From: Sasha Levin <levinsasha928@gmail.com>
To: "Sjur Brændeland" <sjurbren@gmail.com>
Cc: davem@davemloft.net, davej@redhat.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: caif: Don't act on notification for non-caif devices
Date: Tue, 24 Jan 2012 10:23:26 -0500 [thread overview]
Message-ID: <CA+1xoqdZapYjS4gPf_uGwEdFQQdZ525mASr7iFKPXJdCBdRLKA@mail.gmail.com> (raw)
In-Reply-To: <CAJK669ZWJsxnSiyKWFFFUWOA3TaGMY-AmgWuVsYfR=tKQaODgg@mail.gmail.com>
On Tue, Jan 24, 2012 at 10:06 AM, Sjur Brændeland <sjurbren@gmail.com> wrote:
> Hi Sasha,
>
>>> Nack, we have to handle other device types than just ARPHDR_CAIF after
>>> introducing CAIF over USB/NCM.
>> What my patch did was simply move the type check to above the net_generic call,
>> it didn't add any new checks - which according to what you said, you'll need to do anyway.
>
> As I said I, don't think your patch would work. Try to see what happens if
> dev->type != ARPHDR_CAIF and caifd != NULL. Then the statement:
>
> if (caifd == NULL && dev->type != ARPHRD_CAIF)
> return 0;
> is very different from:
>
> if (dev->type != ARPHRD_CAIF)
> return 0;
> ...
> if (caifd == NULL)
> return 0;
Right.
> Anyway, another option could be to explicitly check if name space is
> initialized,
> similar to what net_generic() does,e.g. something like:
>
> diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
> index 673728a..3197bc2 100644
> --- a/net/caif/caif_dev.c
> +++ b/net/caif/caif_dev.c
> @@ -371,6 +371,13 @@ static int caif_device_notify(struct notifier_block *me, un
> struct cflayer *layer, *link_support;
> int head_room = 0;
> struct caif_device_entry_list *caifdevs;
> + int len;
> +
> + rcu_read_lock();
> + len = rcu_dereference(dev_net(dev)->gen)->len;
> + rcu_read_unlock();
> + if (caif_net_id > len)
> + return 0;
>
> cfg = get_cfcnfg(dev_net(dev));
> caifdevs = caif_device_list(dev_net(dev));
We could, in that case we'd just need to handle the case where it was
initialized by a device with higher id than CAIF (which we already do
I think), and do it without touching net_generic structure directly.
btw, Why do we store the devices per-namespace instead of globally? Is
it such a big benefit in performance?
next prev parent reply other threads:[~2012-01-24 15:23 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-24 7:30 [PATCH] net: caif: Don't act on notification for non-caif devices Sasha Levin
2012-01-24 10:52 ` Sjur Brændeland
2012-01-24 14:49 ` Sasha Levin
2012-01-24 15:06 ` Sjur Brændeland
2012-01-24 15:23 ` Sasha Levin [this message]
2012-01-24 22:27 ` [PATCH net] caif: Fix crash due to uninitialized net name-space Sjur Brændeland
2012-01-24 22:44 ` David Miller
2012-01-25 16:13 ` Sasha Levin
2012-01-25 20:33 ` Sjur Brændeland
2012-01-26 6:14 ` Eric Dumazet
2012-01-26 10:41 ` [PATCH] netns: fix net_alloc_generic() Eric Dumazet
2012-01-26 10:44 ` Pavel Emelyanov
2012-01-26 10:51 ` Eric Dumazet
2012-01-26 22:57 ` Eric W. Biederman
2012-01-26 23:07 ` David Miller
2012-01-26 23:57 ` Eric W. Biederman
2012-01-27 0:02 ` [PATCH 1/2] netns: Fail conspicously if someone uses net_generic at an inappropriate time Eric W. Biederman
2012-01-27 0:04 ` [PATCH 2/2] net caif: Register properly as a pernet subsystem Eric W. Biederman
2012-01-27 13:24 ` Sasha Levin
2012-01-27 14:48 ` Sjur BRENDELAND
2012-01-28 2:07 ` David Miller
2012-01-28 2:07 ` [PATCH 1/2] netns: Fail conspicously if someone uses net_generic at an inappropriate time David Miller
2012-01-27 6:09 ` [PATCH] netns: fix net_alloc_generic() Eric Dumazet
2012-01-27 6:54 ` Eric W. Biederman
2012-01-27 7:07 ` Eric Dumazet
2012-01-26 14:40 ` Sasha Levin
2012-01-26 18:37 ` David Miller
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