From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754144Ab2B0Rep (ORCPT ); Mon, 27 Feb 2012 12:34:45 -0500 Received: from mail-qy0-f174.google.com ([209.85.216.174]:58584 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753324Ab2B0Reo (ORCPT ); Mon, 27 Feb 2012 12:34:44 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of mcgrathr@google.com designates 10.224.178.136 as permitted sender) smtp.mail=mcgrathr@google.com; dkim=pass header.i=mcgrathr@google.com MIME-Version: 1.0 In-Reply-To: <20120227172208.GC10608@redhat.com> References: <1330140111-17201-1-git-send-email-wad@chromium.org> <1330140111-17201-8-git-send-email-wad@chromium.org> <20120227172208.GC10608@redhat.com> From: Roland McGrath Date: Mon, 27 Feb 2012 09:34:19 -0800 Message-ID: Subject: Re: [PATCH v11 08/12] signal, x86: add SIGSYS info and make it synchronous. To: Oleg Nesterov Cc: Will Drewry , 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, hpa@zytor.com, mingo@redhat.com, peterz@infradead.org, rdunlap@xenotime.net, tglx@linutronix.de, luto@mit.edu, eparis@redhat.com, serge.hallyn@canonical.com, djm@mindrot.org, scarybeasts@gmail.com, indan@nul.nu, pmoore@redhat.com, akpm@linux-foundation.org, corbet@lwn.net, eric.dumazet@gmail.com, markus@chromium.org, coreyb@linux.vnet.ibm.com, keescook@chromium.org Content-Type: text/plain; charset=ISO-8859-1 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 27, 2012 at 9:22 AM, Oleg Nesterov wrote: > SYNCHRONOUS_MASK just tells dequeue_signal() "pick them first". > This is needed to make sure that the handler for, say SIGSEGV, > can use ucontext->ip as a faulting addr. It's desireable to have these signals handled first just so that the thread state that provoked the signal is not obscured by an unrelated asynchronous signal having its handler setup done beforehand.