From owner-freebsd-current@FreeBSD.ORG Wed Aug 4 16:04:12 2010 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 07FE21065670 for ; Wed, 4 Aug 2010 16:04:12 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.zoral.com.ua (mx0.zoral.com.ua [91.193.166.200]) by mx1.freebsd.org (Postfix) with ESMTP id 67ABE8FC29 for ; Wed, 4 Aug 2010 16:04:09 +0000 (UTC) Received: from deviant.kiev.zoral.com.ua (root@deviant.kiev.zoral.com.ua [10.1.1.148]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id o74G44Px004832 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 4 Aug 2010 19:04:04 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4) with ESMTP id o74G44Rl069025; Wed, 4 Aug 2010 19:04:04 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4/Submit) id o74G44gb069024; Wed, 4 Aug 2010 19:04:04 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Wed, 4 Aug 2010 19:04:04 +0300 From: Kostik Belousov To: Andrew Gallatin Message-ID: <20100804160404.GZ22295@deviant.kiev.zoral.com.ua> References: <4C597AE8.5090703@cs.duke.edu> <20100804154604.GY22295@deviant.kiev.zoral.com.ua> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ttdIJ16FdHy9Oveo" Content-Disposition: inline In-Reply-To: <20100804154604.GY22295@deviant.kiev.zoral.com.ua> User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: clamav-milter 0.95.2 at skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-2.2 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_50, DNS_FROM_OPENWHOIS autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on skuns.kiev.zoral.com.ua Cc: current@freebsd.org Subject: Re: Incorrect cv_wait_sig() return values? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 Aug 2010 16:04:12 -0000 --ttdIJ16FdHy9Oveo Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Aug 04, 2010 at 06:46:04PM +0300, Kostik Belousov wrote: > On Wed, Aug 04, 2010 at 10:36:24AM -0400, Andrew Gallatin wrote: > > Hi, > >=20 > > I recently noticed that cv_wait_sig() will return -1 > > rather than EINTR when a SIGINT is delivered. This is > > in contrast to CONDVAR(9) which states: > >=20 > > <...> > > cv_wait_sig() and cv_timedwait_sig() return prematurely with a > > value of EINTR or ERESTART if a signal is caught > > <...> > >=20 > > To demonstrate the problem outside my out-of-tree driver, I > > took the skeleton driver from > > http://www.captain.at/programming/freebsd/ > > and added the following function, invoked at module > > load: > >=20 > > static struct mtx m; > > static struct cv c; > >=20 > > static void > > cv_test(void) > > { > > int rc; > >=20 > > mtx_init(&m, "skel_m", MTX_DEF, MTX_DEF); > > cv_init(&c, "skel_c"); > > mtx_lock(&m); > > rc =3D cv_wait_sig(&c, &m); > > mtx_unlock(&m); > > printf("cv_wait_sig returned %d\n", rc); > > cv_destroy(&c); > > mtx_destroy(&m); > > } > >=20 > >=20 > > I load the module, and I ^C kldload after a few seconds > > to break out of the cv_wait_sig(), which results in this > > output on console: > >=20 > > Skeleton KLD loaded. > > cv_wait_sig returned -1 > >=20 > > Am I doing something wrong, or are condvars broken? > > I've tried to track this down with dtrace, but failed.. >=20 > What version of the system do you use ? I cannot confirm this on > the HEAD from several hours ago with the following test module. > On the SIGINT I get `4' printed, which is EINTR. BTW, -1 is ERESTART, so if you have SIGINT catched with SA_RESTART flag in the process that initiated kldload(2) syscall, then -1 is the right return code for cv_wait_sig. --ttdIJ16FdHy9Oveo Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (FreeBSD) iEYEARECAAYFAkxZj3QACgkQC3+MBN1Mb4irxQCdGqUdhzGbjYTsFgG0fyd1Nt6M s3QAn29/2ijqRbtad2o2+2Z9qXcRnjBx =G6JT -----END PGP SIGNATURE----- --ttdIJ16FdHy9Oveo--