On 01.02.23 18:32, Edgecombe, Rick P wrote:

On Wed, 2023-02-01 at 10:03 +0100, David Hildenbrand wrote:

quoted

quoted

The other problem is that one of NULL passers is not for kernel
memory.
huge_pte_mkwrite() calls pte_mkwrite(). Shadow stack memory can't
be
created with MAP_HUGETLB, so it is not needed. Using
pte_mkwrite_kernel() would look weird in this case, but making
huge_pte_mkwrite() take a VMA would be for no reason. Maybe making
huge_pte_mkwrite() take a VMA is the better of those two options.
Or
keep the NULL semantics...  Any thoughts?

Well, the reason would be consistency. From a core-mm point of view
it
makes sense to handle this all consistency, even if the single user
(x86) wouldn't strictly require it right now.

I'd just pass in the VMA and call it a day :)

Ok, I'll give it a spin.

It would be good to get more opinions on that, but I'm afraid we won't 
get more deep down in this thread :)

-- 
Thanks,

David / dhildenb