[PATCH 3.12 015/118] ARM: 7917/1: cacheflush: correctly limit range of memory region being flushed

Greg Kroah-Hartman
2013-12-18T21:13:01Z

From: Jon Medhurst <tixy@linaro.org>

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>

---
arch/arm/kernel/traps.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- 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();