From e0170cab2bf4e40d360d8e7cc45a65594a631667 Mon Sep 17 00:00:00 2001
From: Kautuk Consul <consul.kautuk@gmail.com>
Date: Mon, 30 Jul 2012 14:39:25 -0700
Subject: [PATCH] --- yaml --- r: 319879 b: refs/heads/master c:
 bf7c27e9887af48952743753916f9cfbe900d0e9 h: refs/heads/master i:   319877:
 dfd9fe417213173e800bf827ea3dd2a91faae19f   319875:
 0dd2a1447cd6a7a857451b1c69428c1758d84751   319871:
 d1f6efdb5ca123a0a8c1809810b48db3eee376e6 v: v3

---
 [refs]                      |  2 +-
 trunk/arch/avr32/mm/fault.c | 33 +++++++++++++++++++++++++--------
 2 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/[refs] b/[refs]
index 9222490f7f0a..4db77938aabc 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 7eafef6d1d712aa9973c3cbd0013a5b66d5a6604
+refs/heads/master: bf7c27e9887af48952743753916f9cfbe900d0e9
diff --git a/trunk/arch/avr32/mm/fault.c b/trunk/arch/avr32/mm/fault.c
index f7040a1e399f..b92e60958617 100644
--- a/trunk/arch/avr32/mm/fault.c
+++ b/trunk/arch/avr32/mm/fault.c
@@ -61,10 +61,10 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
 	const struct exception_table_entry *fixup;
 	unsigned long address;
 	unsigned long page;
-	int writeaccess;
 	long signr;
 	int code;
 	int fault;
+	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	if (notify_page_fault(regs, ecr))
 		return;
@@ -86,6 +86,7 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
 
 	local_irq_enable();
 
+retry:
 	down_read(&mm->mmap_sem);
 
 	vma = find_vma(mm, address);
@@ -104,7 +105,6 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
 	 */
 good_area:
 	code = SEGV_ACCERR;
-	writeaccess = 0;
 
 	switch (ecr) {
 	case ECR_PROTECTION_X:
@@ -121,7 +121,7 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
 	case ECR_TLB_MISS_W:
 		if (!(vma->vm_flags & VM_WRITE))
 			goto bad_area;
-		writeaccess = 1;
+		flags |= FAULT_FLAG_WRITE;
 		break;
 	default:
 		panic("Unhandled case %lu in do_page_fault!", ecr);
@@ -132,7 +132,11 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
 	 * sure we exit gracefully rather than endlessly redo the
 	 * fault.
 	 */
-	fault = handle_mm_fault(mm, vma, address, writeaccess ? FAULT_FLAG_WRITE : 0);
+	fault = handle_mm_fault(mm, vma, address, flags);
+
+	if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+		return;
+
 	if (unlikely(fault & VM_FAULT_ERROR)) {
 		if (fault & VM_FAULT_OOM)
 			goto out_of_memory;
@@ -140,10 +144,23 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
 			goto do_sigbus;
 		BUG();
 	}
-	if (fault & VM_FAULT_MAJOR)
-		tsk->maj_flt++;
-	else
-		tsk->min_flt++;
+
+	if (flags & FAULT_FLAG_ALLOW_RETRY) {
+		if (fault & VM_FAULT_MAJOR)
+			tsk->maj_flt++;
+		else
+			tsk->min_flt++;
+		if (fault & VM_FAULT_RETRY) {
+			flags &= ~FAULT_FLAG_ALLOW_RETRY;
+
+			/*
+			 * No need to up_read(&mm->mmap_sem) as we would have
+			 * already released it in __lock_page_or_retry() in
+			 * mm/filemap.c.
+			 */
+			goto retry;
+		}
+	}
 
 	up_read(&mm->mmap_sem);
 	return;