From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Fri, 08 Jul 2011 13:55:30 +0200
From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
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Subject: Re: [Adeos-main] [PATCH] ipipe: Prevent unwritable pages after
	mprotect
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To: Jan Kiszka <jan.kiszka@domain.hid>
Cc: adeos-main <adeos-main@gna.org>, Philippe Gerum <rpm@xenomai.org>

On 07/07/2011 09:14 PM, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@domain.hid>
> 
> Page protection changes issued via mprotect, e.g. to enable executable
> stacks, cause spurious minor faults as they remove the write permission
> from the modified range again. Avoid this by faking shared pages so that
> vm_get_page_prot returns the desired page permissions.

This looks dangerous to me. Have you checked that write to private heaps
will not end up corrupting shared data?

-- 
					    Gilles.