diff options
| author |   Yu-cheng Yu <yu-cheng.yu@intel.com> | 2023-06-12 17:10:40 -0700 |
|---|---|---|
| committer |   Rick Edgecombe <rick.p.edgecombe@intel.com> | 2023-07-11 14:12:19 -0700 |
| commit | 54007f818206dc27309ca423df4c87dd160a7208 (patch) | |
| tree | 54933f8de1e7b40ee022b99e35038ddd158fa7c8 /include/linux/mm.h | |
| parent | x86/mm: Remove _PAGE_DIRTY from kernel RO pages (diff) | |
| download | wireguard-linux-54007f818206dc27309ca423df4c87dd160a7208.tar.xz wireguard-linux-54007f818206dc27309ca423df4c87dd160a7208.zip | |
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 <rick.p.edgecombe@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Mark Brown <broonie@kernel.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-15-rick.p.edgecombe%40intel.com
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 82990f3390f6..f6c2ebde62b3 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -319,11 +319,13 @@ extern unsigned int kobjsize(const void *objp); #define VM_HIGH_ARCH_BIT_2 34 /* bit only usable on 64-bit architectures */ #define VM_HIGH_ARCH_BIT_3 35 /* bit only usable on 64-bit architectures */ #define VM_HIGH_ARCH_BIT_4 36 /* bit only usable on 64-bit architectures */ +#define VM_HIGH_ARCH_BIT_5 37 /* bit only usable on 64-bit architectures */ #define VM_HIGH_ARCH_0 BIT(VM_HIGH_ARCH_BIT_0) #define VM_HIGH_ARCH_1 BIT(VM_HIGH_ARCH_BIT_1) #define VM_HIGH_ARCH_2 BIT(VM_HIGH_ARCH_BIT_2) #define VM_HIGH_ARCH_3 BIT(VM_HIGH_ARCH_BIT_3) #define VM_HIGH_ARCH_4 BIT(VM_HIGH_ARCH_BIT_4) +#define VM_HIGH_ARCH_5 BIT(VM_HIGH_ARCH_BIT_5) #endif /* CONFIG_ARCH_USES_HIGH_VMA_FLAGS */ #ifdef CONFIG_ARCH_HAS_PKEYS @@ -339,6 +341,12 @@ extern unsigned int kobjsize(const void *objp); #endif #endif /* CONFIG_ARCH_HAS_PKEYS */ +#ifdef CONFIG_X86_USER_SHADOW_STACK +# define VM_SHADOW_STACK VM_HIGH_ARCH_5 /* Should not be set with VM_SHARED */ +#else +# define VM_SHADOW_STACK VM_NONE +#endif + #if defined(CONFIG_X86) # define VM_PAT VM_ARCH_1 /* PAT reserves whole VMA at once (x86) */ #elif defined(CONFIG_PPC) |