[PATCH] ARM: allow, but warn, when issuing ioremap() on RAM

Nicolas Pitre nico at fluxnic.net
Mon Oct 11 18:53:43 EDT 2010

On Mon, 11 Oct 2010, Catalin Marinas wrote:

> It may be just theoretical but architecture licensees implement the
> hardware according to the ARM ARM. If it says "unpredictable", they
> don't need to care much about this scenario as it is not allowed in
> software and the hardware can be further optimised (well, I think
> "unpredictable" doesn't allow hardware deadlocking or security
> implications, so the memory corruption cannot be that random, possibly
> just restricted to that memory range). It is probably ok on current
> hardware but I cannot guarantee, you would have to check on a
> case-by-case basis (CPU implementation).

I've seen real designs where "security implications" was interpreted 
rather liberally by the hardware people, and not exactly in the same way 
as software people do.


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