From 54007f818206dc27309ca423df4c87dd160a7208 Mon Sep 17 00:00:00 2001 From: Yu-cheng Yu Date: Mon, 12 Jun 2023 17:10:40 -0700 Subject: mm: Introduce VM_SHADOW_STACK for shadow stack memory New hardware extensions implement support for shadow stack memory, such as x86 Control-flow Enforcement Technology (CET). Add a new VM flag to identify these areas, for example, to be used to properly indicate shadow stack PTEs to the hardware. Shadow stack VMA creation will be tightly controlled and limited to anonymous memory to make the implementation simpler and since that is all that is required. The solution will rely on pte_mkwrite() to create the shadow stack PTEs, so it will not be required for vm_get_page_prot() to learn how to create shadow stack memory. For this reason document that VM_SHADOW_STACK should not be mixed with VM_SHARED. Co-developed-by: Rick Edgecombe Signed-off-by: Yu-cheng Yu Signed-off-by: Rick Edgecombe Signed-off-by: Dave Hansen Reviewed-by: Borislav Petkov (AMD) Reviewed-by: Kees Cook Reviewed-by: Kirill A. Shutemov Reviewed-by: Mark Brown Acked-by: Mike Rapoport (IBM) Acked-by: David Hildenbrand Tested-by: Mark Brown Tested-by: Pengfei Xu Tested-by: John Allen Tested-by: Kees Cook Link: https://lore.kernel.org/all/20230613001108.3040476-15-rick.p.edgecombe%40intel.com --- Documentation/filesystems/proc.rst | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation/filesystems') diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst index 7897a7dafcbc..6ccb57089a06 100644 --- a/Documentation/filesystems/proc.rst +++ b/Documentation/filesystems/proc.rst @@ -566,6 +566,7 @@ encoded manner. The codes are the following: mt arm64 MTE allocation tags are enabled um userfaultfd missing tracking uw userfaultfd wr-protect tracking + ss shadow stack page == ======================================= Note that there is no guarantee that every flag and associated mnemonic will -- cgit v1.2.3