From 69149e6a5fffb8484b93bfd7c40ab2fa4dfbf4f5 Mon Sep 17 00:00:00 2001
From: "H. Peter Anvin" <hpa@linux.intel.com>
Date: Fri, 21 Sep 2012 12:43:14 -0700
Subject: [PATCH] --- yaml --- r: 326239 b: refs/heads/master c:
 40d3cd6695014bf3c44e2ca66b610b18acaf923d h: refs/heads/master i:   326237:
 e802d0b7943ca6ba75933cab8d0bc2434a3c8cc2   326235:
 400c410ca4bc757c3a6aeed80de742321e1c47a3   326231:
 a70bbe6b38eeb215a289f9c60f48b3da79515afa   326223:
 d1cff23a37517bb2948da540736278356e0dcbf4   326207:
 3e799828e3fe6acde0ae80ea0bc680d5236009d9 v: v3

---
 [refs]                    |  2 +-
 trunk/arch/x86/mm/fault.c | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index f1ec3a22ecce..86680a0ff867 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 52b6179ac87d33c2eeaff5292786a10fe98cff64
+refs/heads/master: 40d3cd6695014bf3c44e2ca66b610b18acaf923d
diff --git a/trunk/arch/x86/mm/fault.c b/trunk/arch/x86/mm/fault.c
index 76dcd9d8e0bc..f2fb75d46b96 100644
--- a/trunk/arch/x86/mm/fault.c
+++ b/trunk/arch/x86/mm/fault.c
@@ -995,6 +995,17 @@ static int fault_in_kernel_space(unsigned long address)
 	return address >= TASK_SIZE_MAX;
 }
 
+static inline bool smap_violation(int error_code, struct pt_regs *regs)
+{
+	if (error_code & PF_USER)
+		return false;
+
+	if (!user_mode_vm(regs) && (regs->flags & X86_EFLAGS_AC))
+		return false;
+
+	return true;
+}
+
 /*
  * This routine handles page faults.  It determines the address,
  * and the problem, and then passes it off to one of the appropriate
@@ -1088,6 +1099,13 @@ do_page_fault(struct pt_regs *regs, unsigned long error_code)
 	if (unlikely(error_code & PF_RSVD))
 		pgtable_bad(regs, error_code, address);
 
+	if (static_cpu_has(X86_FEATURE_SMAP)) {
+		if (unlikely(smap_violation(error_code, regs))) {
+			bad_area_nosemaphore(regs, error_code, address);
+			return;
+		}
+	}
+
 	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
 
 	/*