From: David Miller <davem@davemloft.net>
To: luto@amacapital.net
Cc: torvalds@linux-foundation.org, kaber@trash.net,
netdev@vger.kernel.org, tgraf@suug.ch
Subject: Re: Netlink mmap tx security?
Date: Tue, 14 Oct 2014 22:09:08 -0400 (EDT) [thread overview]
Message-ID: <20141014.220908.123550384430402000.davem@davemloft.net> (raw)
In-Reply-To: <CALCETrW1HFJ3QXMfV9Hv922eax0hbHJn5GmHPvtED8_JR5KOVg@mail.gmail.com>
From: Andy Lutomirski <luto@amacapital.net>
Date: Tue, 14 Oct 2014 19:03:11 -0700
> On Tue, Oct 14, 2014 at 7:01 PM, David Miller <davem@davemloft.net> wrote:
>> I really think this means I'll have to remove all of the netlink
>> mmap() support in order to prevent from breaking applications. :(
>>
>> The other option is to keep NETLINK_TX_RING, but copy the data into
>> a kernel side buffer before acting upon it.
>
> Option 3, which sucks but maybe not that badly: change the value of
> NETLINK_RX_RING. (Practically: add NETLINK_RX_RING2 or something like
> that.)
That would work as well.
There are pros and cons to all of these approaches.
I was thinking that if we do the "TX mmap --> copy to kernel buffer"
approach, then if in the future we find a way to make it work
reliably, we can avoid the copy. And frankly performance wise it's no
worse than what happens via normal sendmsg() calls.
And all applications using NETLINK_RX_RING keep working and keep
getting the performance boost.
next prev parent reply other threads:[~2014-10-15 2:09 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CALCETrWsCqy7KEKPTOeHjrO1c2JE1E_seO_J+yA=sYFhS11NXQ@mail.gmail.com>
2014-05-12 21:08 ` Netlink mmap tx security? Andy Lutomirski
2014-10-11 22:29 ` Andy Lutomirski
2014-10-11 23:09 ` David Miller
2014-10-14 19:19 ` David Miller
2014-10-14 19:33 ` Andy Lutomirski
2014-10-14 20:00 ` David Miller
2014-10-14 22:16 ` Andy Lutomirski
2014-10-15 2:01 ` David Miller
2014-10-15 2:03 ` Andy Lutomirski
2014-10-15 2:09 ` David Miller [this message]
2014-10-16 6:45 ` Daniel Borkmann
2014-10-16 7:07 ` Thomas Graf
2014-12-16 22:58 ` David Miller
2014-12-16 23:58 ` Daniel Borkmann
2014-12-17 16:27 ` Thomas Graf
2014-12-18 17:36 ` David Miller
2014-12-17 0:02 ` Eric Dumazet
2014-12-17 16:26 ` Thomas Graf
2014-12-18 10:30 ` [PATCH net] netlink: Don't reorder loads/stores before marking mmap netlink frame as available Thomas Graf
2014-12-18 17:36 ` David Miller
2014-12-18 19:13 ` Linus Torvalds
2014-10-15 23:45 ` Netlink mmap tx security? Daniel Borkmann
2014-10-15 23:57 ` David Miller
2014-10-15 23:58 ` Andy Lutomirski
2014-10-16 3:34 ` David Miller
2014-10-16 5:52 ` Thomas Graf
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