--- /dev/null
+This was added in commit 46d3ceabd8d98ed0ad10f20c595ca784e34786c5 (tcp:
+TCP Small Queues) but we need it for pppoatm too.
+
+--- a/include/net/sock.h
++++ b/include/net/sock.h
+@@ -858,6 +858,8 @@ struct proto {
+ int (*backlog_rcv) (struct sock *sk,
+ struct sk_buff *skb);
+
++ void (*release_cb)(struct sock *sk);
++
+ /* Keeping track of sk's, looking them up, and port selection methods. */
+ void (*hash)(struct sock *sk);
+ void (*unhash)(struct sock *sk);
+--- a/net/core/sock.c
++++ b/net/core/sock.c
+@@ -2159,6 +2159,10 @@ void release_sock(struct sock *sk)
+ spin_lock_bh(&sk->sk_lock.slock);
+ if (sk->sk_backlog.tail)
+ __release_sock(sk);
++
++ if (sk->sk_prot->release_cb)
++ sk->sk_prot->release_cb(sk);
++
+ sk->sk_lock.owned = 0;
+ if (waitqueue_active(&sk->sk_lock.wq))
+ wake_up(&sk->sk_lock.wq);
--- /dev/null
+commit 86768086727a60335b08c34b2966c784029a24cf
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Wed Nov 28 10:15:05 2012 +0000
+
+ pppoatm: optimise PPP channel wakeups after sock_owned_by_user()
+
+ We don't need to schedule the wakeup tasklet on *every* unlock; only if we
+ actually blocked the channel in the first place.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit a009aa5fde926350f7a7e558a3ac0180e10eb24a
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Wed Nov 28 09:08:04 2012 +0100
+
+ br2684: allow assign only on a connected socket
+
+ The br2684 does not check if used vcc is in connected state,
+ causing potential Oops in pppoatm_send() when vcc->send() is called
+ on not fully connected socket.
+
+ Now br2684 can be assigned only on connected sockets; otherwise
+ -EINVAL error is returned.
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit ae2169bcb6375fb214cadd0ea50ac54bcf39b0d6
+Author: Nathan Williams <nathan@traverse.com.au>
+Date: Tue Nov 27 17:34:09 2012 +1100
+
+ solos-pci: Fix leak of skb received for unknown vcc
+
+ ... and ensure that the next skb is set up for RX in the DMA case.
+
+ Signed-off-by: Nathan Williams <nathan@traverse.com.au>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 6227612becaebe2f9f4ad7d0cdf27e298bb56687
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Wed Nov 28 00:46:45 2012 +0000
+
+ br2684: fix module_put() race
+
+ The br2684 code used module_put() during unassignment from vcc with
+ hope that we have BKL. This assumption is no longer true.
+
+ Now owner field in atmvcc is used to move this module_put()
+ to vcc_destroy_socket().
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit 44abbb464896dc2270716d25e12fe47e57eeb1d3
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Wed Nov 28 00:05:52 2012 +0000
+
+ pppoatm: fix missing wakeup in pppoatm_send()
+
+ Now that we can return zero from pppoatm_send() for reasons *other* than
+ the queue being full, that means we can't depend on a subsequent call to
+ pppoatm_pop() waking the queue, and we might leave it stalled
+ indefinitely.
+
+ Use the ->release_cb() callback to wake the queue after the sock is
+ unlocked.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit c93eeac2ebee497dbc9b6ad39c235ff3061be141
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Wed Nov 28 00:03:11 2012 +0000
+
+ atm: Add release_cb() callback to vcc
+
+ The immediate use case for this is that it will allow us to ensure that a
+ pppoatm queue is woken after it has to drop a packet due to the sock being
+ locked.
+
+ Note that 'release_cb' is called when the socket is *unlocked*. This is
+ not to be confused with vcc_release() — which probably ought to be called
+ vcc_close().
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit 9b3e2e224cc4326d8897243b24d778abf9098a8d
+Author: David Woodhouse <dwmw2@infradead.org>
+Date: Tue Nov 27 23:28:36 2012 +0000
+
+ br2684: don't send frames on not-ready vcc
+
+ Avoid submitting packets to a vcc which is being closed. Things go badly
+ wrong when the ->pop method gets later called after everything's been
+ torn down.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit 26c7c53318cf56a690ae553104f4a60181734fb5
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Tue Nov 27 23:49:24 2012 +0000
+
+ solos-pci: Wait for pending TX to complete when releasing vcc
+
+ We should no longer be calling the old pop routine for the vcc, after
+ vcc_release() has completed. Make sure we wait for any pending TX skbs
+ to complete, by waiting for our own PKT_PCLOSE control skb to be sent.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 1a3304e89b9ba168340a37926014be11c3ad110e
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:17:02 2012 +0100
+
+ pppoatm: do not inline pppoatm_may_send()
+
+ The pppoatm_may_send() is quite heavy and it's called three times
+ in pppoatm_send() and inlining costs more than 200 bytes of code
+ (more than 10% of total pppoatm driver code size).
+
+ add/remove: 1/0 grow/shrink: 0/1 up/down: 132/-367 (-235)
+ function old new delta
+ pppoatm_may_send - 132 +132
+ pppoatm_send 900 533 -367
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 294398bcd0fe26335059a185b59cfb5de1fc4c71
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Sat Nov 10 23:33:19 2012 +0100
+
+ pppoatm: drop frames to not-ready vcc
+
+ Patches "atm: detach protocol before closing vcc"
+ and "pppoatm: allow assign only on a connected socket" fixed
+ common cases where the pppoatm_send() crashes while sending
+ frame to not-ready vcc. However there are still some other cases
+ where we can send frames to vcc, which is flagged as ATM_VF_CLOSE
+ (for instance after vcc_release_async()) or it's opened but not
+ ready yet.
+
+ Now pppoatm_send(), like vcc_sendmsg(), checks for vcc flags that
+ indicate that vcc is not ready. If the vcc is not ready we just
+ drop frame. Queueing frames is much more complicated because we
+ don't have callbacks that inform us about vcc flags changes.
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 3ac108006fd7f20cb8fc8ea2287f1497bcda00a1
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:17:00 2012 +0100
+
+ pppoatm: take ATM socket lock in pppoatm_send()
+
+ The pppoatm_send() does not take any lock that will prevent concurrent
+ vcc_sendmsg(). This causes two problems:
+
+ - there is no locking between checking the send queue size
+ with atm_may_send() and incrementing sk_wmem_alloc,
+ and the real queue size can be a little higher than sk_sndbuf
+
+ - the vcc->sendmsg() can be called concurrently. I'm not sure
+ if it's allowed. Some drivers (eni, nicstar, ...) seem
+ to assume it will never happen.
+
+ Now pppoatm_send() takes ATM socket lock, the same that is used
+ in vcc_sendmsg() and other ATM socket functions. The pppoatm_send()
+ is called with BH disabled, so bh_lock_sock() is used instead
+ of lock_sock().
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Cc: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit e41faed9cde1acce657f75a0b19a1787e9850d3f
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:16:59 2012 +0100
+
+ pppoatm: fix module_put() race
+
+ The pppoatm used module_put() during unassignment from vcc with
+ hope that we have BKL. This assumption is no longer true.
+
+ Now owner field in atmvcc is used to move this module_put()
+ to vcc_destroy_socket().
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 3b1a914595f3f9beb9e38ff3ddc7bdafa092ba22
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:16:58 2012 +0100
+
+ pppoatm: allow assign only on a connected socket
+
+ The pppoatm does not check if used vcc is in connected state,
+ causing an Oops in pppoatm_send() when vcc->send() is called
+ on not fully connected socket.
+
+ Now pppoatm can be assigned only on connected sockets; otherwise
+ -EINVAL error is returned.
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Cc: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit ec809bd817dfa1905283468e4c813684ed4efe78
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:16:57 2012 +0100
+
+ atm: add owner of push() callback to atmvcc
+
+ The atm is using atmvcc->push(vcc, NULL) callback to notify protocol
+ that vcc will be closed and protocol must detach from it. This callback
+ is usually used by protocol to decrement module usage count by module_put(),
+ but it leaves small window then module is still used after module_put().
+
+ Now the owner of push() callback is kept in atmvcc and
+ module_put(atmvcc->owner) is called after the protocol is detached from vcc.
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Chas Williams <chas@cmf.nrl.navy.mil>
+
+commit ae088d663beebb3cad0e7abaac67ee61a7c578d5
+Author: David Woodhouse <dwmw2@infradead.org>
+Date: Sun Nov 25 12:06:52 2012 +0000
+
+ atm: br2684: Fix excessive queue bloat
+
+ There's really no excuse for an additional wmem_default of buffering
+ between the netdev queue and the ATM device. Two packets (one in-flight,
+ and one ready to send) ought to be fine. It's not as if it should take
+ long to get another from the netdev queue when we need it.
+
+ If necessary we can make the queue space configurable later, but I don't
+ think it's likely to be necessary.
+
+ cf. commit 9d02daf754238adac48fa075ee79e7edd3d79ed3 (pppoatm: Fix
+ excessive queue bloat) which did something very similar for PPPoATM.
