From: Rik van Riel <riel@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: "Larry H." <research@subreption.com>,
linux-kernel@vger.kernel.org, Linus Torvalds <torvalds@osdl.org>,
linux-mm@kvack.org, Ingo Molnar <mingo@redhat.com>
Subject: Re: [patch 0/5] Support for sanitization flag in low-level page allocator
Date: Thu, 21 May 2009 15:08:15 -0400 [thread overview]
Message-ID: <4A15A69F.3040604@redhat.com> (raw)
In-Reply-To: <1242852158.6582.231.camel@laptop>
Peter Zijlstra wrote:
> Seems like a particularly wasteful use of a pageflag. Why not simply
> erase the buffer before freeing in those few places where we know its
> important (ie. exactly those places you now put the pageflag in)?
You don't always know this at page free time.
I could see the PG_sensitive flag being used from
userspace through mmap or madvise flags. This way
the sensitive memory from a program like gpg would
be cleaned, even if gpg died in a segfault accident.
I could also imagine the suspend-to-disk code skipping
PG_sensitive pages when storing data to disk, and
replacing it with some magic signature so programs
that use special PG_sensitive buffers can know that
their crypto key disappeared after a restore.
WARNING: multiple messages have this Message-ID (diff)
From: Rik van Riel <riel@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: "Larry H." <research@subreption.com>,
linux-kernel@vger.kernel.org, Linus Torvalds <torvalds@osdl.org>,
linux-mm@kvack.org, Ingo Molnar <mingo@redhat.com>
Subject: Re: [patch 0/5] Support for sanitization flag in low-level page allocator
Date: Thu, 21 May 2009 15:08:15 -0400 [thread overview]
Message-ID: <4A15A69F.3040604@redhat.com> (raw)
In-Reply-To: <1242852158.6582.231.camel@laptop>
Peter Zijlstra wrote:
> Seems like a particularly wasteful use of a pageflag. Why not simply
> erase the buffer before freeing in those few places where we know its
> important (ie. exactly those places you now put the pageflag in)?
You don't always know this at page free time.
I could see the PG_sensitive flag being used from
userspace through mmap or madvise flags. This way
the sensitive memory from a program like gpg would
be cleaned, even if gpg died in a segfault accident.
I could also imagine the suspend-to-disk code skipping
PG_sensitive pages when storing data to disk, and
replacing it with some magic signature so programs
that use special PG_sensitive buffers can know that
their crypto key disappeared after a restore.
--
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next prev parent reply other threads:[~2009-05-21 19:09 UTC|newest]
Thread overview: 220+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-20 18:30 [patch 0/5] Support for sanitization flag in low-level page allocator Larry H.
2009-05-20 18:30 ` Larry H.
2009-05-20 20:42 ` Peter Zijlstra
2009-05-20 20:42 ` Peter Zijlstra
2009-05-20 21:24 ` Larry H.
2009-05-20 21:24 ` Larry H.
2009-05-21 15:21 ` Robin Holt
2009-05-21 15:21 ` Robin Holt
2009-05-21 18:43 ` Larry H.
2009-05-21 18:43 ` Larry H.
2009-05-29 22:58 ` Andrew Morton
2009-05-29 22:58 ` Andrew Morton
2009-05-30 7:00 ` Larry H.
2009-05-30 7:12 ` Pekka Enberg
2009-05-30 7:12 ` Pekka Enberg
2009-05-30 7:35 ` Larry H.
2009-05-30 7:35 ` Larry H.
2009-05-30 7:39 ` Pekka Enberg
2009-05-30 7:39 ` Pekka Enberg
2009-05-21 19:08 ` Rik van Riel [this message]
2009-05-21 19:08 ` Rik van Riel
2009-05-21 19:26 ` Alan Cox
2009-05-21 19:26 ` Alan Cox
2009-05-21 19:56 ` Larry H.
2009-05-21 19:56 ` Larry H.
2009-05-21 20:47 ` Alan Cox
2009-05-21 20:47 ` Alan Cox
2009-05-21 21:46 ` Larry H.
2009-05-21 22:47 ` Alan Cox
2009-05-21 22:47 ` Alan Cox
2009-05-22 11:22 ` Larry H.
2009-05-22 11:22 ` Larry H.
2009-05-22 13:37 ` Alan Cox
2009-05-22 13:37 ` Alan Cox
2009-05-26 19:02 ` Pavel Machek
2009-05-26 19:02 ` Pavel Machek
2009-05-21 19:17 ` Rik van Riel
2009-05-21 19:30 ` Larry H.
2009-05-22 7:34 ` Ingo Molnar
2009-05-22 11:38 ` Larry H.
2009-05-22 11:38 ` Larry H.
2009-05-22 13:39 ` Alan Cox
2009-05-22 13:39 ` Alan Cox
2009-05-22 18:03 ` Larry H.
