X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=net%2Fxfrm%2Fxfrm_policy.c;h=fd6986634e6fe4dc77993854323d7558637b94bc;hb=9a687aea2ffd8ab1e3c6239ea53c0a2209707bd5;hp=45f9cf97ea25d98bea83a7dd48365357fb8f4bee;hpb=609555213a36359dcadf7f84412d0489961ab085;p=karo-tx-linux.git

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 45f9cf97ea25..fd6986634e6f 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -49,6 +49,7 @@ static struct xfrm_policy_afinfo __rcu *xfrm_policy_afinfo[NPROTO]
 						__read_mostly;
 
 static struct kmem_cache *xfrm_dst_cache __read_mostly;
+static __read_mostly seqcount_t xfrm_policy_hash_generation;
 
 static void xfrm_init_pmtu(struct dst_entry *dst);
 static int stale_bundle(struct dst_entry *dst);
@@ -59,6 +60,11 @@ static void __xfrm_policy_link(struct xfrm_policy *pol, int dir);
 static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
 						int dir);
 
+static inline bool xfrm_pol_hold_rcu(struct xfrm_policy *policy)
+{
+	return atomic_inc_not_zero(&policy->refcnt);
+}
+
 static inline bool
 __xfrm4_selector_match(const struct xfrm_selector *sel, const struct flowi *fl)
 {
@@ -385,9 +391,11 @@ static struct hlist_head *policy_hash_bysel(struct net *net,
 	__get_hash_thresh(net, family, dir, &dbits, &sbits);
 	hash = __sel_hash(sel, family, hmask, dbits, sbits);
 
-	return (hash == hmask + 1 ?
-		&net->xfrm.policy_inexact[dir] :
-		net->xfrm.policy_bydst[dir].table + hash);
+	if (hash == hmask + 1)
+		return &net->xfrm.policy_inexact[dir];
+
+	return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
+		     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
 }
 
 static struct hlist_head *policy_hash_direct(struct net *net,
@@ -403,7 +411,8 @@ static struct hlist_head *policy_hash_direct(struct net *net,
 	__get_hash_thresh(net, family, dir, &dbits, &sbits);
 	hash = __addr_hash(daddr, saddr, family, hmask, dbits, sbits);
 
-	return net->xfrm.policy_bydst[dir].table + hash;
+	return rcu_dereference_check(net->xfrm.policy_bydst[dir].table,
+		     lockdep_is_held(&net->xfrm.xfrm_policy_lock)) + hash;
 }
 
 static void xfrm_dst_hash_transfer(struct net *net,
@@ -426,14 +435,14 @@ redo:
 		h = __addr_hash(&pol->selector.daddr, &pol->selector.saddr,
 				pol->family, nhashmask, dbits, sbits);
 		if (!entry0) {
-			hlist_del(&pol->bydst);
-			hlist_add_head(&pol->bydst, ndsttable+h);
+			hlist_del_rcu(&pol->bydst);
+			hlist_add_head_rcu(&pol->bydst, ndsttable + h);
 			h0 = h;
 		} else {
 			if (h != h0)
 				continue;
-			hlist_del(&pol->bydst);
-			hlist_add_behind(&pol->bydst, entry0);
+			hlist_del_rcu(&pol->bydst);
+			hlist_add_behind_rcu(&pol->bydst, entry0);
 		}
 		entry0 = &pol->bydst;
 	}
@@ -468,22 +477,32 @@ static void xfrm_bydst_resize(struct net *net, int dir)
 	unsigned int hmask = net->xfrm.policy_bydst[dir].hmask;
 	unsigned int nhashmask = xfrm_new_hash_mask(hmask);
 	unsigned int nsize = (nhashmask + 1) * sizeof(struct hlist_head);
-	struct hlist_head *odst = net->xfrm.policy_bydst[dir].table;
 	struct hlist_head *ndst = xfrm_hash_alloc(nsize);
+	struct hlist_head *odst;
 	int i;
 
 	if (!ndst)
 		return;
 
-	write_lock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
+	write_seqcount_begin(&xfrm_policy_hash_generation);
+
+	odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
+				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
+
+	odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
+				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
 
 	for (i = hmask; i >= 0; i--)
 		xfrm_dst_hash_transfer(net, odst + i, ndst, nhashmask, dir);
 
