Re: [patch 0/6] lightweight robust futexes: -V3

Ingo Molnar
2006-02-16T21:56:53Z

* Christopher Friesen <cfriesen@nortel.com> wrote:

> Ingo Molnar wrote:
>
> >basically, ->futex_offset is not blindly trusted by the kernel either:
> >it's simply used to calculate a "userspace pointer" value, which it then
> >uses in a (secure) get_user() access, to do a FUTEX_WAKEUP. [Note that
> >FUTEX_WAKEUP is already done at do_exit() time via the ->clear_child_tid
> >userspace pointer.] All in one: this is totally safe.
>
> As mentioned by Paul...how do you deal with 32/64 compatibility where
> your pointers are different sizes?

i just replied to Paul's mail with details about this. (Please reply to
that mail if there are any open questions.)

Ingo