From: Roel Kluin <12o3l@tiscali•nl>
To: Segher Boessenkool <segher@kernel•crashing.org>
Cc: Colin Leroy <colin@colino•net>,
"Darrick J. Wong" <djwong@us•ibm.com>,
lkml <linux-kernel@vger•kernel.org>,
linuxppc-dev@ozlabs•org
Subject: Re: ADT746X: logical-bitwise & confusion in set_max_duty_at_crit()
Date: Mon, 10 Mar 2008 10:59:43 +0100 [thread overview]
Message-ID: <47D5068F.8050709@tiscali.nl> (raw)
In-Reply-To: <64d5b5e6dfd0d1820d21db323ef88e25@kernel.crashing.org>
Segher Boessenkool wrote:
>> diff --git a/drivers/hwmon/adt7473.c b/drivers/hwmon/adt7473.c
>> index 9587869..8ea7da2 100644
>> --- a/drivers/hwmon/adt7473.c
>> +++ b/drivers/hwmon/adt7473.c
>> @@ -570,7 +570,7 @@ static ssize_t set_max_duty_at_crit(struct device
>> *dev,
>> struct i2c_client *client = to_i2c_client(dev);
>> struct adt7473_data *data = i2c_get_clientdata(client);
>> int temp = simple_strtol(buf, NULL, 10);
>> - temp = temp && 0xFF;
>> + temp &= 0xFF;
>>
>> mutex_lock(&data->lock);
>> data->max_duty_at_overheat = temp;
>
> The & 0xff here is bogus anyway; temp is only ever used as an u8,
> so just declare it as that, or do proper overflow/underflow checking
> on it. The patch will need testing on hardware too, since it changes
> behaviour (it should be a bugfix, but who knows).
Maybe someone can test this?
---
logical-bitwise & confusion
Signed-off-by: Roel Kluin <12o3l@tiscali•nl>
---
diff --git a/drivers/hwmon/adt7473.c b/drivers/hwmon/adt7473.c
index 9587869..2a2de73 100644
--- a/drivers/hwmon/adt7473.c
+++ b/drivers/hwmon/adt7473.c
@@ -566,11 +566,11 @@ static ssize_t set_max_duty_at_crit(struct device *dev,
const char *buf,
size_t count)
{
- u8 reg;
+ u8 reg, temp;
struct i2c_client *client = to_i2c_client(dev);
struct adt7473_data *data = i2c_get_clientdata(client);
- int temp = simple_strtol(buf, NULL, 10);
- temp = temp && 0xFF;
+
+ temp = simple_strtol(buf, NULL, 10) & 0xFF;
mutex_lock(&data->lock);
data->max_duty_at_overheat = temp;
next prev parent reply other threads:[~2008-03-10 9:59 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <47D47B11.1000303@tiscali.nl>
[not found] ` <20080310084633.5246ecfe@paperstreet.colino.net>
[not found] ` <1205136413.8621.3.camel@pasglop>
2008-03-10 8:22 ` ADT746X: logical-bitwise & confusion in set_max_duty_at_crit() Roel Kluin
2008-03-10 9:13 ` Segher Boessenkool
2008-03-10 9:59 ` Roel Kluin [this message]
2008-03-10 18:13 ` Darrick J. Wong
2008-03-10 21:17 ` Roel Kluin
2008-03-10 21:56 ` Segher Boessenkool
2008-03-10 22:15 ` Roel Kluin
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