Messages in this thread | | | Date | Fri, 30 Sep 2016 14:45:42 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH locking/Documentation 1/2] Add note of release-acquire store vulnerability |
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On Fri, Sep 30, 2016 at 05:17:21AM -0700, Paul E. McKenney wrote: > On Fri, Sep 30, 2016 at 12:25:16PM +0200, Peter Zijlstra wrote:
> > So its a pretty dumb thing to do in any case (and yes the kernel does > > this). Its also entirely expected in my book, that if you generate > > conflicting writes on a release, ordering is out the window. > > > > Why do we need to call this out? Who in his right mind would want to do > > this and expect anything other than wreckage? > > > > Not that we're not having too much 'fun' discussing this,.. but I do > > wonder why we need to call this out. > > You lost me on this one... If no one does this, sure, we can leave it out. > But if some part of the kernel does rely on this, we should call it out as > forbidden. And fix the kernel, of course.
Well, the kernel does this, but doesn't rely on ordering. Do "git grep zap_locks". Its disgusting, can (and does) fail and generally is a sign of badly broken code (printk is all that).
> Or am I missing your point?
My point was, its obvious crack, anybody doing this needs to have his head examined. Then again, maybe we should just say that :-)
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