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From:   Yu-cheng Yu <yu-cheng.yu@intel.com>
To:     x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
        Thomas Gleixner <tglx@linutronix.de>,
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        Vedvyas Shanbhogue <vedvyas.shanbhogue@intel.com>
Cc:     Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH v5 09/27] mm: Introduce VM_SHSTK for shadow stack memory
Date:   Thu, 11 Oct 2018 08:15:05 -0700
Message-Id: <20181011151523.27101-10-yu-cheng.yu@intel.com>
In-Reply-To: <20181011151523.27101-1-yu-cheng.yu@intel.com>
References: <20181011151523.27101-1-yu-cheng.yu@intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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.yu@intel.com>
---
 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 5ea1d64cb0b4..b20450dde5b7 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 53cfc104c0fb..f658923e76ad 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