Subject: Re: Importing PaX features to NetBSD
To: Elad Efrat <>
From: Pavel Cahyna <>
List: tech-security
Date: 12/18/2005 23:20:18
On Sun, Dec 18, 2005 at 12:12:50PM +0200, Elad Efrat wrote:
> Some information that might help figuring what would be the costs of
> ASLR calculates 3 random values on execution and saves these as offsets
> to be used when a random value is needed. How expensive are 3
> arc4random() calls in the context of an entire sys_execve()?

Wouldn't it prevent future optimizations of the dynamic linker, which
might require constant and known addresses of dynamic libraries? I think
IRIX does that (don't know how RelCache was designed, maybe it applies
there too).

Pavel Cahyna