Merge branch 'rdma_mmap' into rdma.git for-next

Merge branch 'rdma_mmap' into rdma.git for-next

Jason Gunthorpe says:

====================
Upon review it turns out there are some long standing problems in BAR
mapping area:
 * BAR pages intended for read-only can be switched to writable via mprotect.
 * Missing use of rdma_user_mmap_io for the mlx5 clock BAR page.
 * Disassociate causes SIGBUS when touching the pages.
 * CPU pages are being mapped through to the process via remap_pfn_range
   instead of the more appropriate vm_insert_page, causing weird behaviors
   during disassociation.

This series adds the missing VM_* flag manipulation, adds faulting a zero
page for disassociation and revises the CPU page mappings to use
vm_insert_page.
====================

For dependencies this branch is based on for-rc from
git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git

* branch 'rdma_mmap':
  RDMA: Remove rdma_user_mmap_page
  RDMA/mlx5: Use get_zeroed_page() for clock_info
  RDMA/ucontext: Fix regression with disassociate
  RDMA/mlx5: Use rdma_user_map_io for mapping BAR pages
  RDMA/mlx5: Do not allow the user to write to the clock page

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>