Re: [PATCH -fixes v2 3/3] riscv: No need to relocate the dtb as it lies in the fixmap region

From: Palmer Dabbelt
Date: Thu Apr 13 2023 - 21:17:25 EST


On Wed, 29 Mar 2023 08:33:45 PDT (-0700), Conor Dooley wrote:
On Wed, Mar 29, 2023 at 04:40:18PM +0200, Alexandre Ghiti wrote:
On Wed, Mar 29, 2023 at 3:56 PM Conor Dooley <conor@xxxxxxxxxx> wrote:
>
> On Wed, Mar 29, 2023 at 10:19:32AM +0200, Alexandre Ghiti wrote:
> > We used to access the dtb via its linear mapping address but now that the
> > dtb early mapping was moved in the fixmap region, we can keep using this
> > address since it is present in swapper_pg_dir, and remove the dtb
> > relocation.
> >
> > Note that the relocation was wrong anyway since early_memremap() is
> > restricted to 256K whereas the maximum fdt size is 2MB.
>
> So, should this be marked as a fix, and backported along with 1/3?

Hmmm the whole series should be backported, it does not make sense to
move the dtb mapping and keep accessing it using its linear mapping
address since it could fail for the exact reason the relocation was
implemented in the first place and the relocation is wrong.

Maybe we should simply add a "Cc: stable@xxxxxxxxxxxxxxx" on all the patches?

Yup, although hopefully Palmer can handle that if nothing else needs
changing.

The bots usually pick it up anyway, but in general I try and put the stable CC on there when I see stuff go by. I actually missed it this time until seeing the comment, though...