On Mon, 2015-10-26 at 16:26 +0000, Luck, Tony wrote:
> -     pfn = PFN_DOWN(param1 & param2);
> -     if (!page_is_ram(pfn) || ((param2 & PAGE_MASK) != PAGE_MASK))
> +     base_addr = param1 & param2;
> +     size = (~param2) + 1;
> 
> We expect the user will supply us with param2 in the form 
> 0xffffffff[fec8]00000
> with various numbers of leading 'f' and trailing '0' ... but I don't think we 
> actually
> check that anywhere.  But we have a bunch of places that assume it is OK, 
> including
> this new one.
> 
> It's time to fix that.  Maybe even provide a default 0xfffffffffffff000 so I 
> can save 
> myself some typing?

+       if (((region_intersects_ram(base_addr, size) != REGION_INTERSECTS) &&
+            (region_intersects_pmem(base_addr, size) != REGION_INTERSECTS)) ||
+           ((param2 & PAGE_MASK) != PAGE_MASK))
                return -EINVAL;

The 3rd condition check makes sure that the param2 mask is the page size or 
less.  So, I
think we are OK on this.

Thanks,
-Toshi
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