netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: maowenan <maowenan@huawei.com>,
	vyasevich@gmail.com, nhorman@tuxdriver.com, davem@davemloft.net,
	linux-sctp@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH net 1/2] sctp: remove redundant assignment when call sctp_get_port_local
Date: Wed, 11 Sep 2019 11:30:08 -0300	[thread overview]
Message-ID: <20190911143008.GD3499@localhost.localdomain> (raw)
In-Reply-To: <20190911083038.GF20699@kadam>

On Wed, Sep 11, 2019 at 11:30:38AM +0300, Dan Carpenter wrote:
> On Wed, Sep 11, 2019 at 09:30:47AM +0800, maowenan wrote:
> > 
> > 
> > On 2019/9/11 3:22, Dan Carpenter wrote:
> > > On Tue, Sep 10, 2019 at 09:57:10PM +0300, Dan Carpenter wrote:
> > >> On Tue, Sep 10, 2019 at 03:13:42PM +0800, Mao Wenan wrote:
> > >>> There are more parentheses in if clause when call sctp_get_port_local
> > >>> in sctp_do_bind, and redundant assignment to 'ret'. This patch is to
> > >>> do cleanup.
> > >>>
> > >>> Signed-off-by: Mao Wenan <maowenan@huawei.com>
> > >>> ---
> > >>>  net/sctp/socket.c | 3 +--
> > >>>  1 file changed, 1 insertion(+), 2 deletions(-)
> > >>>
> > >>> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> > >>> index 9d1f83b10c0a..766b68b55ebe 100644
> > >>> --- a/net/sctp/socket.c
> > >>> +++ b/net/sctp/socket.c
> > >>> @@ -399,9 +399,8 @@ static int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len)
> > >>>  	 * detection.
> > >>>  	 */
> > >>>  	addr->v4.sin_port = htons(snum);
> > >>> -	if ((ret = sctp_get_port_local(sk, addr))) {
> > >>> +	if (sctp_get_port_local(sk, addr))
> > >>>  		return -EADDRINUSE;
> > >>
> > >> sctp_get_port_local() returns a long which is either 0,1 or a pointer
> > >> casted to long.  It's not documented what it means and neither of the
> > >> callers use the return since commit 62208f12451f ("net: sctp: simplify
> > >> sctp_get_port").
> > > 
> > > Actually it was commit 4e54064e0a13 ("sctp: Allow only 1 listening
> > > socket with SO_REUSEADDR") from 11 years ago.  That patch fixed a bug,
> > > because before the code assumed that a pointer casted to an int was the
> > > same as a pointer casted to a long.
> > 
> > commit 4e54064e0a13 treated non-zero return value as unexpected, so the current
> > cleanup is ok?
> 
> Yeah.  It's fine, I was just confused why we weren't preserving the
> error code and then I saw that we didn't return errors at all and got
> confused.

But please lets seize the moment and do the change Dean suggested.
This was the last place saving this return value somewhere. It makes
sense to cleanup sctp_get_port_local() now and remove that masked
pointer return.

Then you may also cleanup:
socket.c:       return !!sctp_get_port_local(sk, &addr);
as it will be a direct map.

  Marcelo

  reply	other threads:[~2019-09-11 14:36 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-10  7:13 [PATCH net 0/2] fix memory leak for sctp_do_bind Mao Wenan
2019-09-10  7:13 ` [PATCH net 1/2] sctp: remove redundant assignment when call sctp_get_port_local Mao Wenan
2019-09-10 18:57   ` Dan Carpenter
2019-09-10 19:22     ` Dan Carpenter
2019-09-11  1:30       ` maowenan
2019-09-11  8:30         ` Dan Carpenter
2019-09-11 14:30           ` Marcelo Ricardo Leitner [this message]
2019-09-11 14:39             ` Marcelo Ricardo Leitner
2019-09-12  2:05               ` maowenan
2019-09-12  4:02                 ` [PATCH v2 net 0/3] fix memory leak for sctp_do_bind Mao Wenan
2019-09-12  4:02                   ` [PATCH v2 net 1/3] sctp: change return type of sctp_get_port_local Mao Wenan
2019-09-12 14:51                     ` Marcelo Ricardo Leitner
2019-09-12  4:02                   ` [PATCH v2 net 2/3] sctp: remove redundant assignment when call sctp_get_port_local Mao Wenan
2019-09-12 14:52                     ` Marcelo Ricardo Leitner
2019-09-12  4:02                   ` [PATCH v2 net 3/3] sctp: destroy bucket if failed to bind addr Mao Wenan
2019-09-12 14:52                     ` Marcelo Ricardo Leitner
2019-09-13 20:06                   ` [PATCH v2 net 0/3] fix memory leak for sctp_do_bind David Miller
2019-09-10  7:13 ` [PATCH net 2/2] sctp: destroy bucket if failed to bind addr Mao Wenan
2019-09-10  7:16 ` [PATCH net 0/2] fix memory leak for sctp_do_bind Neil Horman

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=20190911143008.GD3499@localhost.localdomain \
    --to=marcelo.leitner@gmail.com \
    --cc=dan.carpenter@oracle.com \
    --cc=davem@davemloft.net \
    --cc=kernel-janitors@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-sctp@vger.kernel.org \
    --cc=maowenan@huawei.com \
    --cc=netdev@vger.kernel.org \
    --cc=nhorman@tuxdriver.com \
    --cc=vyasevich@gmail.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).