VM_SHSTK indicates a shadow stack memory area.
The shadow stack is implemented only for the 64-bit kernel.

Signed-off-by: Yu-cheng Yu <yu-cheng...@intel.com>
---
 include/linux/mm.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a61ebe8ad4ca..f40387ecd920 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -224,11 +224,13 @@ 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
@@ -266,6 +268,12 @@ extern unsigned int kobjsize(const void *objp);
 # define VM_MPX                VM_NONE
 #endif
 
+#ifdef CONFIG_X86_INTEL_SHADOW_STACK_USER
+# define VM_SHSTK      VM_HIGH_ARCH_5
+#else
+# define VM_SHSTK      VM_NONE
+#endif
+
 #ifndef VM_GROWSUP
 # define VM_GROWSUP    VM_NONE
 #endif
-- 
2.17.1

Reply via email to