From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46970) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dcq5w-0005Co-9Z for qemu-devel@nongnu.org; Wed, 02 Aug 2017 05:37:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dcq5t-0007Yd-6E for qemu-devel@nongnu.org; Wed, 02 Aug 2017 05:37:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50954) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dcq5t-0007Xh-0i for qemu-devel@nongnu.org; Wed, 02 Aug 2017 05:37:33 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E1FC85AFC8 for ; Wed, 2 Aug 2017 09:37:31 +0000 (UTC) Date: Wed, 2 Aug 2017 17:37:27 +0800 From: Peter Xu Message-ID: <20170802093727.GA5561@pxdev.xzpeter.org> References: <1501644321-17721-1-git-send-email-peterx@redhat.com> <1501644321-17721-3-git-send-email-peterx@redhat.com> <20170802093020.GD4098@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20170802093020.GD4098@redhat.com> Subject: Re: [Qemu-devel] [PATCH 2/2] io: fix qio_channel_socket_accept err handling List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: qemu-devel@nongnu.org, Laurent Vivier , Juan Quintela , "Dr . David Alan Gilbert" On Wed, Aug 02, 2017 at 10:30:20AM +0100, Daniel P. Berrange wrote: > On Wed, Aug 02, 2017 at 11:25:21AM +0800, Peter Xu wrote: > > When accept failed, we should setup errp with the reason. More > > importantly, the caller may assume errp be non-NULL when error happens, > > and not setting the errp may crash QEMU. > > > > At the same time, move the trace_qio_channel_socket_accept_fail() after > > the if check on EINTR. Two reasons: > > > > 1. when EINTR happened, it's not really a fault (we should just try > > again), so we should not log with an "accept failure". > > > > 2. trace_*() functions may overwrite errno, then the old errno will be > > missing. We need to either check errno before trace_*() calls, or > > reserve the errno. > > > > Signed-off-by: Peter Xu > > --- > > io/channel-socket.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/io/channel-socket.c b/io/channel-socket.c > > index 53386b7..442f230 100644 > > --- a/io/channel-socket.c > > +++ b/io/channel-socket.c > > @@ -340,10 +340,11 @@ qio_channel_socket_accept(QIOChannelSocket *ioc, > > cioc->fd = qemu_accept(ioc->fd, (struct sockaddr *)&cioc->remoteAddr, > > &cioc->remoteAddrLen); > > if (cioc->fd < 0) { > > - trace_qio_channel_socket_accept_fail(ioc); > > if (errno == EINTR) { > > goto retry; > > } > > + trace_qio_channel_socket_accept_fail(ioc); > > + error_setg_errno(errp, errno, "Unable to accept connection"); > > Err, you're still clobbering errno in trace_qio_channel_socket_accept_fail > before calling error_setg_errno Oops! I'll do a quick respin. Thanks for pointing out. -- Peter Xu