archive mirror
 help / color / mirror / Atom feed
From: Jiri Pirko <>
To: Linus Torvalds <>
Cc: Arnd Bergmann <>,
	"David S. Miller" <>,
	Alexander Duyck <>,
	Tom Herbert <>, Jiri Pirko <>,
	Hadar Hen Zion <>,
	Gao Feng <>,
	Eric Garver <>, Amir Vadai <>,
	Network Development <>,
	Linux Kernel Mailing List <>
Subject: Re: [PATCH] flow_dissector: avoid uninitialized variable access
Date: Sat, 22 Oct 2016 08:55:48 +0200	[thread overview]
Message-ID: <20161022065548.GA1625@nanopsycho.orion> (raw)
In-Reply-To: <>

Sat, Oct 22, 2016 at 03:48:48AM CEST, wrote:
>On Fri, Oct 21, 2016 at 9:31 AM, Jiri Pirko <> 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.

On the other hand, I would agrue that initializing a var to "some" value
that is never used might confuse the reader. He would naturally try to
understand the reason for that exact value in initialization.

      reply	other threads:[~2016-10-22  6:55 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-21 15:55 [PATCH] flow_dissector: avoid uninitialized variable access 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   ` [PATCH] flow_dissector: avoid uninitialized variable access Linus Torvalds
2016-10-22  6:55     ` Jiri Pirko [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:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20161022065548.GA1625@nanopsycho.orion \ \ \ \ \ \ \ \ \ \ \ \ \ \

* 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).