[PATCH AUTOSEL for 4.4 040/101] IB/mlx4: Change vma from shared to private

Sasha Levin
2018-03-08T05:35:52Z

From: Maor Gottlieb <maorg@mellanox.com>

[ 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>
---
drivers/infiniband/hw/mlx4/main.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index 9119e0b3c2b8..67c4c73343d4 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -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;
}
--
2.14.1