-	net->xfrm.policy_bydst[dir].table = ndst;
+	rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
 	net->xfrm.policy_bydst[dir].hmask = nhashmask;
 
-	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	write_seqcount_end(&xfrm_policy_hash_generation);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
+
+	synchronize_rcu();
 
 	xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
 }
@@ -500,7 +519,7 @@ static void xfrm_byidx_resize(struct net *net, int total)
 	if (!nidx)
 		return;
 
-	write_lock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 
 	for (i = hmask; i >= 0; i--)
 		xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
@@ -508,7 +527,7 @@ static void xfrm_byidx_resize(struct net *net, int total)
 	net->xfrm.policy_byidx = nidx;
 	net->xfrm.policy_idx_hmask = nhashmask;
 
-	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
 }
@@ -541,7 +560,6 @@ static inline int xfrm_byidx_should_resize(struct net *net, int total)
 
 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
 {
-	read_lock_bh(&net->xfrm.xfrm_policy_lock);
 	si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
 	si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
 	si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
@@ -550,7 +568,6 @@ void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
 	si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
 	si->spdhcnt = net->xfrm.policy_idx_hmask;
 	si->spdhmcnt = xfrm_policy_hashmax;
-	read_unlock_bh(&net->xfrm.xfrm_policy_lock);
 }
 EXPORT_SYMBOL(xfrm_spd_getinfo);
 
@@ -600,7 +617,7 @@ static void xfrm_hash_rebuild(struct work_struct *work)
 		rbits6 = net->xfrm.policy_hthresh.rbits6;
 	} while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
 
-	write_lock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 
 	/* reset the bydst and inexact table in all directions */
 	for (dir = 0; dir < XFRM_POLICY_MAX; dir++) {
@@ -646,7 +663,7 @@ static void xfrm_hash_rebuild(struct work_struct *work)
 			hlist_add_head(&policy->bydst, chain);
 	}
 
-	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	mutex_unlock(&hash_resize_mutex);
 }
@@ -757,7 +774,7 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 	struct hlist_head *chain;
 	struct hlist_node *newpos;
 
-	write_lock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 	chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
 	delpol = NULL;
 	newpos = NULL;
@@ -768,7 +785,7 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 		    xfrm_sec_ctx_match(pol->security, policy->security) &&
 		    !WARN_ON(delpol)) {
 			if (excl) {
-				write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+				spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 				return -EEXIST;
 			}
 			delpol = pol;
@@ -804,7 +821,7 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 	policy->curlft.use_time = 0;
 	if (!mod_timer(&policy->timer, jiffies + HZ))
 		xfrm_pol_hold(policy);
-	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	if (delpol)
 		xfrm_policy_kill(delpol);
@@ -824,7 +841,7 @@ struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
 	struct hlist_head *chain;
 
 	*err = 0;
-	write_lock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 	chain = policy_hash_bysel(net, sel, sel->family, dir);
 	ret = NULL;
 	hlist_for_each_entry(pol, chain, bydst) {
@@ -837,7 +854,7 @@ struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
 				*err = security_xfrm_policy_delete(
 								pol->security);
 				if (*err) {
-					write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+					spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 					return pol;
 				}
 				__xfrm_policy_unlink(pol, dir);
@@ -846,7 +863,7 @@ struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
 			break;
 		}
 	}
-	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	if (ret && delete)
 		xfrm_policy_kill(ret);
@@ -865,7 +882,7 @@ struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
 		return NULL;
 
 	*err = 0;
-	write_lock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 	chain = net->xfrm.policy_byidx + idx_hash(net, id);
 	ret = NULL;
 	hlist_for_each_entry(pol, chain, byidx) {
@@ -876,7 +893,7 @@ struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
 				*err = security_xfrm_policy_delete(
 								pol->security);
 				if (*err) {
-					write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+					spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 					return pol;
 				}
 				__xfrm_policy_unlink(pol, dir);
@@ -885,7 +902,7 @@ struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
 			break;
 		}
 	}
-	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	if (ret && delete)
 		xfrm_policy_kill(ret);
@@ -943,7 +960,7 @@ int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
 {
 	int dir, err = 0, cnt = 0;
 
