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Date: Tue, 20 Jun 2006 20:03:53 +0300
From: Giorgos Keramidas <keramida@freebsd.org>
To: Dan Lukes <dan@obluda.cz>, Jason Evans <jasone@freebsd.org>
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Cc: freebsd-security@freebsd.org
Subject: Re: memory pages nulling when releasing
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On 2006-06-20 17:05, Dan Lukes <dan@obluda.cz> wrote:
>> There's "Z" malloc option that's used to initialise page with zeros
>> instead of 0xd0
>
> Difference betwen Z and J isn't the fill value only. Z apply
> for allocations of new memory (when imalloc() called); J apply
> on changes in allocated block size (e.g. realloc) and free. So
> 'Z' doesn't "zero on free" but "zero on alloc". Well, things
> aren't simple as Z implies J ...
>
> BTW, Z nor J doesn't imply 'R' despite of text of manual page.

Are you sure?  Then we should fix the manpage.
Cc'ing Jason Evans, who may be interested too.