From: Ingo Molnar <mingo@kernel.org>
To: akpm@linux-foundation.org
Cc: mingo@elte.hu, hpa@zytor.com, tglx@linutronix.de,
kirill.shutemov@linux.intel.com, dave.hansen@intel.com,
mingo@redhat.com, n-horiguchi@ah.jp.nec.com,
willy@linux.intel.com, linux-kernel@vger.kernel.org
Subject: Re: [patch 3/3] x86, mm: get ASLR work for hugetlb mappings
Date: Tue, 19 Nov 2013 09:30:53 +0100 [thread overview]
Message-ID: <20131119083053.GB1243@gmail.com> (raw)
In-Reply-To: <20131115221406.1692E1E418F@corp2gmr1-2.eem.corp.google.com>
* akpm@linux-foundation.org <akpm@linux-foundation.org> wrote:
> From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
> Subject: x86, mm: get ASLR work for hugetlb mappings
>
> 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.
So the title and the changelog has typos (I counted three), which
makes me wonder how well this was tested.
To show/document the testing effort a before/after /proc/PID/maps
output showing hugetlb vma addresses would be nice, showing that ASLR
didn't work before and that it works adequately after the patch.
A word about the range and granularity of randomization in the typical
case would be nice as well.
Thanks,
Ingo
next parent reply other threads:[~2013-11-19 8:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20131115221406.1692E1E418F@corp2gmr1-2.eem.corp.google.com>
2013-11-19 8:30 ` Ingo Molnar [this message]
2013-11-19 13:17 ` [patch 3/3] x86, mm: get ASLR work for hugetlb mappings Kirill A. Shutemov
2013-11-19 13:20 ` Ingo Molnar
2013-11-19 19:18 ` [tip:x86/mm] x86/mm: Implement ASLR " tip-bot for Kirill A. Shutemov
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