On Mon, Oct 24, 2022 at 05:11:13PM -0700, Linus Torvalds wrote: > All of this comes from "poking_init()" being a steaming pile of bovine > excrement, doing random odd things, and having that special > "copy_init_mm()" helper that just makes things even worse. Nothing > else uses that, and it shouldn't have called "dup_mm()" in the first > place. Agreed; dup_mm() makes no sense and it is easily removed, see my earlier patch. Perhaps it can be simplified further to: __poking_mm = init_mm omitting the mm_init() I retained, but I need to stare harder at all that. > I'm not even sure why "poking_mm" exists at all, and why it has > created a whole new copy of "init_mm", and why this code isn't just > using '&init_mm' like everything else that wants to just walk the > kernel page tables. Because it instantiates user-space page-tables in it, you really don't want those in init_mm. The whole (and sole) purpose of poking_mm is to contain the writable aliases. Only the CPU that has the poking_mm active has access to them.