+
+ Note that there is a tremendously unlikely race condition which may
+ result in qspace temporarily going negative. If a CPU running the
+ br2684_pop() function goes off into the weeds for a long period of time
+ after incrementing qspace to 1, but before calling netdev_wake_queue()...
+ and another CPU ends up calling br2684_start_xmit() and *stopping* the
+ queue again before the first CPU comes back, the netdev queue could
+ end up being woken when qspace has already reached zero.
+
+ An alternative approach to coping with this race would be to check in
+ br2684_start_xmit() for qspace==0 and return NETDEV_TX_BUSY, but just
+ using '> 0' and '< 1' for comparison instead of '== 0' and '!= 0' is
+ simpler. It just warranted a mention of *why* we do it that way...
+
+ Move the call to atmvcc->send() to happen *after* the accounting and
+ potentially stopping the netdev queue, in br2684_xmit_vcc(). This matters
+ if the ->send() call suffers an immediate failure, because it'll call
+ br2684_pop() with the offending skb before returning. We want that to
+ happen *after* we've done the initial accounting for the packet in
+ question. Also make it return an appropriate success/failure indication
+ while we're at it.
+
+ Tested by running 'ping -l 1000 bottomless.aaisp.net.uk' from within my
+ network, with only a single PPPoE-over-BR2684 link running. And after
+ setting txqueuelen on the nas0 interface to something low (5, in fact).
+ Before the patch, we'd see about 15 packets being queued and a resulting
+ latency of ~56ms being reached. After the patch, we see only about 8,
+ which is fairly much what we expect. And a max latency of ~36ms. On this
+ OpenWRT box, wmem_default is 163840.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Reviewed-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David S. Miller <davem@davemloft.net>
+
+diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
+index 9851093..6258961 100644
+--- a/drivers/atm/solos-pci.c
++++ b/drivers/atm/solos-pci.c
+@@ -92,6 +92,7 @@ struct pkt_hdr {
+ };
+
+ struct solos_skb_cb {
++ struct completion c;
+ struct atm_vcc *vcc;
+ uint32_t dma_addr;
+ };
+@@ -710,7 +711,8 @@ 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);
+@@ -881,11 +883,18 @@ static void pclose(struct atm_vcc *vcc)
+ header->vci = cpu_to_le16(vcc->vci);
+ header->type = cpu_to_le16(PKT_PCLOSE);
+
++ init_completion(&SKB_CB(skb)->c);
++
+ fpga_queue(card, SOLOS_CHAN(vcc->dev), skb, NULL);
+
+ clear_bit(ATM_VF_ADDR, &vcc->flags);
+ clear_bit(ATM_VF_READY, &vcc->flags);
+
++ if (!wait_for_completion_timeout(&SKB_CB(skb)->c,
++ msecs_to_jiffies(5000)))
++ dev_warn(&card->dev->dev, "Timeout waiting for VCC close on port %d\n",
++ SOLOS_CHAN(vcc->dev));
++
+ /* 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). */
+@@ -1011,9 +1020,12 @@ static uint32_t fpga_tx(struct solos_card *card)
+ if (vcc) {
+ atomic_inc(&vcc->stats->tx);
+ solos_pop(vcc, oldskb);
+- } else
++ } else {
++ struct pkt_hdr *header = (void *)oldskb->data;
++ if (le16_to_cpu(header->type) == PKT_PCLOSE)
++ complete(&SKB_CB(oldskb)->c);
+ dev_kfree_skb_irq(oldskb);
+-
++ }
+ }
+ }
+ /* For non-DMA TX, write the 'TX start' bit for all four ports simultaneously */
+@@ -1345,6 +1357,8 @@ 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);
+ }
+diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h
+index 22ef21c..c1da539 100644
+--- a/include/linux/atmdev.h
++++ b/include/linux/atmdev.h
+@@ -99,6 +99,7 @@ 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);
+@@ -106,6 +107,7 @@ struct atm_vcc {
+ 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;
+diff --git a/net/atm/br2684.c b/net/atm/br2684.c
+index 4819d315..a4ee4ad 100644
+--- a/net/atm/br2684.c
++++ b/net/atm/br2684.c
+@@ -68,12 +68,14 @@ 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);
++ struct module *old_owner;
+ enum br2684_encaps encaps;
+ struct list_head brvccs;
+ #ifdef CONFIG_ATM_BR2684_IPFILTER
+ struct br2684_filter filter;
+ #endif /* CONFIG_ATM_BR2684_IPFILTER */
+ unsigned copies_needed, copies_failed;
++ atomic_t qspace;
+ };
+
+ struct br2684_dev {
+@@ -181,18 +183,15 @@ static struct notifier_block atm_dev_notifier = {
+ static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb)
+ {
+ struct br2684_vcc *brvcc = BR2684_VCC(vcc);
+- struct net_device *net_dev = skb->dev;
+
+- pr_debug("(vcc %p ; net_dev %p )\n", vcc, net_dev);
++ pr_debug("(vcc %p ; net_dev %p )\n", vcc, brvcc->device);
+ brvcc->old_pop(vcc, skb);
+
+- if (!net_dev)
+- return;
+-
+- if (atm_may_send(vcc, 0))
+- netif_wake_queue(net_dev);
+-
++ /* If the queue space just went up from zero, wake */
++ if (atomic_inc_return(&brvcc->qspace) == 1)
++ netif_wake_queue(brvcc->device);
+ }
++
+ /*
+ * Send a packet out a particular vcc. Not to useful right now, but paves
+ * the way for multiple vcc's per itf. Returns true if we can send,
+@@ -251,21 +250,30 @@ static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,
+ skb_debug(skb);
+
+ ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
++ if (test_bit(ATM_VF_RELEASED, &atmvcc->flags) ||
++ test_bit(ATM_VF_CLOSE, &atmvcc->flags) ||
++ !test_bit(ATM_VF_READY, &atmvcc->flags)) {
++ dev_kfree_skb(skb);
++ return 0;
++ }
+ pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
+ atomic_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
+ ATM_SKB(skb)->atm_options = atmvcc->atm_options;
+ dev->stats.tx_packets++;
+ dev->stats.tx_bytes += skb->len;
+- atmvcc->send(atmvcc, skb);
+
+- if (!atm_may_send(atmvcc, 0)) {
++ if (atomic_dec_return(&brvcc->qspace) < 1) {
++ /* No more please! */
+ netif_stop_queue(brvcc->device);
+- /*check for race with br2684_pop*/
+- if (atm_may_send(atmvcc, 0))
+- netif_start_queue(brvcc->device);
++ /* We might have raced with br2684_pop() */
++ if (unlikely(atomic_read(&brvcc->qspace) > 0))
++ netif_wake_queue(brvcc->device);
+ }
+
+- return 1;
++ /* If this fails immediately, the skb will be freed and br2684_pop()
++ will wake the queue if appropriate. Just return an error so that
++ the stats are updated correctly */
++ return !atmvcc->send(atmvcc, skb);
+ }
+
+ static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
+@@ -378,8 +386,8 @@ static void br2684_close_vcc(struct br2684_vcc *brvcc)
+ write_unlock_irq(&devs_lock);
+ brvcc->atmvcc->user_back = NULL; /* what about vcc->recvq ??? */
+ 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: */
+@@ -504,6 +512,13 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
+ brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
+ if (!brvcc)
+ return -ENOMEM;
++ /*
++ * Allow two packets in the ATM queue. One actually being sent, and one
++ * for the ATM 'TX done' handler to send. It shouldn't take long to get
++ * the next one from the netdev queue, when we need it. More than that
++ * would be bufferbloat.
++ */
++ atomic_set(&brvcc->qspace, 2);
+ write_lock_irq(&devs_lock);
+ net_dev = br2684_find_dev(&be.ifspec);
+ if (net_dev == NULL) {
+@@ -546,9 +561,11 @@ 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_owner = atmvcc->owner;
+ barrier();
+ atmvcc->push = br2684_push;
+ atmvcc->pop = br2684_pop;
++ atmvcc->owner = THIS_MODULE;
+
+ /* initialize netdev carrier state */
+ if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
+@@ -687,10 +704,13 @@ 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)
+diff --git a/net/atm/common.c b/net/atm/common.c
+index 0c0ad93..806fc0a 100644
+--- a/net/atm/common.c
++++ b/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);
+diff --git a/net/atm/pppoatm.c b/net/atm/pppoatm.c
+index 226dca9..8c93267 100644
+--- a/net/atm/pppoatm.c
++++ b/net/atm/pppoatm.c
+@@ -60,6 +60,8 @@ struct pppoatm_vcc {
+ struct atm_vcc *atmvcc; /* VCC descriptor */
+ void (*old_push)(struct atm_vcc *, struct sk_buff *);
+ void (*old_pop)(struct atm_vcc *, struct sk_buff *);
++ void (*old_release_cb)(struct atm_vcc *);
++ struct module *old_owner;
+ /* keep old push/pop for detaching */
+ enum pppoatm_encaps encaps;
+ atomic_t inflight;
+@@ -107,6 +109,24 @@ static void pppoatm_wakeup_sender(unsigned long arg)
+ ppp_output_wakeup((struct ppp_channel *) arg);
+ }
+
++static void pppoatm_release_cb(struct atm_vcc *atmvcc)
++{
++ struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
++
++ /*
++ * As in pppoatm_pop(), it's safe to clear the BLOCKED bit here because
++ * the wakeup *can't* race with pppoatm_send(). They both hold the PPP
++ * channel's ->downl lock. And the potential race with *setting* it,
++ * which leads to the double-check dance in pppoatm_may_send(), doesn't
++ * exist here. In the sock_owned_by_user() case in pppoatm_send(), we
++ * set the BLOCKED bit while the socket is still locked. We know that
++ * ->release_cb() can't be called until that's done.
