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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
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Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org,
 Mateusz Guzik <mjguzik@gmail.com>, kib@freebsd.org, src-committers@freebsd.org
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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.