Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756134Ab2BWWQL (ORCPT ); Thu, 23 Feb 2012 17:16:11 -0500 Received: from smarthost1.greenhost.nl ([195.190.28.78]:60529 "EHLO smarthost1.greenhost.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754575Ab2BWWQI (ORCPT ); Thu, 23 Feb 2012 17:16:08 -0500 Message-ID: In-Reply-To: References: <1329845435-2313-1-git-send-email-wad@chromium.org> <1329845435-2313-7-git-send-email-wad@chromium.org> <9edbabb2262e3d91a7b8c75dbec03d7f.squirrel@webmail.greenhost.nl> <4F45887A.5010809@zytor.com> <4F459109.1060205@zytor.com> Date: Thu, 23 Feb 2012 23:15:51 +0100 Subject: Re: [PATCH v10 07/11] signal, x86: add SIGSYS info and make it synchronous. From: "Indan Zupancic" To: "Will Drewry" Cc: "Roland McGrath" , "H. Peter Anvin" , "Kees Cook" , "Andrew Lutomirski" , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, kernel-hardening@lists.openwall.com, netdev@vger.kernel.org, x86@kernel.org, arnd@arndb.de, davem@davemloft.net, mingo@redhat.com, oleg@redhat.com, peterz@infradead.org, rdunlap@xenotime.net, tglx@linutronix.de, eparis@redhat.com, serge.hallyn@canonical.com, djm@mindrot.org, scarybeasts@gmail.com, pmoore@redhat.com, akpm@linux-foundation.org, corbet@lwn.net, eric.dumazet@gmail.com, markus@chromium.org User-Agent: SquirrelMail/1.4.22 MIME-Version: 1.0 Content-Type: text/plain;charset=UTF-8 Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) Importance: Normal X-Spam-Score: 0.1 X-Scan-Signature: 71684ae416b12bc74806129cb02de027 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1127 Lines: 29 On Thu, February 23, 2012 20:26, Will Drewry wrote: > Seems like there's an argument for another return code, > SECCOMP_RET_CORE, that resets/unblocks the SIGSYS handler since the > existing TRAP and KILL options seem to cover the other paths (signal > handler and do_exit). What about making SECCOMP_RET_TRAP dump core/send SIGSYS if there is no tracer with PTRACE_O_SECCOMP set? And perhaps go for a blockable SIGSYS? That way you only have KILL, ERRNO and TRAP, with the last one meaning deny, but giving someone else a chance to do something. Or is that just confusing? I don't think there should be too many return values, or else you put too much runtime policy into the filters. Sending SIGSYS is useful, but it's quite a bit less useful if user space can't handle it in a signal handler, so I don't think it's worth it to make a unblockable version. Greetings, Indan -- 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/