linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Jiri Pirko <jiri@resnulli.us>
Cc: Arnd Bergmann <arnd@arndb.de>,
	"David S. Miller" <davem@davemloft.net>,
	Alexander Duyck <aduyck@mirantis.com>,
	Tom Herbert <tom@herbertland.com>, Jiri Pirko <jiri@mellanox.com>,
	Hadar Hen Zion <hadarh@mellanox.com>,
	Gao Feng <fgao@48lvckh6395k16k5.yundunddos.com>,
	Eric Garver <e@erig.me>, Amir Vadai <amir@vadai.me>,
	Network Development <netdev@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] flow_dissector: avoid uninitialized variable access
Date: Fri, 21 Oct 2016 18:48:48 -0700	[thread overview]
Message-ID: <CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com> (raw)
In-Reply-To: <20161021163118.GA2155@nanopsycho.orion>

On Fri, Oct 21, 2016 at 9:31 AM, Jiri Pirko <jiri@resnulli.us> wrote:
>
> I don't see how vlan could be used uninitialized. But I understand that
> this is impossible for gcc to track it. Please just use uninitialized_var()

Actually, I think we should never use "uninitialized_var()" except
possibly for arrays or structures that gcc can complain about.

It's a horrible thing to use, in that it adds extra cruft to the
source code, and then shuts up a compiler warning (even the _reliable_
warnings from gcc).

It's much better to just initialize the variable, and if gcc some day
gets smarter and sees that it  is unnecessary and always overwritten,
so much the better. The cost of initializing a single word is
basically zero.

            Linus

  parent reply	other threads:[~2016-10-22  1:48 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-21 15:55 Arnd Bergmann
2016-10-21 16:31 ` Jiri Pirko
2016-10-21 21:05   ` Arnd Bergmann
2016-10-21 22:16     ` Arnd Bergmann
2016-10-22 15:57       ` Eric Garver
2016-10-22 18:20         ` Tom Herbert
2016-10-22 20:30           ` [PATCH net-next] flow_dissector: fix vlan tag handling Arnd Bergmann
2016-10-24  8:17             ` Jiri Pirko
2016-10-24 16:00               ` Arnd Bergmann
2016-10-22  1:48   ` Linus Torvalds [this message]
2016-10-22  6:55     ` [PATCH] flow_dissector: avoid uninitialized variable access Jiri Pirko

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='CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com' \
    --to=torvalds@linux-foundation.org \
    --cc=aduyck@mirantis.com \
    --cc=amir@vadai.me \
    --cc=arnd@arndb.de \
    --cc=davem@davemloft.net \
    --cc=e@erig.me \
    --cc=fgao@48lvckh6395k16k5.yundunddos.com \
    --cc=hadarh@mellanox.com \
    --cc=jiri@mellanox.com \
    --cc=jiri@resnulli.us \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=tom@herbertland.com \
    --subject='Re: [PATCH] flow_dissector: avoid uninitialized variable access' \
    /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

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).