From: Michal Hocko <mhocko@kernel.org>
To: Dan Williams <dan.j.williams@intel.com>
Cc: akpm@linux-foundation.org,
Dave Hansen <dave.hansen@linux.intel.com>,
Kees Cook <keescook@chromium.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 0/3] Randomize free memory
Date: Thu, 4 Oct 2018 09:44:57 +0200 [thread overview]
Message-ID: <20181004074457.GD22173@dhcp22.suse.cz> (raw)
In-Reply-To: <153861931865.2863953.11185006931458762795.stgit@dwillia2-desk3.amr.corp.intel.com>
On Wed 03-10-18 19:15:18, Dan Williams wrote:
> Changes since v1:
> * Add support for shuffling hot-added memory (Andrew)
> * Update cover letter and commit message to clarify the performance impact
> and relevance to future platforms
I believe this hasn't addressed my questions in
http://lkml.kernel.org/r/20181002143015.GX18290@dhcp22.suse.cz. Namely
"
It is the more general idea that I am not really sure about. First of
all. Does it make _any_ sense to randomize 4MB blocks by default? Why
cannot we simply have it disabled? Then and more concerning question is,
does it even make sense to have this randomization applied to higher
orders than 0? Attacker might fragment the memory and keep recycling the
lowest order and get the predictable behavior that we have right now.
"
> [1]: https://lkml.org/lkml/2018/9/15/366
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2018-10-04 7:45 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-04 2:15 [PATCH v2 0/3] Randomize free memory Dan Williams
2018-10-04 2:15 ` [PATCH v2 1/3] mm: Shuffle initial " Dan Williams
2018-10-04 7:48 ` Michal Hocko
2018-10-04 16:51 ` Dan Williams
2018-10-09 11:12 ` Michal Hocko
2018-10-09 17:36 ` Dan Williams
2018-10-04 2:15 ` [PATCH v2 2/3] mm: Move buddy list manipulations into helpers Dan Williams
2018-10-04 2:15 ` [PATCH v2 3/3] mm: Maintain randomization of page free lists Dan Williams
2018-10-04 7:44 ` Michal Hocko [this message]
2018-10-04 16:44 ` [PATCH v2 0/3] Randomize free memory Dan Williams
2018-10-06 17:01 ` Dan Williams
2018-10-09 11:22 ` Michal Hocko
2018-10-09 17:34 ` Dan Williams
2018-10-10 8:47 ` Michal Hocko
2018-10-11 0:13 ` Dan Williams
2018-10-11 11:52 ` Michal Hocko
2018-10-11 18:03 ` Dan Williams
2018-10-18 13:44 ` Michal Hocko
2018-10-12 8:22 ` Mel Gorman
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