linux-kernel - Re: [PATCH -fixes] riscv: Fix relocatable kernels with early alternatives using -fno-pie

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Date:   Wed, 31 May 2023 09:26:27 +0200
From:   Alexandre Ghiti <alex@...ti.fr>
To:     Conor Dooley <conor@...nel.org>,
        Alexandre Ghiti <alexghiti@...osinc.com>
Cc:     Conor Dooley <conor.dooley@...rochip.com>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        Andreas Schwab <schwab@...ux-m68k.org>,
        linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH -fixes] riscv: Fix relocatable kernels with early
 alternatives using -fno-pie

On 30/05/2023 22:22, Conor Dooley wrote:
> On Tue, May 30, 2023 at 08:04:17PM +0200, Alexandre Ghiti wrote:
>> Ahah, I think we found the culprit!
>>
>> With CONFIG_RELOCATABLE, vmlinux is actually stripped from all the
>> relocations (so that it can be shipped) and vmlinux.relocs is what you
>> should use instead, since it is just a copy of vmlinux before the
>> removal of the relocations!
> That probably makes us both eejits for not realising sooner...

Ahah, TIL a new word, thanks :)

>
> Tested-by: Conor Dooley <conor.dooley@...rochip.com> # booted on nezha & unmatched
>
> Thanks for your patience here Alex.

So I checked again if the -fno-pie should be applied to 
mm/dma-noncoherent.c as I suggested, but actually no: 
errata/thead/errata.c never reaches riscv_noncoherent_supported() in 
early boot (you can see how 'fragile' it is though and why something 
needs to be done...).

Oh and I realized that I forgot the Reported-by from Andreas and the 
Fixes tags, so here they are:

Fixes: 39b33072941f ("riscv: Introduce CONFIG_RELOCATABLE")
Reported-by: Andreas Schwab <schwab@...ux-m68k.org>

Thank you too for your patience and your quick answers!

Alex

>
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