From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1IbKYY-00019m-4G for user-mode-linux-devel@lists.sourceforge.net; Fri, 28 Sep 2007 11:27:18 -0700 Received: from smtp2.linux-foundation.org ([207.189.120.14]) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1IbKYW-0001Nv-Km for user-mode-linux-devel@lists.sourceforge.net; Fri, 28 Sep 2007 11:27:17 -0700 Date: Fri, 28 Sep 2007 11:26:34 -0700 From: Andrew Morton 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> Mime-Version: 1.0 Subject: Re: [uml-devel] [PATCH] UML - Fix locking in skb alloction failure fix List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: user-mode-linux-devel-bounces@lists.sourceforge.net Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net To: Jeff Dike Cc: LKML , uml-devel 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?? ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel From mboxrd@z Thu Jan 1 00:00:00 1970 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 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??