On 6/27/18 9:10 PM, Linus Torvalds wrote: > On Wed, Jun 27, 2018 at 6:45 PM Eric Sandeen <sandeen@xxxxxxxxxx> wrote: >> >> Thus the invalid flag combination of (MAP_SHARED|MAP_PRIVATE) now >> passes without error, which is a regression. > > It's not a regression, it's just new behavior. > > "regression" doesn't mean "things changed". It means "something broke". > > What broke? My commit log perhaps was not clear enough. What broke is that mmap(MAP_SHARED|MAP_PRIVATE) now succeeds without error, whereas before it rightly returned -EINVAL. What behavior should a user expect from a successful mmap(MAP_SHARED|MAP_PRIVATE)? -Eric > Because if it's some manual page breakage, just fix the manual. That's > what "new behavior" is all about. > > There is nothing that says that "MAP_SHARED_VALIDATE" can't work with > just the legacy flags. > > Because I'd be worried about your patch breaking some actual new user > of MAP_SHARED_VALIDATE. > > Because it's actual *users* of behavior we care about, not some > test-suite or manual pages. > > Linus
