Re: [PATCH] x86/boot: Remove x86_32 PIC using ebx workaround

From: Uros Bizjak
Date: Tue Nov 29 2022 - 08:26:58 EST


On Tue, Nov 29, 2022 at 2:24 PM Brian Gerst <brgerst@xxxxxxxxx> wrote:
>
> On Tue, Nov 29, 2022 at 3:32 AM Borislav Petkov <bp@xxxxxxxxx> wrote:
> >
> > On Mon, Nov 28, 2022 at 10:41:11PM -0500, Brian Gerst wrote:
> > > x86-64 uses a PIC register for the medium and large PIC code models,
> > > where offsets can be larger than +/- 2GB.
> >
> > Right but 64-bit is built with -mcmodel=kernel which obviously generates
> > rip-relative.
>
> Correct. He quoted the specific part of the GCC changelog that fixed
> the issue for the 32-bit kernel, but it's not applicable to the 64-bit
> kernel.

It says so right in the summary.

Uros.