[PATCH] arm: cmpxchg syscall should data abort if page not write or not young

[Russell King - ARM Linux]

On Mon, Mar 14, 2011 at 06:28:36PM +0800, Po-Yu Chuang wrote:
> From: Po-Yu Chuang <ratbert at faraday-tech.com>
> 
> If the page to cmpxchg is user mode read only (not write)
> or invalid (not young), we should simulate a data abort first.

No.  If it is not young then it should be made young.  Age is an effect
of accesses.  It's not a permission.