From owner-svn-src-all@FreeBSD.ORG Wed Feb 29 15:33:40 2012 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E651C1065675; Wed, 29 Feb 2012 15:33:39 +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 696038FC1D; Wed, 29 Feb 2012 15:33:39 +0000 (UTC) Received: from skuns.kiev.zoral.com.ua (localhost [127.0.0.1]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id q1TFXTrq015364; Wed, 29 Feb 2012 17:33:29 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.5/8.14.5) with ESMTP id q1TFXSco097409; Wed, 29 Feb 2012 17:33:28 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.5/8.14.5/Submit) id q1TFXSFs097408; Wed, 29 Feb 2012 17:33:28 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Wed, 29 Feb 2012 17:33:28 +0200 From: Konstantin Belousov To: John Baldwin Message-ID: <20120229153328.GG55074@deviant.kiev.zoral.com.ua> References: <201202261425.q1QEPm9g069102@svn.freebsd.org> <86mx81byt6.fsf@in138.ua3> <20120229132507.GB55074@deviant.kiev.zoral.com.ua> <201202290936.02309.jhb@freebsd.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="cl8+tZBacEYae1bh" Content-Disposition: inline In-Reply-To: <201202290936.02309.jhb@freebsd.org> 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=-4.0 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on skuns.kiev.zoral.com.ua Cc: src-committers@freebsd.org, Pawel Jakub Dawidek , svn-src-all@freebsd.org, Mikolaj Golub , "Robert N. M. Watson" , svn-src-head@freebsd.org, Julian Elischer Subject: Re: svn commit: r232181 - in head/sys: kern sys X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Feb 2012 15:33:40 -0000 --cl8+tZBacEYae1bh Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Feb 29, 2012 at 09:36:02AM -0500, John Baldwin wrote: > On Wednesday, February 29, 2012 8:25:07 am Konstantin Belousov wrote: > > On Wed, Feb 29, 2012 at 02:37:25PM +0200, Mikolaj Golub wrote: > > >=20 > > > On Wed, 29 Feb 2012 12:03:00 +0000 Robert N. M. Watson wrote: > > >=20 > > > RNMW> I think the monitoring aspect of the patch is fine. > > >=20 > > > RNMW> The bit I was worried about was external umask changes. This c= an cause > > > RNMW> race conditions for applications that manage their umask -- for > > > RNMW> example, bsdtar, if I recall correctly. It's one thing to use a > > > RNMW> debugger to force an application to change its umask -- the de= veloper > > > RNMW> needs to know they are changing application behaviour. But exp= osing a > > > RNMW> feature that can lead to correct applications but incorrect re= sults is > > > RNMW> a risky thing to do, hence my objection. > > >=20 > > > RNMW> I think given the other objections, it would be wise to remove= write > > > RNMW> access to process umasks, but retain read access for procstat = (which is > > > RNMW> quite useful, I agree). > > >=20 > > > I still don't see why having a sysctl RW is worse than asking users t= o run > > > something like in the attach when they need to change umask for anoth= er > > > process, but ok, if people don't like RW I will remove it. > > >=20 > > What is done is attach is much worse then the sysctl, just because > > debugger attach often causes spurious EINTR, indeed seriously disrupting > > applications, as opposed to some uncertain damage that could be done in > > theory. >=20 > kgdb doesn't though, and presumably for umask you would change it via kgd= b, so > from the running process' perspective it would look the same as changing = it via > sysctl. Right, but an idea of the change was to allow to do this for somebody who does not know how to perform it in kgdb. Not to mention that kgdb -w is risky, e.g. because filedesc might have changed under kgdb, so you would write over freed memory. --cl8+tZBacEYae1bh Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (FreeBSD) iEYEARECAAYFAk9ORUgACgkQC3+MBN1Mb4hkgQCg4eZSfK8M8FK2ywsijJ7pD58F kQAAoOUtORWe6fX3d8qK10JBlXRHZUG9 =NiSX -----END PGP SIGNATURE----- --cl8+tZBacEYae1bh--