From: Jon Medhurst <tixy@linaro.org>
Date: Mon, 9 Dec 2013 12:45:46 +0000 (+0100)
Subject: ARM: 7917/1: cacheflush: correctly limit range of memory region being flushed
X-Git-Tag: next-20131212~114^2
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b31459adeab018b297541e288ac88873011da82a;p=karo-tx-linux.git

ARM: 7917/1: cacheflush: correctly limit range of memory region being flushed

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.

Cc: <stable@vger.kernel.org>
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>
---

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index dbf0923e8d76..7940241f0576 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -509,9 +509,10 @@ 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();