hwmon: (fam15h_power) Fix unintentional integer overflow

Expression with two unsigned integer variables is calculated as unsigned integer before it is converted to u64. This may result in an integer overflow. Fix by typecasting the left operand to u64 before performing the left shift. This patch addresses Coverity #402320: Unintentional integer overflow. Signed-off-by: Guenter Roeck <[email protected]> Acked-by: Jean Delvare <[email protected]> Acked-by: Andreas Herrmann <[email protected]>
josf · Jul 22, 2012 · 62867d4 · 62867d4
1 parent 58c3667
commit 62867d4
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c
@@ -67,7 +67,8 @@ static ssize_t show_power(struct device *dev,
 				  REG_TDP_LIMIT3, &val);
 
 	tdp_limit = val >> 16;
-	curr_pwr_watts = (tdp_limit + data->base_tdp) << running_avg_range;
+	curr_pwr_watts = ((u64)(tdp_limit +
+				data->base_tdp)) << running_avg_range;
 	curr_pwr_watts -= running_avg_capture;
 	curr_pwr_watts *= data->tdp_to_watts;