From: bluhm <bluhm@openbsd.org>
Date: Fri, 7 Apr 2023 22:02:58 +0000 (+0000)
Subject: Remove kernel locks from the ARP input path.  Caller if_netisr()
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=ccf4d05a4934071260420df6ad19e6629af985ac;p=openbsd

Remove kernel locks from the ARP input path.  Caller if_netisr()
grabs the exclusive netlock and that is sufficent for in_arpinput()
and arpcache().
with kn@; OK mvs@; tested by Hrvoje Popovski
---

diff --git a/sys/net/if.c b/sys/net/if.c
index dbd9890531f..ab0ec63c61a 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.c,v 1.686 2023/04/05 19:35:23 bluhm Exp $	*/
+/*	$OpenBSD: if.c,v 1.687 2023/04/07 22:02:58 bluhm Exp $	*/
 /*	$NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $	*/
 
 /*
@@ -927,11 +927,8 @@ if_netisr(void *unused)
 		atomic_clearbits_int(&netisr, n);
 
 #if NETHER > 0
-		if (n & (1 << NETISR_ARP)) {
-			KERNEL_LOCK();
+		if (n & (1 << NETISR_ARP))
 			arpintr();
-			KERNEL_UNLOCK();
-		}
 #endif
 		if (n & (1 << NETISR_IP))
 			ipintr();
diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c
index 46aa3c26acb..56146365e5f 100644
--- a/sys/netinet/if_ether.c
+++ b/sys/netinet/if_ether.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ether.c,v 1.260 2023/04/05 21:51:47 bluhm Exp $	*/
+/*	$OpenBSD: if_ether.c,v 1.261 2023/04/07 22:02:58 bluhm Exp $	*/
 /*	$NetBSD: if_ether.c,v 1.31 1996/05/11 12:59:58 mycroft Exp $	*/
 
 /*
@@ -609,12 +609,7 @@ in_arpinput(struct ifnet *ifp, struct mbuf *m)
 		    "address %s\n", addr, ether_sprintf(ea->arp_sha));
 		itaddr = isaddr;
 	} else if (rt != NULL) {
-		int error;
-
-		KERNEL_LOCK();
-		error = arpcache(ifp, ea, rt);
-		KERNEL_UNLOCK();
-		if (error)
+		if (arpcache(ifp, ea, rt))
 			goto out;
 	}
 
@@ -656,7 +651,7 @@ arpcache(struct ifnet *ifp, struct ether_arp *ea, struct rtentry *rt)
 	time_t uptime;
 	int changed = 0;
 
-	KERNEL_ASSERT_LOCKED();
+	NET_ASSERT_LOCKED_EXCLUSIVE();
 	KASSERT(sdl != NULL);
 
 	/*