Merge branch 'locking/urgent' into locking/core, to pick up fixes before applying new changes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

12 files changed, 139 insertions, 76 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 2cf0f79f1fc9..2c9eae6ad970 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -46,7 +46,6 @@
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/rwsem.h>
-#include <linux/percpu-rwsem.h>
 #include <linux/string.h>
 #include <linux/sort.h>
 #include <linux/kmod.h>
@@ -104,8 +103,6 @@ static DEFINE_SPINLOCK(cgroup_idr_lock);
  */
 static DEFINE_SPINLOCK(release_agent_path_lock);
 
-struct percpu_rw_semaphore cgroup_threadgroup_rwsem;
-
 #define cgroup_assert_mutex_or_rcu_locked()				\
 	RCU_LOCKDEP_WARN(!rcu_read_lock_held() &&			\
 			   !lockdep_is_held(&cgroup_mutex),		\
@@ -874,6 +871,48 @@ static struct css_set *find_css_set(struct css_set *old_cset,
 	return cset;
 }
 
+void cgroup_threadgroup_change_begin(struct task_struct *tsk)
+{
+	down_read(&tsk->signal->group_rwsem);
+}
+
+void cgroup_threadgroup_change_end(struct task_struct *tsk)
+{
+	up_read(&tsk->signal->group_rwsem);
+}
+
+/**
+ * threadgroup_lock - lock threadgroup
+ * @tsk: member task of the threadgroup to lock
+ *
+ * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
+ * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
+ * change ->group_leader/pid.  This is useful for cases where the threadgroup
+ * needs to stay stable across blockable operations.
+ *
+ * fork and exit explicitly call threadgroup_change_{begin|end}() for
+ * synchronization.  While held, no new task will be added to threadgroup
+ * and no existing live task will have its PF_EXITING set.
+ *
+ * de_thread() does threadgroup_change_{begin|end}() when a non-leader
+ * sub-thread becomes a new leader.
+ */
+static void threadgroup_lock(struct task_struct *tsk)
+{
+	down_write(&tsk->signal->group_rwsem);
+}
+
+/**
+ * threadgroup_unlock - unlock threadgroup
+ * @tsk: member task of the threadgroup to unlock
+ *
+ * Reverse threadgroup_lock().
+ */
+static inline void threadgroup_unlock(struct task_struct *tsk)
+{
+	up_write(&tsk->signal->group_rwsem);
+}
+
 static struct cgroup_root *cgroup_root_from_kf(struct kernfs_root *kf_root)
 {
 	struct cgroup *root_cgrp = kf_root->kn->priv;
@@ -2074,9 +2113,9 @@ static void cgroup_task_migrate(struct cgroup *old_cgrp,
 	lockdep_assert_held(&css_set_rwsem);
 
 	/*
-	 * We are synchronized through cgroup_threadgroup_rwsem against
-	 * PF_EXITING setting such that we can't race against cgroup_exit()
-	 * changing the css_set to init_css_set and dropping the old one.
+	 * We are synchronized through threadgroup_lock() against PF_EXITING
+	 * setting such that we can't race against cgroup_exit() changing the
+	 * css_set to init_css_set and dropping the old one.
 	 */
 	WARN_ON_ONCE(tsk->flags & PF_EXITING);
 	old_cset = task_css_set(tsk);
@@ -2133,11 +2172,10 @@ static void cgroup_migrate_finish(struct list_head *preloaded_csets)
  * @src_cset and add it to @preloaded_csets, which should later be cleaned
  * up by cgroup_migrate_finish().
  *
- * This function may be called without holding cgroup_threadgroup_rwsem
- * even if the target is a process.  Threads may be created and destroyed
- * but as long as cgroup_mutex is not dropped, no new css_set can be put
- * into play and the preloaded css_sets are guaranteed to cover all
- * migrations.
+ * This function may be called without holding threadgroup_lock even if the
+ * target is a process.  Threads may be created and destroyed but as long
+ * as cgroup_mutex is not dropped, no new css_set can be put into play and
+ * the preloaded css_sets are guaranteed to cover all migrations.
  */
 static void cgroup_migrate_add_src(struct css_set *src_cset,
 				   struct cgroup *dst_cgrp,
@@ -2240,7 +2278,7 @@ err:
  * @threadgroup: whether @leader points to the whole process or a single task
  *
  * Migrate a process or task denoted by @leader to @cgrp.  If migrating a
- * process, the caller must be holding cgroup_threadgroup_rwsem.  The
+ * process, the caller must be holding threadgroup_lock of @leader.  The
  * caller is also responsible for invoking cgroup_migrate_add_src() and
  * cgroup_migrate_prepare_dst() on the targets before invoking this
  * function and following up with cgroup_migrate_finish().
@@ -2368,7 +2406,7 @@ out_release_tset:
  * @leader: the task or the leader of the threadgroup to be attached
  * @threadgroup: attach the whole threadgroup?
  *
- * Call holding cgroup_mutex and cgroup_threadgroup_rwsem.
+ * Call holding cgroup_mutex and threadgroup_lock of @leader.
  */
 static int cgroup_attach_task(struct cgroup *dst_cgrp,
 			      struct task_struct *leader, bool threadgroup)
@@ -2460,13 +2498,14 @@ static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf,
 	if (!cgrp)
 		return -ENODEV;
 
