tables" for me.
--=20
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University