Re: [PATCH 2/2] IB/mlx5: Free mpi in mp_slave mode

[Jason Gunthorpe <jgg@mellanox.com>]

On Mon, Sep 16, 2019 at 09:48:18AM +0300, Leon Romanovsky wrote:
> From: Danit Goldberg <danitg@mellanox.com>
> 
> ib_add_slave_port() allocates a multiport struct but never frees it.
> Don't leak memory, free the allocated mpi struct during driver unload.
> 
> Fixes: 32f69e4be269 ("{net, IB}/mlx5: Manage port association for multiport RoCE")
> Signed-off-by: Danit Goldberg <danitg@mellanox.com>
>  drivers/infiniband/hw/mlx5/main.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
> index 0569bcab02d4..14807ea8dc3f 100644
> +++ b/drivers/infiniband/hw/mlx5/main.c
> @@ -6959,6 +6959,7 @@ static void mlx5_ib_remove(struct mlx5_core_dev *mdev, void *context)
>  			mlx5_ib_unbind_slave_port(mpi->ibdev, mpi);
>  		list_del(&mpi->list);
>  		mutex_unlock(&mlx5_ib_multiport_mutex);
> +		kfree(mpi);
>  		return;
>  	}

Personally I think the way this code was written to try to share the
struct mlx5_interface between two completely different usages, with
totally different opaque structs is really obtuse. 

Two interfaces callback blocks for the two parallel uses would have
been cleaner and might have made this missing kfree clearer.

Jason