-	percpu_down_write(&cgroup_threadgroup_rwsem);
+retry_find_task:
 	rcu_read_lock();
 	if (pid) {
 		tsk = find_task_by_vpid(pid);
 		if (!tsk) {
+			rcu_read_unlock();
 			ret = -ESRCH;
-			goto out_unlock_rcu;
+			goto out_unlock_cgroup;
 		}
 	} else {
 		tsk = current;
@@ -2482,23 +2521,37 @@ static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf,
 	 */
 	if (tsk == kthreadd_task || (tsk->flags & PF_NO_SETAFFINITY)) {
 		ret = -EINVAL;
-		goto out_unlock_rcu;
+		rcu_read_unlock();
+		goto out_unlock_cgroup;
 	}
 
 	get_task_struct(tsk);
 	rcu_read_unlock();
 
+	threadgroup_lock(tsk);
+	if (threadgroup) {
+		if (!thread_group_leader(tsk)) {
+			/*
+			 * a race with de_thread from another thread's exec()
+			 * may strip us of our leadership, if this happens,
+			 * there is no choice but to throw this task away and
+			 * try again; this is
+			 * "double-double-toil-and-trouble-check locking".
+			 */
+			threadgroup_unlock(tsk);
+			put_task_struct(tsk);
+			goto retry_find_task;
+		}
+	}
+
 	ret = cgroup_procs_write_permission(tsk, cgrp, of);
 	if (!ret)
 		ret = cgroup_attach_task(cgrp, tsk, threadgroup);
 
-	put_task_struct(tsk);
-	goto out_unlock_threadgroup;
+	threadgroup_unlock(tsk);
 
-out_unlock_rcu:
-	rcu_read_unlock();
-out_unlock_threadgroup:
-	percpu_up_write(&cgroup_threadgroup_rwsem);
+	put_task_struct(tsk);
+out_unlock_cgroup:
 	cgroup_kn_unlock(of->kn);
 	return ret ?: nbytes;
 }
@@ -2643,8 +2696,6 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
 
 	lockdep_assert_held(&cgroup_mutex);
 
-	percpu_down_write(&cgroup_threadgroup_rwsem);
-
 	/* look up all csses currently attached to @cgrp's subtree */
 	down_read(&css_set_rwsem);
 	css_for_each_descendant_pre(css, cgroup_css(cgrp, NULL)) {
@@ -2700,8 +2751,17 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
 				goto out_finish;
 			last_task = task;
 
+			threadgroup_lock(task);
+			/* raced against de_thread() from another thread? */
+			if (!thread_group_leader(task)) {
+				threadgroup_unlock(task);
+				put_task_struct(task);
+				continue;
+			}
+
 			ret = cgroup_migrate(src_cset->dfl_cgrp, task, true);
 