++ */
++ if (test_and_clear_bit(BLOCKED, &pvcc->blocked))
++ tasklet_schedule(&pvcc->wakeup_tasklet);
++ if (pvcc->old_release_cb)
++ pvcc->old_release_cb(atmvcc);
++}
+ /*
+ * This gets called every time the ATM card has finished sending our
+ * skb. The ->old_pop will take care up normal atm flow control,
+@@ -151,12 +171,11 @@ static void pppoatm_unassign_vcc(struct atm_vcc *atmvcc)
+ pvcc = atmvcc_to_pvcc(atmvcc);
+ atmvcc->push = pvcc->old_push;
+ atmvcc->pop = pvcc->old_pop;
++ atmvcc->release_cb = pvcc->old_release_cb;
+ tasklet_kill(&pvcc->wakeup_tasklet);
+ ppp_unregister_channel(&pvcc->chan);
+ atmvcc->user_back = NULL;
+ kfree(pvcc);
+- /* Gee, I hope we have the big kernel lock here... */
+- module_put(THIS_MODULE);
+ }
+
+ /* Called when an AAL5 PDU comes in */
+@@ -165,9 +184,13 @@ static void pppoatm_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
+ struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
+ pr_debug("\n");
+ if (skb == NULL) { /* VCC was closed */
++ struct module *module;
++
+ pr_debug("removing ATMPPP VCC %p\n", pvcc);
++ module = pvcc->old_owner;
+ pppoatm_unassign_vcc(atmvcc);
+ atmvcc->push(atmvcc, NULL); /* Pass along bad news */
++ module_put(module);
+ return;
+ }
+ atm_return(atmvcc, skb->truesize);
+@@ -211,7 +234,7 @@ error:
+ ppp_input_error(&pvcc->chan, 0);
+ }
+
+-static inline int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
++static int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
+ {
+ /*
+ * It's not clear that we need to bother with using atm_may_send()
+@@ -269,10 +292,33 @@ static inline int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
+ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+ {
+ struct pppoatm_vcc *pvcc = chan_to_pvcc(chan);
++ struct atm_vcc *vcc;
++ int ret;
++
+ ATM_SKB(skb)->vcc = pvcc->atmvcc;
+ pr_debug("(skb=0x%p, vcc=0x%p)\n", skb, pvcc->atmvcc);
+ if (skb->data[0] == '\0' && (pvcc->flags & SC_COMP_PROT))
+ (void) skb_pull(skb, 1);
++
++ vcc = ATM_SKB(skb)->vcc;
++ bh_lock_sock(sk_atm(vcc));
++ if (sock_owned_by_user(sk_atm(vcc))) {
++ /*
++ * Needs to happen (and be flushed, hence test_and_) before we unlock
++ * the socket. It needs to be seen by the time our ->release_cb gets
++ * called.
++ */
++ test_and_set_bit(BLOCKED, &pvcc->blocked);
++ goto nospace;
++ }
++ if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
++ test_bit(ATM_VF_CLOSE, &vcc->flags) ||
++ !test_bit(ATM_VF_READY, &vcc->flags)) {
++ bh_unlock_sock(sk_atm(vcc));
++ kfree_skb(skb);
++ return DROP_PACKET;
++ }
++
+ switch (pvcc->encaps) { /* LLC encapsulation needed */
+ case e_llc:
+ if (skb_headroom(skb) < LLC_LEN) {
+@@ -285,8 +331,10 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+ }
+ consume_skb(skb);
+ skb = n;
+- if (skb == NULL)
++ if (skb == NULL) {
++ bh_unlock_sock(sk_atm(vcc));
+ return DROP_PACKET;
++ }
+ } else if (!pppoatm_may_send(pvcc, skb->truesize))
+ goto nospace;
+ memcpy(skb_push(skb, LLC_LEN), pppllc, LLC_LEN);
+@@ -296,6 +344,7 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+ goto nospace;
+ break;
+ case e_autodetect:
++ bh_unlock_sock(sk_atm(vcc));
+ pr_debug("Trying to send without setting encaps!\n");
+ kfree_skb(skb);
+ return 1;
+@@ -305,9 +354,12 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+ ATM_SKB(skb)->atm_options = ATM_SKB(skb)->vcc->atm_options;
+ pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n",
+ skb, ATM_SKB(skb)->vcc, ATM_SKB(skb)->vcc->dev);
+- return ATM_SKB(skb)->vcc->send(ATM_SKB(skb)->vcc, skb)
++ ret = ATM_SKB(skb)->vcc->send(ATM_SKB(skb)->vcc, skb)
+ ? DROP_PACKET : 1;
++ bh_unlock_sock(sk_atm(vcc));
++ return ret;
+ nospace:
++ bh_unlock_sock(sk_atm(vcc));
+ /*
+ * We don't have space to send this SKB now, but we might have
+ * already applied SC_COMP_PROT compression, so may need to undo
+@@ -362,6 +414,8 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
+ atomic_set(&pvcc->inflight, NONE_INFLIGHT);
+ pvcc->old_push = atmvcc->push;
+ pvcc->old_pop = atmvcc->pop;
++ pvcc->old_owner = atmvcc->owner;
++ pvcc->old_release_cb = atmvcc->release_cb;
+ pvcc->encaps = (enum pppoatm_encaps) be.encaps;
+ pvcc->chan.private = pvcc;
+ pvcc->chan.ops = &pppoatm_ops;
+@@ -377,7 +431,9 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
+ atmvcc->user_back = pvcc;
+ atmvcc->push = pppoatm_push;
+ atmvcc->pop = pppoatm_pop;
++ atmvcc->release_cb = pppoatm_release_cb;
+ __module_get(THIS_MODULE);
++ atmvcc->owner = THIS_MODULE;
+
+ /* re-process everything received between connection setup and
+ backend setup */
+@@ -406,6 +462,8 @@ static int pppoatm_ioctl(struct socket *sock, unsigned int cmd,
+ return -ENOIOCTLCMD;
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
++ if (sock->state != SS_CONNECTED)
++ return -EINVAL;
+ return pppoatm_assign_vcc(atmvcc, argp);
+ }
+ case PPPIOCGCHAN:
--- /dev/null
+commit 86768086727a60335b08c34b2966c784029a24cf
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Wed Nov 28 10:15:05 2012 +0000
+
+ pppoatm: optimise PPP channel wakeups after sock_owned_by_user()
+
+ We don't need to schedule the wakeup tasklet on *every* unlock; only if we
+ actually blocked the channel in the first place.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit a009aa5fde926350f7a7e558a3ac0180e10eb24a
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Wed Nov 28 09:08:04 2012 +0100
+
+ br2684: allow assign only on a connected socket
+
+ The br2684 does not check if used vcc is in connected state,
+ causing potential Oops in pppoatm_send() when vcc->send() is called
+ on not fully connected socket.
+
+ Now br2684 can be assigned only on connected sockets; otherwise
+ -EINVAL error is returned.
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit ae2169bcb6375fb214cadd0ea50ac54bcf39b0d6
+Author: Nathan Williams <nathan@traverse.com.au>
+Date: Tue Nov 27 17:34:09 2012 +1100
+
+ solos-pci: Fix leak of skb received for unknown vcc
+
+ ... and ensure that the next skb is set up for RX in the DMA case.
+
+ Signed-off-by: Nathan Williams <nathan@traverse.com.au>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 6227612becaebe2f9f4ad7d0cdf27e298bb56687
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Wed Nov 28 00:46:45 2012 +0000
+
+ br2684: fix module_put() race
+
+ The br2684 code used module_put() during unassignment from vcc with
+ hope that we have BKL. This assumption is no longer true.
+
+ Now owner field in atmvcc is used to move this module_put()
+ to vcc_destroy_socket().
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit 44abbb464896dc2270716d25e12fe47e57eeb1d3
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Wed Nov 28 00:05:52 2012 +0000
+
+ pppoatm: fix missing wakeup in pppoatm_send()
+
+ Now that we can return zero from pppoatm_send() for reasons *other* than
+ the queue being full, that means we can't depend on a subsequent call to
+ pppoatm_pop() waking the queue, and we might leave it stalled
+ indefinitely.
+
+ Use the ->release_cb() callback to wake the queue after the sock is
+ unlocked.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit c93eeac2ebee497dbc9b6ad39c235ff3061be141
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Wed Nov 28 00:03:11 2012 +0000
+
+ atm: Add release_cb() callback to vcc
+
+ The immediate use case for this is that it will allow us to ensure that a
+ pppoatm queue is woken after it has to drop a packet due to the sock being
+ locked.
