Messages in this thread | | | Date | Tue, 2 Aug 2005 08:30:37 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [patch 2.6.13-rc4] fix get_user_pages bug |
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On Tue, 2 Aug 2005, Martin Schwidefsky wrote: > > Why do we require the !pte_dirty(pte) check? I don't get it. If a writeable > clean pte is just fine then why do we check the dirty bit at all? Doesn't > pte_dirty() imply pte_write()?
A _non_writable and clean pty is _also_ fine sometimes. But only if we have broken COW and marked it dirty.
> 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.
On the other hand, this being s390, maybe nobody cares?
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