From: Guenter Roeck <linux@roeck-us.net>
Date: Wed, 30 Jul 2014 03:48:59 +0000 (-0700)
Subject: hwmon: (lm78) Fix overflow problems seen when writing large temperature limits
X-Git-Tag: v3.2.63~95
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=48371f90fbbc3aec891825ad3242d7ef723802b7;p=thirdparty%2Fkernel%2Fstable.git

hwmon: (lm78) Fix overflow problems seen when writing large temperature limits

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@ingics.com>
Reviewed-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/drivers/hwmon/lm78.c b/drivers/hwmon/lm78.c
index a42a7b0cd8eb3..5ce5d5a88c033 100644
--- a/drivers/hwmon/lm78.c
+++ b/drivers/hwmon/lm78.c
@@ -102,7 +102,7 @@ static inline int FAN_FROM_REG(u8 val, int div)
 
 /* 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;