+
+ Note that 'release_cb' is called when the socket is *unlocked*. This is
+ not to be confused with vcc_release() — which probably ought to be called
+ vcc_close().
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit 9b3e2e224cc4326d8897243b24d778abf9098a8d
+Author: David Woodhouse <dwmw2@infradead.org>
+Date: Tue Nov 27 23:28:36 2012 +0000
+
+ br2684: don't send frames on not-ready vcc
+
+ Avoid submitting packets to a vcc which is being closed. Things go badly
+ wrong when the ->pop method gets later called after everything's been
+ torn down.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit 26c7c53318cf56a690ae553104f4a60181734fb5
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Tue Nov 27 23:49:24 2012 +0000
+
+ solos-pci: Wait for pending TX to complete when releasing vcc
+
+ We should no longer be calling the old pop routine for the vcc, after
+ vcc_release() has completed. Make sure we wait for any pending TX skbs
+ to complete, by waiting for our own PKT_PCLOSE control skb to be sent.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 1a3304e89b9ba168340a37926014be11c3ad110e
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:17:02 2012 +0100
+
+ pppoatm: do not inline pppoatm_may_send()
+
+ The pppoatm_may_send() is quite heavy and it's called three times
+ in pppoatm_send() and inlining costs more than 200 bytes of code
+ (more than 10% of total pppoatm driver code size).
+
+ add/remove: 1/0 grow/shrink: 0/1 up/down: 132/-367 (-235)
+ function old new delta
+ pppoatm_may_send - 132 +132
+ pppoatm_send 900 533 -367
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 294398bcd0fe26335059a185b59cfb5de1fc4c71
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Sat Nov 10 23:33:19 2012 +0100
+
+ pppoatm: drop frames to not-ready vcc
+
+ Patches "atm: detach protocol before closing vcc"
+ and "pppoatm: allow assign only on a connected socket" fixed
+ common cases where the pppoatm_send() crashes while sending
+ frame to not-ready vcc. However there are still some other cases
+ where we can send frames to vcc, which is flagged as ATM_VF_CLOSE
+ (for instance after vcc_release_async()) or it's opened but not
+ ready yet.
+
+ Now pppoatm_send(), like vcc_sendmsg(), checks for vcc flags that
+ indicate that vcc is not ready. If the vcc is not ready we just
+ drop frame. Queueing frames is much more complicated because we
+ don't have callbacks that inform us about vcc flags changes.
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 3ac108006fd7f20cb8fc8ea2287f1497bcda00a1
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:17:00 2012 +0100
+
+ pppoatm: take ATM socket lock in pppoatm_send()
+
+ The pppoatm_send() does not take any lock that will prevent concurrent
+ vcc_sendmsg(). This causes two problems:
+
+ - there is no locking between checking the send queue size
+ with atm_may_send() and incrementing sk_wmem_alloc,
+ and the real queue size can be a little higher than sk_sndbuf
+
+ - the vcc->sendmsg() can be called concurrently. I'm not sure
+ if it's allowed. Some drivers (eni, nicstar, ...) seem
+ to assume it will never happen.
+
+ Now pppoatm_send() takes ATM socket lock, the same that is used
+ in vcc_sendmsg() and other ATM socket functions. The pppoatm_send()
+ is called with BH disabled, so bh_lock_sock() is used instead
+ of lock_sock().
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Cc: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit e41faed9cde1acce657f75a0b19a1787e9850d3f
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:16:59 2012 +0100
+
+ pppoatm: fix module_put() race
+
+ The pppoatm used module_put() during unassignment from vcc with
+ hope that we have BKL. This assumption is no longer true.
+
+ Now owner field in atmvcc is used to move this module_put()
+ to vcc_destroy_socket().
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 3b1a914595f3f9beb9e38ff3ddc7bdafa092ba22
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:16:58 2012 +0100
+
+ pppoatm: allow assign only on a connected socket
+
+ The pppoatm does not check if used vcc is in connected state,
+ causing an Oops in pppoatm_send() when vcc->send() is called
+ on not fully connected socket.
+
+ Now pppoatm can be assigned only on connected sockets; otherwise
+ -EINVAL error is returned.
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Cc: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit ec809bd817dfa1905283468e4c813684ed4efe78
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:16:57 2012 +0100
+
+ atm: add owner of push() callback to atmvcc
+
+ The atm is using atmvcc->push(vcc, NULL) callback to notify protocol
+ that vcc will be closed and protocol must detach from it. This callback
+ is usually used by protocol to decrement module usage count by module_put(),
+ but it leaves small window then module is still used after module_put().
+
+ Now the owner of push() callback is kept in atmvcc and
+ module_put(atmvcc->owner) is called after the protocol is detached from vcc.
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Chas Williams <chas@cmf.nrl.navy.mil>
+
+commit ae088d663beebb3cad0e7abaac67ee61a7c578d5
+Author: David Woodhouse <dwmw2@infradead.org>
+Date: Sun Nov 25 12:06:52 2012 +0000
+
+ atm: br2684: Fix excessive queue bloat
+
+ There's really no excuse for an additional wmem_default of buffering
+ between the netdev queue and the ATM device. Two packets (one in-flight,
+ and one ready to send) ought to be fine. It's not as if it should take
+ long to get another from the netdev queue when we need it.
+
+ If necessary we can make the queue space configurable later, but I don't
+ think it's likely to be necessary.
+
+ cf. commit 9d02daf754238adac48fa075ee79e7edd3d79ed3 (pppoatm: Fix
+ excessive queue bloat) which did something very similar for PPPoATM.
+
+ Note that there is a tremendously unlikely race condition which may
+ result in qspace temporarily going negative. If a CPU running the
+ br2684_pop() function goes off into the weeds for a long period of time
+ after incrementing qspace to 1, but before calling netdev_wake_queue()...
+ and another CPU ends up calling br2684_start_xmit() and *stopping* the
+ queue again before the first CPU comes back, the netdev queue could
+ end up being woken when qspace has already reached zero.
+
+ An alternative approach to coping with this race would be to check in
+ br2684_start_xmit() for qspace==0 and return NETDEV_TX_BUSY, but just
+ using '> 0' and '< 1' for comparison instead of '== 0' and '!= 0' is
+ simpler. It just warranted a mention of *why* we do it that way...
+
+ Move the call to atmvcc->send() to happen *after* the accounting and
+ potentially stopping the netdev queue, in br2684_xmit_vcc(). This matters
+ if the ->send() call suffers an immediate failure, because it'll call
+ br2684_pop() with the offending skb before returning. We want that to
+ happen *after* we've done the initial accounting for the packet in
+ question. Also make it return an appropriate success/failure indication
+ while we're at it.
+
+ Tested by running 'ping -l 1000 bottomless.aaisp.net.uk' from within my
+ network, with only a single PPPoE-over-BR2684 link running. And after
+ setting txqueuelen on the nas0 interface to something low (5, in fact).
