From owner-svn-src-head@FreeBSD.ORG  Thu Sep  4 09:18:48 2014
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id DA19FFCA;
 Thu,  4 Sep 2014 09:18:48 +0000 (UTC)
Received: from cell.glebius.int.ru (glebius.int.ru [81.19.69.10])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client CN "cell.glebius.int.ru", Issuer "cell.glebius.int.ru" (not verified))
 by mx1.freebsd.org (Postfix) with ESMTPS id 58A301A69;
 Thu,  4 Sep 2014 09:18:47 +0000 (UTC)
Received: from cell.glebius.int.ru (localhost [127.0.0.1])
 by cell.glebius.int.ru (8.14.9/8.14.9) with ESMTP id s849IiGC011171
 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO);
 Thu, 4 Sep 2014 13:18:44 +0400 (MSK)
 (envelope-from glebius@FreeBSD.org)
Received: (from glebius@localhost)
 by cell.glebius.int.ru (8.14.9/8.14.9/Submit) id s849IiCh011170;
 Thu, 4 Sep 2014 13:18:44 +0400 (MSK)
 (envelope-from glebius@FreeBSD.org)
X-Authentication-Warning: cell.glebius.int.ru: glebius set sender to
 glebius@FreeBSD.org using -f
Date: Thu, 4 Sep 2014 13:18:44 +0400
From: Gleb Smirnoff <glebius@FreeBSD.org>
To: John-Mark Gurney <jmg@funkthat.com>
Subject: Re: svn commit: r270999 - head/sys/kern
Message-ID: <20140904091844.GC7693@FreeBSD.org>
References: <201409030814.s838E7A2084257@svn.freebsd.org>
 <20140903085523.GB13871@dft-labs.eu>
 <20140903094916.GO7693@FreeBSD.org>
 <20140903191028.GG71691@funkthat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20140903191028.GG71691@funkthat.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org,
 Mateusz Guzik <mjguzik@gmail.com>, kib@freebsd.org, src-committers@freebsd.org
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.18-1
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
 <svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head/>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 04 Sep 2014 09:18:49 -0000

On Wed, Sep 03, 2014 at 12:10:28PM -0700, John-Mark Gurney wrote:
J> > M> > +	if (p->p_pptr) {
J> > M> >  		kp->ki_ppid = proc_realparent(p)->p_pid;
J> > M> > -	if (p->p_flag & P_TRACED)
J> > M> > -		kp->ki_tracer = p->p_pptr->p_pid;
J> > M> > +		if (p->p_flag & P_TRACED)
J> > M> > +			kp->ki_tracer = p->p_pptr->p_pid;
J> > M> > +	}
J> > M> >  }
J> > M> >  
J> > M> >  /*
J> > M> > 
J> > M> 
J> > M> p_pptr must be non-NULL if P_TRACED is set. If there is no way to
J> > M> annotate it for coverity, this change deserves a comment in the code
J> > M> (and in retrospect previous code should have had appropriate comment as
J> > M> well).
J> > 
J> > Thanks for explanation.
J> > 
J> > I'd suggest to leave the change in, since now it is a micro-micro-optimization :)
J> 
J> If you must leave it in, then at least compare the pointer against
J> NULL, and collapse two if statements into one...
J> 
J> We should never introduce new pointer checks that aren't against NULL...

I don't see how two if statements can be collapsed? We need to assign
ki_ppid regardless of P_TRACED flag.

-- 
Totus tuus, Glebius.