On 02.02.21 15:22, Michal Hocko wrote:
On Tue 02-02-21 15:12:21, David Hildenbrand wrote:
[...]
I think secretmem behaves much more like longterm GUP right now
("unmigratable", "lifetime controlled by user space", "cannot go on
CMA/ZONE_MOVABLE"). I'd either want to reasonably well control/limit it or
make it behave more like mlocked pages.
I thought I have already asked but I must have forgotten. Is there any
actual reason why the memory is not movable? Timing attacks?
I think the reason is simple: no direct map, no copying of memory.
As I mentioned, we would have to temporarily map in order to copy.
Mapping it somewhere else (like kmap), outside of the direct map might
reduce possible attacks.
--
Thanks,
David / dhildenb
