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Subject: Re: Executing from readablee, no-exec pages
From: David Woodhouse <dwmw2@infradead.org>
To: Scott Wood <scottwood@freescale.com>
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Date: Fri, 06 Jul 2007 10:42:01 -0400
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On Thu, 2007-07-05 at 16:55 -0500, Scott Wood wrote:
> To maintain compatibility with these versions, we could change the test 
> in do_page_fault() to include VM_READ as well as VM_EXEC on targets that 
> don't have a separate exec-bit in hardware (are there any powerpc mmus 
> that do?).  

64-bit implementations since POWER4 have separate exec permissions,
don't they? So any userspace which tries to execute non-executable pages
is already broken when running on a ppc64 machine; I wouldn't worry too
much about letting it break on ppc32 too.

We already use vDSO signal trampolines even on the 32-bit kernel, right?

-- 
dwmw2