+ Before the patch, we'd see about 15 packets being queued and a resulting
+ latency of ~56ms being reached. After the patch, we see only about 8,
+ which is fairly much what we expect. And a max latency of ~36ms. On this
+ OpenWRT box, wmem_default is 163840.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Reviewed-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David S. Miller <davem@davemloft.net>
+
+diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
+index 9851093..6258961 100644
+--- a/drivers/atm/solos-pci.c
++++ b/drivers/atm/solos-pci.c
+@@ -92,6 +92,7 @@ struct pkt_hdr {
+ };
+
+ struct solos_skb_cb {
++ struct completion c;
+ struct atm_vcc *vcc;
+ uint32_t dma_addr;
+ };
+@@ -710,7 +711,8 @@ 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);
+@@ -881,11 +883,18 @@ static void pclose(struct atm_vcc *vcc)
+ header->vci = cpu_to_le16(vcc->vci);
+ header->type = cpu_to_le16(PKT_PCLOSE);
+
++ init_completion(&SKB_CB(skb)->c);
++
+ fpga_queue(card, SOLOS_CHAN(vcc->dev), skb, NULL);
+
+ clear_bit(ATM_VF_ADDR, &vcc->flags);
+ clear_bit(ATM_VF_READY, &vcc->flags);
+
++ if (!wait_for_completion_timeout(&SKB_CB(skb)->c,
++ msecs_to_jiffies(5000)))
++ dev_warn(&card->dev->dev, "Timeout waiting for VCC close on port %d\n",
++ SOLOS_CHAN(vcc->dev));
++
+ /* 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). */
+@@ -1011,9 +1020,12 @@ static uint32_t fpga_tx(struct solos_card *card)
+ if (vcc) {
+ atomic_inc(&vcc->stats->tx);
+ solos_pop(vcc, oldskb);
+- } else
++ } else {
++ struct pkt_hdr *header = (void *)oldskb->data;
++ if (le16_to_cpu(header->type) == PKT_PCLOSE)
++ complete(&SKB_CB(oldskb)->c);
+ dev_kfree_skb_irq(oldskb);
+-
++ }
+ }
+ }
+ /* For non-DMA TX, write the 'TX start' bit for all four ports simultaneously */
+@@ -1345,6 +1357,8 @@ 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);
+ }
+diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h
+index 22ef21c..c1da539 100644
+--- a/include/linux/atmdev.h
++++ b/include/linux/atmdev.h
+@@ -99,6 +99,7 @@ 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);
+@@ -106,6 +107,7 @@ struct atm_vcc {
+ 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;
+diff --git a/net/atm/br2684.c b/net/atm/br2684.c
+index 4819d315..a4ee4ad 100644
+--- a/net/atm/br2684.c
++++ b/net/atm/br2684.c
+@@ -68,12 +68,14 @@ 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);
++ struct module *old_owner;
+ enum br2684_encaps encaps;
+ struct list_head brvccs;
+ #ifdef CONFIG_ATM_BR2684_IPFILTER
+ struct br2684_filter filter;
+ #endif /* CONFIG_ATM_BR2684_IPFILTER */
+ unsigned int copies_needed, copies_failed;
++ atomic_t qspace;
+ };
+
+ struct br2684_dev {
+@@ -181,18 +183,15 @@ static struct notifier_block atm_dev_notifier = {
+ static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb)
+ {
+ struct br2684_vcc *brvcc = BR2684_VCC(vcc);
+- struct net_device *net_dev = skb->dev;
+
+- pr_debug("(vcc %p ; net_dev %p )\n", vcc, net_dev);
++ pr_debug("(vcc %p ; net_dev %p )\n", vcc, brvcc->device);
+ brvcc->old_pop(vcc, skb);
+
+- if (!net_dev)
+- return;
+-
+- if (atm_may_send(vcc, 0))
+- netif_wake_queue(net_dev);
+-
++ /* If the queue space just went up from zero, wake */
++ if (atomic_inc_return(&brvcc->qspace) == 1)
++ netif_wake_queue(brvcc->device);
+ }
++
+ /*
+ * Send a packet out a particular vcc. Not to useful right now, but paves
+ * the way for multiple vcc's per itf. Returns true if we can send,
+@@ -251,21 +250,30 @@ static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,
+ skb_debug(skb);
+
+ ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
++ if (test_bit(ATM_VF_RELEASED, &atmvcc->flags) ||
++ test_bit(ATM_VF_CLOSE, &atmvcc->flags) ||
++ !test_bit(ATM_VF_READY, &atmvcc->flags)) {
++ dev_kfree_skb(skb);
++ return 0;
++ }
+ pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
+ atomic_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
+ ATM_SKB(skb)->atm_options = atmvcc->atm_options;
+ dev->stats.tx_packets++;
+ dev->stats.tx_bytes += skb->len;
+- atmvcc->send(atmvcc, skb);
+
+- if (!atm_may_send(atmvcc, 0)) {
++ if (atomic_dec_return(&brvcc->qspace) < 1) {
++ /* No more please! */
+ netif_stop_queue(brvcc->device);
+- /*check for race with br2684_pop*/
+- if (atm_may_send(atmvcc, 0))
+- netif_start_queue(brvcc->device);
++ /* We might have raced with br2684_pop() */
++ if (unlikely(atomic_read(&brvcc->qspace) > 0))
++ netif_wake_queue(brvcc->device);
+ }
+
+- return 1;
++ /* If this fails immediately, the skb will be freed and br2684_pop()
++ will wake the queue if appropriate. Just return an error so that
++ the stats are updated correctly */
++ return !atmvcc->send(atmvcc, skb);
+ }
+
+ static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
+@@ -378,8 +386,8 @@ static void br2684_close_vcc(struct br2684_vcc *brvcc)
+ write_unlock_irq(&devs_lock);
+ brvcc->atmvcc->user_back = NULL; /* what about vcc->recvq ??? */
+ 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: */
+@@ -504,6 +512,13 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
+ brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
+ if (!brvcc)
+ return -ENOMEM;
++ /*
++ * Allow two packets in the ATM queue. One actually being sent, and one
++ * for the ATM 'TX done' handler to send. It shouldn't take long to get
++ * the next one from the netdev queue, when we need it. More than that
++ * would be bufferbloat.
++ */
++ atomic_set(&brvcc->qspace, 2);
+ write_lock_irq(&devs_lock);
+ net_dev = br2684_find_dev(&be.ifspec);
+ if (net_dev == NULL) {
+@@ -546,9 +561,11 @@ 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_owner = atmvcc->owner;
+ barrier();
+ atmvcc->push = br2684_push;
+ atmvcc->pop = br2684_pop;
++ atmvcc->owner = THIS_MODULE;
+
+ /* initialize netdev carrier state */
+ if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
+@@ -687,10 +704,13 @@ 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)
+diff --git a/net/atm/common.c b/net/atm/common.c
+index 0c0ad93..806fc0a 100644
+--- a/net/atm/common.c
++++ b/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);
+diff --git a/net/atm/pppoatm.c b/net/atm/pppoatm.c
+index 226dca9..8c93267 100644
+--- a/net/atm/pppoatm.c
++++ b/net/atm/pppoatm.c
+@@ -60,6 +60,8 @@ struct pppoatm_vcc {
+ struct atm_vcc *atmvcc; /* VCC descriptor */
+ void (*old_push)(struct atm_vcc *, struct sk_buff *);
+ void (*old_pop)(struct atm_vcc *, struct sk_buff *);
++ void (*old_release_cb)(struct atm_vcc *);
++ struct module *old_owner;
+ /* keep old push/pop for detaching */
+ enum pppoatm_encaps encaps;
+ atomic_t inflight;
+@@ -107,6 +109,24 @@ static void pppoatm_wakeup_sender(unsigned long arg)
+ ppp_output_wakeup((struct ppp_channel *) arg);
+ }
+
++static void pppoatm_release_cb(struct atm_vcc *atmvcc)
++{
++ struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
++
++ /*
++ * As in pppoatm_pop(), it's safe to clear the BLOCKED bit here because
++ * the wakeup *can't* race with pppoatm_send(). They both hold the PPP
++ * channel's ->downl lock. And the potential race with *setting* it,
++ * which leads to the double-check dance in pppoatm_may_send(), doesn't
++ * exist here. In the sock_owned_by_user() case in pppoatm_send(), we
++ * set the BLOCKED bit while the socket is still locked. We know that
++ * ->release_cb() can't be called until that's done.
++ */
++ if (test_and_clear_bit(BLOCKED, &pvcc->blocked))
++ tasklet_schedule(&pvcc->wakeup_tasklet);
++ if (pvcc->old_release_cb)
++ pvcc->old_release_cb(atmvcc);
++}
+ /*
+ * This gets called every time the ATM card has finished sending our
+ * skb. The ->old_pop will take care up normal atm flow control,
+@@ -151,12 +171,11 @@ static void pppoatm_unassign_vcc(struct atm_vcc *atmvcc)
+ pvcc = atmvcc_to_pvcc(atmvcc);
+ atmvcc->push = pvcc->old_push;
+ atmvcc->pop = pvcc->old_pop;
++ atmvcc->release_cb = pvcc->old_release_cb;
+ tasklet_kill(&pvcc->wakeup_tasklet);
+ ppp_unregister_channel(&pvcc->chan);
+ atmvcc->user_back = NULL;
+ kfree(pvcc);
+- /* Gee, I hope we have the big kernel lock here... */
+- module_put(THIS_MODULE);
+ }
+
+ /* Called when an AAL5 PDU comes in */
+@@ -165,9 +184,13 @@ static void pppoatm_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
+ struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
+ pr_debug("\n");
+ if (skb == NULL) { /* VCC was closed */
++ struct module *module;
++
+ pr_debug("removing ATMPPP VCC %p\n", pvcc);
++ module = pvcc->old_owner;
+ pppoatm_unassign_vcc(atmvcc);
+ atmvcc->push(atmvcc, NULL); /* Pass along bad news */
++ module_put(module);
+ return;
+ }
+ atm_return(atmvcc, skb->truesize);
+@@ -211,7 +234,7 @@ error:
+ ppp_input_error(&pvcc->chan, 0);
+ }
+
+-static inline int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
++static int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
+ {
+ /*
+ * It's not clear that we need to bother with using atm_may_send()
+@@ -269,10 +292,33 @@ static inline int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
+ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+ {
+ struct pppoatm_vcc *pvcc = chan_to_pvcc(chan);
++ struct atm_vcc *vcc;
++ int ret;
++
+ ATM_SKB(skb)->vcc = pvcc->atmvcc;
+ pr_debug("(skb=0x%p, vcc=0x%p)\n", skb, pvcc->atmvcc);
+ if (skb->data[0] == '\0' && (pvcc->flags & SC_COMP_PROT))
+ (void) skb_pull(skb, 1);
++
++ vcc = ATM_SKB(skb)->vcc;
++ bh_lock_sock(sk_atm(vcc));
++ if (sock_owned_by_user(sk_atm(vcc))) {
++ /*
++ * Needs to happen (and be flushed, hence test_and_) before we unlock
++ * the socket. It needs to be seen by the time our ->release_cb gets
++ * called.
