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From: Doug Rabson <dfr@nlsystems.com>
To: David Xu <davidxu@freebsd.org>
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Subject: Re: sigaltstack with threads
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On Thu, 2004-01-01 at 15:24, David Xu wrote:
> Doug Rabson wrote:
> > I think that if its supported at all in threaded programs, it must be
> > per-thread state otherwise you can't prevent two different threads
> > colliding on the same signal stack. I can't quite see how this maps to
> > KSE/KSEG since I only have the most hazy model of that stuff in my head
> > right now.
> > 
> > Anyway, I've worked around things by not setting SA_ONSTACK for the
> > handlers that I want to run on the thread stack.
> > 
> > 
> I have worked out a patch to support per-thread sigaltstack() state,
> in most cases, it is just a literally replacement.
> 
> http://people.freebsd.org/~davidxu/kse/kern_sigaltstack.diffs

Looks fine to me.