Re: [PATCH v4 15/39] mm: Introduce VM_SHADOW_STACK for shadow stack memory
From: Kees Cook <hidden>
Date: 2022-12-03 02:34:38
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linux-arch, linux-doc, linux-mm, lkml
On Fri, Dec 02, 2022 at 04:35:42PM -0800, Rick Edgecombe wrote:
From: Yu-cheng Yu <redacted> 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. A shadow stack PTE must be read-only and have _PAGE_DIRTY set. However, read-only and Dirty PTEs also exist for copy-on-write (COW) pages. These two cases are handled differently for page faults. Introduce VM_SHADOW_STACK to track shadow stack VMAs. Tested-by: Pengfei Xu <redacted> Tested-by: John Allen <john.allen@amd.com> Signed-off-by: Yu-cheng Yu <redacted>
Reviewed-by: Kees Cook <redacted> -- Kees Cook