net: add missing instance lock to dev_set_promiscuity

Accidentally spotted while trying to understand what else needs
to be renamed to netif_ prefix. Most of the calls to dev_set_promiscuity
are adjacent to dev_set_allmulti or dev_disable_lro so it should
be safe to add the lock. Note that new netif_set_promiscuity is
currently unused, the locked paths call __dev_set_promiscuity directly.

Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

include/linux/netdevice.h

···
 
 /* Functions used for secondary unicast and multicast support */
 void dev_set_rx_mode(struct net_device *dev);
+int netif_set_promiscuity(struct net_device *dev, int inc);
 int dev_set_promiscuity(struct net_device *dev, int inc);
 int netif_set_allmulti(struct net_device *dev, int inc, bool notify);
 int dev_set_allmulti(struct net_device *dev, int inc);

net/core/dev.c

···
 	return 0;
 }
 
-/**
- *	dev_set_promiscuity	- update promiscuity count on a device
- *	@dev: device
- *	@inc: modifier
- *
- *	Add or remove promiscuity from a device. While the count in the device
- *	remains above zero the interface remains promiscuous. Once it hits zero
- *	the device reverts back to normal filtering operation. A negative inc
- *	value is used to drop promiscuity on the device.
- *	Return 0 if successful or a negative errno code on error.
- */
-int dev_set_promiscuity(struct net_device *dev, int inc)
+int netif_set_promiscuity(struct net_device *dev, int inc)
 {
 	unsigned int old_flags = dev->flags;
 	int err;
···
 		dev_set_rx_mode(dev);
 	return err;
 }
-EXPORT_SYMBOL(dev_set_promiscuity);
 
 int netif_set_allmulti(struct net_device *dev, int inc, bool notify)
 {

net/core/dev_api.c

···
 EXPORT_SYMBOL(dev_disable_lro);
 
 /**
+ * dev_set_promiscuity() - update promiscuity count on a device
+ * @dev: device
+ * @inc: modifier
+ *
+ * Add or remove promiscuity from a device. While the count in the device
+ * remains above zero the interface remains promiscuous. Once it hits zero
+ * the device reverts back to normal filtering operation. A negative inc
+ * value is used to drop promiscuity on the device.
+ * Return 0 if successful or a negative errno code on error.
+ */
+int dev_set_promiscuity(struct net_device *dev, int inc)
+{
+	int ret;
+
+	netdev_lock_ops(dev);
+	ret = netif_set_promiscuity(dev, inc);
+	netdev_unlock_ops(dev);
+
+	return ret;
+}
+EXPORT_SYMBOL(dev_set_promiscuity);
+
+/**
  * dev_set_allmulti() - update allmulti count on a device
  * @dev: device
  * @inc: modifier