[PATCH 3.2 036/131] hwmon: (lm78) Fix overflow problems seen when writing large temperature limits

[Ben Hutchings]

3.2.63-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Guenter Roeck <linux@xxxxxxxxxxxx>

commit 1074d683a51f1aded3562add9ef313e75d557327 upstream.

On platforms with sizeof(int) < sizeof(long), writing a temperature
limit larger than MAXINT will result in unpredictable limit values
written to the chip. Avoid auto-conversion from long to int to fix
the problem.

Cc: Axel Lin <axel.lin@xxxxxxxxxx>
Reviewed-by: Axel Lin <axel.lin@xxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/hwmon/lm78.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/hwmon/lm78.c
+++ b/drivers/hwmon/lm78.c
@@ -102,7 +102,7 @@ static inline int FAN_FROM_REG(u8 val, i
 
 /* TEMP: mC (-128C to +127C)
    REG: 1C/bit, two's complement */
-static inline s8 TEMP_TO_REG(int val)
+static inline s8 TEMP_TO_REG(long val)
 {
 	int nval = SENSORS_LIMIT(val, -128000, 127000) ;
 	return nval<0 ? (nval-500)/1000 : (nval+500)/1000;

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