++ */
++ test_and_set_bit(BLOCKED, &pvcc->blocked);
++ goto nospace;
++ }
++ if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
++ test_bit(ATM_VF_CLOSE, &vcc->flags) ||
++ !test_bit(ATM_VF_READY, &vcc->flags)) {
++ bh_unlock_sock(sk_atm(vcc));
++ kfree_skb(skb);
++ return DROP_PACKET;
++ }
++
+ switch (pvcc->encaps) { /* LLC encapsulation needed */
+ case e_llc:
+ if (skb_headroom(skb) < LLC_LEN) {
+@@ -285,8 +331,10 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+ }
+ consume_skb(skb);
+ skb = n;
+- if (skb == NULL)
++ if (skb == NULL) {
++ bh_unlock_sock(sk_atm(vcc));
+ return DROP_PACKET;
++ }
+ } else if (!pppoatm_may_send(pvcc, skb->truesize))
+ goto nospace;
+ memcpy(skb_push(skb, LLC_LEN), pppllc, LLC_LEN);
+@@ -296,6 +344,7 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+ goto nospace;
+ break;
+ case e_autodetect:
++ bh_unlock_sock(sk_atm(vcc));
+ pr_debug("Trying to send without setting encaps!\n");
+ kfree_skb(skb);
+ return 1;
+@@ -305,9 +354,12 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+ ATM_SKB(skb)->atm_options = ATM_SKB(skb)->vcc->atm_options;
+ pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n",
+ skb, ATM_SKB(skb)->vcc, ATM_SKB(skb)->vcc->dev);
+- return ATM_SKB(skb)->vcc->send(ATM_SKB(skb)->vcc, skb)
++ ret = ATM_SKB(skb)->vcc->send(ATM_SKB(skb)->vcc, skb)
+ ? DROP_PACKET : 1;
++ bh_unlock_sock(sk_atm(vcc));
++ return ret;
+ nospace:
++ bh_unlock_sock(sk_atm(vcc));
+ /*
+ * We don't have space to send this SKB now, but we might have
+ * already applied SC_COMP_PROT compression, so may need to undo
+@@ -362,6 +414,8 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
+ atomic_set(&pvcc->inflight, NONE_INFLIGHT);
+ pvcc->old_push = atmvcc->push;
+ pvcc->old_pop = atmvcc->pop;
++ pvcc->old_owner = atmvcc->owner;
++ pvcc->old_release_cb = atmvcc->release_cb;
+ pvcc->encaps = (enum pppoatm_encaps) be.encaps;
+ pvcc->chan.private = pvcc;
+ pvcc->chan.ops = &pppoatm_ops;
+@@ -377,7 +431,9 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
+ atmvcc->user_back = pvcc;
+ atmvcc->push = pppoatm_push;
+ atmvcc->pop = pppoatm_pop;
++ atmvcc->release_cb = pppoatm_release_cb;
+ __module_get(THIS_MODULE);
++ atmvcc->owner = THIS_MODULE;
+
+ /* re-process everything received between connection setup and
+ backend setup */
+@@ -406,6 +462,8 @@ static int pppoatm_ioctl(struct socket *sock, unsigned int cmd,
+ return -ENOIOCTLCMD;
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
++ if (sock->state != SS_CONNECTED)
++ return -EINVAL;
+ return pppoatm_assign_vcc(atmvcc, argp);
+ }
+ case PPPIOCGCHAN:
--- /dev/null
+commit 86768086727a60335b08c34b2966c784029a24cf
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Wed Nov 28 10:15:05 2012 +0000
+
+ pppoatm: optimise PPP channel wakeups after sock_owned_by_user()
+
+ We don't need to schedule the wakeup tasklet on *every* unlock; only if we
+ actually blocked the channel in the first place.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit a009aa5fde926350f7a7e558a3ac0180e10eb24a
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Wed Nov 28 09:08:04 2012 +0100
+
+ br2684: allow assign only on a connected socket
+
+ The br2684 does not check if used vcc is in connected state,
+ causing potential Oops in pppoatm_send() when vcc->send() is called
+ on not fully connected socket.
+
+ Now br2684 can be assigned only on connected sockets; otherwise
+ -EINVAL error is returned.
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit ae2169bcb6375fb214cadd0ea50ac54bcf39b0d6
+Author: Nathan Williams <nathan@traverse.com.au>
+Date: Tue Nov 27 17:34:09 2012 +1100
+
+ solos-pci: Fix leak of skb received for unknown vcc
+
+ ... and ensure that the next skb is set up for RX in the DMA case.
+
+ Signed-off-by: Nathan Williams <nathan@traverse.com.au>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 6227612becaebe2f9f4ad7d0cdf27e298bb56687
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Wed Nov 28 00:46:45 2012 +0000
+
+ br2684: fix module_put() race
+
+ The br2684 code used module_put() during unassignment from vcc with
+ hope that we have BKL. This assumption is no longer true.
+
+ Now owner field in atmvcc is used to move this module_put()
+ to vcc_destroy_socket().
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit 44abbb464896dc2270716d25e12fe47e57eeb1d3
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Wed Nov 28 00:05:52 2012 +0000
+
+ pppoatm: fix missing wakeup in pppoatm_send()
+
+ Now that we can return zero from pppoatm_send() for reasons *other* than
+ the queue being full, that means we can't depend on a subsequent call to
+ pppoatm_pop() waking the queue, and we might leave it stalled
+ indefinitely.
+
+ Use the ->release_cb() callback to wake the queue after the sock is
+ unlocked.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit c93eeac2ebee497dbc9b6ad39c235ff3061be141
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Wed Nov 28 00:03:11 2012 +0000
+
+ atm: Add release_cb() callback to vcc
+
+ The immediate use case for this is that it will allow us to ensure that a
+ pppoatm queue is woken after it has to drop a packet due to the sock being
+ locked.
+
+ Note that 'release_cb' is called when the socket is *unlocked*. This is
+ not to be confused with vcc_release() — which probably ought to be called
+ vcc_close().
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit 9b3e2e224cc4326d8897243b24d778abf9098a8d
+Author: David Woodhouse <dwmw2@infradead.org>
+Date: Tue Nov 27 23:28:36 2012 +0000
+
+ br2684: don't send frames on not-ready vcc
+
+ Avoid submitting packets to a vcc which is being closed. Things go badly
+ wrong when the ->pop method gets later called after everything's been
+ torn down.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
+
+commit 26c7c53318cf56a690ae553104f4a60181734fb5
+Author: David Woodhouse <David.Woodhouse@intel.com>
+Date: Tue Nov 27 23:49:24 2012 +0000
+
+ solos-pci: Wait for pending TX to complete when releasing vcc
+
+ We should no longer be calling the old pop routine for the vcc, after
+ vcc_release() has completed. Make sure we wait for any pending TX skbs
+ to complete, by waiting for our own PKT_PCLOSE control skb to be sent.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 1a3304e89b9ba168340a37926014be11c3ad110e
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:17:02 2012 +0100
+
+ pppoatm: do not inline pppoatm_may_send()
+
+ The pppoatm_may_send() is quite heavy and it's called three times
+ in pppoatm_send() and inlining costs more than 200 bytes of code
+ (more than 10% of total pppoatm driver code size).
+
+ add/remove: 1/0 grow/shrink: 0/1 up/down: 132/-367 (-235)
+ function old new delta
+ pppoatm_may_send - 132 +132
+ pppoatm_send 900 533 -367
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 294398bcd0fe26335059a185b59cfb5de1fc4c71
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Sat Nov 10 23:33:19 2012 +0100
+
+ pppoatm: drop frames to not-ready vcc
+
+ Patches "atm: detach protocol before closing vcc"
+ and "pppoatm: allow assign only on a connected socket" fixed
+ common cases where the pppoatm_send() crashes while sending
+ frame to not-ready vcc. However there are still some other cases
+ where we can send frames to vcc, which is flagged as ATM_VF_CLOSE
+ (for instance after vcc_release_async()) or it's opened but not
+ ready yet.
+
+ Now pppoatm_send(), like vcc_sendmsg(), checks for vcc flags that
+ indicate that vcc is not ready. If the vcc is not ready we just
+ drop frame. Queueing frames is much more complicated because we
+ don't have callbacks that inform us about vcc flags changes.
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 3ac108006fd7f20cb8fc8ea2287f1497bcda00a1
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:17:00 2012 +0100
+
+ pppoatm: take ATM socket lock in pppoatm_send()
+
+ The pppoatm_send() does not take any lock that will prevent concurrent
+ vcc_sendmsg(). This causes two problems:
+
+ - there is no locking between checking the send queue size
+ with atm_may_send() and incrementing sk_wmem_alloc,
+ and the real queue size can be a little higher than sk_sndbuf
+
+ - the vcc->sendmsg() can be called concurrently. I'm not sure
+ if it's allowed. Some drivers (eni, nicstar, ...) seem
+ to assume it will never happen.
+
+ Now pppoatm_send() takes ATM socket lock, the same that is used
+ in vcc_sendmsg() and other ATM socket functions. The pppoatm_send()
+ is called with BH disabled, so bh_lock_sock() is used instead
+ of lock_sock().