-	write_lock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 
 	err = xfrm_policy_flush_secctx_check(net, type, task_valid);
 	if (err)
@@ -959,14 +976,14 @@ int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
 			if (pol->type != type)
 				continue;
 			__xfrm_policy_unlink(pol, dir);
-			write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+			spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 			cnt++;
 
 			xfrm_audit_policy_delete(pol, 1, task_valid);
 
 			xfrm_policy_kill(pol);
 
-			write_lock_bh(&net->xfrm.xfrm_policy_lock);
+			spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 			goto again1;
 		}
 
@@ -978,13 +995,13 @@ int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
 				if (pol->type != type)
 					continue;
 				__xfrm_policy_unlink(pol, dir);
-				write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+				spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 				cnt++;
 
 				xfrm_audit_policy_delete(pol, 1, task_valid);
 				xfrm_policy_kill(pol);
 
-				write_lock_bh(&net->xfrm.xfrm_policy_lock);
+				spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 				goto again2;
 			}
 		}
@@ -993,7 +1010,7 @@ int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
 	if (!cnt)
 		err = -ESRCH;
 out:
-	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 	return err;
 }
 EXPORT_SYMBOL(xfrm_policy_flush);
@@ -1013,7 +1030,7 @@ int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
 	if (list_empty(&walk->walk.all) && walk->seq != 0)
 		return 0;
 
-	write_lock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 	if (list_empty(&walk->walk.all))
 		x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
 	else
@@ -1041,7 +1058,7 @@ int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
 	}
 	list_del_init(&walk->walk.all);
 out:
-	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 	return error;
 }
 EXPORT_SYMBOL(xfrm_policy_walk);
@@ -1060,9 +1077,9 @@ void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
 	if (list_empty(&walk->walk.all))
 		return;
 
-	write_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
+	spin_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
 	list_del(&walk->walk.all);
-	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 }
 EXPORT_SYMBOL(xfrm_policy_walk_done);
 
@@ -1100,17 +1117,24 @@ static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
 	struct xfrm_policy *pol, *ret;
 	const xfrm_address_t *daddr, *saddr;
 	struct hlist_head *chain;
-	u32 priority = ~0U;
+	unsigned int sequence;
+	u32 priority;
 
 	daddr = xfrm_flowi_daddr(fl, family);
 	saddr = xfrm_flowi_saddr(fl, family);
 	if (unlikely(!daddr || !saddr))
 		return NULL;
 
-	read_lock_bh(&net->xfrm.xfrm_policy_lock);
-	chain = policy_hash_direct(net, daddr, saddr, family, dir);
+	rcu_read_lock();
+ retry:
+	do {
+		sequence = read_seqcount_begin(&xfrm_policy_hash_generation);
+		chain = policy_hash_direct(net, daddr, saddr, family, dir);
+	} while (read_seqcount_retry(&xfrm_policy_hash_generation, sequence));
+
+	priority = ~0U;
 	ret = NULL;
-	hlist_for_each_entry(pol, chain, bydst) {
+	hlist_for_each_entry_rcu(pol, chain, bydst) {
 		err = xfrm_policy_match(pol, fl, type, family, dir);
 		if (err) {
 			if (err == -ESRCH)
@@ -1126,7 +1150,7 @@ static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
 		}
 	}
 	chain = &net->xfrm.policy_inexact[dir];
-	hlist_for_each_entry(pol, chain, bydst) {
+	hlist_for_each_entry_rcu(pol, chain, bydst) {
 		if ((pol->priority >= priority) && ret)
 			break;
 
@@ -1144,9 +1168,13 @@ static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
 		}
 	}
 
