From: Kees Cook <keescook@chromium.org>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Mel Gorman <mgorman@suse.de>,
Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Mike Rapoport <rppt@linux.ibm.com>,
Keith Busch <keith.busch@intel.com>,
Linux MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v7 1/3] mm: Shuffle initial free memory to improve memory-side-cache utilization
Date: Thu, 10 Jan 2019 14:52:29 -0800 [thread overview]
Message-ID: <CAGXu5jL1sivv70_Uahbg=cMZP2UM=eYBn4u8nx3NU5ayzHf28g@mail.gmail.com> (raw)
In-Reply-To: <CAPcyv4gkSBW5Te0RZLrkxzufyVq56-7pHu__YfffBiWhoqg7Yw@mail.gmail.com>
On Thu, Jan 10, 2019 at 1:29 PM Dan Williams <dan.j.williams@intel.com> wrote:
> Note that higher order merging is not a current concern since the
> implementation is already randomizing on MAX_ORDER sized pages. Since
> memory side caches are so large there's no worry about a 4MB
> randomization boundary.
>
> However, for the (unproven) security use case where folks want to
> experiment with randomizing on smaller granularity, they should be
> wary of this (/me nudges Kees).
Yup. And I think this is well noted in the Kconfig help already. I
view this as slightly more fine grain randomization than we get from
just effectively the base address randomization that
CONFIG_RANDOMIZE_MEMORY performs.
I remain a fan of this series. :)
--
Kees Cook
next prev parent reply other threads:[~2019-01-10 22:52 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-07 23:21 [PATCH v7 0/3] mm: Randomize free memory Dan Williams
2019-01-07 23:21 ` Dan Williams
2019-01-07 23:21 ` [PATCH v7 1/3] mm: Shuffle initial free memory to improve memory-side-cache utilization Dan Williams
2019-01-07 23:21 ` Dan Williams
2019-01-08 0:18 ` Kees Cook
2019-01-08 0:18 ` Kees Cook
2019-01-08 1:48 ` Dan Williams
2019-01-08 1:48 ` Dan Williams
2019-01-08 23:24 ` Kees Cook
2019-01-08 23:24 ` Kees Cook
2019-01-10 10:56 ` Mel Gorman
2019-01-10 21:29 ` Dan Williams
2019-01-10 21:29 ` Dan Williams
2019-01-10 22:52 ` Kees Cook [this message]
2019-01-10 22:52 ` Kees Cook
2019-01-25 14:20 ` Michal Hocko
2019-01-29 19:26 ` Dan Williams
2019-01-29 20:04 ` Dan Williams
2019-01-07 23:21 ` [PATCH v7 2/3] mm: Move buddy list manipulations into helpers Dan Williams
2019-01-07 23:21 ` Dan Williams
2019-01-25 14:30 ` Michal Hocko
2019-01-29 19:27 ` Dan Williams
2019-01-07 23:21 ` [PATCH v7 3/3] mm: Maintain randomization of page free lists Dan Williams
2019-01-07 23:21 ` Dan Williams
2019-01-08 0:19 ` Kees Cook
2019-01-08 0:19 ` Kees Cook
2019-01-25 14:32 ` Michal Hocko
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