On 10/30/18 10:58 AM, Matthew Wilcox wrote: > Does this satisfy Igor's requirements? We wouldn't be able to > copy_to/from_user() while rare_mm was active. I think that's a feature > though! It certainly satisfies my interests (kernel code be able to > mark things as dynamically-allocated-and-read-only-after-initialisation) It has to be more than copy_to/from_user(), though, I think. rare_modify(q) either has to preempt_disable(), or we need to teach the context-switching code when and how to switch in/out of the rare_mm. preempt_disable() would also keep us from sleeping.
