lkml.org 
[lkml]   [2009]   [Jan]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3] tcp: splice as many packets as possible at once
On Tue, Jan 27, 2009 at 12:16:42PM +0000, Jarek Poplawski wrote:
> On Tue, Jan 27, 2009 at 10:48:05PM +1100, Herbert Xu wrote:
> > On Tue, Jan 27, 2009 at 10:35:11AM +0000, Jarek Poplawski wrote:
> > > > > Yes, but ip_append_data() (and skb_append_datato_frags() for
> > > > > NETIF_F_UFO only, so currently not a problem), uses this differently,
> > > > > and these pages in sk->sk_sndmsg_page could leak or be used after
> > > > > kfree. (I didn't track locking in these other places).
> > > >
> > > > It'll be freed when the socket is freed so that should be fine.
> > >
> > > I don't think so: these places can overwrite sk->sk_sndmsg_page left
> > > after tcp_sendmsg(), or skb_splice_bits() now, with NULL or a new
> > > pointer without put_page() (they only reference copied chunks and
> > > expect auto freeing). On the other hand, if tcp_sendmsg() reads after
> > > them it could use a pointer after the page is freed, I guess.
> >
> > I wasn't referring to the first part of your sentence. That can't
> > happen because they're only used for UDP sockets, this is a TCP
> > socket.
>
> Do you mean this part from ip_append_data() isn't used for TCP?:

Actually, the beginning part of ip_append_data() should be enough too.
So I guess I missed your point...

Jarek P.


\
 
 \ /
  Last update: 2009-01-27 13:33    [from the cache]
©2003-2011 Jasper Spaans