diff options
| author | Maor Gottlieb <maorg@mellanox.com> | 2017-03-29 06:03:00 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-24 10:58:42 +0100 |
| commit | b5834cc1690102c46f839ac4cbfb1f44c06ad1da (patch) | |
| tree | 6180b7f841cb9eac17ea7a129e9d976f06be50f4 | |
| parent | fd63c2b253338edd6fc594860333b2e4e1a0a910 (diff) | |
IB/mlx4: Take write semaphore when changing the vma struct
[ Upstream commit 22c3653d04bd0c67b75e99d85e0c0bdf83947df5 ]
When the driver disassociate user context, it changes the vma to
anonymous by setting the vm_ops to null and zap the vma ptes.
In order to avoid race in the kernel, we need to take write lock
before we change the vma entries.
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>
| -rw-r--r-- | drivers/infiniband/hw/mlx4/main.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c index 5a2a0b5db938..9119e0b3c2b8 100644 --- a/drivers/infiniband/hw/mlx4/main.c +++ b/drivers/infiniband/hw/mlx4/main.c @@ -1041,7 +1041,7 @@ static void mlx4_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) /* need to protect from a race on closing the vma as part of * mlx4_ib_vma_close(). */ - down_read(&owning_mm->mmap_sem); + down_write(&owning_mm->mmap_sem); for (i = 0; i < HW_BAR_COUNT; i++) { vma = context->hw_bar_info[i].vma; if (!vma) @@ -1059,7 +1059,7 @@ static void mlx4_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) context->hw_bar_info[i].vma->vm_ops = NULL; } - up_read(&owning_mm->mmap_sem); + up_write(&owning_mm->mmap_sem); mmput(owning_mm); put_task_struct(owning_process); } |