-	xfrm_pol_hold(ret);
+	if (read_seqcount_retry(&xfrm_policy_hash_generation, sequence))
+		goto retry;
+
+	if (ret && !xfrm_pol_hold_rcu(ret))
+		goto retry;
 fail:
-	read_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	rcu_read_unlock();
 
 	return ret;
 }
@@ -1223,10 +1251,9 @@ static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
 						 const struct flowi *fl)
 {
 	struct xfrm_policy *pol;
-	struct net *net = sock_net(sk);
 
 	rcu_read_lock();
-	read_lock_bh(&net->xfrm.xfrm_policy_lock);
+ again:
 	pol = rcu_dereference(sk->sk_policy[dir]);
 	if (pol != NULL) {
 		bool match = xfrm_selector_match(&pol->selector, fl,
@@ -1241,8 +1268,8 @@ static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
 			err = security_xfrm_policy_lookup(pol->security,
 						      fl->flowi_secid,
 						      policy_to_flow_dir(dir));
-			if (!err)
-				xfrm_pol_hold(pol);
+			if (!err && !xfrm_pol_hold_rcu(pol))
+				goto again;
 			else if (err == -ESRCH)
 				pol = NULL;
 			else
@@ -1251,7 +1278,6 @@ static struct xfrm_policy *xfrm_sk_policy_lookup(const struct sock *sk, int dir,
 			pol = NULL;
 	}
 out:
-	read_unlock_bh(&net->xfrm.xfrm_policy_lock);
 	rcu_read_unlock();
 	return pol;
 }
@@ -1275,7 +1301,7 @@ static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
 
 	/* Socket policies are not hashed. */
 	if (!hlist_unhashed(&pol->bydst)) {
-		hlist_del(&pol->bydst);
+		hlist_del_rcu(&pol->bydst);
 		hlist_del(&pol->byidx);
 	}
 
@@ -1299,9 +1325,9 @@ int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
 {
 	struct net *net = xp_net(pol);
 
-	write_lock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 	pol = __xfrm_policy_unlink(pol, dir);
-	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 	if (pol) {
 		xfrm_policy_kill(pol);
 		return 0;
@@ -1320,7 +1346,7 @@ int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
 		return -EINVAL;
 #endif
 
-	write_lock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 	old_pol = rcu_dereference_protected(sk->sk_policy[dir],
 				lockdep_is_held(&net->xfrm.xfrm_policy_lock));
 	if (pol) {
@@ -1338,7 +1364,7 @@ int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
 		 */
 		xfrm_sk_policy_unlink(old_pol, dir);
 	}
-	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	if (old_pol) {
 		xfrm_policy_kill(old_pol);
@@ -1368,9 +1394,9 @@ static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
 		newp->type = old->type;
 		memcpy(newp->xfrm_vec, old->xfrm_vec,
 		       newp->xfrm_nr*sizeof(struct xfrm_tmpl));
-		write_lock_bh(&net->xfrm.xfrm_policy_lock);
+		spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 		xfrm_sk_policy_link(newp, dir);
-		write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+		spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 		xfrm_pol_put(newp);
 	}
 	return newp;
@@ -3052,7 +3078,7 @@ static int __net_init xfrm_net_init(struct net *net)
 
 	/* Initialize the per-net locks here */
 	spin_lock_init(&net->xfrm.xfrm_state_lock);
-	rwlock_init(&net->xfrm.xfrm_policy_lock);
+	spin_lock_init(&net->xfrm.xfrm_policy_lock);
 	mutex_init(&net->xfrm.xfrm_cfg_mutex);
 
 	return 0;
@@ -3086,6 +3112,7 @@ static struct pernet_operations __net_initdata xfrm_net_ops = {
 void __init xfrm_init(void)
 {
 	register_pernet_subsys(&xfrm_net_ops);
+	seqcount_init(&xfrm_policy_hash_generation);
 	xfrm_input_init();
 }
 
@@ -3183,7 +3210,7 @@ static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *
 	struct hlist_head *chain;
 	u32 priority = ~0U;
 
-	read_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME*/
+	spin_lock_bh(&net->xfrm.xfrm_policy_lock);
 	chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
 	hlist_for_each_entry(pol, chain, bydst) {
 		if (xfrm_migrate_selector_match(sel, &pol->selector) &&
@@ -3207,7 +3234,7 @@ static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *
 
 	xfrm_pol_hold(ret);
 
-	read_unlock_bh(&net->xfrm.xfrm_policy_lock);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	return ret;
 }