linux-kernel - Re: [PATCH] staging/iio/meter: fix the coding style problem

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <4F9FA3DF.9060603@metafoo.de>
Date:	Tue, 01 May 2012 10:50:39 +0200
From:	Lars-Peter Clausen <lars@...afoo.de>
To:	Jonathan Cameron <jic23@....ac.uk>
CC:	joseph daniel <josephdanielwalter@...il.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Wolfram Sang <w.sang@...gutronix.de>,
	Paul Gortmaker <paul.gortmaker@...driver.com>,
	linux-iio@...r.kernel.org, devel@...verdev.osuosl.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] staging/iio/meter: fix the coding style problem

On 05/01/2012 09:56 AM, Jonathan Cameron wrote:
> On 4/30/2012 9:01 PM, Lars-Peter Clausen wrote:
>> On 04/30/2012 09:26 PM, joseph daniel wrote:
>>> Signed-off-by: joseph daniel<josephdanielwalter@...il.com>
>>> ---
>>> Hi Lars,
>>>     Thanks for review. how about the below change?
>>>   drivers/staging/iio/meter/ade7854-i2c.c |    6 +++++-
>>>   1 file changed, 5 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/staging/iio/meter/ade7854-i2c.c
>>> b/drivers/staging/iio/meter/ade7854-i2c.c
>>> index 1e1faa0..52bdb05 100644
>>> --- a/drivers/staging/iio/meter/ade7854-i2c.c
>>> +++ b/drivers/staging/iio/meter/ade7854-i2c.c
>>> @@ -181,6 +181,7 @@ static int ade7854_i2c_read_reg_32(struct device
>>> *dev,
>>>   {
>>>       struct iio_dev *indio_dev = dev_get_drvdata(dev);
>>>       struct ade7854_state *st = iio_priv(indio_dev);
>>> +    uint32_t value;
>>>       int ret;
>>>
>>>       mutex_lock(&st->buf_lock);
>>> @@ -195,7 +196,10 @@ static int ade7854_i2c_read_reg_32(struct device
>>> *dev,
>>>       if (ret)
>>>           goto out;
>>>
>>> -    *val = (st->rx[0]<<  24) | (st->rx[1]<<  16) | (st->rx[2]<<  8)
>>> | st->rx[3];
>>> +    memcpy(&value, st->rx, sizeof(uint32_t));
>>> +
>> Uhm, yes, you are right st->rx is unaligned. The memcpy is not
>> necessary though
>> if you use get_unaligned_be32. Sorry for the pointer to the wrong
>> function.
> Or we could just force the alignment of st->rx? Might not be worth
> bothering.

Yes, but be32_to_cpu wants a be32 and there is another functions which only
does a 16 bit access on rx, so we'd need to cast and things get messy. Also for
tx we store first a 16bit value and then a 32bit value and while it is possible
to get this properly aligned this gets a bit messy too. I think we are fine
with {get,set}_unaligned for now.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/