From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38659) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dcMsG-0000Cz-9H for qemu-devel@nongnu.org; Mon, 31 Jul 2017 22:25:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dcMsB-0006Hh-Ba for qemu-devel@nongnu.org; Mon, 31 Jul 2017 22:25:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49866) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dcMsB-0006H1-5N for qemu-devel@nongnu.org; Mon, 31 Jul 2017 22:25:27 -0400 Date: Tue, 1 Aug 2017 10:25:19 +0800 From: Peter Xu Message-ID: <20170801022519.GB15697@pxdev.xzpeter.org> References: <1501229198-30588-1-git-send-email-peterx@redhat.com> <1501229198-30588-4-git-send-email-peterx@redhat.com> <20170731165339.GD2122@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20170731165339.GD2122@work-vm> Subject: Re: [Qemu-devel] [RFC 03/29] io: fix qio_channel_socket_accept err handling List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: qemu-devel@nongnu.org, Laurent Vivier , Alexey Perevalov , Juan Quintela , Andrea Arcangeli , berrange@redhat.com, stefanha@redhat.com On Mon, Jul 31, 2017 at 05:53:39PM +0100, Dr. David Alan Gilbert wrote: > * Peter Xu (peterx@redhat.com) 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. > > > > Signed-off-by: Peter Xu > > --- > > io/channel-socket.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/io/channel-socket.c b/io/channel-socket.c > > index 53386b7..7bc308e 100644 > > --- a/io/channel-socket.c > > +++ b/io/channel-socket.c > > @@ -344,6 +344,7 @@ qio_channel_socket_accept(QIOChannelSocket *ioc, > > if (errno == EINTR) { > > goto retry; > > } > > + error_setg_errno(errp, errno, "Unable to accept connection"); > > goto error; > > OK, but this code actually has a bigger problem as well: > > the original is: > > 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; > } > goto error; > } > > Stefan confirmed that trace_ doesn't preserve errno; so the if > following it is wrong. It needs to preserve errno. Ah... If so, not sure whether we can do the reservation in trace codes in general? For this one, I can just move the trace_*() below the errno check. After all, if EINTR is got, it's not really a fail, so imho we should not trace it with "accept fail". > > (Again this patch can go on it's own) Yes. For these patches, I intentionally put them at the beginning of the series (for easier picking up standalone). Do you (or Juan?) want me to repost these patches separately? -- Peter Xu