Re: [PATCH stable 5.10 0/3] ARM FDT relocation backports

[Linus Walleij]

On Mon, May 10, 2021 at 9:43 AM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Sun, May 09, 2021 at 06:22:05PM -0700, Florian Fainelli wrote:

> > This does not qualify as a regression in that it has never worked for
> > the specific platform that I have shown above until your 3 commits came
> > in and fixed that particular FDT placement. To me this qualifies as a
> > bug fix, and given that the 3 (now 4) commits applied without hunks, it
> > seems reasonable to me to back port those to stable.
>
> As this isn't a regression, why not just use 5.12 on these platforms?
> Why is 5.4 and 5.10 needed?

Actually I think it *is* a regression, but not a common one. The bug that
Ard is fixing can appear when the kernel grows over a certain size.

If a user compile in a new set of functionality and the kernel size
reach a tripping point so that the DTB ends up just outside the 1:1
lowmem map, disaster strikes.

This has been a long standing mysterious bug for people using
attached device trees.

Yours,
Linus Walleij