Re: [PATCHv7 5/4] x86/boot/compressed/64: Support switching from 5- to 4-level paging

From: Kirill A. Shutemov
Date: Mon Jan 29 2018 - 10:39:53 EST


On Mon, Jan 29, 2018 at 06:07:58PM +0300, Kirill A. Shutemov wrote:
> + /*
> + * We are in 5-level paging mode, but we want to switch to 4-level.
> + * Let's take the first entry in the top-level page table as our new CR3.
> + */
> + movl %cr3, %eax
> + movl (%eax), %eax
> + movl %eax, %cr3

Aghh.. Please ignore this.

It would fail if CR3 points above 4G.

--
Kirill A. Shutemov