From patchwork Wed Jul 20 05:01:29 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Raymond X-Patchwork-Id: 105581 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id E2647B6F74 for ; Wed, 20 Jul 2011 15:05:39 +1000 (EST) Received: from localhost ([::1]:56853 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QjOyV-0007P0-Q3 for incoming@patchwork.ozlabs.org; Wed, 20 Jul 2011 01:05:35 -0400 Received: from eggs.gnu.org ([140.186.70.92]:46298) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QjOvL-0007OK-F2 for qemu-devel@nongnu.org; Wed, 20 Jul 2011 01:02:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QjOvJ-0005CM-NE for qemu-devel@nongnu.org; Wed, 20 Jul 2011 01:02:18 -0400 Received: from mail-vx0-f173.google.com ([209.85.220.173]:49605) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QjOvJ-0005Bj-JV for qemu-devel@nongnu.org; Wed, 20 Jul 2011 01:02:17 -0400 Received: by mail-vx0-f173.google.com with SMTP id 29so3304581vxi.4 for ; Tue, 19 Jul 2011 22:02:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=phRugYaZ0uV3po39PwGN/Jk8BfGU5SMnF8mYqO1DyMc=; b=dwhRqyG/ZhZBiw6H7ru2omp1nWFDuQ3K+CGCoJtkE3RjB0ypeWvUm0IV6sstFGUhVE OJkPzywZmCYjIqfzARHRhmE37T7gbfFSIsXejINl2sGoOvSaZZG7tV9mtgwftit3pkAG BH1IHEFvj1iFAkqNJxqdZBWBtgDUdcLQCQIEo= Received: by 10.220.3.72 with SMTP id 8mr2279304vcm.21.1311138137286; Tue, 19 Jul 2011 22:02:17 -0700 (PDT) Received: from localhost.localdomain (modemcable055.201-23-96.mc.videotron.ca [96.23.201.55]) by mx.google.com with ESMTPS id m9sm2554792vcv.40.2011.07.19.22.02.15 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 19 Jul 2011 22:02:16 -0700 (PDT) From: Alexandre Raymond To: qemu-devel@nongnu.org Date: Wed, 20 Jul 2011 01:01:29 -0400 Message-Id: <1311138090-2909-2-git-send-email-cerbere@gmail.com> X-Mailer: git-send-email 1.7.5 In-Reply-To: <1311138090-2909-1-git-send-email-cerbere@gmail.com> References: <1311138090-2909-1-git-send-email-cerbere@gmail.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-Received-From: 209.85.220.173 Cc: Alexandre Raymond , pbonzini@redhat.com, andreas.faerber@web.de, agraf@suse.de, jan.kiszka@siemens.com Subject: [Qemu-devel] [RFC PATCH 1/2] Signals: fix race condition with aio-compat X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org There appears to be a race condition when SIGUSR2 is not handled synchronously by the signalfd thread. This caused random freezes/segfaults under OS X. This fix also appears to fix most of the I/O errors that occur when the io-thread is enabled on OS X. Signed-off-by: Alexandre Raymond --- cpus.c | 6 ++---- 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/cpus.c b/cpus.c index 3035314..f466d95 100644 --- a/cpus.c +++ b/cpus.c @@ -391,10 +391,6 @@ static int qemu_signal_init(void) sigset_t set; #ifdef CONFIG_IOTHREAD - /* SIGUSR2 used by posix-aio-compat.c */ - sigemptyset(&set); - sigaddset(&set, SIGUSR2); - pthread_sigmask(SIG_UNBLOCK, &set, NULL); /* * SIG_IPI must be blocked in the main thread and must not be caught @@ -406,11 +402,13 @@ static int qemu_signal_init(void) pthread_sigmask(SIG_BLOCK, &set, NULL); sigemptyset(&set); + sigaddset(&set, SIGUSR2); sigaddset(&set, SIGIO); sigaddset(&set, SIGALRM); sigaddset(&set, SIGBUS); #else sigemptyset(&set); + sigaddset(&set, SIGUSR2); sigaddset(&set, SIGBUS); if (kvm_enabled()) { /*