From: Eric Dumazet <edumazet@google.com>
Date: Thu, 21 May 2026 17:14:39 +0000 (+0000)
Subject: dpll: change dpll_netdev_pin_handle_size() to assume DPLL_A_PIN_ID will be used
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=7409fad779e271f252d844ae16e1a7429626b13e;p=thirdparty%2Fkernel%2Flinux.git

dpll: change dpll_netdev_pin_handle_size() to assume DPLL_A_PIN_ID will be used

We plan to no longer hold RTNL in "ip link show", and use RCU instead.

Assume rtnl_fill_dpll_pin() will have to fill DPLL_A_PIN_ID.

It is fine to over-estimate skb size (by 8 bytes) in if_nlmsg_size().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20260521171440.114956-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c
index 53ca24d0f191..095ef8703c0b 100644
--- a/drivers/dpll/dpll_netlink.c
+++ b/drivers/dpll/dpll_netlink.c
@@ -89,17 +89,6 @@ static struct dpll_pin *dpll_netdev_pin(const struct net_device *dev)
 	return rcu_dereference_rtnl(dev->dpll_pin);
 }
 
-/**
- * dpll_netdev_pin_handle_size - get size of pin handle attribute of a netdev
- * @dev: netdev from which to get the pin
- *
- * Return: byte size of pin handle attribute, or 0 if @dev has no pin.
- */
-size_t dpll_netdev_pin_handle_size(const struct net_device *dev)
-{
-	return dpll_netdev_pin(dev) ? nla_total_size(4) : 0; /* DPLL_A_PIN_ID */
-}
-
 int dpll_netdev_add_pin_handle(struct sk_buff *msg,
 			       const struct net_device *dev)
 {
diff --git a/include/linux/dpll.h b/include/linux/dpll.h
index 82dfadd9f593..4071fd974dd7 100644
--- a/include/linux/dpll.h
+++ b/include/linux/dpll.h
@@ -13,6 +13,7 @@
 #include <linux/netdevice.h>
 #include <linux/notifier.h>
 #include <linux/rtnetlink.h>
+#include <net/netlink.h>
 
 struct dpll_device;
 struct dpll_pin;
@@ -238,7 +239,11 @@ struct dpll_pin_notifier_info {
 void dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin);
 void dpll_netdev_pin_clear(struct net_device *dev);
 
-size_t dpll_netdev_pin_handle_size(const struct net_device *dev);
+static inline size_t dpll_netdev_pin_handle_size(void)
+{
+	return nla_total_size(4); /* DPLL_A_PIN_ID */
+}
+
 int dpll_netdev_add_pin_handle(struct sk_buff *msg,
 			       const struct net_device *dev);
 
@@ -249,7 +254,7 @@ static inline void
 dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin) { }
 static inline void dpll_netdev_pin_clear(struct net_device *dev) { }
 
-static inline size_t dpll_netdev_pin_handle_size(const struct net_device *dev)
+static inline size_t dpll_netdev_pin_handle_size(void)
 {
 	return 0;
 }
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 5e461c752df1..0aa429336ffe 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1263,11 +1263,11 @@ static size_t rtnl_devlink_port_size(const struct net_device *dev)
 	return size;
 }
 
-static size_t rtnl_dpll_pin_size(const struct net_device *dev)
+static size_t rtnl_dpll_pin_size(void)
 {
 	size_t size = nla_total_size(0); /* nest IFLA_DPLL_PIN */
 
-	size += dpll_netdev_pin_handle_size(dev);
+	size += dpll_netdev_pin_handle_size();
 
 	return size;
 }
@@ -1348,7 +1348,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + nla_total_size(4)  /* IFLA_MAX_MTU */
 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_PERM_ADDRESS */
 	       + rtnl_devlink_port_size(dev)
-	       + rtnl_dpll_pin_size(dev)
+	       + rtnl_dpll_pin_size()
 	       + nla_total_size(8)  /* IFLA_MAX_PACING_OFFLOAD_HORIZON */
 	       + nla_total_size(2)  /* IFLA_HEADROOM */
 	       + nla_total_size(2)  /* IFLA_TAILROOM */