Re: [PATCH v7 22/41] mm/mmap: Add shadow stack pages to memory accounting

Edgecombe, Rick P
2023-03-06T18:13:51Z

On Mon, 2023-03-06 at 14:01 +0100, Borislav Petkov wrote:
> On Mon, Feb 27, 2023 at 02:29:38PM -0800, Rick Edgecombe wrote:
> > From: Yu-cheng Yu <yu-cheng.yu@intel.com>
> >
> > The x86 Control-flow Enforcement Technology (CET) feature includes
> > a new
> > type of memory called shadow stack. This shadow stack memory has
> > some
> > unusual properties, which requires some core mm changes to function
> > properly.
> >
> > Account shadow stack pages to stack memory. Do this by adding a
> > VM_SHADOW_STACK check in is_stack_mapping().
>
> That last sentence is superfluous.

Before this version it was open coded, but David Hildenbrand suggested
this is_stack_mapping() solution. Should it be explained more, or just
dropped?