Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754285AbaGOPzQ (ORCPT ); Tue, 15 Jul 2014 11:55:16 -0400 Received: from mail-la0-f46.google.com ([209.85.215.46]:35468 "EHLO mail-la0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750722AbaGOPzO (ORCPT ); Tue, 15 Jul 2014 11:55:14 -0400 MIME-Version: 1.0 In-Reply-To: <53C54CA0.1060904@oracle.com> References: <195642a5e9fd4515ad8ca4cd8bcffd4900df5790.1405437568.git.luto@amacapital.net> <20140715153801.GX3403@laptop.dumpdata.com> <53C54CA0.1060904@oracle.com> From: Andy Lutomirski Date: Tue, 15 Jul 2014 08:54:53 -0700 Message-ID: Subject: Re: [PATCH] x86_64,xen,espfix: Initialize espfix on secondary CPUs To: Boris Ostrovsky Cc: Konrad Rzeszutek Wilk , "H. Peter Anvin" , "linux-kernel@vger.kernel.org" , stable Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 15, 2014 at 8:45 AM, Boris Ostrovsky wrote: > On 07/15/2014 11:38 AM, Konrad Rzeszutek Wilk wrote: >> >> On Tue, Jul 15, 2014 at 08:26:41AM -0700, Andy Lutomirski wrote: >>> >>> Xen doesn't call start_secondary. >> >> Duh! >>> >>> Cc: stable@vger.kernel.org >>> Signed-off-by: Andy Lutomirski >>> --- >>> >>> espfix still doesn't seem to work on Xen (it goes boom in some way that >>> I don't understand right now), but initializing all CPUs instead of just >>> one of them seems like a good start. >>> >>> ISTM the right fix is probably to shove the espfix logic into >>> native_iret and to tweak the paravirt logic so that native_iret always >>> gets invoked. I suspect that Xen will need its own implementation of >>> espfix64 in the hypervisor and that, ultimately, someone may want to >>> stop initializing espfix64 at all on Xen guests. >> >> I think just disallowing would be preferrable. > > > I've been looking at sigreturn_64 and it seems to be crashing dom0 (with > both mine and your patches). In kprobe_int3_handler(). You need: http://lkml.kernel.org/g/c4e339882c121aa76254f2adde3fcbdf502faec2.1405099506.git.luto@amacapital.net The newer version of sigreturn_32 that I pushed is a much better test -- it tests the 64-bit cases (yay thunks!) and works on kernels without my SS sigcontext fix. --Andy -- 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/