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;
Date:   Wed, 27 Oct 2021 16:09:05 -0700 (PDT)
Subject:     Re: [PATCH] RISC-V: Make CONFIG_RELOCATABLE user selectable
In-Reply-To: <87ee86ajig.fsf@igel.home>
CC:     alexandre.ghiti@canonical.com, alex@ghiti.fr,
        Paul Walmsley <paul.walmsley@sifive.com>,
        aou@eecs.berkeley.edu, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org, kernel-team@android.com
From:   Palmer Dabbelt <palmerdabbelt@google.com>
To:     schwab@linux-m68k.org
Message-ID: <mhng-95082d33-c7f4-4d3e-9794-7e0534324218@palmerdabbelt-glaptop>
Mime-Version: 1.0 (MHng)
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

On Wed, 27 Oct 2021 02:45:27 PDT (-0700), schwab@linux-m68k.org wrote:
> On Okt 27 2021, Alexandre Ghiti wrote:
>
>> On Wed, Oct 27, 2021 at 10:03 AM Andreas Schwab <schwab@linux-m68k.org> wrote:
>>>
>>> On Okt 26 2021, Palmer Dabbelt wrote:
>>>
>>> > +config RELOCATABLE
>>> > +     bool "Build a relocatable kernel"
>>> > +     depends on MMU && 64BIT && !XIP_KERNEL
>>> > +     help
>>> > +          This builds a kernel as a Position Independent Executable (PIE),
>>> > +          which retains all relocation metadata required to relocate the
>>> > +          kernel binary at runtime to a different virtual address than the
>>> > +          address it was linked at.
>>> > +          Since RISCV uses the RELA relocation format, this requires a
>>> > +          relocation pass at runtime even if the kernel is loaded at the
>>> > +          same address it was linked at.
>>>
>>> When in doubt, do what?
>>
>> Then do not enable.
>
> Please add that to the help string.

Thanks, I forgot about that.  I've added it, but this is still a bit in 
flux so I'm not going to send a v2 right now (it's on top of Alex's 
other patches and should probably be squashed in, anyway).