From mboxrd@z Thu Jan  1 00:00:00 1970
From: linux@arm.linux.org.uk (Russell King - ARM Linux)
Date: Tue, 30 Mar 2010 08:29:19 +0100
Subject: [PATCH] ARM: Implement copy_to_user_page() for noMMU
In-Reply-To: <20100330013132.GA15598@shareable.org>
References: <20100329132457.1967.3394.stgit@e102109-lin.cambridge.arm.com>
	<20100330013132.GA15598@shareable.org>
Message-ID: <20100330072919.GA14500@n2100.arm.linux.org.uk>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tue, Mar 30, 2010 at 02:31:32AM +0100, Jamie Lokier wrote:
> Other variations such as writing when a mapping is !VM_EXEC and later
> mapping or mprotecting the same shmem VM_EXEC, but it's even more
> forbidden semantically to write to a read-only mapping (and just as
> unchecked on nommu), and conversion of writable to VM_EXEC ought to
> flush i-cache at mprotect time.

If NX isn't implemented, then arm_elf_read_implies_exec() must return 1
for the CPU - so that any region that is marked readable will have
VM_EXEC set.