2009-05-22 18:03 ` Larry H.
2009-05-22 18:21 ` Alan Cox
2009-05-22 18:21 ` Alan Cox
2009-05-22 23:25 ` [PATCH] Support for kernel memory sanitization Larry H.
2009-05-22 23:52 ` Randy Dunlap
2009-05-22 23:40 ` [patch 0/5] Support for sanitization flag in low-level page allocator Larry H.
2009-05-23 8:09 ` Alan Cox
2009-05-23 8:09 ` Alan Cox
2009-05-23 15:56 ` Arjan van de Ven
2009-05-23 15:56 ` Arjan van de Ven
2009-05-23 18:21 ` [PATCH] Support for unconditional page sanitization Larry H.
2009-05-23 18:21 ` Larry H.
2009-05-23 21:05 ` Arjan van de Ven
2009-05-23 21:05 ` Arjan van de Ven
2009-05-24 10:19 ` pageexec
2009-05-24 10:19 ` pageexec
2009-05-24 16:38 ` Arjan van de Ven
2009-05-24 16:38 ` Arjan van de Ven
2009-05-28 19:36 ` [patch 0/5] Support for sanitization flag in low-level page allocator Peter Zijlstra
2009-05-28 19:36 ` Peter Zijlstra
2009-05-29 14:32 ` Arjan van de Ven
2009-05-29 14:32 ` Arjan van de Ven
2009-05-30 5:48 ` Larry H.
2009-05-30 5:48 ` Larry H.
2009-05-30 10:39 ` Peter Zijlstra
2009-05-30 10:39 ` Peter Zijlstra
2009-05-30 10:43 ` Larry H.
2009-05-30 10:43 ` Larry H.
2009-05-30 11:42 ` pageexec
2009-05-30 11:42 ` pageexec
2009-05-30 13:21 ` Peter Zijlstra
2009-05-30 13:21 ` Peter Zijlstra
2009-05-30 13:24 ` Peter Zijlstra
2009-05-30 13:24 ` Peter Zijlstra
2009-05-30 13:54 ` pageexec
2009-05-30 13:54 ` pageexec
2009-05-30 14:04 ` Larry H.
2009-05-30 14:04 ` Larry H.
2009-05-30 14:13 ` Rik van Riel
2009-05-30 14:13 ` Rik van Riel
2009-05-30 14:08 ` Rik van Riel
2009-05-30 14:08 ` Rik van Riel
2009-05-30 14:30 ` Alan Cox
2009-05-30 14:45 ` Peter Zijlstra
2009-05-30 14:45 ` Peter Zijlstra
2009-05-30 14:48 ` Rik van Riel
2009-05-30 14:48 ` Rik van Riel
2009-05-30 17:00 ` Larry H.
2009-05-30 17:00 ` Larry H.
2009-05-30 17:25 ` Larry H.
2009-05-30 17:25 ` Larry H.
2009-05-30 18:32 ` Ingo Molnar
2009-05-30 18:32 ` Ingo Molnar
2009-06-05 13:15 ` Pavel Machek
2009-05-31 14:38 ` Arjan van de Ven
2009-05-31 14:38 ` Arjan van de Ven
2009-05-31 15:03 ` Arjan van de Ven
2009-05-31 15:03 ` Arjan van de Ven
2009-05-22 18:37 ` Nai Xia
2009-05-22 18:37 ` Nai Xia
2009-05-22 19:18 ` Nai Xia
2009-05-22 19:18 ` Nai Xia
2009-05-23 12:49 ` Ingo Molnar
2009-05-23 12:49 ` Ingo Molnar
2009-05-23 22:28 ` Larry H.
2009-05-23 22:28 ` Larry H.
2009-05-23 22:42 ` Rik van Riel
2009-05-23 22:42 ` Rik van Riel
2009-05-25 1:17 ` [PATCH] Sanitize memory on kfree() and kmem_cache_free() Larry H.
2009-05-25 1:17 ` Larry H.
2009-05-27 22:34 ` [patch 0/5] Support for sanitization flag in low-level page allocator Ingo Molnar
2009-05-27 22:34 ` Ingo Molnar
2009-05-28 6:27 ` Alan Cox
2009-05-28 6:27 ` Alan Cox
2009-05-28 7:00 ` Larry H.
2009-05-28 7:00 ` Larry H.
2009-05-28 9:08 ` Ingo Molnar
2009-05-28 9:08 ` Ingo Molnar
2009-05-28 11:50 ` Alan Cox
2009-05-28 11:50 ` Alan Cox
2009-05-28 19:44 ` Peter Zijlstra
2009-05-28 19:44 ` Peter Zijlstra
2009-05-30 7:35 ` Pekka Enberg
2009-05-30 7:35 ` Pekka Enberg
2009-05-30 7:50 ` Larry H.
