On Sat, Sep 19, 2020 at 10:39 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > My concern with that is people might use kmap() and then pass the address > to a different task. So we need to audit the current users of kmap() > and convert any that do that into using vmap() instead. Ahh. Yes, I guess they might do that. It sounds strange, but not entirely crazy - I could imagine some "PIO thread" that does IO to a page that has been set up by somebody else using kmap(). Or similar. Linus