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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
cc: pgsql-hackers@lists.postgresql.org
Subject: Re: segmentation fault when cassert enabled
In-reply-to: <20191025175929.7e90dbf5@firost>
References: <20191025175929.7e90dbf5@firost>
Comments: In-reply-to Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
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Date: Fri, 25 Oct 2019 12:28:38 -0400
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Jehan-Guillaume de Rorthais <jgdr@dalibo.com> writes:
> When investigating for the bug reported in thread "logical replication -
> negative bitmapset member not allowed", I found a way to seg fault postg=
resql
> only when cassert is enabled.
> ...
> I hadn't time to digg further yet. However, I don't understand why this =
crash
> is triggered when cassert is enabled.

Most likely, it's not so much assertions that provoke the crash as
CLOBBER_FREED_MEMORY, ie the actual problem here is use of already-freed
memory.

			regards, tom lane