Re: [RFC PATCH v8 06/10] netdev: expose DPLL pin handle for netdevice

[Jiri Pirko <jiri@resnulli.us>]

Mon, Jun 12, 2023 at 11:17:23AM CEST, poros@redhat.com wrote:
>Arkadiusz Kubalewski píše v Pá 09. 06. 2023 v 14:18 +0200:
>> From: Jiri Pirko <jiri@nvidia.com>

[...]


>> +static size_t rtnl_dpll_pin_size(const struct net_device *dev)
>> +{
>> +       size_t size = nla_total_size(0); /* nest IFLA_DPLL_PIN */
>> +
>> +       if (dev->dpll_pin)
>> +               size += dpll_msg_pin_handle_size(dev->dpll_pin);
>
>Hi Arkadiusz,
>
>net_device->dpll_pin is only valid if IS_ENABLED(CONFIG_DPLL)
>But the code in net/core/rtnetlink.c doesn't respect that.
>If CONFIG_DPLL is not set, net/core/rtnetlink.c cannot be compiled.
>
>Regards,
>Petr 

You are correct. Here's the squash-patch to fix this. Arkadiusz, could
you please make the squash? Thanks!

diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c
index e6efc17aaf26..00dc96c3ade4 100644
--- a/drivers/dpll/dpll_netlink.c
+++ b/drivers/dpll/dpll_netlink.c
@@ -303,12 +303,14 @@ dpll_cmd_pin_fill_details(struct sk_buff *msg, struct dpll_pin *pin,
 
 size_t dpll_msg_pin_handle_size(struct dpll_pin *pin)
 {
-	return nla_total_size(4); /* DPLL_A_PIN_ID */
+	return pin ? nla_total_size(4) : 0; /* DPLL_A_PIN_ID */
 }
 EXPORT_SYMBOL_GPL(dpll_msg_pin_handle_size);
 
 int dpll_msg_add_pin_handle(struct sk_buff *msg, struct dpll_pin *pin)
 {
+	if (!pin)
+		return 0;
 	if (nla_put_u32(msg, DPLL_A_PIN_ID, pin->id))
 		return -EMSGSIZE;
 	return 0;
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index b002e3cc9943..82ad12fd4266 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3967,6 +3967,16 @@ int dev_get_port_parent_id(struct net_device *dev,
 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b);
 void netdev_dpll_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin);
 void netdev_dpll_pin_clear(struct net_device *dev);
+
+static inline struct dpll_pin *netdev_dpll_pin(const struct net_device *dev)
+{
+#if IS_ENABLED(CONFIG_DPLL)
+	return dev->dpll_pin;
+#else
+	return NULL;
+#endif
+}
+
 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again);
 struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
 				    struct netdev_queue *txq, int *ret);
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index ebe9ae8608fc..67dd455e15c7 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1056,8 +1056,7 @@ static size_t rtnl_dpll_pin_size(const struct net_device *dev)
 {
 	size_t size = nla_total_size(0); /* nest IFLA_DPLL_PIN */
 
-	if (dev->dpll_pin)
-		size += dpll_msg_pin_handle_size(dev->dpll_pin);
+	size += dpll_msg_pin_handle_size(netdev_dpll_pin(dev));
 
 	return size;
 }
@@ -1790,11 +1789,9 @@ static int rtnl_fill_dpll_pin(struct sk_buff *skb,
 	if (!dpll_pin_nest)
 		return -EMSGSIZE;
 
-	if (dev->dpll_pin) {
-		ret = dpll_msg_add_pin_handle(skb, dev->dpll_pin);
-		if (ret < 0)
-			goto nest_cancel;
-	}
+	ret = dpll_msg_add_pin_handle(skb, netdev_dpll_pin(dev));
+	if (ret < 0)
+		goto nest_cancel;
 
 	nla_nest_end(skb, dpll_pin_nest);
 	return 0;