Merge git://git.infradead.org/users/dwmw2/atm

David Woodhouse says:

====================
This is the result of pulling on the thread started by Krzysztof Mazur's
original patch 'pppoatm: don't send frames to destroyed vcc'.

Various problems in the pppoatm and br2684 code are solved, some of which
were easily triggered and would panic the kernel.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/atm/solos-pci.c

@@ -164,7 +164,6 @@ static void fpga_queue(struct solos_card *card, int port, struct sk_buff *skb,
 static uint32_t fpga_tx(struct solos_card *);
 static irqreturn_t solos_irq(int irq, void *dev_id);
 static struct atm_vcc* find_vcc(struct atm_dev *dev, short vpi, int vci);
-static int list_vccs(int vci);
 static int atm_init(struct solos_card *, struct device *);
 static void atm_remove(struct solos_card *);
 static int send_command(struct solos_card *card, int dev, const char *buf, size_t size);
@@ -710,7 +709,8 @@ void solos_bh(unsigned long card_arg)
 						dev_warn(&card->dev->dev, "Received packet for unknown VPI.VCI %d.%d on port %d\n",
 							 le16_to_cpu(header->vpi), le16_to_cpu(header->vci),
 							 port);
-					continue;
+					dev_kfree_skb_any(skb);
+					break;
 				}
 				atm_charge(vcc, skb->truesize);
 				vcc->push(vcc, skb);
@@ -790,44 +790,6 @@ static struct atm_vcc *find_vcc(struct atm_dev *dev, short vpi, int vci)
 	return vcc;
 }
 
-static int list_vccs(int vci)
-{
-	struct hlist_head *head;
-	struct atm_vcc *vcc;
-	struct hlist_node *node;
-	struct sock *s;
-	int num_found = 0;
-	int i;
-
-	read_lock(&vcc_sklist_lock);
-	if (vci != 0){
-		head = &vcc_hash[vci & (VCC_HTABLE_SIZE -1)];
-		sk_for_each(s, node, head) {
-			num_found ++;
-			vcc = atm_sk(s);
-			printk(KERN_DEBUG "Device: %d Vpi: %d Vci: %d\n",
-			       vcc->dev->number,
-			       vcc->vpi,
-			       vcc->vci);
-		}
-	} else {
-		for(i = 0; i < VCC_HTABLE_SIZE; i++){
-			head = &vcc_hash[i];
-			sk_for_each(s, node, head) {
-				num_found ++;
-				vcc = atm_sk(s);
-				printk(KERN_DEBUG "Device: %d Vpi: %d Vci: %d\n",
-				       vcc->dev->number,
-				       vcc->vpi,
-				       vcc->vci);
-			}
-		}
-	}
-	read_unlock(&vcc_sklist_lock);
-	return num_found;
-}
-
-
 static int popen(struct atm_vcc *vcc)
 {
 	struct solos_card *card = vcc->dev->dev_data;
@@ -840,7 +802,7 @@ static int popen(struct atm_vcc *vcc)
 		return -EINVAL;
 	}
 
-	skb = alloc_skb(sizeof(*header), GFP_ATOMIC);
+	skb = alloc_skb(sizeof(*header), GFP_KERNEL);
 	if (!skb) {
 		if (net_ratelimit())
 			dev_warn(&card->dev->dev, "Failed to allocate sk_buff in popen()\n");
@@ -857,19 +819,28 @@ static int popen(struct atm_vcc *vcc)
 
 	set_bit(ATM_VF_ADDR, &vcc->flags);
 	set_bit(ATM_VF_READY, &vcc->flags);
-	list_vccs(0);
-
 
 	return 0;
 }
 
 static void pclose(struct atm_vcc *vcc)
 {
 	struct solos_card *card = vcc->dev->dev_data;
-	struct sk_buff *skb;
+	unsigned char port = SOLOS_CHAN(vcc->dev);
+	struct sk_buff *skb, *tmpskb;
 	struct pkt_hdr *header;
 
-	skb = alloc_skb(sizeof(*header), GFP_ATOMIC);
+	/* Remove any yet-to-be-transmitted packets from the pending queue */
+	spin_lock(&card->tx_queue_lock);
+	skb_queue_walk_safe(&card->tx_queue[port], skb, tmpskb) {
+		if (SKB_CB(skb)->vcc == vcc) {
+			skb_unlink(skb, &card->tx_queue[port]);
+			solos_pop(vcc, skb);
+		}
+	}
+	spin_unlock(&card->tx_queue_lock);
+
+	skb = alloc_skb(sizeof(*header), GFP_KERNEL);
 	if (!skb) {
 		dev_warn(&card->dev->dev, "Failed to allocate sk_buff in pclose()\n");
 		return;
@@ -881,15 +852,22 @@ static void pclose(struct atm_vcc *vcc)
 	header->vci = cpu_to_le16(vcc->vci);
 	header->type = cpu_to_le16(PKT_PCLOSE);
 
