From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57810) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XSSfA-00058m-6H for qemu-devel@nongnu.org; Fri, 12 Sep 2014 11:21:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XSSf5-0005Od-5G for qemu-devel@nongnu.org; Fri, 12 Sep 2014 11:21:28 -0400 Date: Fri, 12 Sep 2014 11:21:10 -0400 From: Luiz Capitulino Message-ID: <20140912112110.3b61c84b@redhat.com> In-Reply-To: <1410530852-13631-1-git-send-email-psomas@grnet.gr> References: <87wq991g1c.fsf@blackfin.pond.sub.org> <1410530852-13631-1-git-send-email-psomas@grnet.gr> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH resend 1/2] monitor: Reset HMP mon->rs on CHR_EVENT_CLOSED List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stratos Psomadakis Cc: synnefo-devel@googlegroups.com, qemu-devel@nongnu.org, armbru@redhat.com, qemu-stable@nongnu.org On Fri, 12 Sep 2014 17:07:32 +0300 Stratos Psomadakis wrote: > Commit cdaa86a54 ("Add G_IO_HUP handler for socket chardev") exposed a bug in > the way the HMP monitor handles its command buffer. When a client closes the > connection to the monitor, tcp_chr_read() will detect the G_IO_HUP condition > and call tcp_chr_disconnect() to close the server-side connection too. Due to > the fact that monitor reads 1 byte at a time (for each tcp_chr_read()), the > monitor readline state / buffers might contain junk (i.e. a half-finished > command). Thus, without calling readline_restart() on mon->rs upon > CHR_EVENT_CLOSED, future HMP commands will fail. What's your reproducer? Are you using the mux feature? We also reset it in CHR_EVENT_OPENED if the mux feature is not used, why isn't that good enough? > > Signed-off-by: Stratos Psomadakis > Signed-off-by: Dimitris Aragiorgis > --- > monitor.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/monitor.c b/monitor.c > index 34cee74..7857300 100644 > --- a/monitor.c > +++ b/monitor.c > @@ -5252,6 +5252,7 @@ static void monitor_event(void *opaque, int event) > break; > > case CHR_EVENT_CLOSED: > + readline_restart(mon->rs); > mon_refcount--; > monitor_fdsets_cleanup(); > break;