From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: Colin King <colin.king@canonical.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>,
linux-rtc@vger.kernel.org, kernel-janitors@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] rtc: 88pm80x: fix unintended sign extension
Date: Thu, 07 Feb 2019 20:53:36 +0000 [thread overview]
Message-ID: <20190207205336.GL4719@piout.net> (raw)
In-Reply-To: <20190206100811.13315-1-colin.king@canonical.com>
On 06/02/2019 10:08:11+0000, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> Shifting a u8 by 24 will cause the value to be promoted to an integer. If
> the top bit of the u8 is set then the following conversion to an unsigned
> long will sign extend the value causing the upper 32 bits to be set in
> the result.
>
> Fix this by casting the u8 value to an unsigned long before the shift.
>
> Detected by CoverityScan, CID#714646-714649 ("Unintended sign extension")
>
> Fixes: 2985c29c1964 ("rtc: Add rtc support to 88PM80X PMIC")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> drivers/rtc/rtc-88pm80x.c | 21 ++++++++++++++-------
> 1 file changed, 14 insertions(+), 7 deletions(-)
>
Applied, thanks.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
WARNING: multiple messages have this Message-ID (diff)
From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: Colin King <colin.king@canonical.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>,
linux-rtc@vger.kernel.org, kernel-janitors@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] rtc: 88pm80x: fix unintended sign extension
Date: Thu, 7 Feb 2019 21:53:36 +0100 [thread overview]
Message-ID: <20190207205336.GL4719@piout.net> (raw)
In-Reply-To: <20190206100811.13315-1-colin.king@canonical.com>
On 06/02/2019 10:08:11+0000, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> Shifting a u8 by 24 will cause the value to be promoted to an integer. If
> the top bit of the u8 is set then the following conversion to an unsigned
> long will sign extend the value causing the upper 32 bits to be set in
> the result.
>
> Fix this by casting the u8 value to an unsigned long before the shift.
>
> Detected by CoverityScan, CID#714646-714649 ("Unintended sign extension")
>
> Fixes: 2985c29c1964 ("rtc: Add rtc support to 88PM80X PMIC")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> drivers/rtc/rtc-88pm80x.c | 21 ++++++++++++++-------
> 1 file changed, 14 insertions(+), 7 deletions(-)
>
Applied, thanks.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
next prev parent reply other threads:[~2019-02-07 20:53 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-06 10:08 [PATCH] rtc: 88pm80x: fix unintended sign extension Colin King
2019-02-06 10:08 ` Colin King
2019-02-07 20:53 ` Alexandre Belloni [this message]
2019-02-07 20:53 ` Alexandre Belloni
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=20190207205336.GL4719@piout.net \
--to=alexandre.belloni@bootlin.com \
--cc=a.zummo@towertech.it \
--cc=colin.king@canonical.com \
--cc=kernel-janitors@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rtc@vger.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.