1 files changed, 29 insertions, 15 deletions

diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 13028833bee3..a404552555d4 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -120,6 +120,7 @@ struct ppp {
 	int		n_channels;	/* how many channels are attached 54 */
 	spinlock_t	rlock;		/* lock for receive side 58 */
 	spinlock_t	wlock;		/* lock for transmit side 5c */
+	int		*xmit_recursion __percpu; /* xmit recursion detect */
 	int		mru;		/* max receive unit 60 */
 	unsigned int	flags;		/* control bits 64 */
 	unsigned int	xstate;		/* transmit state bits 68 */
@@ -1025,6 +1026,7 @@ static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
 	struct ppp *ppp = netdev_priv(dev);
 	int indx;
 	int err;
+	int cpu;
 
 	ppp->dev = dev;
 	ppp->ppp_net = src_net;
@@ -1039,6 +1041,15 @@ static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
 	INIT_LIST_HEAD(&ppp->channels);
 	spin_lock_init(&ppp->rlock);
 	spin_lock_init(&ppp->wlock);
+
+	ppp->xmit_recursion = alloc_percpu(int);
+	if (!ppp->xmit_recursion) {
+		err = -ENOMEM;
+		goto err1;
+	}
+	for_each_possible_cpu(cpu)
+		(*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0;
+
 #ifdef CONFIG_PPP_MULTILINK
 	ppp->minseq = -1;
 	skb_queue_head_init(&ppp->mrq);
@@ -1050,11 +1061,15 @@ static int ppp_dev_configure(struct net *src_net, struct net_device *dev,
 
 	err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set);
 	if (err < 0)
-		return err;
+		goto err2;
 
 	conf->file->private_data = &ppp->file;
 
 	return 0;
+err2:
+	free_percpu(ppp->xmit_recursion);
+err1:
+	return err;
 }
 
 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = {
@@ -1400,18 +1415,16 @@ static void __ppp_xmit_process(struct ppp *ppp)
 	ppp_xmit_unlock(ppp);
 }
 
-static DEFINE_PER_CPU(int, ppp_xmit_recursion);
-
 static void ppp_xmit_process(struct ppp *ppp)
 {
 	local_bh_disable();
 
-	if (unlikely(__this_cpu_read(ppp_xmit_recursion)))
+	if (unlikely(*this_cpu_ptr(ppp->xmit_recursion)))
 		goto err;
 
-	__this_cpu_inc(ppp_xmit_recursion);
+	(*this_cpu_ptr(ppp->xmit_recursion))++;
 	__ppp_xmit_process(ppp);
-	__this_cpu_dec(ppp_xmit_recursion);
+	(*this_cpu_ptr(ppp->xmit_recursion))--;
 
 	local_bh_enable();
 
@@ -1902,23 +1915,23 @@ static void __ppp_channel_push(struct channel *pch)
 	spin_unlock(&pch->downl);
 	/* see if there is anything from the attached unit to be sent */
 	if (skb_queue_empty(&pch->file.xq)) {
-		read_lock(&pch->upl);
 		ppp = pch->ppp;
 		if (ppp)
 			__ppp_xmit_process(ppp);
-		read_unlock(&pch->upl);
 	}
 }
 
 static void ppp_channel_push(struct channel *pch)
 {
-	local_bh_disable();
-
-	__this_cpu_inc(ppp_xmit_recursion);
-	__ppp_channel_push(pch);
-	__this_cpu_dec(ppp_xmit_recursion);
-
-	local_bh_enable();
+	read_lock_bh(&pch->upl);
+	if (pch->ppp) {
+		(*this_cpu_ptr(pch->ppp->xmit_recursion))++;
+		__ppp_channel_push(pch);
+		(*this_cpu_ptr(pch->ppp->xmit_recursion))--;
+	} else {
+		__ppp_channel_push(pch);
+	}
+	read_unlock_bh(&pch->upl);
 }
 
 /*
@@ -3057,6 +3070,7 @@ static void ppp_destroy_interface(struct ppp *ppp)
 #endif /* CONFIG_PPP_FILTER */
 
 	kfree_skb(ppp->xmit_pending);
+	free_percpu(ppp->xmit_recursion);
 
 	free_netdev(ppp->dev);
 }