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From:   Atish Patra <atishp@atishpatra.org>
Date:   Fri, 16 Oct 2020 11:24:16 -0700
Message-ID: <CAOnJCUJWf9Hu4frFOJGQLUZ2BQ8qHBd7mvspgvfM1k6e4z5CcA@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>
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On Tue, Oct 13, 2020 at 10:24 PM Atish Patra <atishp@atishpatra.org> wrote:
>
> 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.
>

It may be a toolchain issue. Here is the ongoing discussion in case
anybody else is interested.

https://github.com/riscv/riscv-gnu-toolchain/issues/738

> > Jim
>
>
>
> --
> Regards,
> Atish


-- 
Regards,
Atish