From 2925f142d855585427a63da50744766a47659e0f Mon Sep 17 00:00:00 2001
From: Jon Medhurst <tixy@linaro.org>
Date: Mon, 9 Dec 2013 13:45:46 +0100
Subject: ARM: 7917/1: cacheflush: correctly limit range of memory region being
 flushed

commit b31459adeab018b297541e288ac88873011da82a upstream.

The __do_cache_op function operates with a 'chunk' size of one page
but fails to limit the size of the final chunk so as to not exceed
the specified memory region. Fix this.

Reported-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Tested-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 8fcda14..65ed63f 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -503,9 +503,10 @@ static inline int
 __do_cache_op(unsigned long start, unsigned long end)
 {
 	int ret;
-	unsigned long chunk = PAGE_SIZE;
 
 	do {
+		unsigned long chunk = min(PAGE_SIZE, end - start);
+
 		if (signal_pending(current)) {
 			struct thread_info *ti = current_thread_info();
 
-- 
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