thermal: power_allocator: req_range multiplication should be a 64 bit type

Javi Merino · Eduardo Valentin · commit f9d038144a17 · 2016-04-20T16:22:45.000-07:00
req_range is declared as a u64 to cope with overflows in the
multiplication of two u32.  As both req_power and power_range are u32,
we need to make sure the multiplication is done with u64 types.

Reported-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Cc: Zhang Rui &lt;rui.zhang@intel.com&gt;
Cc: Eduardo Valentin &lt;edubezval@gmail.com&gt;
Signed-off-by: Javi Merino &lt;javi.merino@arm.com&gt;
Signed-off-by: Eduardo Valentin &lt;edubezval@gmail.com&gt;
diff --git a/drivers/thermal/power_allocator.c b/drivers/thermal/power_allocator.c
@@ -301,7 +301,7 @@ static void divvy_up_power(u32 *req_power, u32 *max_power, int num_actors,
 	capped_extra_power = 0;
 	extra_power = 0;
 	for (i = 0; i < num_actors; i++) {
-		u64 req_range = req_power[i] * power_range;
+		u64 req_range = (u64)req_power[i] * power_range;
 
 		granted_power[i] = DIV_ROUND_CLOSEST_ULL(req_range,
 							 total_req_power);
