usnic has a modified version of the core codes' ib_umem_get() and
related, and the copy misses many of the bug fixes done over the years:

Commit bc3e53f6 ("mm: distinguish between mlocked and pinned pages")
Commit 87773dd5 ("IB: ib_umem_release() should decrement mm->pinned_vm
                      from ib_umem_get")
Commit 8494057a ("IB/uverbs: Prevent integer overflow in ib_umem_get
                      address arithmetic")
Commit 8abaae62 ("IB/core: disallow registering 0-sized memory region")
Commit 66578b0b ("IB/core: don't disallow registering region starting
                      at 0x0")
Commit 53376fed ("RDMA/core: not to set page dirty bit if it's already
                      set.")
Commit 8e907ed4 ("IB/umem: Use the correct mm during ib_umem_release")
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>