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Cc: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit e41faed9cde1acce657f75a0b19a1787e9850d3f
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:16:59 2012 +0100
+
+ pppoatm: fix module_put() race
+
+ The pppoatm used module_put() during unassignment from vcc with
+ hope that we have BKL. This assumption is no longer true.
+
+ Now owner field in atmvcc is used to move this module_put()
+ to vcc_destroy_socket().
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit 3b1a914595f3f9beb9e38ff3ddc7bdafa092ba22
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:16:58 2012 +0100
+
+ pppoatm: allow assign only on a connected socket
+
+ The pppoatm does not check if used vcc is in connected state,
+ causing an Oops in pppoatm_send() when vcc->send() is called
+ on not fully connected socket.
+
+ Now pppoatm can be assigned only on connected sockets; otherwise
+ -EINVAL error is returned.
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Cc: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+
+commit ec809bd817dfa1905283468e4c813684ed4efe78
+Author: Krzysztof Mazur <krzysiek@podlesie.net>
+Date: Tue Nov 6 23:16:57 2012 +0100
+
+ atm: add owner of push() callback to atmvcc
+
+ The atm is using atmvcc->push(vcc, NULL) callback to notify protocol
+ that vcc will be closed and protocol must detach from it. This callback
+ is usually used by protocol to decrement module usage count by module_put(),
+ but it leaves small window then module is still used after module_put().
+
+ Now the owner of push() callback is kept in atmvcc and
+ module_put(atmvcc->owner) is called after the protocol is detached from vcc.
+
+ Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Acked-by: Chas Williams <chas@cmf.nrl.navy.mil>
+
+commit ae088d663beebb3cad0e7abaac67ee61a7c578d5
+Author: David Woodhouse <dwmw2@infradead.org>
+Date: Sun Nov 25 12:06:52 2012 +0000
+
+ atm: br2684: Fix excessive queue bloat
+
+ There's really no excuse for an additional wmem_default of buffering
+ between the netdev queue and the ATM device. Two packets (one in-flight,
+ and one ready to send) ought to be fine. It's not as if it should take
+ long to get another from the netdev queue when we need it.
+
+ If necessary we can make the queue space configurable later, but I don't
+ think it's likely to be necessary.
+
+ cf. commit 9d02daf754238adac48fa075ee79e7edd3d79ed3 (pppoatm: Fix
+ excessive queue bloat) which did something very similar for PPPoATM.
+
+ Note that there is a tremendously unlikely race condition which may
+ result in qspace temporarily going negative. If a CPU running the
+ br2684_pop() function goes off into the weeds for a long period of time
+ after incrementing qspace to 1, but before calling netdev_wake_queue()...
+ and another CPU ends up calling br2684_start_xmit() and *stopping* the
+ queue again before the first CPU comes back, the netdev queue could
+ end up being woken when qspace has already reached zero.
+
+ An alternative approach to coping with this race would be to check in
+ br2684_start_xmit() for qspace==0 and return NETDEV_TX_BUSY, but just
+ using '> 0' and '< 1' for comparison instead of '== 0' and '!= 0' is
+ simpler. It just warranted a mention of *why* we do it that way...
+
+ Move the call to atmvcc->send() to happen *after* the accounting and
+ potentially stopping the netdev queue, in br2684_xmit_vcc(). This matters
+ if the ->send() call suffers an immediate failure, because it'll call
+ br2684_pop() with the offending skb before returning. We want that to
+ happen *after* we've done the initial accounting for the packet in
+ question. Also make it return an appropriate success/failure indication
+ while we're at it.
+
+ Tested by running 'ping -l 1000 bottomless.aaisp.net.uk' from within my
+ network, with only a single PPPoE-over-BR2684 link running. And after
+ setting txqueuelen on the nas0 interface to something low (5, in fact).
+ Before the patch, we'd see about 15 packets being queued and a resulting
+ latency of ~56ms being reached. After the patch, we see only about 8,
+ which is fairly much what we expect. And a max latency of ~36ms. On this
+ OpenWRT box, wmem_default is 163840.
+
+ Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
+ Reviewed-by: Krzysztof Mazur <krzysiek@podlesie.net>
+ Signed-off-by: David S. Miller <davem@davemloft.net>
+
+diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
+index 9851093..6258961 100644
+--- a/drivers/atm/solos-pci.c
++++ b/drivers/atm/solos-pci.c
+@@ -92,6 +92,7 @@ struct pkt_hdr {
+ };
+
+ struct solos_skb_cb {
++ struct completion c;
+ struct atm_vcc *vcc;
+ uint32_t dma_addr;
+ };
+@@ -710,7 +711,8 @@ 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);
+@@ -881,11 +883,18 @@ static void pclose(struct atm_vcc *vcc)
+ header->vci = cpu_to_le16(vcc->vci);
+ header->type = cpu_to_le16(PKT_PCLOSE);
+
++ init_completion(&SKB_CB(skb)->c);
++
+ fpga_queue(card, SOLOS_CHAN(vcc->dev), skb, NULL);
+
+ clear_bit(ATM_VF_ADDR, &vcc->flags);
+ clear_bit(ATM_VF_READY, &vcc->flags);
+
++ if (!wait_for_completion_timeout(&SKB_CB(skb)->c,
++ msecs_to_jiffies(5000)))
++ dev_warn(&card->dev->dev, "Timeout waiting for VCC close on port %d\n",
++ SOLOS_CHAN(vcc->dev));
++
+ /* 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). */
+@@ -1011,9 +1020,12 @@ static uint32_t fpga_tx(struct solos_card *card)
+ if (vcc) {
+ atomic_inc(&vcc->stats->tx);
+ solos_pop(vcc, oldskb);
+- } else
++ } else {
++ struct pkt_hdr *header = (void *)oldskb->data;
++ if (le16_to_cpu(header->type) == PKT_PCLOSE)
++ complete(&SKB_CB(oldskb)->c);
+ dev_kfree_skb_irq(oldskb);
+-
++ }
+ }
+ }
+ /* For non-DMA TX, write the 'TX start' bit for all four ports simultaneously */
+@@ -1345,6 +1357,8 @@ 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);
+ }
+diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h
+index 22ef21c..c1da539 100644
+--- a/include/linux/atmdev.h
++++ b/include/linux/atmdev.h
+@@ -99,6 +99,7 @@ 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);
+@@ -106,6 +107,7 @@ struct atm_vcc {
+ 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;
+diff --git a/net/atm/br2684.c b/net/atm/br2684.c
+index 4819d315..a4ee4ad 100644
+--- a/net/atm/br2684.c
++++ b/net/atm/br2684.c
+@@ -68,12 +68,14 @@ 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);
++ struct module *old_owner;
+ enum br2684_encaps encaps;
+ struct list_head brvccs;
+ #ifdef CONFIG_ATM_BR2684_IPFILTER
+ struct br2684_filter filter;
+ #endif /* CONFIG_ATM_BR2684_IPFILTER */
+ unsigned int copies_needed, copies_failed;
++ atomic_t qspace;
+ };
+
+ struct br2684_dev {
+@@ -181,18 +183,15 @@ static struct notifier_block atm_dev_notifier = {
+ static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb)
+ {
+ struct br2684_vcc *brvcc = BR2684_VCC(vcc);
+- struct net_device *net_dev = skb->dev;
+
+- pr_debug("(vcc %p ; net_dev %p )\n", vcc, net_dev);
++ pr_debug("(vcc %p ; net_dev %p )\n", vcc, brvcc->device);
+ brvcc->old_pop(vcc, skb);
+
+- if (!net_dev)
+- return;
+-
+- if (atm_may_send(vcc, 0))
+- netif_wake_queue(net_dev);
+-
++ /* If the queue space just went up from zero, wake */
++ if (atomic_inc_return(&brvcc->qspace) == 1)
++ netif_wake_queue(brvcc->device);
+ }
++
+ /*
+ * Send a packet out a particular vcc. Not to useful right now, but paves
+ * the way for multiple vcc's per itf. Returns true if we can send,
+@@ -251,21 +250,30 @@ static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,
+ skb_debug(skb);
+
+ ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
++ if (test_bit(ATM_VF_RELEASED, &atmvcc->flags) ||
++ test_bit(ATM_VF_CLOSE, &atmvcc->flags) ||
++ !test_bit(ATM_VF_READY, &atmvcc->flags)) {
++ dev_kfree_skb(skb);
++ return 0;
++ }
+ pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
+ atomic_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
+ ATM_SKB(skb)->atm_options = atmvcc->atm_options;
+ dev->stats.tx_packets++;
+ dev->stats.tx_bytes += skb->len;
+- atmvcc->send(atmvcc, skb);
+
+- if (!atm_may_send(atmvcc, 0)) {
++ if (atomic_dec_return(&brvcc->qspace) < 1) {
++ /* No more please! */
+ netif_stop_queue(brvcc->device);
+- /*check for race with br2684_pop*/
+- if (atm_may_send(atmvcc, 0))
+- netif_start_queue(brvcc->device);
++ /* We might have raced with br2684_pop() */
++ if (unlikely(atomic_read(&brvcc->qspace) > 0))
++ netif_wake_queue(brvcc->device);
+ }
+
+- return 1;
++ /* If this fails immediately, the skb will be freed and br2684_pop()
++ will wake the queue if appropriate. Just return an error so that
++ the stats are updated correctly */
++ return !atmvcc->send(atmvcc, skb);
+ }
+
+ static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
+@@ -378,8 +386,8 @@ static void br2684_close_vcc(struct br2684_vcc *brvcc)
+ write_unlock_irq(&devs_lock);
+ brvcc->atmvcc->user_back = NULL; /* what about vcc->recvq ??? */
+ 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: */
+@@ -504,6 +512,13 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
+ brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
+ if (!brvcc)
+ return -ENOMEM;
++ /*
++ * Allow two packets in the ATM queue. One actually being sent, and one
++ * for the ATM 'TX done' handler to send. It shouldn't take long to get
++ * the next one from the netdev queue, when we need it. More than that
++ * would be bufferbloat.