-	fpga_queue(card, SOLOS_CHAN(vcc->dev), skb, NULL);
+	skb_get(skb);
+	fpga_queue(card, port, skb, NULL);
 
-	clear_bit(ATM_VF_ADDR, &vcc->flags);
-	clear_bit(ATM_VF_READY, &vcc->flags);
+	if (!wait_event_timeout(card->param_wq, !skb_shared(skb), 5 * HZ))
+		dev_warn(&card->dev->dev,
+			 "Timeout waiting for VCC close on port %d\n", port);
+
+	dev_kfree_skb(skb);
 
 	/* Hold up vcc_destroy_socket() (our caller) until solos_bh() in the
 	   tasklet has finished processing any incoming packets (and, more to
 	   the point, using the vcc pointer). */
 	tasklet_unlock_wait(&card->tlet);
+
+	clear_bit(ATM_VF_ADDR, &vcc->flags);
+
 	return;
 }
 
@@ -1011,9 +989,10 @@ static uint32_t fpga_tx(struct solos_card *card)
 			if (vcc) {
 				atomic_inc(&vcc->stats->tx);
 				solos_pop(vcc, oldskb);
-			} else
+			} else {
 				dev_kfree_skb_irq(oldskb);
-
+				wake_up(&card->param_wq);
+			}
 		}
 	}
 	/* For non-DMA TX, write the 'TX start' bit for all four ports simultaneously */
@@ -1248,7 +1227,7 @@ static int atm_init(struct solos_card *card, struct device *parent)
 		card->atmdev[i]->phy_data = (void *)(unsigned long)i;
 		atm_dev_signal_change(card->atmdev[i], ATM_PHY_SIG_FOUND);
 
-		skb = alloc_skb(sizeof(*header), GFP_ATOMIC);
+		skb = alloc_skb(sizeof(*header), GFP_KERNEL);
 		if (!skb) {
 			dev_warn(&card->dev->dev, "Failed to allocate sk_buff in atm_init()\n");
 			continue;
@@ -1345,6 +1324,8 @@ static struct pci_driver fpga_driver = {
 
 static int __init solos_pci_init(void)
 {
+	BUILD_BUG_ON(sizeof(struct solos_skb_cb) > sizeof(((struct sk_buff *)0)->cb));
+
 	printk(KERN_INFO "Solos PCI Driver Version %s\n", VERSION);
 	return pci_register_driver(&fpga_driver);
 }

include/linux/atmdev.h

@@ -99,13 +99,15 @@ struct atm_vcc {
 	struct atm_dev	*dev;		/* device back pointer */
 	struct atm_qos	qos;		/* QOS */
 	struct atm_sap	sap;		/* SAP */
+	void (*release_cb)(struct atm_vcc *vcc); /* release_sock callback */
 	void (*push)(struct atm_vcc *vcc,struct sk_buff *skb);
 	void (*pop)(struct atm_vcc *vcc,struct sk_buff *skb); /* optional */
 	int (*push_oam)(struct atm_vcc *vcc,void *cell);
 	int (*send)(struct atm_vcc *vcc,struct sk_buff *skb);
 	void		*dev_data;	/* per-device data */
 	void		*proto_data;	/* per-protocol data */
 	struct k_atm_aal_stats *stats;	/* pointer to AAL stats group */
+	struct module *owner;		/* owner of ->push function */
 	/* SVC part --- may move later ------------------------------------- */
 	short		itf;		/* interface number */
 	struct sockaddr_atmsvc local;

net/atm/br2684.c

@@ -68,6 +68,8 @@ struct br2684_vcc {
 	/* keep old push, pop functions for chaining */
 	void (*old_push)(struct atm_vcc *vcc, struct sk_buff *skb);
 	void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb);
+	void (*old_release_cb)(struct atm_vcc *vcc);
+	struct module *old_owner;
 	enum br2684_encaps encaps;
 	struct list_head brvccs;
 #ifdef CONFIG_ATM_BR2684_IPFILTER
@@ -269,6 +271,17 @@ static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,
 	return !atmvcc->send(atmvcc, skb);
 }
 
+static void br2684_release_cb(struct atm_vcc *atmvcc)
+{
+	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
+
+	if (atomic_read(&brvcc->qspace) > 0)
+		netif_wake_queue(brvcc->device);
+
+	if (brvcc->old_release_cb)
+		brvcc->old_release_cb(atmvcc);
+}
+
 static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
 						   const struct br2684_dev *brdev)
 {
@@ -280,6 +293,8 @@ static netdev_tx_t br2684_start_xmit(struct sk_buff *skb,
 {
 	struct br2684_dev *brdev = BRPRIV(dev);
 	struct br2684_vcc *brvcc;
+	struct atm_vcc *atmvcc;
+	netdev_tx_t ret = NETDEV_TX_OK;
 
