[RFC PATCH v6 08/26] mm: Introduce VM_SHSTK for shadow stack memory
From: Yu-cheng Yu <hidden>
Date: 2018-11-19 21:57:43
Also in:
linux-arch, linux-doc, linux-mm, lkml
Subsystem:
filesystems (vfs and infrastructure), memory management - core, memory mapping, proc filesystem, the rest · Maintainers:
Alexander Viro, Christian Brauner, Andrew Morton, David Hildenbrand, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
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 <redacted> --- fs/proc/task_mmu.c | 3 +++ include/linux/mm.h | 8 ++++++++ 2 files changed, 11 insertions(+)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 47c3764c469b..1ed311759dfb 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c@@ -652,6 +652,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) [ilog2(VM_PKEY_BIT4)] = "", #endif #endif /* CONFIG_ARCH_HAS_PKEYS */ +#ifdef CONFIG_X86_INTEL_SHADOW_STACK_USER + [ilog2(VM_SHSTK)] = "ss" +#endif }; size_t i;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5411de93a363..7873ac3635a7 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