Re: [PATCH] Gerd Hoffman's move-vsyscall-into-user-address-range patch

Ingo Molnar
2006-05-18T07:54:49Z

* Rusty Russell <rusty@rustcorp.com.au> wrote:

> Thanks, I looked at the exec-shield patch. It has some rough
> edges (at least the 2.6.16 version I found).

the most recent one is always in the Fedora rawhide kernel RPM/SRPM.
(that means it closely tracks upstream.)

> Gerd's is basically a minimal subset of the exec-shield: we
> can go further towards exec-shield by using get_unmapped_area for the
> vsyscall page rather than nailing it above the stack, but it takes us
> from a 280-line patch to a 480-line patch.

certainly looks good to me! What are the changes you did to the
exec-shield implementation of vdso randomization? The patch seems
largely identical to the one in exec-shield.

(and it would be nice to do this on x86_64 too - exploits already exist
using the fixmapped VDSO there as a trampoline.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>

Ingo