IB/mlx4: Change vma from shared to private
authorMaor Gottlieb <maorg@mellanox.com>
Wed, 29 Mar 2017 03:03:01 +0000 (06:03 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 24 Mar 2018 09:58:43 +0000 (10:58 +0100)
[ Upstream commit ca37a664a8e4e9988b220988ceb4d79e3316f195 ]

Anonymous VMA (->vm_ops == NULL) cannot be shared, otherwise
it would lead to SIGBUS.

Remove the shared flags from the vma after we change it to be
anonymous.

This is easily reproduced by doing modprobe -r while running a
user-space application such as raw_ethernet_bw.

Fixes: ae184ddeca5db ('IB/mlx4_ib: Disassociate support')
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/infiniband/hw/mlx4/main.c

index 9119e0b..67c4c73 100644 (file)
@@ -1055,6 +1055,8 @@ static void mlx4_ib_disassociate_ucontext(struct ib_ucontext *ibcontext)
                        BUG_ON(1);
                }
 
+               context->hw_bar_info[i].vma->vm_flags &=
+                       ~(VM_SHARED | VM_MAYSHARE);
                /* context going to be destroyed, should not access ops any more */
                context->hw_bar_info[i].vma->vm_ops = NULL;
        }