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From: David Miller <davem@davemloft.net>
To: daniel@iogearbox.net
Cc: chamaken@gmail.com, netdev@vger.kernel.org, fw@strlen.de
Subject: Re: [PATCHv1 net-next 0/5] netlink: mmap: kernel panic and some issues
Date: Tue, 08 Sep 2015 22:59:57 -0700 (PDT)	[thread overview]
Message-ID: <20150908.225957.1900230517834836583.davem@davemloft.net> (raw)
In-Reply-To: <55EDA536.10707@iogearbox.net>

From: Daniel Borkmann <daniel@iogearbox.net>
Date: Mon, 07 Sep 2015 16:54:46 +0200

> On 08/17/2015 11:02 PM, David Miller wrote:
> ...
>> I would seriously rather see us do an expensive full copy of the SKB
>> than to have traffic which is unexpectedly invisible to taps.
> 
> I've been looking into this issue a bit further, so the copy for the
> tap seems doable, but while further going through the code to find
> similar
> issues elsewhere, and doing some experiments, it looks like we write
> shared info also in some edge-cases of upcalls such as nfqueue or ovs
> when mmaped netlink is used for rx. I did a test with nfqueue using
> the libmnl mmap branch [1].

Honestly if it's something isolated to something like nf_queue it can
be contained to just being a special fix there.

nf_queue is usually very special and needs hacks to handle things
properly since it acts as an "escape" point for various SKB things.

But if it's in OVS too....

I guess we need a more generic fix.

  reply	other threads:[~2015-09-09  5:59 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-22 13:17 [RFC PATCH 0/5] netlink: mmap kernel panic and some issues Ken-ichirou MATSUZAWA
2015-08-12  8:28 ` [PATCHv1 net-next 0/5] netlink: mmap: " Ken-ichirou MATSUZAWA
2015-08-12  8:31   ` [PATCHv1 net-next 1/5] netlink: mmap: introduce mmaped skb helper functions Ken-ichirou MATSUZAWA
2015-08-12  8:32   ` [PATCHv1 net-next 2/5] netlink: mmap: apply " Ken-ichirou MATSUZAWA
2015-08-12  8:34   ` [PATCHv1 net-next 3/5] netlink: mmap: fix status for not delivered skb Ken-ichirou MATSUZAWA
2015-08-12  8:35   ` [PATCHv1 net-next 4/5] netlink: mmap: update tx type check Ken-ichirou MATSUZAWA
2015-08-12  8:38   ` [PATCHv1 net-next 5/5] netlink: mmap: notify only when NL_MMAP_STATUS_VALID frame exists Ken-ichirou MATSUZAWA
2015-08-12 23:38   ` [PATCHv1 net-next 0/5] netlink: mmap: kernel panic and some issues David Miller
2015-08-14  8:58     ` Ken-ichirou MATSUZAWA
2015-08-14 10:01       ` Daniel Borkmann
2015-08-14 10:38         ` Daniel Borkmann
2015-08-15  2:25           ` Ken-ichirou MATSUZAWA
2015-08-17 21:02           ` David Miller
2015-08-19 14:29             ` Daniel Borkmann
2015-09-02  0:04               ` Ken-ichirou MATSUZAWA
2015-09-02  9:47                 ` Daniel Borkmann
2015-09-02 11:35                   ` Ken-ichirou MATSUZAWA
2015-09-02 15:56                     ` Daniel Borkmann
2015-09-02 22:27                       ` Ken-ichirou MATSUZAWA
2015-09-07 14:54             ` Daniel Borkmann
2015-09-09  5:59               ` David Miller [this message]
2015-09-09  8:53               ` Thomas Graf
2015-09-09  9:22                 ` Daniel Borkmann
2015-08-20  3:43           ` [PATCH net] netlink: mmap: fix tx type check Ken-ichirou MATSUZAWA
2015-08-23 23:06             ` David Miller
2015-08-20  5:54           ` [PATCH net] netlink: rx mmap: fix POLLIN condition Ken-ichirou MATSUZAWA
2015-08-26  3:17             ` David Miller
2015-08-28  7:00               ` Ken-ichirou MATSUZAWA
2015-08-28  7:05                 ` [PATCH net] netlink: mmap: fix lookup frame position Ken-ichirou MATSUZAWA
2015-08-29  5:26                   ` David Miller
2015-08-30 22:54                 ` [PATCH net] netlink: rx mmap: fix POLLIN condition Ken-ichirou MATSUZAWA
2015-08-31  4:56                   ` David Miller
2015-08-20  7:07           ` [PATCH net] netlink: mmap: fix status setting in skb destructor Ken-ichirou MATSUZAWA
2015-08-26  3:22             ` David Miller
2015-08-28  7:37               ` Ken-ichirou MATSUZAWA

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