+			threadgroup_unlock(task);
 			put_task_struct(task);
 
 			if (WARN(ret, "cgroup: failed to update controllers for the default hierarchy (%d), further operations may crash or hang\n", ret))
@@ -2711,7 +2771,6 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
 
 out_finish:
 	cgroup_migrate_finish(&preloaded_csets);
-	percpu_up_write(&cgroup_threadgroup_rwsem);
 	return ret;
 }
 
@@ -5024,7 +5083,6 @@ int __init cgroup_init(void)
 	unsigned long key;
 	int ssid, err;
 
-	BUG_ON(percpu_init_rwsem(&cgroup_threadgroup_rwsem));
 	BUG_ON(cgroup_init_cftypes(NULL, cgroup_dfl_base_files));
 	BUG_ON(cgroup_init_cftypes(NULL, cgroup_legacy_base_files));
 
diff --git a/kernel/fork.c b/kernel/fork.c
index 7d5f0f118a63..2845623fb582 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1149,6 +1149,10 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 	tty_audit_fork(sig);
 	sched_autogroup_fork(sig);
 
+#ifdef CONFIG_CGROUPS
+	init_rwsem(&sig->group_rwsem);
+#endif
+
 	sig->oom_score_adj = current->signal->oom_score_adj;
 	sig->oom_score_adj_min = current->signal->oom_score_adj_min;
 
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 6e40a9539763..e28169dd1c36 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -83,7 +83,7 @@ int irq_set_handler_data(unsigned int irq, void *data)
 
 	if (!desc)
 		return -EINVAL;
-	desc->irq_data.handler_data = data;
+	desc->irq_common_data.handler_data = data;
 	irq_put_desc_unlock(desc, flags);
 	return 0;
 }
@@ -105,7 +105,7 @@ int irq_set_msi_desc_off(unsigned int irq_base, unsigned int irq_offset,
 
 	if (!desc)
 		return -EINVAL;
-	desc->irq_data.msi_desc = entry;
+	desc->irq_common_data.msi_desc = entry;
 	if (entry && !irq_offset)
 		entry->irq = irq_base;
 	irq_put_desc_unlock(desc, flags);
@@ -372,7 +372,6 @@ static bool irq_may_run(struct irq_desc *desc)
 
 /**
  *	handle_simple_irq - Simple and software-decoded IRQs.
- *	@irq:	the interrupt number
  *	@desc:	the interrupt description structure for this irq
  *
  *	Simple interrupts are either sent from a demultiplexing interrupt
@@ -382,8 +381,7 @@ static bool irq_may_run(struct irq_desc *desc)
  *	Note: The caller is expected to handle the ack, clear, mask and
  *	unmask issues if necessary.
  */
-void
-handle_simple_irq(unsigned int irq, struct irq_desc *desc)
+void handle_simple_irq(struct irq_desc *desc)
 {
 	raw_spin_lock(&desc->lock);
 
@@ -425,7 +423,6 @@ static void cond_unmask_irq(struct irq_desc *desc)
 
 /**
  *	handle_level_irq - Level type irq handler
- *	@irq:	the interrupt number
  *	@desc:	the interrupt description structure for this irq
  *
  *	Level type interrupts are active as long as the hardware line has
@@ -433,8 +430,7 @@ static void cond_unmask_irq(struct irq_desc *desc)
  *	it after the associated handler has acknowledged the device, so the
  *	interrupt line is back to inactive.
  */
-void
-handle_level_irq(unsigned int irq, struct irq_desc *desc)
+void handle_level_irq(struct irq_desc *desc)
 {
 	raw_spin_lock(&desc->lock);
 	mask_ack_irq(desc);
@@ -496,7 +492,6 @@ static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
 
 /**
  *	handle_fasteoi_irq - irq handler for transparent controllers
- *	@irq:	the interrupt number
  *	@desc:	the interrupt description structure for this irq
  *
  *	Only a single callback will be issued to the chip: an ->eoi()
@@ -504,8 +499,7 @@ static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
  *	for modern forms of interrupt handlers, which handle the flow
  *	details in hardware, transparently.
  */
-void
-handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
+void handle_fasteoi_irq(struct irq_desc *desc)
 {
 	struct irq_chip *chip = desc->irq_data.chip;
 