 	pr_debug("skb_dst(skb)=%p\n", skb_dst(skb));
 	read_lock(&devs_lock);
@@ -290,9 +305,26 @@ static netdev_tx_t br2684_start_xmit(struct sk_buff *skb,
 		dev->stats.tx_carrier_errors++;
 		/* netif_stop_queue(dev); */
 		dev_kfree_skb(skb);
-		read_unlock(&devs_lock);
-		return NETDEV_TX_OK;
+		goto out_devs;
 	}
+	atmvcc = brvcc->atmvcc;
+
+	bh_lock_sock(sk_atm(atmvcc));
+
+	if (test_bit(ATM_VF_RELEASED, &atmvcc->flags) ||
+	    test_bit(ATM_VF_CLOSE, &atmvcc->flags) ||
+	    !test_bit(ATM_VF_READY, &atmvcc->flags)) {
+		dev->stats.tx_dropped++;
+		dev_kfree_skb(skb);
+		goto out;
+	}
+
+	if (sock_owned_by_user(sk_atm(atmvcc))) {
+		netif_stop_queue(brvcc->device);
+		ret = NETDEV_TX_BUSY;
+		goto out;
+	}
+
 	if (!br2684_xmit_vcc(skb, dev, brvcc)) {
 		/*
 		 * We should probably use netif_*_queue() here, but that
@@ -304,8 +336,11 @@ static netdev_tx_t br2684_start_xmit(struct sk_buff *skb,
 		dev->stats.tx_errors++;
 		dev->stats.tx_fifo_errors++;
 	}
+ out:
+	bh_unlock_sock(sk_atm(atmvcc));
+ out_devs:
 	read_unlock(&devs_lock);
-	return NETDEV_TX_OK;
+	return ret;
 }
 
 /*
@@ -378,9 +413,10 @@ static void br2684_close_vcc(struct br2684_vcc *brvcc)
 	list_del(&brvcc->brvccs);
 	write_unlock_irq(&devs_lock);
 	brvcc->atmvcc->user_back = NULL;	/* what about vcc->recvq ??? */
+	brvcc->atmvcc->release_cb = brvcc->old_release_cb;
 	brvcc->old_push(brvcc->atmvcc, NULL);	/* pass on the bad news */
+	module_put(brvcc->old_owner);
 	kfree(brvcc);
-	module_put(THIS_MODULE);
 }
 
 /* when AAL5 PDU comes in: */
@@ -554,9 +590,13 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
 	brvcc->encaps = (enum br2684_encaps)be.encaps;
 	brvcc->old_push = atmvcc->push;
 	brvcc->old_pop = atmvcc->pop;
+	brvcc->old_release_cb = atmvcc->release_cb;
+	brvcc->old_owner = atmvcc->owner;
 	barrier();
 	atmvcc->push = br2684_push;
 	atmvcc->pop = br2684_pop;
+	atmvcc->release_cb = br2684_release_cb;
+	atmvcc->owner = THIS_MODULE;
 
 	/* initialize netdev carrier state */
 	if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
@@ -695,10 +735,13 @@ static int br2684_ioctl(struct socket *sock, unsigned int cmd,
 			return -ENOIOCTLCMD;
 		if (!capable(CAP_NET_ADMIN))
 			return -EPERM;
-		if (cmd == ATM_SETBACKEND)
+		if (cmd == ATM_SETBACKEND) {
+			if (sock->state != SS_CONNECTED)
+				return -EINVAL;
 			return br2684_regvcc(atmvcc, argp);
-		else
+		} else {
 			return br2684_create(argp);
+		}
 #ifdef CONFIG_ATM_BR2684_IPFILTER
 	case BR2684_SETFILT:
 		if (atmvcc->push != br2684_push)

net/atm/common.c

@@ -126,10 +126,19 @@ static void vcc_write_space(struct sock *sk)
 	rcu_read_unlock();
 }
 
+static void vcc_release_cb(struct sock *sk)
+{
+	struct atm_vcc *vcc = atm_sk(sk);
+
+	if (vcc->release_cb)
+		vcc->release_cb(vcc);
+}
+
 static struct proto vcc_proto = {
 	.name	  = "VCC",
 	.owner	  = THIS_MODULE,
 	.obj_size = sizeof(struct atm_vcc),
+	.release_cb = vcc_release_cb,
 };
 
 int vcc_create(struct net *net, struct socket *sock, int protocol, int family)
@@ -156,7 +165,9 @@ int vcc_create(struct net *net, struct socket *sock, int protocol, int family)
 	atomic_set(&sk->sk_rmem_alloc, 0);
 	vcc->push = NULL;
 	vcc->pop = NULL;
+	vcc->owner = NULL;
 	vcc->push_oam = NULL;
+	vcc->release_cb = NULL;
 	vcc->vpi = vcc->vci = 0; /* no VCI/VPI yet */
 	vcc->atm_options = vcc->aal_options = 0;
 	sk->sk_destruct = vcc_sock_destruct;
@@ -175,6 +186,7 @@ static void vcc_destroy_socket(struct sock *sk)
 			vcc->dev->ops->close(vcc);
 		if (vcc->push)
 			vcc->push(vcc, NULL); /* atmarpd has no push */
+		module_put(vcc->owner);
 
 		while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 			atm_return(vcc, skb->truesize);