Re: [PATCH] pid: change task_struct::pid to read-only

From: Richard Guy Briggs
Date: Fri Dec 20 2013 - 09:04:56 EST


On 13/12/20, Peter Zijlstra wrote:
> On Thu, Dec 19, 2013 at 11:48:26PM -0500, Richard Guy Briggs wrote:
> > On 13/12/17, Peter Zijlstra wrote:
> > > On Mon, Dec 16, 2013 at 04:03:38PM -0500, Richard Guy Briggs wrote:
> > > > task->pid is only ever assigned once (well ok, twice). For system health and
> > > > secure logging confidence, make it const to make it much more intentional when
> > > > it is being changed.
> > > > ---
> > > >
> > > > Peter, as you had suggested, does this approach work for you in terms of making
> > > > task_struct::pid a lot more difficult to accidentally change to try to preserve
> > > > its integrity?
> > >
> > > Yeah, looks good to me.
> >
> > Ok, who would carry this patch? You? AKPM? Me?
>
> Andrew seems to be the him who carries PID stuff. I don't think I can make
> a case that its scheduler related.
>
> > Any opinions about Oleg's macro idea?
>
> I'm undecided.. on the one hand the macro makes it too easy to change
> const stuff, on the other hand it makes it explicit and easily
> greppable.

My first reaction was it makes it too easy. Easy, but much more clear
in its intentions. greppable hadn't occured to me.

I figure the accompanying comment covers intent.

- RGB

--
Richard Guy Briggs <rbriggs@xxxxxxxxxx>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545
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