Re: [patch 2.6.13-rc4] fix get_user_pages bug

Martin Schwidefsky
2005-08-02T16:44:21Z

Linus Torvalds <torvalds@osdl.org> wrote on 08/02/2005 05:30:37 PM:

> > With the additional !pte_write(pte) check (and if I haven't overlooked
> > something which is not unlikely) s390 should work fine even without the
> > software-dirty bit hack.
>
> No it won't. It will just loop forever in a tight loop if somebody tries
> to put a breakpoint on a read-only location.

Yes, I have realized that as well nowe after staring at the code a little
bit longer. That maybe_mkwrite is really tricky.

> On the other hand, this being s390, maybe nobody cares?

Some will care. At least I do. I've tested the latest git with gdb and
it will indeed loop forever if I try to write to a read-only vma.

blue skies,
Martin

Martin Schwidefsky
Linux for zSeries Development & Services
IBM Deutschland Entwicklung GmbH