Revert to 3.8 (no rt, no stable)

This is a merge from rtmerge, which has been similarly reverted.

Conflicts:
	drivers/crypto/caam/caamalg.c
	drivers/misc/Makefile

1 files changed, 28 insertions, 85 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 67c8074..147a682 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -203,7 +203,7 @@ static struct list_head offload_base __read_mostly;
 DEFINE_RWLOCK(dev_base_lock);
 EXPORT_SYMBOL(dev_base_lock);
 
-DEFINE_MUTEX(devnet_rename_mutex);
+seqcount_t devnet_rename_seq;
 
 static inline void dev_base_seq_inc(struct net *net)
 {
@@ -225,14 +225,14 @@ static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
 static inline void rps_lock(struct softnet_data *sd)
 {
 #ifdef CONFIG_RPS
-	raw_spin_lock(&sd->input_pkt_queue.raw_lock);
+	spin_lock(&sd->input_pkt_queue.lock);
 #endif
 }
 
 static inline void rps_unlock(struct softnet_data *sd)
 {
 #ifdef CONFIG_RPS
-	raw_spin_unlock(&sd->input_pkt_queue.raw_lock);
+	spin_unlock(&sd->input_pkt_queue.lock);
 #endif
 }
 
@@ -1093,11 +1093,10 @@ int dev_change_name(struct net_device *dev, const char *newname)
 	if (dev->flags & IFF_UP)
 		return -EBUSY;
 
-
-	mutex_lock(&devnet_rename_mutex);
+	write_seqcount_begin(&devnet_rename_seq);
 
 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
-		mutex_unlock(&devnet_rename_mutex);
+		write_seqcount_end(&devnet_rename_seq);
 		return 0;
 	}
 
@@ -1105,7 +1104,7 @@ int dev_change_name(struct net_device *dev, const char *newname)
 
 	err = dev_get_valid_name(net, dev, newname);
 	if (err < 0) {
-		mutex_unlock(&devnet_rename_mutex);
+		write_seqcount_end(&devnet_rename_seq);
 		return err;
 	}
 
@@ -1113,11 +1112,11 @@ rollback:
 	ret = device_rename(&dev->dev, dev->name);
 	if (ret) {
 		memcpy(dev->name, oldname, IFNAMSIZ);
-		mutex_unlock(&devnet_rename_mutex);
+		write_seqcount_end(&devnet_rename_seq);
 		return ret;
 	}
 
-	mutex_unlock(&devnet_rename_mutex);
+	write_seqcount_end(&devnet_rename_seq);
 
 	write_lock_bh(&dev_base_lock);
 	hlist_del_rcu(&dev->name_hlist);
@@ -1136,7 +1135,7 @@ rollback:
 		/* err >= 0 after dev_alloc_name() or stores the first errno */
 		if (err >= 0) {
 			err = ret;
-			mutex_lock(&devnet_rename_mutex);
+			write_seqcount_begin(&devnet_rename_seq);
 			memcpy(dev->name, oldname, IFNAMSIZ);
 			goto rollback;
 		} else {
@@ -1592,6 +1591,7 @@ void net_enable_timestamp(void)
 		return;
 	}
 #endif
+	WARN_ON(in_interrupt());
 	static_key_slow_inc(&netstamp_needed);
 }
 EXPORT_SYMBOL(net_enable_timestamp);
@@ -1738,7 +1738,6 @@ int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
 	skb->mark = 0;
 	secpath_reset(skb);
 	nf_reset(skb);
-	nf_reset_trace(skb);
 	return netif_rx(skb);
 }
 EXPORT_SYMBOL_GPL(dev_forward_skb);
@@ -1947,7 +1946,6 @@ static inline void __netif_reschedule(struct Qdisc *q)
 	sd->output_queue_tailp = &q->next_sched;
 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
 	local_irq_restore(flags);
-	preempt_check_resched_rt();
 }
 
 void __netif_schedule(struct Qdisc *q)
@@ -1969,7 +1967,6 @@ void dev_kfree_skb_irq(struct sk_buff *skb)
 		sd->completion_queue = skb;
 		raise_softirq_irqoff(NET_TX_SOFTIRQ);
 		local_irq_restore(flags);
-		preempt_check_resched_rt();
 	}
 }
 EXPORT_SYMBOL(dev_kfree_skb_irq);
@@ -2021,9 +2018,6 @@ static void skb_warn_bad_offload(const struct sk_buff *skb)
 	struct net_device *dev = skb->dev;
 	const char *driver = "";
 
