From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leon Romanovsky Subject: [PATCH rdma-next 3/4] IB/mlx5: Take write semaphore when changing the vma struct Date: Wed, 29 Mar 2017 06:03:02 +0300 Message-ID: <20170329030303.4942-3-leon@kernel.org> References: <20170329030303.4942-1-leon@kernel.org> Return-path: In-Reply-To: <20170329030303.4942-1-leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Doug Ledford Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Maor Gottlieb List-Id: linux-rdma@vger.kernel.org From: Maor Gottlieb 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: 7c2344c3bbf97 ('IB/mlx5: Implements disassociate_ucontext API') Signed-off-by: Maor Gottlieb Signed-off-by: Leon Romanovsky --- drivers/infiniband/hw/mlx5/main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index 4dc0a8785fe0..88070a7cde48 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -1478,7 +1478,7 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) /* need to protect from a race on closing the vma as part of * mlx5_ib_vma_close. */ - down_read(&owning_mm->mmap_sem); + down_write(&owning_mm->mmap_sem); list_for_each_entry_safe(vma_private, n, &context->vma_private_list, list) { vma = vma_private->vma; @@ -1492,7 +1492,7 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) list_del(&vma_private->list); kfree(vma_private); } - up_read(&owning_mm->mmap_sem); + up_write(&owning_mm->mmap_sem); mmput(owning_mm); put_task_struct(owning_process); } -- 2.12.0 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html