From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Linus Torvalds <torvalds@osdl.org>
Cc: Andrew Morton <akpm@osdl.org>,
Linux Kernel list <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@elte.hu>, Ben LaHaise <bcrl@redhat.com>,
linux-mm@kvack.org
Subject: Re: [PATCH] ppc64: Fix possible race with set_pte on a present PTE
Date: Mon, 24 May 2004 15:52:17 +1000 [thread overview]
Message-ID: <1085377936.15024.55.camel@gaston> (raw)
In-Reply-To: <1085377091.15281.49.camel@gaston>
On Mon, 2004-05-24 at 15:38, Benjamin Herrenschmidt wrote:
> > Well, the original scenario triggering that from userland is, imho, so
> > broken, that we may just not care losing that dirty bit ... Oh well :)
> > Anyway, apply my patch. If pte is not present, this will have no effect,
> > if it is, it makes sure we never leave a stale HPTE in the hash, which
> > is fatal in far worse ways.
>
> Hrm... Or maybe I should just do in set_pte something like
>
> BUG_ON(pte_present(ptep))
>
> That would make me sleep better ;)
... And would not work in the case you mentioned where we set it with
the dirty bit set... for write protect, we have a separate function now,
though. But I'm a bit paranoid with those PTE manipulations, so I think
it would be better to play it the safe way and keep my original patch.
Ben.
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Linus Torvalds <torvalds@osdl.org>
Cc: Andrew Morton <akpm@osdl.org>,
Linux Kernel list <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@elte.hu>, Ben LaHaise <bcrl@redhat.com>,
linux-mm@kvack.org
Subject: Re: [PATCH] ppc64: Fix possible race with set_pte on a present PTE
Date: Mon, 24 May 2004 15:52:17 +1000 [thread overview]
Message-ID: <1085377936.15024.55.camel@gaston> (raw)
In-Reply-To: <1085377091.15281.49.camel@gaston>
On Mon, 2004-05-24 at 15:38, Benjamin Herrenschmidt wrote:
> > Well, the original scenario triggering that from userland is, imho, so
> > broken, that we may just not care losing that dirty bit ... Oh well :)
> > Anyway, apply my patch. If pte is not present, this will have no effect,
> > if it is, it makes sure we never leave a stale HPTE in the hash, which
> > is fatal in far worse ways.
>
> Hrm... Or maybe I should just do in set_pte something like
>
> BUG_ON(pte_present(ptep))
>
> That would make me sleep better ;)
... And would not work in the case you mentioned where we set it with
the dirty bit set... for write protect, we have a separate function now,
though. But I'm a bit paranoid with those PTE manipulations, so I think
it would be better to play it the safe way and keep my original patch.
Ben.
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next prev parent reply other threads:[~2004-05-24 5:54 UTC|newest]
Thread overview: 153+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-05-24 3:29 [PATCH] ppc64: Fix possible race with set_pte on a present PTE Benjamin Herrenschmidt
