Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757582AbbFCQNe (ORCPT ); Wed, 3 Jun 2015 12:13:34 -0400 Received: from mail-ig0-f181.google.com ([209.85.213.181]:37273 "EHLO mail-ig0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754777AbbFCQNY (ORCPT ); Wed, 3 Jun 2015 12:13:24 -0400 Date: Wed, 3 Jun 2015 10:13:21 -0600 From: Tycho Andersen To: Oleg Nesterov Cc: Andrey Wagin , LKML , linux-api@vger.kernel.org, Kees Cook , Andy Lutomirski , Will Drewry , Roland McGrath , Pavel Emelyanov , "Serge E. Hallyn" Subject: Re: [PATCH] seccomp: add ptrace commands for suspend/resume Message-ID: <20150603161321.GD3337@hopstrocity> References: <1433186918-9626-1-git-send-email-tycho.andersen@canonical.com> <20150602130506.GA1823@hopstrocity> <20150602184848.GA24907@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150602184848.GA24907@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1259 Lines: 31 On Tue, Jun 02, 2015 at 08:48:48PM +0200, Oleg Nesterov wrote: > On 06/02, Tycho Andersen wrote: > > > > > Do we need to re-enable seccomp if a tracer detaches unexpectedly. > > > CRIU can be killed and we should try to not affect the task state even > > > in this case. > > > > Yes, I think Pavel's suggestion on the CRIU list of simply > > automatically re-enabling seccomp on ptrace detach > > But note that you can't enable tsc if the tracer dies, in this case > the tracee can be running. Yes, this does complicate things. I think I'll get rid of the TSC manipulation, since it's not clear to me how to resolve this. (I do think it makes the API slightly incomplete, though, so suggestions how to resolve it would be welcome.) > Otherwise, if we use PTRACE_O_ instead, it goes away automatically if > the tracer dies or does PTRACE_DETACH. IIRC the flag goes away, but we still have to do something in __ptrace_unlink to clear the seccomp suspended, so I'm not sure if the automatic-ness helps us. Tycho -- 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/