From patchwork Wed Sep 2 03:25:22 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 513278 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 510511401F0 for ; Wed, 2 Sep 2015 13:29:05 +1000 (AEST) Received: from localhost ([::1]:32967 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZWyjP-0004A0-57 for incoming@patchwork.ozlabs.org; Tue, 01 Sep 2015 23:29:03 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43257) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZWyg9-0007FK-D9 for qemu-devel@nongnu.org; Tue, 01 Sep 2015 23:25:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZWyg8-0006lV-Mt for qemu-devel@nongnu.org; Tue, 01 Sep 2015 23:25:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34346) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZWyg8-0006kw-HW for qemu-devel@nongnu.org; Tue, 01 Sep 2015 23:25:40 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id 3C02231CED8; Wed, 2 Sep 2015 03:25:40 +0000 (UTC) Received: from jason-ThinkPad-T430s.nay.redhat.com (dhcp-14-122.nay.redhat.com [10.66.14.122]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t823PQfl024102; Tue, 1 Sep 2015 23:25:37 -0400 From: Jason Wang To: qemu-devel@nongnu.org Date: Wed, 2 Sep 2015 11:25:22 +0800 Message-Id: <1441164325-14417-6-git-send-email-jasowang@redhat.com> In-Reply-To: <1441164325-14417-1-git-send-email-jasowang@redhat.com> References: <1441164325-14417-1-git-send-email-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Peter Maydell , mst@redhat.com, Jason Wang , cornelia.huck@de.ibm.com, Paolo Bonzini , Greg Kurz Subject: [Qemu-devel] [PATCH V2 5/8] memory: don't try to adjust endianness for zero length eventfd 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's no need to adjust endianness for zero length eventfd since the data wrote was actually ignored by kernel. So skip the adjust in this case to fix a possible crash when trying to use wildcard mmio eventfd in ppc. Cc: Greg Kurz Cc: Peter Maydell Cc: Paolo Bonzini Signed-off-by: Jason Wang Acked-by: Greg Kurz --- memory.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/memory.c b/memory.c index 0d8b2d9..de2d999 100644 --- a/memory.c +++ b/memory.c @@ -1653,7 +1653,9 @@ void memory_region_add_eventfd(MemoryRegion *mr, }; unsigned i; - adjust_endianness(mr, &mrfd.data, size); + if (size) { + adjust_endianness(mr, &mrfd.data, size); + } memory_region_transaction_begin(); for (i = 0; i < mr->ioeventfd_nb; ++i) { if (memory_region_ioeventfd_before(mrfd, mr->ioeventfds[i])) { @@ -1686,7 +1688,9 @@ void memory_region_del_eventfd(MemoryRegion *mr, }; unsigned i; - adjust_endianness(mr, &mrfd.data, size); + if (size) { + adjust_endianness(mr, &mrfd.data, size); + } memory_region_transaction_begin(); for (i = 0; i < mr->ioeventfd_nb; ++i) { if (memory_region_ioeventfd_equal(mrfd, mr->ioeventfds[i])) {