net: netlink: Remove unused function

lockdep_genl_is_held() and its caller arm not used now, just remove them.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Link: https://lore.kernel.org/r/20210729074854.8968-1-yajun.deng@linux.devSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/linux/genetlink.h

@@ -8,34 +8,11 @@
 /* All generic netlink requests are serialized by a global lock.  */
 extern void genl_lock(void);
 extern void genl_unlock(void);
-#ifdef CONFIG_LOCKDEP
-extern bool lockdep_genl_is_held(void);
-#endif
 
 /* for synchronisation between af_netlink and genetlink */
 extern atomic_t genl_sk_destructing_cnt;
 extern wait_queue_head_t genl_sk_destructing_waitq;
 
-/**
- * rcu_dereference_genl - rcu_dereference with debug checking
- * @p: The pointer to read, prior to dereferencing
- *
- * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
- * or genl mutex. Note : Please prefer genl_dereference() or rcu_dereference()
- */
-#define rcu_dereference_genl(p)					\
-	rcu_dereference_check(p, lockdep_genl_is_held())
-
-/**
- * genl_dereference - fetch RCU pointer when updates are prevented by genl mutex
- * @p: The pointer to read, prior to dereferencing
- *
- * Return the value of the specified RCU-protected pointer, but omit
- * the READ_ONCE(), because caller holds genl mutex.
- */
-#define genl_dereference(p)					\
-	rcu_dereference_protected(p, lockdep_genl_is_held())
-
 #define MODULE_ALIAS_GENL_FAMILY(family)\
  MODULE_ALIAS_NET_PF_PROTO_NAME(PF_NETLINK, NETLINK_GENERIC, "-family-" family)
 

net/netlink/genetlink.c

@@ -40,14 +40,6 @@ void genl_unlock(void)
 }
 EXPORT_SYMBOL(genl_unlock);
 
-#ifdef CONFIG_LOCKDEP
-bool lockdep_genl_is_held(void)
-{
-	return lockdep_is_held(&genl_mutex);
-}
-EXPORT_SYMBOL(lockdep_genl_is_held);
-#endif
-
 static void genl_lock_all(void)
 {
 	down_write(&cb_lock);