lkml.org 
[lkml]   [2007]   [Jul]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] fix theoretical ccids_{read,write}_lock() race
On 07/21, Andrew Morton wrote:
>
> On Sat, 21 Jul 2007 19:02:06 +0400 Oleg Nesterov <oleg@tv-sign.ru> wrote:
>
> > Make sure that spin_unlock_wait() is properly ordered wrt atomic_inc().
> >
> > Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
> >
> > --- t/net/dccp/ccid.c~ccid 2006-12-18 18:17:31.000000000 +0300
> > +++ t/net/dccp/ccid.c 2007-07-21 18:29:21.000000000 +0400
> > @@ -40,6 +40,7 @@ static inline void ccids_write_unlock(vo
> > static inline void ccids_read_lock(void)
> > {
> > atomic_inc(&ccids_lockct);
> > + smp_mb__after_atomic_inc();
> > spin_unlock_wait(&ccids_lock);
> > }
> >
>
> Why not just use standard rwlocks in there?
>
> (This is probably an FAQ, but it should be).

Perhaps because read_lock() doesn't allow to sleep?

Oleg.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-07-21 21:13    [from the cache]
©2003-2011 Jasper Spaans