hwmon: Prevent some divide by zeros in FAN_TO_REG()

The "rpm * div" operations can overflow here, so this patch adds an
upper limit to rpm to prevent that.  Jean Delvare helped me with this
patch.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Roger Lucas <vt8231@hiddenengine.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
Dan Carpenter 2013-12-12 08:05:33 +01:00 committed by Jean Delvare
parent 33a7ab91d5
commit 3806b45ba4
3 changed files with 5 additions and 1 deletions

View File

@ -94,6 +94,8 @@ static inline u8 FAN_TO_REG(long rpm, int div)
{
if (rpm <= 0)
return 255;
if (rpm > 1350000)
return 1;
return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
}

View File

@ -141,6 +141,8 @@ static inline u8 FAN_TO_REG(long rpm, int div)
{
if (rpm <= 0)
return 255;
if (rpm > 1350000)
return 1;
return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
}

View File

@ -145,7 +145,7 @@ static const u8 regtempmin[] = { 0x3a, 0x3e, 0x2c, 0x2e, 0x30, 0x32 };
*/
static inline u8 FAN_TO_REG(long rpm, int div)
{
if (rpm == 0)
if (rpm <= 0 || rpm > 1310720)
return 0;
return clamp_val(1310720 / (rpm * div), 1, 255);
}