Re: AX.25 in kernel 2.5 status?

[Ralf Baechle DO1GRB <ralf@linux-mips.org>]

On Fri, Oct 11, 2002 at 02:47:36PM +0100, Steven Whitehouse wrote:

> > I yesterday published my changes to redo the /proc files for AX.25,
> > NET/ROM and ROSE with the seq_file stuff.  As usually these changesets
> > are available at http://linux-ham.bkbits.net/linux-2.5.
> > 
> > 73 de DO1GRB op Ralf
> 
> It seems you beat me to it :-) though there is one extra thing that still needs
> to be fixed in the uid code from my patch where ax25_findbyuid() returns
> a pointer to a structure which might disappear at any time. Its only use
> is to check permissions at bind time, so I just moved the check under
> the lock,

Unfortunately the code is full of such funnies.  Remember as the code is
in 2.5 there are no more locks outside protecting us from our own thread
safety - or rather the lack thereof.  In particular the socket locking
is rather hard to get right.

Another problem we still have - and we're sharing it with other protocols
such ipv4 - is that our proc code is holding a lock for the time the
/proc file is open.  That's not a significant time but it may delay
access, so I've made most of those loads rw locks.  Worst case a buggy
or malicious piece of software might even hold a proc file open for a long
time thereby stalling the functioning of the stack partially or fully.

If you could update your fix I certainly would accept it :)

73 de DO1GRB op Ralf

--
Loc. JN47BS / CQ 14 / ITU 28 / DOK A21