From f13a722652fb71f09c5943abad4fac4e82da66b4 Mon Sep 17 00:00:00 2001
From: sam <sam@FreeBSD.org>
Date: Mon, 1 Sep 2003 05:01:55 +0000
Subject: o interlock domain list when adding domains o remove irrlevant spl

Notes:

1. We don't lock domain list traversals as this is safe until we start
   removing domains.
2. The calculation of max_datalen in net_init_domain appears safe as
   noone depends on max_hdr and max_datalen having consistent values.
3. Giant is still held for fast and slow timeouts; this must stay until
   each timeout routine is properly locked (coming soon).

Sponsored by:	FreeBSD Fondation
---
 sys/kern/uipc_domain.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

(limited to 'sys/kern/uipc_domain.c')

diff --git a/sys/kern/uipc_domain.c b/sys/kern/uipc_domain.c
index 0fa21ac..98fba8f 100644
--- a/sys/kern/uipc_domain.c
+++ b/sys/kern/uipc_domain.c
@@ -42,6 +42,8 @@ __FBSDID("$FreeBSD$");
 #include <sys/domain.h>
 #include <sys/mbuf.h>
 #include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
 #include <sys/socketvar.h>
 #include <sys/systm.h>
 #include <vm/uma.h>
@@ -67,7 +69,8 @@ static struct callout pfslow_callout;
 static void	pffasttimo(void *);
 static void	pfslowtimo(void *);
 
-struct domain *domains;
+struct domain *domains;		/* registered protocol domains */
+struct mtx dom_mtx;		/* domain list lock */
 
 /*
  * Add a new protocol domain to the list of supported domains
@@ -77,10 +80,8 @@ struct domain *domains;
 static void
 net_init_domain(struct domain *dp)
 {
-	register struct protosw *pr;
-	int	s;
+	struct protosw *pr;
 
-	s = splnet();
 	if (dp->dom_init)
 		(*dp->dom_init)();
 	for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++){
@@ -96,7 +97,6 @@ net_init_domain(struct domain *dp)
 	 */
 	max_hdr = max_linkhdr + max_protohdr;
 	max_datalen = MHLEN - max_hdr;
-	splx(s);
 }
 
 /*
@@ -107,14 +107,13 @@ net_init_domain(struct domain *dp)
 void
 net_add_domain(void *data)
 {
-	int	s;
 	struct domain *dp;
 
 	dp = (struct domain *)data;
-	s = splnet();
+	mtx_lock(&dom_mtx);
 	dp->dom_next = domains;
 	domains = dp;
-	splx(s);
+	mtx_unlock(&dom_mtx);
 	net_init_domain(dp);
 }
 
@@ -131,6 +130,8 @@ domaininit(void *dummy)
 	    NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 	uma_zone_set_max(socket_zone, maxsockets);
 
+	mtx_init(&dom_mtx, "domain list lock", NULL, MTX_DEF);
+
 	if (max_linkhdr < 16)		/* XXX */
 		max_linkhdr = 16;
 
-- 
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