2009-05-30 7:50 ` Larry H.
2009-05-30 7:53 ` Pekka Enberg
2009-05-30 7:53 ` Pekka Enberg
2009-05-30 8:20 ` Larry H.
2009-05-30 8:20 ` Larry H.
2009-05-30 8:33 ` Pekka Enberg
2009-05-30 8:33 ` Pekka Enberg
2009-05-30 15:05 ` Ray Lee
2009-05-30 15:05 ` Ray Lee
2009-05-30 17:34 ` Ingo Molnar
2009-05-30 17:34 ` Ingo Molnar
2009-05-30 18:03 ` Larry H.
2009-05-30 18:03 ` Larry H.
2009-05-30 18:21 ` Ingo Molnar
2009-05-30 18:21 ` Ingo Molnar
2009-05-30 18:45 ` Larry H.
2009-05-30 18:45 ` Larry H.
2009-05-30 19:08 ` Ingo Molnar
2009-05-30 19:08 ` Ingo Molnar
2009-05-30 20:39 ` Rik van Riel
2009-05-30 20:39 ` Rik van Riel
2009-05-30 20:53 ` Pekka Enberg
2009-05-30 20:53 ` Pekka Enberg
2009-05-30 21:33 ` Larry H.
2009-05-30 21:33 ` Larry H.
2009-05-30 23:13 ` Alan Cox
2009-05-30 23:13 ` Alan Cox
2009-05-30 23:18 ` Larry H.
2009-05-30 23:18 ` Larry H.
2009-05-31 6:30 ` Pekka Enberg
2009-05-31 6:30 ` Pekka Enberg
2009-05-31 11:49 ` Larry H.
2009-05-31 11:49 ` Larry H.
2009-05-31 7:17 ` Pekka Enberg
2009-05-31 7:17 ` Pekka Enberg
2009-05-31 11:58 ` Larry H.
2009-05-31 11:58 ` Larry H.
2009-05-31 12:16 ` Pekka Enberg
2009-05-31 12:16 ` Pekka Enberg
2009-05-31 12:30 ` Larry H.
2009-05-31 12:30 ` Larry H.
2009-05-31 12:35 ` Pekka Enberg
2009-05-31 12:35 ` Pekka Enberg
2009-05-30 23:10 ` Alan Cox
2009-05-30 23:10 ` Alan Cox
2009-05-31 6:14 ` Pekka Enberg
2009-05-31 6:14 ` Pekka Enberg
2009-05-31 10:24 ` Alan Cox
2009-05-31 10:24 ` Alan Cox
2009-05-31 10:24 ` Pekka Enberg
2009-05-31 10:24 ` Pekka Enberg
2009-05-31 12:16 ` Larry H.
2009-05-31 12:16 ` Larry H.
2009-05-31 12:19 ` Pekka Enberg
2009-05-31 12:19 ` Pekka Enberg
2009-05-31 16:25 ` Alan Cox
2009-05-31 16:25 ` Alan Cox
2009-05-30 22:10 ` Ingo Molnar
2009-05-30 22:10 ` Ingo Molnar
2009-05-30 23:15 ` Alan Cox
2009-05-30 23:15 ` Alan Cox
2009-05-30 20:22 ` Pekka Enberg
2009-05-30 20:22 ` Pekka Enberg
2009-05-30 22:14 ` Ingo Molnar
2009-05-30 22:14 ` Ingo Molnar
2009-05-30 17:39 ` Ingo Molnar
2009-05-30 17:39 ` Ingo Molnar
2009-05-30 7:57 ` Pekka Enberg
2009-05-30 7:57 ` Pekka Enberg
2009-05-30 9:05 ` Larry H.
2009-05-30 9:05 ` Larry H.
2009-05-30 17:46 ` Ingo Molnar
2009-05-30 17:46 ` Ingo Molnar
2009-05-30 18:09 ` Larry H.
2009-05-30 18:09 ` Larry H.
2009-05-30 8:31 ` Alan Cox
2009-05-30 8:31 ` Alan Cox
2009-05-30 8:35 ` Pekka Enberg
2009-05-30 8:35 ` Pekka Enberg
2009-05-30 9:27 ` Larry H.
2009-05-30 9:27 ` Larry H.
2009-05-28 18:48 ` pageexec
2009-05-28 18:48 ` pageexec
2009-05-30 17:50 ` Ingo Molnar
2009-05-30 17:50 ` Ingo Molnar
2009-05-28 12:48 ` Pavel Machek
2009-05-28 12:48 ` Pavel Machek
2009-05-28 12:55 ` Larry H.
2009-05-28 12:55 ` Larry H.
-- strict thread matches above, loose matches on Subject: below --
2009-05-28 18:56 pageexec
2009-05-28 18:56 ` pageexec
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