Re: [PATCH] Undo some of the pseudo-security madness

From: Samium Gromoff
Date: Sat Feb 24 2007 - 08:34:25 EST


At Sat, 24 Feb 2007 10:40:51 +0100,
Florian Weimer wrote:
>
> * Samium Gromoff:
>
> > Lisp environments can produce standalone executables
>
> If you've got a stand-alone executable, you don't need MAP_FIXED. The
> ELF loader maps the program at a fixed address anyway (at least on
> i386 and x86_64, I haven't checked others).

Not so.

The thing is that the picture is of two pieces:

- the executable
- the unrelocatable lisp core (which is unrelocatable by the virtue
of non-PIC code) which is mapped into the AS of the executable.

It is the latter which breaks, as its map can overlap with randomized
pieces of the executable (along with its libraries).

> AFAIK, PolyML has recently made the switch to stand-alone executables
> for this reason.

regards, Samium Gromoff
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