Hi Linus, On Thu, Jul 11, 2024 at 10:57:17AM -0700, Linus Torvalds wrote: > May I suggest a slightly different approach: do what we did for "pte_mkwrite()". > > It needed the vma too, for not too dissimilar reasons: special dirty > bit handling for the shadow stack. See Thanks for the suggestion. That seems pretty clean. It still needs to avoid setting swapbacked in the first place, but ensuring that it's never dirty means it won't get turned back on. The first patch renames pte_dirty() to pte_dirty_novma(). The second patch adds an inline function, pte_dirty(pte, vma) that just forwards the pte to pte_dirty_novma(), and then converts callers that have a vma available to pass to call pte_dirty(). And then the VM_DROPPABLE patch simply adds the `&& !(vma->vm_flags & VM_DROPPABLE)` condition to pte_dirty(). I put these in https://git.zx2c4.com/linux-rng/log/ per usual, and I'll post a new version to the list not before long (unless objections). Jason
