Re: [PATCH 09/11] x86: remove address space overrides using set_fs()

From: Kees Cook
Date: Tue Aug 18 2020 - 15:46:47 EST


On Mon, Aug 17, 2020 at 09:32:10AM +0200, Christoph Hellwig wrote:
> Stop providing the possibility to override the address space using
> set_fs() now that there is no need for that any more. To properly
> handle the TASK_SIZE_MAX checking for 4 vs 5-level page tables on
> x86 a new alternative is introduced, which just like the one in
> entry_64.S has to use the hardcoded virtual address bits to escape
> the fact that TASK_SIZE_MAX isn't actually a constant when 5-level
> page tables are enabled.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Awesome. :)

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

--
Kees Cook