-	if (!net_ratelimit())
-		return;
-
 	if (dev && dev->dev.parent)
 		driver = dev_driver_string(dev->dev.parent);
 
@@ -3084,7 +3078,6 @@ enqueue:
 	rps_unlock(sd);
 
 	local_irq_restore(flags);
-	preempt_check_resched_rt();
 
 	atomic_long_inc(&skb->dev->rx_dropped);
 	kfree_skb(skb);
@@ -3122,7 +3115,7 @@ int netif_rx(struct sk_buff *skb)
 		struct rps_dev_flow voidflow, *rflow = &voidflow;
 		int cpu;
 
-		migrate_disable();
+		preempt_disable();
 		rcu_read_lock();
 
 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
@@ -3132,13 +3125,13 @@ int netif_rx(struct sk_buff *skb)
 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
 
 		rcu_read_unlock();
-		migrate_enable();
+		preempt_enable();
 	} else
 #endif
 	{
 		unsigned int qtail;
-		ret = enqueue_to_backlog(skb, get_cpu_light(), &qtail);
-		put_cpu_light();
+		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
+		put_cpu();
 	}
 	return ret;
 }
@@ -3148,44 +3141,16 @@ int netif_rx_ni(struct sk_buff *skb)
 {
 	int err;
 
-	local_bh_disable();
+	preempt_disable();
 	err = netif_rx(skb);
-	local_bh_enable();
+	if (local_softirq_pending())
+		do_softirq();
+	preempt_enable();
 
 	return err;
 }
 EXPORT_SYMBOL(netif_rx_ni);
 
-#ifdef CONFIG_PREEMPT_RT_FULL
-/*
- * RT runs ksoftirqd as a real time thread and the root_lock is a
- * "sleeping spinlock". If the trylock fails then we can go into an
- * infinite loop when ksoftirqd preempted the task which actually
- * holds the lock, because we requeue q and raise NET_TX softirq
- * causing ksoftirqd to loop forever.
- *
- * It's safe to use spin_lock on RT here as softirqs run in thread
- * context and cannot deadlock against the thread which is holding
- * root_lock.
- *
- * On !RT the trylock might fail, but there we bail out from the
- * softirq loop after 10 attempts which we can't do on RT. And the
- * task holding root_lock cannot be preempted, so the only downside of
- * that trylock is that we need 10 loops to decide that we should have
- * given up in the first one :)
- */
-static inline int take_root_lock(spinlock_t *lock)
-{
-	spin_lock(lock);
-	return 1;
-}
-#else
-static inline int take_root_lock(spinlock_t *lock)
-{
-	return spin_trylock(lock);
-}
-#endif
-
 static void net_tx_action(struct softirq_action *h)
 {
 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
@@ -3224,7 +3189,7 @@ static void net_tx_action(struct softirq_action *h)
 			head = head->next_sched;
 
 			root_lock = qdisc_lock(q);
-			if (take_root_lock(root_lock)) {
+			if (spin_trylock(root_lock)) {
 				smp_mb__before_clear_bit();
 				clear_bit(__QDISC_STATE_SCHED,
 					  &q->state);
@@ -3338,7 +3303,6 @@ int netdev_rx_handler_register(struct net_device *dev,
 	if (dev->rx_handler)
 		return -EBUSY;
 
-	/* Note: rx_handler_data must be set before rx_handler */
 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
 	rcu_assign_pointer(dev->rx_handler, rx_handler);
 
@@ -3359,11 +3323,6 @@ void netdev_rx_handler_unregister(struct net_device *dev)
 
 	ASSERT_RTNL();
 	RCU_INIT_POINTER(dev->rx_handler, NULL);
-	/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
-	 * section has a guarantee to see a non NULL rx_handler_data
-	 * as well.
-	 */
-	synchronize_net();
 	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
 }
 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
@@ -3486,7 +3445,6 @@ ncls:
 		}
 		switch (rx_handler(&skb)) {
 		case RX_HANDLER_CONSUMED:
-			ret = NET_RX_SUCCESS;
 			goto unlock;
 		case RX_HANDLER_ANOTHER:
 			goto another_round;
@@ -3595,7 +3553,7 @@ static void flush_backlog(void *arg)
 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
 		if (skb->dev == dev) {
 			__skb_unlink(skb, &sd->input_pkt_queue);
-			__skb_queue_tail(&sd->tofree_queue, skb);
+			kfree_skb(skb);
 			input_queue_head_incr(sd);
 		}
 	}
@@ -3604,13 +3562,10 @@ static void flush_backlog(void *arg)
 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
 		if (skb->dev == dev) {
 			__skb_unlink(skb, &sd->process_queue);
-			__skb_queue_tail(&sd->tofree_queue, skb);
+			kfree_skb(skb);
 			input_queue_head_incr(sd);
 		}
 	}
-
-	if (!skb_queue_empty(&sd->tofree_queue))
-		raise_softirq_irqoff(NET_RX_SOFTIRQ);
 }
 
