Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Pull rdma fixes from Jason Gunthorpe:
 "One core bug fix and a few driver ones

   - FRWR memory registration for hfi1/qib didn't work with with some
     iovas causing a NFSoRDMA failure regression due to a fix in the NFS
     side

   - A command flow error in mlx5 allowed user space to send a corrupt
     command (and also smash the kernel stack we've since learned)

   - Fix a regression and some bugs with device hot unplug that was
     discovered while reviewing Andrea's patches

   - hns has a failure if the user asks for certain QP configurations"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  RDMA/hns: Bugfix for mapping user db
  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
  IB/mlx5: Fix scatter to CQE in DCT QP creation
  IB/rdmavt: Fix frwr memory registration

diff --cc drivers/infiniband/core/uverbs_main.c
index f2e7ffe6fc546612f62da9cde853b9c1bf37d8bb,db20b6e0f253c92402d422c8080fc5b1385d47fc..7843e89235c34b4e6831dedaebb7d2170986099d
--- 1/drivers/infiniband/core/uverbs_main.c
--- 2/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@@ -992,9 -1039,7 +1039,9 @@@ void uverbs_user_mmap_disassociate(stru
                 * at a time to get the lock ordering right. Typically there
                 * will only be one mm, so no big deal.
                 */
-               down_write(&mm->mmap_sem);
+               down_read(&mm->mmap_sem);
 +              if (!mmget_still_valid(mm))
 +                      goto skip_mm;
                mutex_lock(&ufile->umap_lock);
                list_for_each_entry_safe (priv, next_priv, &ufile->umaps,
                                          list) {
@@@ -1006,11 -1051,9 +1053,10 @@@
  
                        zap_vma_ptes(vma, vma->vm_start,
                                     vma->vm_end - vma->vm_start);
-                       vma->vm_flags &= ~(VM_SHARED | VM_MAYSHARE);
                }
                mutex_unlock(&ufile->umap_lock);
-               up_write(&mm->mmap_sem);
 +      skip_mm:
+               up_read(&mm->mmap_sem);
                mmput(mm);
        }
  }