From owner-freebsd-usb@FreeBSD.ORG Mon Apr 24 14:27:47 2006 Return-Path: X-Original-To: freebsd-usb@freebsd.org Delivered-To: freebsd-usb@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2749B16A401 for ; Mon, 24 Apr 2006 14:27:47 +0000 (UTC) (envelope-from mistry.7@osu.edu) Received: from mail.united-ware.com (am-productions.biz [69.61.164.22]) by mx1.FreeBSD.org (Postfix) with ESMTP id A5E2243D72 for ; Mon, 24 Apr 2006 14:27:38 +0000 (GMT) (envelope-from mistry.7@osu.edu) Received: from [192.168.1.100] (am-productions.biz [69.61.164.22]) (authenticated bits=0) by mail.united-ware.com (8.13.4/8.13.4) with ESMTP id k3OEgqbw048256 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 24 Apr 2006 10:42:58 -0400 (EDT) (envelope-from mistry.7@osu.edu) From: Anish Mistry To: freebsd-usb@freebsd.org Date: Mon, 24 Apr 2006 10:27:44 -0400 User-Agent: KMail/1.9.1 MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1241358.1Mpj4rurJW"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200604241027.44959.mistry.7@osu.edu> X-Spam-Status: No, score=-5.5 required=5.0 tests=ALL_TRUSTED,BAYES_50, MYFREEBSD2 autolearn=failed version=3.1.0 X-Spam-Checker-Version: SpamAssassin 3.1.0 (2005-09-13) on mail.united-ware.com X-Virus-Scanned: ClamAV version 0.88.1, clamav-milter version 0.88.1 on mail.united-ware.com X-Virus-Status: Clean Subject: Fwd: Re: [PATCH] ugen detach race X-BeenThere: freebsd-usb@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: FreeBSD support for USB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 24 Apr 2006 14:27:47 -0000 --nextPart1241358.1Mpj4rurJW Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Sending to the usb list as per jhb's suggestion. =2D--------- Forwarded Message ---------- Subject: Re: [PATCH] ugen detach race Date: Saturday 22 April 2006 16:22 =46rom: Anish Mistry To: freebsd-current@freebsd.org Cc: Ian Dowse On Saturday 22 April 2006 14:59, Anish Mistry wrote: > On Wednesday 05 April 2006 04:44, Anish Mistry wrote: > > On Wednesday 05 April 2006 03:53, Anish Mistry wrote: > > > While working on getting hplip ported I ran across a race > > > condition in the ugen code that causes a crash. The following > > > patch fixes a problem where read, write, and ioctl can be > > > called during a detach since sc_dying isn't checked before > > > bumping the reference count. This puts the sc_dying check > > > before the *_do_* functions are called. This includes the patch > > > from usb/81308 to prevent polling on the control endpoint. As > > > well as a few NULL pointer checks from NetBSD. This patch is > > > applicable to RELENG_6. > > > > And CURRENT. > > > > > http://am-productions.biz/docs/ugen-detach-race.patch > > > > > > This doesn't fix the case where an application has a read/write > > > pending and then detach is called. In this case destroy_devl > > > will just keep looping until the read/write completes. > > I've updated the patch. It now includes the fix for the panic on > detach when a process has a device open when a detach occurs. ugen > now no longer waits for the process to close the connection and > just cuts it off. > Applies to RELENG_6 and CURRENT. > > http://am-productions.biz/docs/ugen-detach-race.patch > > The patch should fix usb/93949 too. > This seems to fix all the panics I'm seeing with the ugen device. > It would be nice if this could make it into 6.1. I added another panic fix. An error was introduced in rev 1.94 on ugen.c in the USB_SET_CONFIG ioctl case that calls ugen_make_devnodes. This causes a panic since this logic was moved to ugen_set_config a while ago. Removing the ugen_make_devnodes() call from ugen_do_ioctl fixes the problem. This bug made it trivial to cause a panic when there was access to any ugen device. http://am-productions.biz/docs/ugen-detach-race.patch =2D- Anish Mistry =2D------------------------------------------------------ =2D-=20 Anish Mistry --nextPart1241358.1Mpj4rurJW Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (FreeBSD) iD8DBQBETOBgxqA5ziudZT0RAsQCAJwOajF85MF43UWSuIH2Tq+bgzyqpgCcC4Gc tEvMI5BPLTe2Rw7LvPpuLoA= =wGGr -----END PGP SIGNATURE----- --nextPart1241358.1Mpj4rurJW--