From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1aWs7H-0004Ec-G6 for mharc-qemu-trivial@gnu.org; Fri, 19 Feb 2016 15:57:31 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53715) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aWs7F-0004Cm-KU for qemu-trivial@nongnu.org; Fri, 19 Feb 2016 15:57:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aWs7E-0007qS-LO for qemu-trivial@nongnu.org; Fri, 19 Feb 2016 15:57:29 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55852) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aWs78-0007mV-MF; Fri, 19 Feb 2016 15:57:22 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id 8D7A4C00DDE0; Fri, 19 Feb 2016 20:57:21 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com ([10.3.113.10]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u1JKvJY5025160; Fri, 19 Feb 2016 15:57:20 -0500 To: Wei Huang , qemu-devel@nongnu.org References: <1455905587-4347-1-git-send-email-wei@redhat.com> From: Laszlo Ersek Message-ID: <56C781AE.5050004@redhat.com> Date: Fri, 19 Feb 2016 21:57:18 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <1455905587-4347-1-git-send-email-wei@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: qemu-trivial@nongnu.org, mst@redhat.com Subject: Re: [Qemu-trivial] [Qemu-devel] [PATCH 1/1] virtio-rng: fix condition checking on period_ms X-BeenThere: qemu-trivial@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 Feb 2016 20:57:30 -0000 On 02/19/16 19:13, Wei Huang wrote: > The condition checking on vrng->conf.period_ms appears to be wrong, > conflicting with the error comment following it. > > Signed-off-by: Wei Huang > --- > hw/virtio/virtio-rng.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/virtio/virtio-rng.c b/hw/virtio/virtio-rng.c > index 473c044..a06427c 100644 > --- a/hw/virtio/virtio-rng.c > +++ b/hw/virtio/virtio-rng.c > @@ -149,7 +149,7 @@ static void virtio_rng_device_realize(DeviceState *dev, Error **errp) > VirtIORNG *vrng = VIRTIO_RNG(dev); > Error *local_err = NULL; > > - if (!vrng->conf.period_ms > 0) { > + if (!(vrng->conf.period_ms > 0)) { > error_setg(errp, "'period' parameter expects a positive integer"); > return; > } > The current condition is absolutely weird, but I think it happens to work correctly: Period_ms has type uint32_t. If it is positive, then !period_ms is zero. 0>0 is false, hence the error message is not printed. If period_ms is zero, then !period_ms is 1. 1>0 is true, hence the error message is printed. I would rewrite the check as if (vrng->conf.period_ms == 0) { error_setg(...) Thanks Laszlo