Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753554AbYHINcV (ORCPT ); Sat, 9 Aug 2008 09:32:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751919AbYHINcC (ORCPT ); Sat, 9 Aug 2008 09:32:02 -0400 Received: from rhun.apana.org.au ([64.62.148.172]:49090 "EHLO arnor.apana.org.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751547AbYHINcA (ORCPT ); Sat, 9 Aug 2008 09:32:00 -0400 Date: Sat, 9 Aug 2008 21:31:38 +0800 From: Herbert Xu To: Suresh Siddha Cc: "H. Peter Anvin" , Wolfgang Walter , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Ingo Molnar , "viro@ZenIV.linux.org.uk" , "vegard.nossum@gmail.com" Subject: Re: Kernel oops with 2.6.26, padlock and ipsec: probably problem with fpu state changes Message-ID: <20080809133138.GA30064@gondor.apana.org.au> References: <200807171653.59177.wolfgang.walter@stwm.de> <20080806201401.GA607@linux-os.sc.intel.com> <200808071823.02364.wolfgang.walter@stwm.de> <200808081236.55172.wolfgang.walter@stwm.de> <20080808185356.GC607@linux-os.sc.intel.com> <489C97FB.2030408@zytor.com> <20080808231121.GA13158@linux-os.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080808231121.GA13158@linux-os.sc.intel.com> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1133 Lines: 28 On Fri, Aug 08, 2008 at 04:11:21PM -0700, Suresh Siddha wrote: > > b) Looking deeper, do we need to disable interrupts in the kernel_fpu_begin()? > Is there a recursive case, where interrupt context also touches FPU/SSE > registers? Even if there wasn't one before, there is going to be one now because as you pointed out yourself, if we get an inbound IPsec packet between any kernel_fpu_begin/kernel_fpu_end area, we could get a nested kernel_fpu_end which puts us back to square one wrt to the original race. So clearly we need to think more about this issue. Unless we can come up with a new solution quickly, I recommend that we back out the FPU changes. Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- 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/