From d5d762b38cf41fdcfd2545b89476b494da45c3a1 Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge <jeremy@goop.org>
Date: Wed, 2 Apr 2008 10:54:10 -0700
Subject: [PATCH] --- yaml --- r: 93183 b: refs/heads/master c:
 2bd50036b5dfc929390ddc48be7f6314447b2be3 h: refs/heads/master i:   93181:
 3d15fd784f41bf0be8db751cefb39164b0de322d   93179:
 e4bc15c6c0cf20ed69256741f4f45fe62de56919   93175:
 33214820f263cfe6a520e4623bdf201236f2baae   93167:
 e6e49020db0ed64783effc90b6f0dff2701ce5c6   93151:
 2d7bb73444e04953c05a27aa8bf874a58f53205d   93119:
 dec4387f92fb7ff3c08e6a168fba48335e931b2c   93055:
 5b1daf47cd9d134cee8ee1ce35b5e2b9249d31c1   92927:
 10ba2ba1266fda5ee31d60089cef9a07e0e49ae8   92671:
 9942408bff2b7af799a99ce8a1024154ddd419bd   92159:
 1c9e807f78ea6b5cf9ccff09944301797fea37b9 v: v3

---
 [refs]                   |  2 +-
 trunk/arch/x86/xen/mmu.c | 12 ++++++++++--
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index 8caf25475c86..82a3a2b1046a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 41e332b2a2dfe514cd441ed0ce1096ed1863e378
+refs/heads/master: 2bd50036b5dfc929390ddc48be7f6314447b2be3
diff --git a/trunk/arch/x86/xen/mmu.c b/trunk/arch/x86/xen/mmu.c
index 272635aaef88..6cbcf65609ad 100644
--- a/trunk/arch/x86/xen/mmu.c
+++ b/trunk/arch/x86/xen/mmu.c
@@ -156,6 +156,10 @@ void set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags)
 void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
 		    pte_t *ptep, pte_t pteval)
 {
+	/* updates to init_mm may be done without lock */
+	if (mm == &init_mm)
+		preempt_disable();
+
 	if (mm == current->mm || mm == &init_mm) {
 		if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
 			struct multicall_space mcs;
@@ -163,12 +167,16 @@ void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
 
 			MULTI_update_va_mapping(mcs.mc, addr, pteval, 0);
 			xen_mc_issue(PARAVIRT_LAZY_MMU);
-			return;
+			goto out;
 		} else
 			if (HYPERVISOR_update_va_mapping(addr, pteval, 0) == 0)
-				return;
+				goto out;
 	}
 	xen_set_pte(ptep, pteval);
+
+out:
+	if (mm == &init_mm)
+		preempt_enable();
 }
 
 pteval_t xen_pte_val(pte_t pte)