 static int napi_gro_complete(struct sk_buff *skb)
@@ -3969,7 +3924,6 @@ static void net_rps_action_and_irq_enable(struct softnet_data *sd)
 	} else
 #endif
 		local_irq_enable();
-	preempt_check_resched_rt();
 }
 
 static int process_backlog(struct napi_struct *napi, int quota)
@@ -4042,7 +3996,6 @@ void __napi_schedule(struct napi_struct *n)
 	local_irq_save(flags);
 	____napi_schedule(&__get_cpu_var(softnet_data), n);
 	local_irq_restore(flags);
-	preempt_check_resched_rt();
 }
 EXPORT_SYMBOL(__napi_schedule);
 
@@ -4117,17 +4070,10 @@ static void net_rx_action(struct softirq_action *h)
 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
 	unsigned long time_limit = jiffies + 2;
 	int budget = netdev_budget;
-	struct sk_buff *skb;
 	void *have;
 
 	local_irq_disable();
 
-	while ((skb = __skb_dequeue(&sd->tofree_queue))) {
-		local_irq_enable();
-		kfree_skb(skb);
-		local_irq_disable();
-	}
-
 	while (!list_empty(&sd->poll_list)) {
 		struct napi_struct *n;
 		int work, weight;
@@ -4250,6 +4196,7 @@ static int dev_ifname(struct net *net, struct ifreq __user *arg)
 {
 	struct net_device *dev;
 	struct ifreq ifr;
+	unsigned seq;
 
 	/*
 	 *	Fetch the caller's info block.
@@ -4258,18 +4205,19 @@ static int dev_ifname(struct net *net, struct ifreq __user *arg)
 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
 		return -EFAULT;
 
-	mutex_lock(&devnet_rename_mutex);
+retry:
+	seq = read_seqcount_begin(&devnet_rename_seq);
 	rcu_read_lock();
 	dev = dev_get_by_index_rcu(net, ifr.ifr_ifindex);
 	if (!dev) {
 		rcu_read_unlock();
-		mutex_unlock(&devnet_rename_mutex);
 		return -ENODEV;
 	}
 
 	strcpy(ifr.ifr_name, dev->name);
 	rcu_read_unlock();
-	mutex_unlock(&devnet_rename_mutex);
+	if (read_seqcount_retry(&devnet_rename_seq, seq))
+		goto retry;
 
 	if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
 		return -EFAULT;
@@ -6597,7 +6545,6 @@ static int dev_cpu_callback(struct notifier_block *nfb,
 
 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
 	local_irq_enable();
-	preempt_check_resched_rt();
 
 	/* Process offline CPU's input_pkt_queue */
 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
@@ -6608,9 +6555,6 @@ static int dev_cpu_callback(struct notifier_block *nfb,
 		netif_rx(skb);
 		input_queue_head_incr(oldsd);
 	}
-	while ((skb = __skb_dequeue(&oldsd->tofree_queue))) {
-		kfree_skb(skb);
-	}
 
 	return NOTIFY_OK;
 }
@@ -6883,9 +6827,8 @@ static int __init net_dev_init(void)
 		struct softnet_data *sd = &per_cpu(softnet_data, i);
 
 		memset(sd, 0, sizeof(*sd));
-		skb_queue_head_init_raw(&sd->input_pkt_queue);
-		skb_queue_head_init_raw(&sd->process_queue);
-		skb_queue_head_init_raw(&sd->tofree_queue);
+		skb_queue_head_init(&sd->input_pkt_queue);
+		skb_queue_head_init(&sd->process_queue);
 		sd->completion_queue = NULL;
 		INIT_LIST_HEAD(&sd->poll_list);
 		sd->output_queue = NULL;