Message-ID: <4A596A57.7080500@zytor.com>
Date: Sat, 11 Jul 2009 21:45:11 -0700
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Rusty Russell <rusty@rustcorp.com.au>
CC: Arjan van de Ven <arjan@infradead.org>, Ingo Molnar <mingo@elte.hu>,
       Siarhei Liakh <sliakh.lkml@gmail.com>, linux-kernel@vger.kernel.org,
       linux-security-module@vger.kernel.org, James Morris <jmorris@namei.org>,
       Andrew Morton <akpm@linux-foundation.org>, Andi Kleen <ak@muc.de>,
       Thomas Gleixner <tglx@linutronix.de>, linux-cris-kernel@axis.com
Subject: Re: [PATCH v5] RO/NX protection for loadable kernel modules
References: <817ecb6f0907081610p6d60341cudbee42685eac1347@mail.gmail.com> <200907111821.47769.rusty@rustcorp.com.au> <20090711084958.69ff9196@infradead.org> <200907121410.39874.rusty@rustcorp.com.au>
In-Reply-To: <200907121410.39874.rusty@rustcorp.com.au>
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Rusty Russell wrote:
> 
> OTOH, a quick grep shows currently only cris does kmalloc, and that's a config 
> option.
> 
> It might be time to unify this code.  If we rename MODULE_START to 
> MODULE_VADDR on MIPS, then ignoring CRIS there's only two real variants; 
> vmalloc and __vmalloc.
> 
> (I like the idea of trying kmalloc and falling back, simply because it reduces 
> TLB pressure, but that's probably best done after unification).
> 

Instead of plain kmalloc we could also have separate R-- and R-X slabs
(the normal kmalloc slabs already being RW-).

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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