Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755988AbXI1S10 (ORCPT ); Fri, 28 Sep 2007 14:27:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752981AbXI1S1T (ORCPT ); Fri, 28 Sep 2007 14:27:19 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:36036 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752624AbXI1S1S (ORCPT ); Fri, 28 Sep 2007 14:27:18 -0400 Date: Fri, 28 Sep 2007 11:26:34 -0700 From: Andrew Morton To: Jeff Dike Cc: LKML , uml-devel Subject: Re: [PATCH] UML - Fix locking in skb alloction failure fix Message-Id: <20070928112634.0bef9525.akpm@linux-foundation.org> In-Reply-To: <20070928154314.GA7185@c2.user-mode-linux.org> References: <20070928154314.GA7185@c2.user-mode-linux.org> X-Mailer: Sylpheed 2.4.1 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1461 Lines: 43 On Fri, 28 Sep 2007 11:43:14 -0400 Jeff Dike wrote: > Add _irqsave/_irqrestore to the locking in update_drop_skb to keep > uml_net_rx out while the drop skb is being messed with. > > Signed-off-by: Jeff Dike > --- > arch/um/drivers/net_kern.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > Index: linux-2.6.22/arch/um/drivers/net_kern.c > =================================================================== > --- linux-2.6.22.orig/arch/um/drivers/net_kern.c 2007-09-28 11:10:19.000000000 -0400 > +++ linux-2.6.22/arch/um/drivers/net_kern.c 2007-09-28 11:13:58.000000000 -0400 > @@ -49,9 +49,10 @@ static int drop_max; > static int update_drop_skb(int max) > { > struct sk_buff *new; > + unsigned long flags; > int err = 0; > > - spin_lock(&drop_lock); > + spin_lock_irqsave(&drop_lock, flags); > > if (max <= drop_max) > goto out; > @@ -68,7 +69,7 @@ static int update_drop_skb(int max) > drop_max = max; > err = 0; > out: > - spin_unlock(&drop_lock); > + spin_unlock_irqrestore(&drop_lock, flags); > > return err; > } Doesn't this assume that the arch is only ever uniprocessor, which I don't think is true on i386 UML?? - 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/