@@ -546,7 +540,6 @@ EXPORT_SYMBOL_GPL(handle_fasteoi_irq);
 
 /**
  *	handle_edge_irq - edge type IRQ handler
- *	@irq:	the interrupt number
  *	@desc:	the interrupt description structure for this irq
  *
  *	Interrupt occures on the falling and/or rising edge of a hardware
@@ -560,8 +553,7 @@ EXPORT_SYMBOL_GPL(handle_fasteoi_irq);
  *	the handler was running. If all pending interrupts are handled, the
  *	loop is left.
  */
-void
-handle_edge_irq(unsigned int irq, struct irq_desc *desc)
+void handle_edge_irq(struct irq_desc *desc)
 {
 	raw_spin_lock(&desc->lock);
 
@@ -618,13 +610,12 @@ EXPORT_SYMBOL(handle_edge_irq);
 #ifdef CONFIG_IRQ_EDGE_EOI_HANDLER
 /**
  *	handle_edge_eoi_irq - edge eoi type IRQ handler
- *	@irq:	the interrupt number
  *	@desc:	the interrupt description structure for this irq
  *
  * Similar as the above handle_edge_irq, but using eoi and w/o the
  * mask/unmask logic.
  */
-void handle_edge_eoi_irq(unsigned int irq, struct irq_desc *desc)
+void handle_edge_eoi_irq(struct irq_desc *desc)
 {
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 
@@ -665,13 +656,11 @@ out_eoi:
 
 /**
  *	handle_percpu_irq - Per CPU local irq handler
- *	@irq:	the interrupt number
  *	@desc:	the interrupt description structure for this irq
  *
  *	Per CPU interrupts on SMP machines without locking requirements
  */
-void
-handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
+void handle_percpu_irq(struct irq_desc *desc)
 {
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 
@@ -688,7 +677,6 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 
 /**
  * handle_percpu_devid_irq - Per CPU local irq handler with per cpu dev ids
- * @irq:	the interrupt number
  * @desc:	the interrupt description structure for this irq
  *
  * Per CPU interrupts on SMP machines without locking requirements. Same as
@@ -698,11 +686,12 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
  * contain the real device id for the cpu on which this handler is
  * called
  */
-void handle_percpu_devid_irq(unsigned int irq, struct irq_desc *desc)
+void handle_percpu_devid_irq(struct irq_desc *desc)
 {
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 	struct irqaction *action = desc->action;
 	void *dev_id = raw_cpu_ptr(action->percpu_dev_id);
+	unsigned int irq = irq_desc_get_irq(desc);
 	irqreturn_t res;
 
 	kstat_incr_irqs_this_cpu(desc);
@@ -796,7 +785,7 @@ irq_set_chained_handler_and_data(unsigned int irq, irq_flow_handler_t handle,
 		return;
 
 	__irq_do_set_handler(desc, handle, 1, NULL);
-	desc->irq_data.handler_data = data;
+	desc->irq_common_data.handler_data = data;
 
 	irq_put_desc_busunlock(desc, flags);
 }
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index b6eeea8a80c5..de41a68fc038 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -27,8 +27,10 @@
  *
  * Handles spurious and unhandled IRQ's. It also prints a debugmessage.
  */
-void handle_bad_irq(unsigned int irq, struct irq_desc *desc)
+void handle_bad_irq(struct irq_desc *desc)
 {
+	unsigned int irq = irq_desc_get_irq(desc);
+
 	print_irq_desc(irq, desc);
 	kstat_incr_irqs_this_cpu(desc);
 	ack_bad_irq(irq);
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index eee4b385cffb..5ef0c2dbe930 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -194,7 +194,7 @@ static inline void kstat_incr_irqs_this_cpu(struct irq_desc *desc)
 
 static inline int irq_desc_get_node(struct irq_desc *desc)
 {
-	return irq_data_get_node(&desc->irq_data);
+	return irq_common_data_get_node(&desc->irq_common_data);
 }
 
