Anyone protecting the stack?

[Sander Vesik]

Hiten Pandya <hmp at xxxxxxxxxxxxx> wrote:
> Pedro Giffuni wrote:
> 
> : I posted this to freebsd-hackers and everyone seemed to agree it was
> : extremely interesting and that it had to be done, but AFAICT no one is
> : doing the tough work. JIC anyone here is interested I repost the link to
> : NetBSD's commit log:
> :
> : http://mail-index.netbsd.org/source-changes/2003/08/24/0027.html
> :
> 
>        Hmm, is this just the pmap mappings that are made non executable
>        if supported by hardware?  Well, aside from the pmap parts, I am
>        not sure we really want this...
> 
>        ... I am understanding right and per the research I have done
>        previously on non-exec stacks, it seems JIT compilers and the
>        new Perl interpreter do not support this, although, I maybe a
>        little outdated on this information.
> 
>        If it can be done without harming any functionality, it will be
>        great!

The obvious way to make this optional is to set a flag in the elf files.
Thios will also avoid loading a non-unexecutable-stack-safe shlib into
a process that won't have a executable stack.


> 
>        Regards,
> 

-- 
	Sander

+++ Out of cheese error +++