2004-05-24 3:47 ` Linus Torvalds
2004-05-24 4:13 ` Benjamin Herrenschmidt
2004-05-24 4:36 ` Linus Torvalds
2004-05-24 4:44 ` Benjamin Herrenschmidt
2004-05-24 5:10 ` Linus Torvalds
2004-05-24 5:10 ` Linus Torvalds
2004-05-24 5:34 ` Benjamin Herrenschmidt
2004-05-24 5:34 ` Benjamin Herrenschmidt
2004-05-24 5:38 ` Benjamin Herrenschmidt
2004-05-24 5:38 ` Benjamin Herrenschmidt
2004-05-24 5:52 ` Benjamin Herrenschmidt [this message]
2004-05-24 5:52 ` Benjamin Herrenschmidt
2004-05-24 7:39 ` Ingo Molnar
2004-05-24 7:39 ` Ingo Molnar
2004-05-24 5:39 ` Benjamin Herrenschmidt
2004-05-24 5:39 ` Benjamin Herrenschmidt
2004-05-25 3:43 ` Andrea Arcangeli
2004-05-25 3:43 ` Andrea Arcangeli
2004-05-25 4:00 ` Linus Torvalds
2004-05-25 4:00 ` Linus Torvalds
2004-05-25 4:17 ` Benjamin Herrenschmidt
2004-05-25 4:17 ` Benjamin Herrenschmidt
2004-05-25 4:37 ` Andrea Arcangeli
2004-05-25 4:37 ` Andrea Arcangeli
2004-05-25 4:40 ` Benjamin Herrenschmidt
2004-05-25 4:40 ` Benjamin Herrenschmidt
2004-05-25 4:20 ` Andrea Arcangeli
2004-05-25 4:20 ` Andrea Arcangeli
2004-05-25 4:39 ` Linus Torvalds
2004-05-25 4:39 ` Linus Torvalds
2004-05-25 4:44 ` Linus Torvalds
2004-05-25 4:44 ` Linus Torvalds
2004-05-25 4:59 ` Andrea Arcangeli
2004-05-25 4:59 ` Andrea Arcangeli
2004-05-25 5:09 ` Andrea Arcangeli
2004-05-25 5:09 ` Andrea Arcangeli
2004-05-25 4:50 ` Andrea Arcangeli
2004-05-25 4:50 ` Andrea Arcangeli
2004-05-25 4:59 ` Linus Torvalds
2004-05-25 4:59 ` Linus Torvalds
2004-05-25 4:43 ` David Mosberger
2004-05-25 4:43 ` David Mosberger
2004-05-25 4:53 ` Andrea Arcangeli
2004-05-25 4:53 ` Andrea Arcangeli
2004-05-27 21:56 ` David Mosberger
2004-05-27 21:56 ` David Mosberger
2004-05-27 22:00 ` Benjamin Herrenschmidt
2004-05-27 22:00 ` Benjamin Herrenschmidt
2004-05-27 22:12 ` David Mosberger
2004-05-27 22:12 ` David Mosberger
2004-05-25 11:44 ` Matthew Wilcox
2004-05-25 11:44 ` Matthew Wilcox
2004-05-25 14:48 ` Linus Torvalds
2004-05-25 14:48 ` Linus Torvalds
2004-05-25 15:35 ` Keith M Wesolowski
2004-05-25 15:35 ` Keith M Wesolowski
2004-05-25 16:19 ` Linus Torvalds
2004-05-25 16:19 ` Linus Torvalds
2004-05-25 17:25 ` David S. Miller
2004-05-25 17:25 ` David S. Miller
2004-05-25 17:49 ` Linus Torvalds
2004-05-25 17:49 ` Linus Torvalds
2004-05-25 17:54 ` David S. Miller
2004-05-25 17:54 ` David S. Miller
2004-05-25 18:05 ` Linus Torvalds
2004-05-25 18:05 ` Linus Torvalds
2004-05-25 20:30 ` Linus Torvalds
2004-05-25 20:30 ` Linus Torvalds
2004-05-25 20:35 ` David S. Miller
2004-05-25 20:35 ` David S. Miller
2004-05-25 20:35 ` David S. Miller
2004-05-25 20:49 ` Linus Torvalds
2004-05-25 20:49 ` Linus Torvalds
2004-05-25 20:57 ` David S. Miller
2004-05-25 20:57 ` David S. Miller
2004-05-26 6:20 ` Keith M Wesolowski
2004-05-26 6:20 ` Keith M Wesolowski
2004-05-25 21:40 ` Benjamin Herrenschmidt
2004-05-25 21:40 ` Benjamin Herrenschmidt
2004-05-25 21:54 ` Linus Torvalds
2004-05-25 21:54 ` Linus Torvalds
