From a1d5181886d8f3a201cfc98985dd228fd629bac4 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 24 Jul 2009 15:23:05 +0200
Subject: [PATCH] x86-decouple-page-fault-logic

commit 9a55d5ea74093fb07569e05f25d8e773c9bb2993 in tip.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index f627779..ed046ed 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1035,7 +1035,7 @@ do_page_fault(struct pt_regs *regs, unsigned long error_code)
 	 * If we're in an interrupt, have no user context or are running
 	 * in an atomic region then we must not take the fault:
 	 */
-	if (unlikely(in_atomic() || !mm)) {
+	if (unlikely(in_atomic() || !mm || current->pagefault_disabled)) {
 		bad_area_nosemaphore(regs, error_code, address);
 		return;
 	}
diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c
index 84e236c..715d822 100644
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -60,6 +60,7 @@ void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
 	enum fixed_addresses idx;
 	unsigned long vaddr;
 
+	preempt_disable();
 	pagefault_disable();
 
 	debug_kmap_atomic(type);
@@ -106,5 +107,6 @@ iounmap_atomic(void *kvaddr, enum km_type type)
 		kpte_clear_flush(kmap_pte-idx, vaddr);
 
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL_GPL(iounmap_atomic);
-- 
1.7.1.1