Re: [External] Re: [PATCH 1/3] Revert "riscv/efistub: Ensure GP-relative addressing is not used"

From: Ard Biesheuvel
Date: Wed Mar 06 2024 - 08:12:39 EST


On Wed, 6 Mar 2024 at 14:08, yunhui cui <cuiyunhui@xxxxxxxxxxxxx> wrote:
>
> Hi Jan,
>
> On Wed, Mar 6, 2024 at 8:52 PM Jan Kiszka <jan.kiszka@xxxxxxxxxxx> wrote:
> >
> > On 06.03.24 09:56, Yunhui Cui wrote:
> > > This reverts commit afb2a4fb84555ef9e61061f6ea63ed7087b295d5.
> > >
> >
> > This comes without a reason - which is likely something around "will fix
> > this properly later". But then you regress first and only fix
> > afterwards. Can't that be done the other way around?
>
> Sorry, I don't quite understand what you mean. Can you help explain it
> more clearly? Do you mean "delete mno-relax instead of revert
> directly?"
>

You should order your patches in a way that does not create
intermediate states (between 1-2 or between 2-3) where the original
problem is being recreated.

So in this case, you should
a) fix the issue
b) revert the existing patches in *opposite* order

However, I don't think the EFI stub can use GP - please refer to my other reply.