From owner-freebsd-stable@FreeBSD.ORG Fri Dec 5 07:51:13 2014 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 619203B5 for ; Fri, 5 Dec 2014 07:51:13 +0000 (UTC) Received: from mail3.transactionware.com (mail.transactionware.com [203.14.245.7]) by mx1.freebsd.org (Postfix) with SMTP id BD9D192 for ; Fri, 5 Dec 2014 07:51:11 +0000 (UTC) Received: (qmail 26644 invoked by uid 907); 5 Dec 2014 07:44:28 -0000 Received: from Unknown (HELO jmmacpro.tmst.com.au) (203.14.245.130) (smtp-auth username janm, mechanism plain) by mail3.transactionware.com (qpsmtpd/0.84) with (DHE-RSA-AES256-SHA encrypted) ESMTPSA; Fri, 05 Dec 2014 18:44:28 +1100 From: Jan Mikkelsen Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: 10.1 regression: process using serial port becomes unkillable when no modem control signals Message-Id: Date: Fri, 5 Dec 2014 18:44:51 +1100 To: FreeBSD Stable Mailing List Mime-Version: 1.0 (Mac OS X Mail 8.1 \(1993\)) X-Mailer: Apple Mail (2.1993) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Dec 2014 07:51:13 -0000 Hi, I have just found this problem on a machine upgraded to 10.1. When running mgetty on a serial port with nothing connected and then = killing it the process becomes unkillable. This prevents =E2=80=9Cshutdown= -r=E2=80=9D from completing, which is particularly annoying. Giving the serial port a device which provides the right modem control = signals lets the process exit immediately. The same hardware with 9.3 = was fine. Below is the kernel stack trace on the unkillable process. Does this ring any bells for anyone? Thanks, Jan Mikkelsen (kgdb) bt #0 sched_switch (td=3D0xfffff80236e1a920, newtd=3D, flags=3D) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/kern/sched_ule.= c:1945 #1 0xffffffff80939ba1 in mi_switch (flags=3D260, newtd=3D0x0) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/kern/kern_synch= .c:494 #2 0xffffffff80976d6b in sleepq_catch_signals = (wchan=3D0xfffff8000c7344b8, pri=3D0) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/kern/subr_sleep= queue.c:426 #3 0xffffffff80976c1f in sleepq_wait_sig (wchan=3D0x0, pri=3D0) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/kern/subr_sleep= queue.c:631 #4 0xffffffff808e345a in _cv_wait_sig (cvp=3D0xfffff8000c7344b8, = lock=3D0xfffff8000c734408) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/kern/kern_condv= ar.c:258 #5 0xffffffff809957a5 in ttydev_leave (tp=3D0xfffff8000c734400) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/kern/tty.c:1392= #6 0xffffffff80994d30 in ttydev_close (dev=3D, = fflag=3D0, devtype=3D0, td=3D0x0) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/kern/tty.c:353 #7 0xffffffff8081ec63 in devfs_close (ap=3D0xfffffe0c541d57e0) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/fs/devfs/devfs_= vnops.c:592 #8 0xffffffff80e6d281 in VOP_CLOSE_APV (vop=3D, = a=3D) at vnode_if.c:535 #9 0xffffffff809df673 in vn_close (vp=3D0xfffff80236a6f588, flags=3D3, = file_cred=3D0xfffff806a300b200, td=3D0xfffff80236e1a920) at = vnode_if.h:225 #10 0xffffffff809de4c8 in vn_closefile (fp=3D0xfffff8001243d9b0, = td=3D0xfffff80236e1a920) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/kern/vfs_vnops.= c:1557 #11 0xffffffff808204bc in devfs_close_f (fp=3D0xfffff8001243d9b0, = td=3D0x0) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/fs/devfs/devfs_= vnops.c:611 #12 0xffffffff808ed249 in _fdrop (fp=3D0xfffff8001243d9b0, td=3D0x0) at = file.h:343 #13 0xffffffff808ef9ae in closef (fp=3D, td=3D) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/kern/kern_descr= ip.c:2335 #14 0xffffffff808ef5c9 in fdescfree (td=3D0xfffff80236e1a920) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/kern/kern_descr= ip.c:2103 #15 0xffffffff808fb8fb in exit1 (td=3D0xfffff80236e1a920, rv=3D) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/kern/kern_exit.= c:329 #16 0xffffffff808fb37e in sys_sys_exit (td=3D0x0, uap=3D) at = /usr/home/janm/p4/freebsd-image-std-2014.2/FreeBSD/src/sys/kern/kern_exit.= c:153 #17 0xffffffff80d4f521 in amd64_syscall (td=3D0xfffff80236e1a920, = traced=3D0) at subr_syscall.c:134