From owner-svn-src-head@FreeBSD.ORG Wed Feb 29 15:21:51 2012 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id B5885106566B; Wed, 29 Feb 2012 15:21:51 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 848AD8FC0A; Wed, 29 Feb 2012 15:21:51 +0000 (UTC) Received: from bigwig.baldwin.cx (bigwig.baldwin.cx [96.47.65.170]) by cyrus.watson.org (Postfix) with ESMTPSA id 21A6D46B17; Wed, 29 Feb 2012 10:21:51 -0500 (EST) Received: from jhbbsd.localnet (unknown [209.249.190.124]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id A79A1B924; Wed, 29 Feb 2012 10:21:50 -0500 (EST) From: John Baldwin To: Konstantin Belousov Date: Wed, 29 Feb 2012 09:36:02 -0500 User-Agent: KMail/1.13.5 (FreeBSD/8.2-CBSD-20110714-p10; KDE/4.5.5; amd64; ; ) References: <201202261425.q1QEPm9g069102@svn.freebsd.org> <86mx81byt6.fsf@in138.ua3> <20120229132507.GB55074@deviant.kiev.zoral.com.ua> In-Reply-To: <20120229132507.GB55074@deviant.kiev.zoral.com.ua> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <201202290936.02309.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (bigwig.baldwin.cx); Wed, 29 Feb 2012 10:21:50 -0500 (EST) 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-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Feb 2012 15:21:51 -0000 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: > > > > On Wed, 29 Feb 2012 12:03:00 +0000 Robert N. M. Watson wrote: > > > > RNMW> I think the monitoring aspect of the patch is fine. > > > > RNMW> The bit I was worried about was external umask changes. This can 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 developer > > RNMW> needs to know they are changing application behaviour. But exposing a > > RNMW> feature that can lead to correct applications but incorrect results is > > RNMW> a risky thing to do, hence my objection. > > > > 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). > > > > I still don't see why having a sysctl RW is worse than asking users to run > > something like in the attach when they need to change umask for another > > process, but ok, if people don't like RW I will remove it. > > > 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. kgdb doesn't though, and presumably for umask you would change it via kgdb, so from the running process' perspective it would look the same as changing it via sysctl. -- John Baldwin