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Date: Thu, 13 Dec 2012 12:58:37 +0400
From: Gleb Smirnoff <glebius@FreeBSD.org>
To: Adrian Chadd <adrian@FreeBSD.org>
Subject: Re: svn commit: r244112 - head/sys/kern
Message-ID: <20121213085837.GO97487@FreeBSD.org>
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On Wed, Dec 12, 2012 at 10:49:44PM -0800, Adrian Chadd wrote:
A> Let me restate it again.
A> 
A> We can ship a STABLE kernel with INVARIANTS enabled, and it not be any
A> less stable than the STABLE kernel is today.

It will be less stable, at least due to thrashing memory on free(9).
Accessing memory after free(9) is a quite a common bug.

However, with current semantics of KASSERT it will panic with good
diagnostics and early, on malloc(9). With perverted semantics that Alfred
suggests and you advocate it won't panic on malloc(9), but will panic later
(no doubt that it will, if a thrashed pointer is dereferenced) with much
more obscure diagnostics.

-- 
Totus tuus, Glebius.