 #ifdef CONFIG_PM_SLEEP
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 0a2a4b697bcb..239e2ae2c947 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -38,12 +38,13 @@ static void __init init_irq_default_affinity(void)
 #ifdef CONFIG_SMP
 static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
 {
-	if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node))
+	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
+				     gfp, node))
 		return -ENOMEM;
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
 	if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
-		free_cpumask_var(desc->irq_data.affinity);
+		free_cpumask_var(desc->irq_common_data.affinity);
 		return -ENOMEM;
 	}
 #endif
@@ -52,11 +53,13 @@ static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
 
 static void desc_smp_init(struct irq_desc *desc, int node)
 {
-	desc->irq_data.node = node;
-	cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
+	cpumask_copy(desc->irq_common_data.affinity, irq_default_affinity);
 #ifdef CONFIG_GENERIC_PENDING_IRQ
 	cpumask_clear(desc->pending_mask);
 #endif
+#ifdef CONFIG_NUMA
+	desc->irq_common_data.node = node;
+#endif
 }
 
 #else
@@ -70,12 +73,13 @@ static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
 {
 	int cpu;
 
+	desc->irq_common_data.handler_data = NULL;
+	desc->irq_common_data.msi_desc = NULL;
+
 	desc->irq_data.common = &desc->irq_common_data;
 	desc->irq_data.irq = irq;
 	desc->irq_data.chip = &no_irq_chip;
 	desc->irq_data.chip_data = NULL;
-	desc->irq_data.handler_data = NULL;
-	desc->irq_data.msi_desc = NULL;
 	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
 	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
 	desc->handle_irq = handle_bad_irq;
@@ -121,7 +125,7 @@ static void free_masks(struct irq_desc *desc)
 #ifdef CONFIG_GENERIC_PENDING_IRQ
 	free_cpumask_var(desc->pending_mask);
 #endif
-	free_cpumask_var(desc->irq_data.affinity);
+	free_cpumask_var(desc->irq_common_data.affinity);
 }
 #else
 static inline void free_masks(struct irq_desc *desc) { }
@@ -343,7 +347,7 @@ int generic_handle_irq(unsigned int irq)
 
 	if (!desc)
 		return -EINVAL;
-	generic_handle_irq_desc(irq, desc);
+	generic_handle_irq_desc(desc);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(generic_handle_irq);
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 79baaf8a7813..dc9d27c0c158 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -844,7 +844,6 @@ static struct irq_data *irq_domain_insert_irq_data(struct irq_domain *domain,
 		child->parent_data = irq_data;
 		irq_data->irq = child->irq;
 		irq_data->common = child->common;
-		irq_data->node = child->node;
 		irq_data->domain = domain;
 	}
 
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index ad1b064f94fe..f9a59f6cabd2 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -192,7 +192,7 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
 	switch (ret) {
 	case IRQ_SET_MASK_OK:
 	case IRQ_SET_MASK_OK_DONE:
-		cpumask_copy(data->affinity, mask);
+		cpumask_copy(desc->irq_common_data.affinity, mask);
 	case IRQ_SET_MASK_OK_NOCOPY:
 		irq_set_thread_affinity(desc);
 		ret = 0;
@@ -304,7 +304,7 @@ static void irq_affinity_notify(struct work_struct *work)
 	if (irq_move_pending(&desc->irq_data))
 		irq_get_pending(cpumask, desc);
 	else
-		cpumask_copy(cpumask, desc->irq_data.affinity);
+		cpumask_copy(cpumask, desc->irq_common_data.affinity);
 	raw_spin_unlock_irqrestore(&desc->lock, flags);
 
