On Wed, Oct 7, 2020 at 2:44 PM Jason Gunthorpe <jgg@xxxxxxxx> wrote: > > On Wed, Oct 07, 2020 at 02:33:56PM +0200, Marek Szyprowski wrote: > > Well, it was in vb2_get_vma() function, but now I see that it has been > > lost in fb639eb39154 and 6690c8c78c74 some time ago... > > There is no guarentee that holding a get on the file says anthing > about the VMA. This needed to check that the file was some special > kind of file that promised the VMA layout and file lifetime are > connected. > > Also, cloning a VMA outside the mm world is just really bad. That > would screw up many assumptions the drivers make. > > If it is all obsolete I say we hide it behind a default n config > symbol and taint the kernel if anything uses it. > > Add a big comment above the follow_pfn to warn others away from this > code. Sadly it's just verbally declared as deprecated and not formally noted anyway. There are a lot of userspace applications relying on user pointer support.
