Lorenzo Stoakes <lstoakes@xxxxxxxxx> wrote: > > iov_iter_extract_pages(), on the other hand, is only used in two places > > with these patches and the pins are always released with > > unpin_user_page*() so it's a lot easier to audit. > > Thanks for the clarification. I guess these are the cases where you're > likely to see zero page usage, but since this is changing all PUP*() callers > don't you need to audit all of those too? I don't think it should be necessary. This only affects pages obtained from gup with FOLL_PIN - and, so far as I know, those always have to be released with unpin_user_page*() which is part of the gup API and thus it should be transparent to the users. Pages obtained FOLL_GET, on the other hand, aren't freed through the gup API - and there are a bunch of ways of releasing them - and getting additional refs too. David
