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Date: Tue, 4 Nov 2014 11:25:58 +0200
From: Konstantin Belousov <kostikbel@gmail.com>
To: Alfred Perlstein <alfred@freebsd.org>
Subject: Re: svn commit: r274017 - head/sys/kern
Message-ID: <20141104092558.GP53947@kib.kiev.ua>
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On Mon, Nov 03, 2014 at 01:45:21PM -0800, Alfred Perlstein wrote:
> Isn't there a problem where the stack can be swapped out?
> 
> I seem to recall a problem where a swapped out process was causing 
> problems due to a buffer passed being stack allocated and that process 
> being swapped out...
> 
> If this is not the case then please disregard.

Sure, stack can be swapped out, but buffer passing is usually not a problem.
At least, I am not aware of cases.

In fact, many compat layers do exactly this, allocate the native-ABI
structure on the stack, copyin the foreighn-ABI structure in pieces
into the native-ABI one, and pass native to kern_foo() implementations.

So I think you worries are not realized.