[pypy-dev] W^X in the PyPy JIT?

[Armin Rigo]

Hi Edd,

On 9 June 2016 at 17:19, Edd Barrett <edd at theunixzoo.co.uk> wrote:
> Recently OpenBSD has started enforcing W^X [1] for all programs, unless
> the program is on a file system with a special 'wxallowed' flag.

We already saw the "W^X" issue.  A possible solution would be indeed
for the JIT to map W when it compiles and then X "when it's done",
except that it is never done, as there are various places that can be
patched at various point (including jump targets, and now also some
young GC pointers that are replaced with their old equivalent during
the next minor collection).  It's not completely easy to do.  It's not
impossible, though.  Patches welcome.


A bientôt,

Armin.