On Wed, Mar 12, 2025 at 03:50:40PM +0000, Lorenzo Stoakes wrote: > What about madvise() with MADV_DONTNEED on a r/o VMA that's not faulted in? > That's a no-op right? But it's not permitted. Hmm, yes, that's a good example. Thank you! > So now we have an inconsistency between the two calls. Yeah, I see your concern now. > I don't know what you mean by 'ergonomic'? I was thinking about idempotent-ness. Like, some library setting up a memory region, it can't call its setup routine twice if the second time through (where no changes are made) it gets rejected. But I think this is likely just a userspace problem: check for the VMAs before blindly trying to do it again. (This is strictly an imagined situation.) > My reply seemed to get truncated at the end here :) So let me ask again - > do you have a practical case in mind for this? Sorry, I didn't have any reply to that part, so I left it off. If Jeff has a specific case in mind, I'll let him answer that part. :) -Kees -- Kees Cook
