On Mon, May 15, 2023 at 08:32:32PM +0100, Lorenzo Stoakes wrote: > As well as fixing the repro described in [1] this also continues to pass > uffd unit tests. Side note on testing, not directly relevant to the patch itself.. I'm wondering whether do we have tests somewhere to just test vma operations on split and merge, then verify it using smap or whatever. The uffd unit test in this case is probably not gonna trigger anything because we always mostly register with a whole vma over the testing ranges, so not immediately helpful. The trick here is we have quite a few ops that will call vma merge/split in different ways, but logically we can still category them into: (1) add/del vmas, or (2) modify vma flags, so at least for case (2) we can have a framework to cover all the cases (mbind, mprotect, uffd reg/unreg, mlock, etc.), the difference will be the flags we'll be looking at for different cases, however how vmas merge/split should be somehow in the same pattern. -- Peter Xu
