linux-kernel - Re: [RFC PATCH v2 0/2] Randomization of address chosen by mmap.

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Message-ID: <20180330133348.GR1436@brightrain.aerifal.cx>
Date:   Fri, 30 Mar 2018 09:33:48 -0400
From:   Rich Felker <dalias@...c.org>
To:     Pavel Machek <pavel@....cz>
Cc:     Ilya Smith <blackzert@...il.com>, rth@...ddle.net,
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Subject: Re: [RFC PATCH v2 0/2] Randomization of address chosen by mmap.

On Fri, Mar 30, 2018 at 09:55:08AM +0200, Pavel Machek wrote:
> Hi!
> 
> > Current implementation doesn't randomize address returned by mmap.
> > All the entropy ends with choosing mmap_base_addr at the process
> > creation. After that mmap build very predictable layout of address
> > space. It allows to bypass ASLR in many cases. This patch make
> > randomization of address on any mmap call.
> 
> How will this interact with people debugging their application, and
> getting different behaviours based on memory layout?
> 
> strace, strace again, get different results?

Normally gdb disables ASLR for the process when invoking a program to
debug. I don't see why that would be terribly useful with strace but
you can do the same if you want.

Rich