Re: [PATCH net] ice: Fix freeing uninitialized pointers

Markus Elfring
2024-03-21T17:59:52Z

> Automatically cleaned up pointers need to be initialized before exiting
> their scope. In this case, they need to be initialized to NULL before
> any return statement.

How will development interests evolve further for such design aspects?

…
> +++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c
> @@ -941,11 +941,11 @@ static u64 ice_loopback_test(struct net_device *netdev)
> struct ice_netdev_priv *np = netdev_priv(netdev);
> struct ice_vsi *orig_vsi = np->vsi, *test_vsi;
> struct ice_pf *pf = orig_vsi->back;
> + u8 *tx_frame __free(kfree) = NULL;
> u8 broadcast[ETH_ALEN], ret = 0;
> int num_frames, valid_frames;
> struct ice_tx_ring *tx_ring;
> struct ice_rx_ring *rx_ring;
> - u8 *tx_frame __free(kfree);
> int i;
>
> netdev_info(netdev, "loopback test\n");

How do you think about to reduce the scope for the affected local variable instead
with the help of a small script (like the following) for the semantic patch language?

@movement@
attribute name __free;
@@
-u8 *tx_frame __free(kfree);
int i;
... when any
if (ice_fltr_add_mac(test_vsi, ...))
{ ... }
+
+{
+u8 *tx_frame __free(kfree) = NULL;
if (ice_lbtest_create_frame(pf, &tx_frame, ...))
{ ... }
... when any
+}
+
valid_frames = ice_lbtest_receive_frames(...);

Regards,
Markus