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Date: Mon, 4 Nov 2013 13:09:51 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Nadia Yvette Chambers <nyc@holomorphy.com>,
        Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Matthew Wilcox <willy@linux.intel.com>
Subject: Re: [PATCH] x86, mm: get ASLR work for hugetlb mappings
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On Mon,  4 Nov 2013 12:41:52 +0200 (EET) "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> wrote:

> Kirill A. Shutemov wrote:
> > Matthew noticed that hugetlb doesn't participate in ASLR on x86-64.
> > The reason is genereic hugetlb_get_unmapped_area() which is used on
> > x86-64. It doesn't support randomization and use bottom-up unmapped area
> > lookup, instead of usual top-down on x86-64.
> > 
> > x86 has arch-specific hugetlb_get_unmapped_area(), but it's used only on
> > x86-32.
> > 
> > Let's use arch-specific hugetlb_get_unmapped_area() on x86-64 too.
> > It fixes the issue and make hugetlb use top-down unmapped area lookup.
> > 
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > Cc: Matthew Wilcox <willy@linux.intel.com>
> 
> Andrew, any comments?

whome?  I'm convinced, but it's an x86 patch.  I tossed it in there so
it gets a bit of linux-next exposure.