From: "Gao Feng" <gfree.wind@foxmail.com>
To: 'Sven Eckelmann' <sven@narfation.org>
Cc: mareklindner@neomailbox.ch, netdev@vger.kernel.org,
b.a.t.m.a.n@lists.open-mesh.org, a@unstable.cc,
'Gao Feng' <fgao@ikuai8.com>,
davem@davemloft.net
Subject: Re: [B.A.T.M.A.N.] [PATCH net] net: batman-adv: Fix possible memleaks when fail to register_netdevice
Date: Wed, 26 Apr 2017 14:44:24 +0800 [thread overview]
Message-ID: <002101d2be58$8bcaaa00$a35ffe00$@foxmail.com> (raw)
In-Reply-To: <3994535.Z9kqCnttI2@bentobox>
> From: Sven Eckelmann [mailto:sven@narfation.org]
> Sent: Wednesday, April 26, 2017 1:58 PM
> On Mittwoch, 26. April 2017 08:41:30 CEST Gao Feng wrote:
> > On Dienstag, 25. April 2017 20:03:20 CEST gfree.wind@foxmail.com wrote:
> > > From: Gao Feng <fgao@ikuai8.com>
> > >
> > > Because the func batadv_softif_init_late allocate some resources and
> > > it would be invoked in register_netdevice. So we need to invoke the
> > > func batadv_softif_free instead of free_netdev to cleanup when fail
> > > to register_netdevice.
> >
> > I could be wrong, but shouldn't the destructor be replaced with
> > free_netdevice and the batadv_softif_free (without the free_netdev)
> > used as ndo_uninit? The line you've changed should then be kept as
> free_netdevice.
> >
> > At least this seems to be important when using rtnl_newlink() instead
> > of the legacy sysfs netdev stuff from batman-adv. rtnl_newlink() would
> > also only call free_netdevice and thus also not run
> > batadv_softif_free. This seems to be only fixable by calling ndo_uninit.
> >
> > Sorry, I don't get you.
> > The net_dev is created in this func batadv_softif_create.
> > Why couldn't invoke batadv_softif_free to cleanup when fail to
> > register_netdevice?
> >
>
> Because it is the legacy way to create the batadv interfaces and there is
a
> "new" one. The new way is to use rtnl link (see batadv_link_ops).
>
> The rtnl linke (rtnl_newlink) would not benefit from your fix and
therefore still
> show the old behavior. I think a different fix is necessary to solve the
problem
> for both ways to create an batadv interface.
>
> Kind regards,
> Sven
I get it now, thanks.
Actually I sent another patch about the memleaks when invoke newlink and
fail to register_netdev.
You could refer to it by
https://www.mail-archive.com/netdev@vger.kernel.org/msg165253.html.
In this patch, I add the cleanup when fail to register_netdev.
It would be more simple if modify the rtnl_newlink and invoke the destructor
of netdev when failed.
Like the following codes.
if (ops->newlink) {
err = ops->newlink(link_net ? : net, dev, tb, data);
if (err < 0) {
if (dev->reg_state == NETREG_UNINITIALIZED)
if (dev->destructor)
dev->destructor(dev)
else
free_netdev(dev);
goto out;
}
} else {
err = register_netdevice(dev);
if (err < 0) {
if (dev->destructor)
dev->destructor(dev);
else
free_netdev(dev);
goto out;
}
}
But I don't know if it breaks the design newlink and destructor.
BTW, I think although the batadv_softif_create is legacy, we should fix it
when it still exists :)
Regards
Feng
next prev parent reply other threads:[~2017-04-26 6:44 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-25 12:03 [B.A.T.M.A.N.] [PATCH net] net: batman-adv: Fix possible memleaks when fail to register_netdevice gfree.wind
2017-04-25 13:53 ` Sven Eckelmann
2017-04-26 0:41 ` Gao Feng
2017-04-26 5:57 ` Sven Eckelmann
2017-04-26 6:44 ` Gao Feng [this message]
2017-04-26 7:16 ` Sven Eckelmann
2017-04-26 7:28 ` Gao Feng
2017-06-09 7:23 ` Sven Eckelmann
2017-06-09 7:26 ` 高峰
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