Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20201009211344.2358688-1-atish.patra@wdc.com> <20201009211344.2358688-5-atish.patra@wdc.com>
 <CAHCEehJvMv=CYD1+QXb0uB36Hv4pvO36BAKSLOcxTXvmADZFbA@mail.gmail.com>
 <CAOnJCUKPjkm_=5eHn6=GjVGr67okZkVzqP7-ciphn986BQoc9w@mail.gmail.com>
 <CAOnJCULZMRu+sHmnjoBwtvaB3BjmCiZLzYxNOeWZmoYLKG+wTw@mail.gmail.com>
 <CAHCEehJJmLQ6W5AdH+hEZSJxpDC8HG0UN=EGt9M0Tp5NTfQnaw@mail.gmail.com>
 <CAOnJCUJN-XMZ+N5w+RbVhJag9D_dey7DAopb0Q35GDfXptyMjA@mail.gmail.com> <CAFyWVaYORWYZTXyXOWiY6xK-SFTvsUxDNDqKQnhVUwzc5N045Q@mail.gmail.com>
In-Reply-To: <CAFyWVaYORWYZTXyXOWiY6xK-SFTvsUxDNDqKQnhVUwzc5N045Q@mail.gmail.com>
From:   Atish Patra <atishp@atishpatra.org>
Date:   Tue, 13 Oct 2020 22:24:49 -0700
Message-ID: <CAOnJCU+3xFyFW4ATCdYAv5zVyBSLE0mTevrJLCXW7HDgy4D4EQ@mail.gmail.com>
Subject: Re: [PATCH 4/5] RISC-V: Protect .init.text & .init.data
To:     Jim Wilson <jimw@sifive.com>
Cc:     Greentime Hu <greentime.hu@sifive.com>,
        Kito Cheng <kito.cheng@gmail.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Atish Patra <atish.patra@wdc.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Kees Cook <keescook@chromium.org>,
        Anup Patel <anup@brainfault.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-riscv <linux-riscv@lists.infradead.org>,
        Guo Ren <guoren@linux.alibaba.com>,
        Zong Li <zong.li@sifive.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Borislav Petkov <bp@suse.de>,
        Michel Lespinasse <walken@google.com>,
        Ard Biesheuvel <ardb@kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Tue, Oct 13, 2020 at 6:21 PM Jim Wilson <jimw@sifive.com> wrote:
>
> On Tue, Oct 13, 2020 at 3:25 PM Atish Patra <atishp@atishpatra.org> wrote:
> > This happens only when copy_from_user is called from function that is
> > annotated with __init.
> > Adding Kito & Jim for their input
> >
> > @kito, @Jim: Please let me know if I should create a issue in
> > riscv-gnu-toolchain repo or somewhere else.
>
> I can't do anything useful without a testcase that I can use to
> reproduce the problem.  The interactions here are complex, so pointing
> at lines of code or kernel config options doesn't give me any useful
> info.
>
> Relaxation can convert calls to a jal.  I don't know of any open bugs
> in this area that can generate relocation errors.  if it is a
> relaxation error then turning off relaxation should work around the
> problem as you suggested.
>
> A kernel build problem is serious.  I think this is worth a bug
> report.  FSF binutils or riscv-gnu-toolchain is fine.
>

I have created an issue with detailed descriptions and reproduction steps.
Please let me know if you need anything else.

> Jim


-- 
Regards,
Atish