Re: [PATCH] prevent NULL mmap in topdown model

Greg Stark
2005-05-29T21:16:33Z

Arjan van de Ven <arjan@infradead.org> writes:

> On Wed, 2005-05-18 at 23:46 -0700, Chris Wright wrote:
>
> sure. Making it *impossible* to mmap that page is bad. People should be
> able to do that if they really want to, just doing it if they don't ask
> for it is bad.
>
> There are plenty of reasons people may want that page mmaped, one of
> them being that the compiler can then do more speculative loads around
> null pointer checks. Not saying it's a brilliant idea always, but making
> such things impossible makes no sense.

More realistically, iirc either Wine or dosemu, i forget which, actually has
to map page 0 to work properly.

--
greg