On Thu, Jul 11, 2024 at 10:07:30PM +0200, Jason A. Donenfeld wrote: > 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). Oh, I didn't catch upthread in time (my mail flow is based on `lei up`, which I guess I should run at greater frequency). It seems like we apparently might go in a different direction. I'll move that to https://git.zx2c4.com/linux-rng/log/?h=jd/pte_dirty in case it's useful later, though. Jason
