From 0fb620c4334eab14e85b7f66389e9061a225fb7e Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Sun, 20 Nov 2016 10:14:09 -0800 Subject: [PATCH] hwmon: (adm9240) Fix overflows seen when writing into limit attributes Module test reports: in0_min: Suspected overflow: [3320 vs. 0] in0_max: Suspected overflow: [3320 vs. 0] in4_min: Suspected overflow: [15938 vs. 0] in4_max: Suspected overflow: [15938 vs. 0] temp1_max: Suspected overflow: [127000 vs. 0] temp1_max_hyst: Suspected overflow: [127000 vs. 0] aout_output: Suspected overflow: [1250 vs. 0] Code analysis reveals that the overflows are caused by conversions from unsigned long to long to int, combined with multiplications on passed values. Reviewed-by: Jean Delvare Signed-off-by: Guenter Roeck --- drivers/hwmon/adm9240.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/adm9240.c b/drivers/hwmon/adm9240.c index 2fe1828bd10b..72bf2489511e 100644 --- a/drivers/hwmon/adm9240.c +++ b/drivers/hwmon/adm9240.c @@ -98,13 +98,15 @@ static inline unsigned int IN_FROM_REG(u8 reg, int n) static inline u8 IN_TO_REG(unsigned long val, int n) { - return clamp_val(SCALE(val, 192, nom_mv[n]), 0, 255); + val = clamp_val(val, 0, nom_mv[n] * 255 / 192); + return SCALE(val, 192, nom_mv[n]); } /* temperature range: -40..125, 127 disables temperature alarm */ static inline s8 TEMP_TO_REG(long val) { - return clamp_val(SCALE(val, 1, 1000), -40, 127); + val = clamp_val(val, -40000, 127000); + return SCALE(val, 1, 1000); } /* two fans, each with low fan speed limit */ @@ -122,7 +124,8 @@ static inline unsigned int FAN_FROM_REG(u8 reg, u8 div) /* analog out 0..1250mV */ static inline u8 AOUT_TO_REG(unsigned long val) { - return clamp_val(SCALE(val, 255, 1250), 0, 255); + val = clamp_val(val, 0, 1250); + return SCALE(val, 255, 1250); } static inline unsigned int AOUT_FROM_REG(u8 reg) -- 2.20.1