From: Segher Boessenkool <segher@kernel.crashing.org>
To: Roel Kluin <12o3l@tiscali.nl>
Cc: Colin Leroy <colin@colino.net>,
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 10:13:34 +0100 [thread overview]
Message-ID: <64d5b5e6dfd0d1820d21db323ef88e25@kernel.crashing.org> (raw)
In-Reply-To: <47D4EFC1.1050403@tiscali.nl>
> 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).
Segher
WARNING: multiple messages have this Message-ID (diff)
From: Segher Boessenkool <segher@kernel.crashing.org>
To: Roel Kluin <12o3l@tiscali.nl>
Cc: benh@kernel.crashing.org, linuxppc-dev@ozlabs.org,
lkml <linux-kernel@vger.kernel.org>,
Colin Leroy <colin@colino.net>
Subject: Re: ADT746X: logical-bitwise & confusion in set_max_duty_at_crit()
Date: Mon, 10 Mar 2008 10:13:34 +0100 [thread overview]
Message-ID: <64d5b5e6dfd0d1820d21db323ef88e25@kernel.crashing.org> (raw)
In-Reply-To: <47D4EFC1.1050403@tiscali.nl>
> 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).
Segher
next prev parent reply other threads:[~2008-03-10 9:13 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-10 0:04 ADT746X: logical-bitwise & confusion in set_max_duty_at_crit() Roel Kluin
2008-03-10 7:46 ` Colin Leroy
2008-03-10 8:06 ` Benjamin Herrenschmidt
2008-03-10 8:22 ` Roel Kluin
2008-03-10 8:22 ` Roel Kluin
2008-03-10 9:13 ` Segher Boessenkool [this message]
2008-03-10 9:13 ` Segher Boessenkool
2008-03-10 9:59 ` Roel Kluin
2008-03-10 9:59 ` Roel Kluin
2008-03-10 18:13 ` Darrick J. Wong
2008-03-10 18:13 ` Darrick J. Wong
2008-03-10 21:17 ` Roel Kluin
2008-03-10 21:17 ` Roel Kluin
2008-03-10 21:56 ` Segher Boessenkool
2008-03-10 21:56 ` Segher Boessenkool
2008-03-10 22:15 ` Roel Kluin
2008-03-10 22:15 ` Roel Kluin
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