Commit 3d43f9f6 authored by Liming Sun's avatar Liming Sun Committed by Hans de Goede
Browse files

platform/mellanox: fix potential race in mlxbf-tmfifo driver 



This commit adds memory barrier for the 'vq' update in function
mlxbf_tmfifo_virtio_find_vqs() to avoid potential race due to
out-of-order memory write. It also adds barrier for the 'is_ready'
flag to make sure the initializations are visible before this flag
is checked.

Signed-off-by: default avatarLiming Sun <limings@nvidia.com>
Reviewed-by: default avatarVadim Pasternak <vadimp@nvidia.com>
Link: https://lore.kernel.org/r/b98c0ab61d644ba38fa9b3fd1607b138b0dd820b.1682518748.git.limings@nvidia.com


Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent 4b65f95c

drivers/platform/mellanox/mlxbf-tmfifo.c

+9 −2
Original line number Diff line number Diff line
@@ -784,7 +784,7 @@ static void mlxbf_tmfifo_rxtx(struct mlxbf_tmfifo_vring *vring, bool is_rx) 
	fifo = vring->fifo;



	/* Return if vdev is not ready. */

	if (!fifo->vdev[devid])

	if (!fifo || !fifo->vdev[devid])

		return;



	/* Return if another vring is running. */
@@ -980,9 +980,13 @@ static int mlxbf_tmfifo_virtio_find_vqs(struct virtio_device *vdev, 


		vq->num_max = vring->num;



		vq->priv = vring;



		/* Make vq update visible before using it. */

		virtio_mb(false);



		vqs[i] = vq;

		vring->vq = vq;

		vq->priv = vring;

	}



	return 0;
@@ -1302,6 +1306,9 @@ static int mlxbf_tmfifo_probe(struct platform_device *pdev) 


	mod_timer(&fifo->timer, jiffies + MLXBF_TMFIFO_TIMER_INTERVAL);



	/* Make all updates visible before setting the 'is_ready' flag. */

	virtio_mb(false);



	fifo->is_ready = true;

	return 0;