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

From: Greg Kroah-Hartman
Date: Mon May 10 2021 - 05:46:53 EST


On Mon, May 10, 2021 at 11:37:01AM +0200, Linus Walleij wrote:
> 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.

Ok, then feel free to ack them when they get resubmitted.

thanks,

greg k-h