linux-kernel - Re: [PATCH] iio: core: Avoid double minus in sysfs output

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

Message-ID: <51E9AA6D.3070007@kernel.org>
Date:	Fri, 19 Jul 2013 22:06:53 +0100
From:	Jonathan Cameron <jic23@...nel.org>
To:	Oleksandr Kravchenko <o.v.kravchenko@...ballogic.com>
CC:	Lars-Peter Clausen <lars@...afoo.de>,
	Oleksandr Kravchenko <x0199363@...com>, jic23@....ac.uk,
	linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] iio: core: Avoid double minus in sysfs output

On 07/19/2013 07:15 AM, Oleksandr Kravchenko wrote:
> On Thu, Jul 18, 2013 at 7:24 PM, Lars-Peter Clausen <lars@...afoo.de> wrote:
>> On 07/18/2013 05:47 PM, Oleksandr Kravchenko wrote:
>>> From: Oleksandr Kravchenko <o.v.kravchenko@...ballogic.com>
>>>
>>> This patch fixes the issue with double minus in output when
>>> reading channels from sysfs for IIO_VAL_INT_PLUS_MICRO and
>>> IIO_VAL_INT_PLUS_NANO cases. Until this patch if val and val2
>>> both are negatives output string contains "--" before
>>> digits. It is result of "-%d..." in sprintf() format.
>>>
>>
>> Hm, this might be a bug in a driver that is triggering this. The idea is
>> that val2 is only allowed to be negative if val is 0.
>>
>> - Lars
>>
> If I calculate val and val2 in next way:
> *val = adc / 1000000;
> *val2 = adc % 1000000;
> both val and val2 could by negative. Do I have to check it in my driver?
> 
I guess it is will happen occasionally.  In the c89 standard, module for a negative
is implementation specific.  Anyone know if we can assume this will work in all cases
within the kernel?
--
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/