From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:56994) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gxBFF-0001xW-MY for qemu-devel@nongnu.org; Fri, 22 Feb 2019 08:52:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gxBFE-0006jN-DD for qemu-devel@nongnu.org; Fri, 22 Feb 2019 08:52:05 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42970) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gxBFB-0005xq-Nf for qemu-devel@nongnu.org; Fri, 22 Feb 2019 08:52:02 -0500 Date: Fri, 22 Feb 2019 13:51:27 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Message-ID: <20190222135127.GX25234@redhat.com> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= References: <48f7e50413f6f222acb1bf3a9de773e387a2855a.1550842915.git.berto@igalia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <48f7e50413f6f222acb1bf3a9de773e387a2855a.1550842915.git.berto@igalia.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v3 3/3] char-socket: Lock tcp_chr_disconnect() and socket_reconnect_timeout() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alberto Garcia Cc: qemu-devel@nongnu.org, Paolo Bonzini , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau On Fri, Feb 22, 2019 at 03:46:26PM +0200, Alberto Garcia wrote: > There's a race condition in which the tcp_chr_read() ioc handler can > close a connection that is being written to from another thread. >=20 > Running iotest 136 in a loop triggers this problem and crashes QEMU. >=20 > (gdb) bt > #0 0x00005558b842902d in object_get_class (obj=3D0x0) at qom/object.c= :860 > #1 0x00005558b84f92db in qio_channel_writev_full (ioc=3D0x0, iov=3D0x= 7ffc355decf0, niov=3D1, fds=3D0x0, nfds=3D0, errp=3D0x0) at io/channel.c:= 76 > #2 0x00005558b84e0e9e in io_channel_send_full (ioc=3D0x0, buf=3D0x555= 8baf5beb0, len=3D138, fds=3D0x0, nfds=3D0) at chardev/char-io.c:123 > #3 0x00005558b84e4a69 in tcp_chr_write (chr=3D0x5558ba460380, buf=3D0= x5558baf5beb0 "...", len=3D138) at chardev/char-socket.c:135 > #4 0x00005558b84dca55 in qemu_chr_write_buffer (s=3D0x5558ba460380, b= uf=3D0x5558baf5beb0 "...", len=3D138, offset=3D0x7ffc355dedd0, write_all=3D= false) at chardev/char.c:112 > #5 0x00005558b84dcbc2 in qemu_chr_write (s=3D0x5558ba460380, buf=3D0x= 5558baf5beb0 "...", len=3D138, write_all=3Dfalse) at chardev/char.c:147 > #6 0x00005558b84dfb26 in qemu_chr_fe_write (be=3D0x5558ba476610, buf=3D= 0x5558baf5beb0 "...", len=3D138) at chardev/char-fe.c:42 > #7 0x00005558b8088c86 in monitor_flush_locked (mon=3D0x5558ba476610) = at monitor.c:406 > #8 0x00005558b8088e8c in monitor_puts (mon=3D0x5558ba476610, str=3D0x= 5558ba921e49 "") at monitor.c:449 > #9 0x00005558b8089178 in qmp_send_response (mon=3D0x5558ba476610, rsp= =3D0x5558bb161600) at monitor.c:498 > #10 0x00005558b808920c in monitor_qapi_event_emit (event=3DQAPI_EVENT_= SHUTDOWN, qdict=3D0x5558bb161600) at monitor.c:526 > #11 0x00005558b8089307 in monitor_qapi_event_queue_no_reenter (event=3D= QAPI_EVENT_SHUTDOWN, qdict=3D0x5558bb161600) at monitor.c:551 > #12 0x00005558b80896c0 in qapi_event_emit (event=3DQAPI_EVENT_SHUTDOWN= , qdict=3D0x5558bb161600) at monitor.c:626 > #13 0x00005558b855f23b in qapi_event_send_shutdown (guest=3Dfalse, rea= son=3DSHUTDOWN_CAUSE_HOST_QMP_QUIT) at qapi/qapi-events-run-state.c:43 > #14 0x00005558b81911ef in qemu_system_shutdown (cause=3DSHUTDOWN_CAUSE= _HOST_QMP_QUIT) at vl.c:1837 > #15 0x00005558b8191308 in main_loop_should_exit () at vl.c:1885 > #16 0x00005558b819140d in main_loop () at vl.c:1924 > #17 0x00005558b8198c84 in main (argc=3D18, argv=3D0x7ffc355df3f8, envp= =3D0x7ffc355df490) at vl.c:4665 >=20 > This patch adds a lock to protect tcp_chr_disconnect() and > socket_reconnect_timeout() >=20 > Signed-off-by: Alberto Garcia > --- > chardev/char-socket.c | 25 +++++++++++++++++++++---- > 1 file changed, 21 insertions(+), 4 deletions(-) Reviewed-by: Daniel P. Berrang=C3=A9 Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|