From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Liam Beguin <liambeguin@gmail.com>
Cc: Peter Rosin <peda@axentia.se>,
Jonathan Cameron <jic23@kernel.org>,
Lars-Peter Clausen <lars@metafoo.de>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-iio <linux-iio@vger.kernel.org>,
devicetree <devicetree@vger.kernel.org>,
Rob Herring <robh+dt@kernel.org>
Subject: Re: [PATCH v11 09/15] iio: afe: rescale: reduce risk of integer overflow
Date: Wed, 22 Dec 2021 14:29:04 +0200 [thread overview]
Message-ID: <CAHp75Vc0aWrFtNK1ZkHkwP62zNXQJaDcn9pc8Uhfq0kOnWzmJg@mail.gmail.com> (raw)
In-Reply-To: <20211222034646.222189-10-liambeguin@gmail.com>
On Wed, Dec 22, 2021 at 5:47 AM Liam Beguin <liambeguin@gmail.com> wrote:
>
> From: Liam Beguin <lvb@xiphos.com>
>
> Reduce the risk of integer overflow by doing the scale calculation on
> a 64-bit integer. Since the rescaling is only performed on *val, reuse
> the IIO_VAL_FRACTIONAL_LOG2 case.
...
> - tmp = 1 << *val2;
At some point this should be BIT()
Rule of thumb (in accordance with C standard), always use unsigned
value as left operand of the _left_ shift.
> + if (scale_type == IIO_VAL_FRACTIONAL)
> + tmp = *val2;
> + else
> + tmp = 1 << *val2;
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2021-12-22 12:31 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-22 3:46 [PATCH v11 00/15] iio: afe: add temperature rescaling support Liam Beguin
2021-12-22 3:46 ` [PATCH v11 01/15] iio: inkern: apply consumer scale on IIO_VAL_INT cases Liam Beguin
2021-12-22 3:46 ` [PATCH v11 02/15] iio: inkern: apply consumer scale when no channel scale is available Liam Beguin
2021-12-22 3:46 ` [PATCH v11 03/15] iio: inkern: make a best effort on offset calculation Liam Beguin
2021-12-22 3:46 ` [PATCH v11 04/15] iio: afe: rescale: expose scale processing function Liam Beguin
2021-12-22 10:21 ` Andy Shevchenko
2021-12-22 18:20 ` Liam Beguin
2021-12-22 18:52 ` Andy Shevchenko
2021-12-22 19:42 ` Liam Beguin
2021-12-22 19:50 ` Andy Shevchenko
2021-12-22 20:04 ` Liam Beguin
2021-12-22 3:46 ` [PATCH v11 05/15] iio: afe: rescale: add INT_PLUS_{MICRO,NANO} support Liam Beguin
2021-12-22 3:46 ` [PATCH v11 06/15] iio: afe: rescale: add offset support Liam Beguin
2021-12-22 3:46 ` [PATCH v11 07/15] iio: afe: rescale: use s64 for temporary scale calculations Liam Beguin
2021-12-22 12:25 ` Andy Shevchenko
2021-12-22 18:21 ` Liam Beguin
2021-12-22 3:46 ` [PATCH v11 08/15] iio: afe: rescale: fix accuracy for small fractional scales Liam Beguin
2021-12-22 12:27 ` Andy Shevchenko
2021-12-22 3:46 ` [PATCH v11 09/15] iio: afe: rescale: reduce risk of integer overflow Liam Beguin
2021-12-22 12:29 ` Andy Shevchenko [this message]
2021-12-22 18:38 ` Liam Beguin
2021-12-22 18:56 ` Andy Shevchenko
2021-12-22 19:58 ` Liam Beguin
2021-12-22 21:32 ` Andy Shevchenko
2022-01-08 16:34 ` Liam Beguin
2022-01-08 17:55 ` Andy Shevchenko
2021-12-22 3:46 ` [PATCH v11 10/15] iio: afe: rescale: make use of units.h Liam Beguin
2021-12-22 12:33 ` Andy Shevchenko
2021-12-22 18:50 ` Liam Beguin
2021-12-22 18:59 ` Andy Shevchenko
2021-12-22 3:46 ` [PATCH v11 11/15] iio: test: add basic tests for the iio-rescale driver Liam Beguin
2021-12-22 12:38 ` Andy Shevchenko
2021-12-22 19:13 ` Liam Beguin
2021-12-22 3:46 ` [PATCH v11 12/15] iio: afe: rescale: add RTD temperature sensor support Liam Beguin
2021-12-22 3:46 ` [PATCH v11 13/15] iio: afe: rescale: add temperature transducers Liam Beguin
2021-12-22 12:40 ` Andy Shevchenko
2021-12-22 3:46 ` [PATCH v11 14/15] dt-bindings: iio: afe: add bindings for temperature-sense-rtd Liam Beguin
2021-12-22 3:46 ` [PATCH v11 15/15] dt-bindings: iio: afe: add bindings for temperature transducers Liam Beguin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAHp75Vc0aWrFtNK1ZkHkwP62zNXQJaDcn9pc8Uhfq0kOnWzmJg@mail.gmail.com \
--to=andy.shevchenko@gmail.com \
--cc=devicetree@vger.kernel.org \
--cc=jic23@kernel.org \
--cc=lars@metafoo.de \
--cc=liambeguin@gmail.com \
--cc=linux-iio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peda@axentia.se \
--cc=robh+dt@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).