From: Charles Keepax <ckeepax@opensource.cirrus.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Lee Jones <lee.jones@linaro.org>,
<clang-built-linux@googlegroups.com>,
Nick Desaulniers <ndesaulniers@google.com>,
Nathan Chancellor <natechancellor@gmail.com>,
Linus Walleij <linus.walleij@linaro.org>,
Sapthagiri Baratam <sapthagiri.baratam@cirrus.com>,
Colin Ian King <colin.king@canonical.com>,
<patches@opensource.cirrus.com>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mfd: arizona: fix undefined behavior
Date: Fri, 22 Mar 2019 17:03:33 +0000 [thread overview]
Message-ID: <20190322170333.GD46536@ediswmail.ad.cirrus.com> (raw)
In-Reply-To: <20190322143345.1208144-1-arnd@arndb.de>
On Fri, Mar 22, 2019 at 03:33:37PM +0100, Arnd Bergmann wrote:
> When the driver is used with a subdevice that is disabled in the
> kernel configuration, clang gets a little confused about the
> control flow and fails to notice that n_subdevs is only
> uninitialized when subdevs is NULL, and we check for that,
> leading to a false-positive warning:
>
> drivers/mfd/arizona-core.c:1423:19: error: variable 'n_subdevs' is uninitialized when used here
> [-Werror,-Wuninitialized]
> subdevs, n_subdevs, NULL, 0, NULL);
> ^~~~~~~~~
> drivers/mfd/arizona-core.c:999:15: note: initialize the variable 'n_subdevs' to silence this warning
> int n_subdevs, ret, i;
> ^
> = 0
>
> Ideally, we would rearrange the code to avoid all those early
> initializations and have an explicit exit in each disabled case,
> but it's much easier to chicken out and add one more initialization
> here to shut up the warning.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Thanks,
Charles
prev parent reply other threads:[~2019-03-22 17:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-22 14:33 [PATCH] mfd: arizona: fix undefined behavior Arnd Bergmann
2019-03-22 15:57 ` Nathan Chancellor
2019-03-22 17:03 ` Charles Keepax [this message]
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=20190322170333.GD46536@ediswmail.ad.cirrus.com \
--to=ckeepax@opensource.cirrus.com \
--cc=arnd@arndb.de \
--cc=clang-built-linux@googlegroups.com \
--cc=colin.king@canonical.com \
--cc=lee.jones@linaro.org \
--cc=linus.walleij@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=natechancellor@gmail.com \
--cc=ndesaulniers@google.com \
--cc=patches@opensource.cirrus.com \
--cc=sapthagiri.baratam@cirrus.com \
/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).