2004-05-25 22:00 ` Linus Torvalds
2004-05-25 22:00 ` Linus Torvalds
2004-05-25 22:07 ` Benjamin Herrenschmidt
2004-05-25 22:07 ` Benjamin Herrenschmidt
2004-05-25 22:14 ` Linus Torvalds
2004-05-25 22:14 ` Linus Torvalds
2004-05-26 0:21 ` Benjamin Herrenschmidt
2004-05-26 0:21 ` Benjamin Herrenschmidt
2004-05-26 0:50 ` Linus Torvalds
2004-05-26 0:50 ` Linus Torvalds
2004-05-26 3:25 ` Benjamin Herrenschmidt
2004-05-26 3:25 ` Benjamin Herrenschmidt
2004-05-26 4:08 ` Linus Torvalds
2004-05-26 4:08 ` Linus Torvalds
2004-05-26 4:12 ` Benjamin Herrenschmidt
2004-05-26 4:12 ` Benjamin Herrenschmidt
2004-05-26 4:18 ` Benjamin Herrenschmidt
2004-05-26 4:18 ` Benjamin Herrenschmidt
2004-05-26 4:50 ` Linus Torvalds
2004-05-26 4:50 ` Linus Torvalds
2004-05-26 4:49 ` Benjamin Herrenschmidt
2004-05-26 4:49 ` Benjamin Herrenschmidt
2004-05-26 4:28 ` Linus Torvalds
2004-05-26 4:28 ` Linus Torvalds
2004-05-26 4:46 ` Benjamin Herrenschmidt
2004-05-26 4:46 ` Benjamin Herrenschmidt
2004-05-26 4:54 ` Linus Torvalds
2004-05-26 4:54 ` Linus Torvalds
2004-05-26 4:55 ` Benjamin Herrenschmidt
2004-05-26 4:55 ` Benjamin Herrenschmidt
2004-05-26 5:41 ` Benjamin Herrenschmidt
2004-05-26 5:41 ` Benjamin Herrenschmidt
2004-05-26 5:59 ` [PATCH] (signoff) " Benjamin Herrenschmidt
2004-05-26 5:59 ` Benjamin Herrenschmidt
2004-05-26 6:55 ` Benjamin Herrenschmidt
2004-05-26 6:55 ` Benjamin Herrenschmidt
2004-05-26 7:11 ` [PATCH] ppc32 implementation of ptep_set_access_flags Benjamin Herrenschmidt
2004-05-26 15:22 ` Linus Torvalds
2004-05-26 18:49 ` David S. Miller
2004-05-26 21:43 ` Benjamin Herrenschmidt
2004-05-28 1:29 ` David Mosberger
2004-05-25 22:05 ` [PATCH] ppc64: Fix possible race with set_pte on a present PTE Benjamin Herrenschmidt
2004-05-25 22:05 ` Benjamin Herrenschmidt
2004-05-25 22:09 ` Linus Torvalds
2004-05-25 22:09 ` Linus Torvalds
2004-05-25 22:19 ` Benjamin Herrenschmidt
2004-05-25 22:19 ` Benjamin Herrenschmidt
2004-05-25 22:24 ` Linus Torvalds
2004-05-25 22:24 ` Linus Torvalds
2004-05-25 21:27 ` Andrea Arcangeli
2004-05-25 21:27 ` Andrea Arcangeli
2004-05-25 21:43 ` Linus Torvalds
2004-05-25 21:43 ` Linus Torvalds
2004-05-25 21:55 ` Andrea Arcangeli
2004-05-25 21:55 ` Andrea Arcangeli
2004-05-25 22:01 ` Linus Torvalds
2004-05-25 22:01 ` Linus Torvalds
2004-05-25 22:18 ` Ivan Kokshaysky
2004-05-25 22:18 ` Ivan Kokshaysky
2004-05-25 22:42 ` Andrea Arcangeli
2004-05-25 22:42 ` Andrea Arcangeli
2004-05-26 2:26 ` Linus Torvalds
2004-05-26 2:26 ` Linus Torvalds
2004-05-26 7:06 ` Andrea Arcangeli
2004-05-26 7:06 ` Andrea Arcangeli
2004-05-25 21:44 ` Andrea Arcangeli
2004-05-25 21:44 ` Andrea Arcangeli
-- strict thread matches above, loose matches on Subject: below --
2004-06-01 12:04 Martin Schwidefsky
2004-06-01 12:04 ` Martin Schwidefsky
2004-06-01 12:10 Martin Schwidefsky
2004-06-01 12:10 ` Martin Schwidefsky
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