 	notify->notify(notify, cpumask);
@@ -375,9 +375,9 @@ static int setup_affinity(struct irq_desc *desc, struct cpumask *mask)
 	 * one of the targets is online.
 	 */
 	if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
-		if (cpumask_intersects(desc->irq_data.affinity,
+		if (cpumask_intersects(desc->irq_common_data.affinity,
 				       cpu_online_mask))
-			set = desc->irq_data.affinity;
+			set = desc->irq_common_data.affinity;
 		else
 			irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
 	}
@@ -829,8 +829,8 @@ irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
 	 * This code is triggered unconditionally. Check the affinity
 	 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
 	 */
-	if (desc->irq_data.affinity)
-		cpumask_copy(mask, desc->irq_data.affinity);
+	if (desc->irq_common_data.affinity)
+		cpumask_copy(mask, desc->irq_common_data.affinity);
 	else
 		valid = false;
 	raw_spin_unlock_irq(&desc->lock);
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 0e97c142ce40..e3a8c9577ba6 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -39,7 +39,7 @@ static struct proc_dir_entry *root_irq_dir;
 static int show_irq_affinity(int type, struct seq_file *m, void *v)
 {
 	struct irq_desc *desc = irq_to_desc((long)m->private);
-	const struct cpumask *mask = desc->irq_data.affinity;
+	const struct cpumask *mask = desc->irq_common_data.affinity;
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
 	if (irqd_is_setaffinity_pending(&desc->irq_data))
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c
index dd95f44f99b2..b86886beee4f 100644
--- a/kernel/irq/resend.c
+++ b/kernel/irq/resend.c
@@ -38,7 +38,7 @@ static void resend_irqs(unsigned long arg)
 		clear_bit(irq, irqs_resend);
 		desc = irq_to_desc(irq);
 		local_irq_disable();
-		desc->handle_irq(irq, desc);
+		desc->handle_irq(desc);
 		local_irq_enable();
 	}
 }
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 8acfbf773e06..4e49cc4c9952 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -3068,7 +3068,7 @@ static int __lock_is_held(struct lockdep_map *lock);
 static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 			  int trylock, int read, int check, int hardirqs_off,
 			  struct lockdep_map *nest_lock, unsigned long ip,
-			  int references)
+			  int references, int pin_count)
 {
 	struct task_struct *curr = current;
 	struct lock_class *class = NULL;
@@ -3157,7 +3157,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 	hlock->waittime_stamp = 0;
 	hlock->holdtime_stamp = lockstat_clock();
 #endif
-	hlock->pin_count = 0;
+	hlock->pin_count = pin_count;
 
 	if (check && !mark_irqflags(curr, hlock))
 		return 0;
@@ -3343,7 +3343,7 @@ found_it:
 			hlock_class(hlock)->subclass, hlock->trylock,
 				hlock->read, hlock->check, hlock->hardirqs_off,
 				hlock->nest_lock, hlock->acquire_ip,
-				hlock->references))
+				hlock->references, hlock->pin_count))
 			return 0;
 	}
 
@@ -3433,7 +3433,7 @@ found_it:
 			hlock_class(hlock)->subclass, hlock->trylock,
 				hlock->read, hlock->check, hlock->hardirqs_off,
 				hlock->nest_lock, hlock->acquire_ip,
-				hlock->references))
+				hlock->references, hlock->pin_count))
 			return 0;
 	}
 
@@ -3583,7 +3583,7 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 	current->lockdep_recursion = 1;
 	trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
 	__lock_acquire(lock, subclass, trylock, read, check,
-		       irqs_disabled_flags(flags), nest_lock, ip, 0);
+		       irqs_disabled_flags(flags), nest_lock, ip, 0, 0);
 	current->lockdep_recursion = 0;
 	raw_local_irq_restore(flags);
 }
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 97d276ff1edb..2f9c92884817 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2669,13 +2669,20 @@ unsigned long nr_running(void)
 
 /*
  * Check if only the current task is running on the cpu.
+ *
+ * Caution: this function does not check that the caller has disabled
+ * preemption, thus the result might have a time-of-check-to-time-of-use
+ * race.  The caller is responsible to use it correctly, for example:
+ *
+ * - from a non-preemptable section (of course)
+ *
+ * - from a thread that is bound to a single CPU
+ *
+ * - in a loop with very short iterations (e.g. a polling loop)
  */
 bool single_task_running(void)
 {
-	if (cpu_rq(smp_processor_id())->nr_running == 1)
-		return true;
-	else
-		return false;
+	return raw_rq()->nr_running == 1;
 }
 EXPORT_SYMBOL(single_task_running);