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From: Andi Kleen <andi@firstfloor•org>
To: Siarhei Liakh <sliakh.lkml@gmail•com>
Cc: linux-kernel@vger•kernel.org,
	linux-security-module@vger•kernel.org,
	linux-next@vger•kernel.org,
	Arjan van de Ven <arjan@infradead•org>,
	James Morris <jmorris@namei•org>,
	Andrew Morton <akpm@linux-foundation•org>, Andi Kleen <ak@muc•de>,
	Thomas Gleixner <tglx@linutronix•de>,
	"H. Peter Anvin" <hpa@zytor•com>, Ingo Molnar <mingo@elte•hu>,
	Rusty Russell <rusty@rustcorp•com.au>,
	Stephen Rothwell <sfr@canb•auug.org.au>,
	Dave Jones <davej@redhat•com>
Subject: Re: [PATCH v8] RO/NX protection for loadable kernel modules
Date: Wed, 03 Feb 2010 00:05:39 +0100	[thread overview]
Message-ID: <873a1jdyrg.fsf@basil.nowhere.org> (raw)
In-Reply-To: <817ecb6f1001311522q52bf4eebmb748c486dcd5ad35@mail.gmail.com> (Siarhei Liakh's message of "Sun, 31 Jan 2010 18:22:35 -0500")

Siarhei Liakh <sliakh.lkml@gmail•com> writes:

> This patch is a logical extension of the protection provided by
> CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting
> module_core and module_init into three logical parts each and setting
> appropriate page access permissions for each individual section:

My current kernel has 52 modules loaded, most of them very small. 
Assuming the additional alignment of the data section cost two more
pages on average (I think that's a good assumption), that's roughly
424KB of additional memory, plus associated runtime costs in increased
TLB usage. 

What would I get for that if I applied the patch and enabled the option? 

That information seems to be missing in this patch submission.

Did you find any bugs with this option?

-Andi

-- 
ak@linux•intel.com -- Speaking for myself only.

  parent reply	other threads:[~2010-02-02 23:05 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-31 23:22 [PATCH v8] RO/NX protection for loadable kernel modules Siarhei Liakh
2010-02-01  1:39 ` Rusty Russell
2010-02-01 16:22   ` Siarhei Liakh
2010-02-02 23:05 ` Andi Kleen [this message]
2010-02-03  4:07   ` Siarhei Liakh
2010-02-08  1:45   ` Rusty Russell
2010-02-08  1:54     ` H. Peter Anvin

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