From ad425b2849343eea8fc65b825a9e8055fd547aa2 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Mon, 12 May 2008 21:21:15 +0200
Subject: [PATCH] --- yaml --- r: 97301 b: refs/heads/master c:
 b1979a5fda7869a790f4fd83fb06c78498d26ba1 h: refs/heads/master i:   97299:
 256d4d8f365ab76948fa851387a725e878e279b2 v: v3

---
 [refs]                           |  2 +-
 trunk/include/asm-x86/tlbflush.h | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 0a2e2bc069ce..4ae49cbc0970 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a1289643adb6272c04db9399653ae195072c482a
+refs/heads/master: b1979a5fda7869a790f4fd83fb06c78498d26ba1
diff --git a/trunk/include/asm-x86/tlbflush.h b/trunk/include/asm-x86/tlbflush.h
index 0c0674d94255..35c76ceb9f40 100644
--- a/trunk/include/asm-x86/tlbflush.h
+++ b/trunk/include/asm-x86/tlbflush.h
@@ -22,12 +22,23 @@ static inline void __native_flush_tlb(void)
 
 static inline void __native_flush_tlb_global(void)
 {
-	unsigned long cr4 = read_cr4();
+	unsigned long flags;
+	unsigned long cr4;
 
+	/*
+	 * Read-modify-write to CR4 - protect it from preemption and
+	 * from interrupts. (Use the raw variant because this code can
+	 * be called from deep inside debugging code.)
+	 */
+	raw_local_irq_save(flags);
+
+	cr4 = read_cr4();
 	/* clear PGE */
 	write_cr4(cr4 & ~X86_CR4_PGE);
 	/* write old PGE again and flush TLBs */
 	write_cr4(cr4);
+
+	raw_local_irq_restore(flags);
 }
 
 static inline void __native_flush_tlb_single(unsigned long addr)