++ */
++ atomic_set(&brvcc->qspace, 2);
+ write_lock_irq(&devs_lock);
+ net_dev = br2684_find_dev(&be.ifspec);
+ if (net_dev == NULL) {
+@@ -546,9 +561,11 @@ 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_owner = atmvcc->owner;
+ barrier();
+ atmvcc->push = br2684_push;
+ atmvcc->pop = br2684_pop;
++ atmvcc->owner = THIS_MODULE;
+
+ /* initialize netdev carrier state */
+ if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
+@@ -687,10 +704,13 @@ 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)
+diff --git a/net/atm/common.c b/net/atm/common.c
+index 0c0ad93..806fc0a 100644
+--- a/net/atm/common.c
++++ b/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);
+diff --git a/net/atm/pppoatm.c b/net/atm/pppoatm.c
+index 226dca9..8c93267 100644
+--- a/net/atm/pppoatm.c
++++ b/net/atm/pppoatm.c
+@@ -60,6 +60,8 @@ struct pppoatm_vcc {
+ struct atm_vcc *atmvcc; /* VCC descriptor */
+ void (*old_push)(struct atm_vcc *, struct sk_buff *);
+ void (*old_pop)(struct atm_vcc *, struct sk_buff *);
++ void (*old_release_cb)(struct atm_vcc *);
++ struct module *old_owner;
+ /* keep old push/pop for detaching */
+ enum pppoatm_encaps encaps;
+ atomic_t inflight;
+@@ -107,6 +109,24 @@ static void pppoatm_wakeup_sender(unsigned long arg)
+ ppp_output_wakeup((struct ppp_channel *) arg);
+ }
+
++static void pppoatm_release_cb(struct atm_vcc *atmvcc)
++{
++ struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
++
++ /*
++ * As in pppoatm_pop(), it's safe to clear the BLOCKED bit here because
++ * the wakeup *can't* race with pppoatm_send(). They both hold the PPP
++ * channel's ->downl lock. And the potential race with *setting* it,
++ * which leads to the double-check dance in pppoatm_may_send(), doesn't
++ * exist here. In the sock_owned_by_user() case in pppoatm_send(), we
++ * set the BLOCKED bit while the socket is still locked. We know that
++ * ->release_cb() can't be called until that's done.
++ */
++ if (test_and_clear_bit(BLOCKED, &pvcc->blocked))
++ tasklet_schedule(&pvcc->wakeup_tasklet);
++ if (pvcc->old_release_cb)
++ pvcc->old_release_cb(atmvcc);
++}
+ /*
+ * This gets called every time the ATM card has finished sending our
+ * skb. The ->old_pop will take care up normal atm flow control,
+@@ -151,12 +171,11 @@ static void pppoatm_unassign_vcc(struct atm_vcc *atmvcc)
+ pvcc = atmvcc_to_pvcc(atmvcc);
+ atmvcc->push = pvcc->old_push;
+ atmvcc->pop = pvcc->old_pop;
++ atmvcc->release_cb = pvcc->old_release_cb;
+ tasklet_kill(&pvcc->wakeup_tasklet);
+ ppp_unregister_channel(&pvcc->chan);
+ atmvcc->user_back = NULL;
+ kfree(pvcc);
+- /* Gee, I hope we have the big kernel lock here... */
+- module_put(THIS_MODULE);
+ }
+
+ /* Called when an AAL5 PDU comes in */
+@@ -165,9 +184,13 @@ static void pppoatm_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
+ struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
+ pr_debug("\n");
+ if (skb == NULL) { /* VCC was closed */
++ struct module *module;
++
+ pr_debug("removing ATMPPP VCC %p\n", pvcc);
++ module = pvcc->old_owner;
+ pppoatm_unassign_vcc(atmvcc);
+ atmvcc->push(atmvcc, NULL); /* Pass along bad news */
++ module_put(module);
+ return;
+ }
+ atm_return(atmvcc, skb->truesize);
+@@ -211,7 +234,7 @@ error:
+ ppp_input_error(&pvcc->chan, 0);
+ }
+
+-static inline int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
++static int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
+ {
+ /*
+ * It's not clear that we need to bother with using atm_may_send()
+@@ -269,10 +292,33 @@ static inline int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
+ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+ {
+ struct pppoatm_vcc *pvcc = chan_to_pvcc(chan);
++ struct atm_vcc *vcc;
++ int ret;
++
+ ATM_SKB(skb)->vcc = pvcc->atmvcc;
+ pr_debug("(skb=0x%p, vcc=0x%p)\n", skb, pvcc->atmvcc);
+ if (skb->data[0] == '\0' && (pvcc->flags & SC_COMP_PROT))
+ (void) skb_pull(skb, 1);
++
++ vcc = ATM_SKB(skb)->vcc;
++ bh_lock_sock(sk_atm(vcc));
++ if (sock_owned_by_user(sk_atm(vcc))) {
++ /*
++ * Needs to happen (and be flushed, hence test_and_) before we unlock
++ * the socket. It needs to be seen by the time our ->release_cb gets
++ * called.
++ */
++ test_and_set_bit(BLOCKED, &pvcc->blocked);
++ goto nospace;
++ }
++ if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
++ test_bit(ATM_VF_CLOSE, &vcc->flags) ||
++ !test_bit(ATM_VF_READY, &vcc->flags)) {
++ bh_unlock_sock(sk_atm(vcc));
++ kfree_skb(skb);
++ return DROP_PACKET;
++ }
++
+ switch (pvcc->encaps) { /* LLC encapsulation needed */
+ case e_llc:
+ if (skb_headroom(skb) < LLC_LEN) {
+@@ -285,8 +331,10 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+ }
+ consume_skb(skb);
+ skb = n;
+- if (skb == NULL)
++ if (skb == NULL) {
++ bh_unlock_sock(sk_atm(vcc));
+ return DROP_PACKET;
++ }
+ } else if (!pppoatm_may_send(pvcc, skb->truesize))
+ goto nospace;
+ memcpy(skb_push(skb, LLC_LEN), pppllc, LLC_LEN);
+@@ -296,6 +344,7 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+ goto nospace;
+ break;
+ case e_autodetect:
++ bh_unlock_sock(sk_atm(vcc));
+ pr_debug("Trying to send without setting encaps!\n");
+ kfree_skb(skb);
+ return 1;
+@@ -305,9 +354,12 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+ ATM_SKB(skb)->atm_options = ATM_SKB(skb)->vcc->atm_options;
+ pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n",
+ skb, ATM_SKB(skb)->vcc, ATM_SKB(skb)->vcc->dev);
+- return ATM_SKB(skb)->vcc->send(ATM_SKB(skb)->vcc, skb)
++ ret = ATM_SKB(skb)->vcc->send(ATM_SKB(skb)->vcc, skb)
+ ? DROP_PACKET : 1;
++ bh_unlock_sock(sk_atm(vcc));
++ return ret;
+ nospace:
++ bh_unlock_sock(sk_atm(vcc));
+ /*
+ * We don't have space to send this SKB now, but we might have
+ * already applied SC_COMP_PROT compression, so may need to undo
+@@ -362,6 +414,8 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
+ atomic_set(&pvcc->inflight, NONE_INFLIGHT);
+ pvcc->old_push = atmvcc->push;
+ pvcc->old_pop = atmvcc->pop;
++ pvcc->old_owner = atmvcc->owner;
++ pvcc->old_release_cb = atmvcc->release_cb;
+ pvcc->encaps = (enum pppoatm_encaps) be.encaps;
+ pvcc->chan.private = pvcc;
+ pvcc->chan.ops = &pppoatm_ops;
+@@ -377,7 +431,9 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
+ atmvcc->user_back = pvcc;
+ atmvcc->push = pppoatm_push;
+ atmvcc->pop = pppoatm_pop;
++ atmvcc->release_cb = pppoatm_release_cb;
+ __module_get(THIS_MODULE);
++ atmvcc->owner = THIS_MODULE;
+
+ /* re-process everything received between connection setup and
+ backend setup */
+@@ -406,6 +462,8 @@ static int pppoatm_ioctl(struct socket *sock, unsigned int cmd,
+ return -ENOIOCTLCMD;
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
++ if (sock->state != SS_CONNECTED)
++ return -EINVAL;
+ return pppoatm_assign_vcc(atmvcc, argp);
+ }
+ case PPPIOCGCHAN:
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