Merge branch 'linus' into x86/cleanups

23 files changed, 596 insertions, 385 deletions

diff --git a/kernel/Kconfig.hz b/kernel/Kconfig.hz
index 382dd5a8b2d..94fabd534b0 100644
--- a/kernel/Kconfig.hz
+++ b/kernel/Kconfig.hz
@@ -55,4 +55,4 @@ config HZ
 	default 1000 if HZ_1000
 
 config SCHED_HRTICK
-	def_bool HIGH_RES_TIMERS && USE_GENERIC_SMP_HELPERS
+	def_bool HIGH_RES_TIMERS && (!SMP || USE_GENERIC_SMP_HELPERS)
diff --git a/kernel/capability.c b/kernel/capability.c
index 0101e847603..33e51e78c2d 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -486,17 +486,22 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
 	return ret;
 }
 
-int __capable(struct task_struct *t, int cap)
+/**
+ * capable - Determine if the current task has a superior capability in effect
+ * @cap: The capability to be tested for
+ *
+ * Return true if the current task has the given superior capability currently
+ * available for use, false if not.
+ *
+ * This sets PF_SUPERPRIV on the task if the capability is available on the
+ * assumption that it's about to be used.
+ */
+int capable(int cap)
 {
-	if (security_capable(t, cap) == 0) {
-		t->flags |= PF_SUPERPRIV;
+	if (has_capability(current, cap)) {
+		current->flags |= PF_SUPERPRIV;
 		return 1;
 	}
 	return 0;
 }
-
-int capable(int cap)
-{
-	return __capable(current, cap);
-}
 EXPORT_SYMBOL(capable);
diff --git a/kernel/cpu.c b/kernel/cpu.c
index e202a68d1cc..f17e9854c24 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -349,6 +349,8 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
 		goto out_notify;
 	BUG_ON(!cpu_online(cpu));
 
+	cpu_set(cpu, cpu_active_map);
+
 	/* Now call notifier in preparation. */
 	raw_notifier_call_chain(&cpu_chain, CPU_ONLINE | mod, hcpu);
 
@@ -367,7 +369,7 @@ int __cpuinit cpu_up(unsigned int cpu)
 	if (!cpu_isset(cpu, cpu_possible_map)) {
 		printk(KERN_ERR "can't online cpu %d because it is not "
 			"configured as may-hotadd at boot time\n", cpu);
-#if defined(CONFIG_IA64) || defined(CONFIG_X86_64) || defined(CONFIG_S390)
+#if defined(CONFIG_IA64) || defined(CONFIG_X86_64)
 		printk(KERN_ERR "please check additional_cpus= boot "
 				"parameter\n");
 #endif
@@ -383,9 +385,6 @@ int __cpuinit cpu_up(unsigned int cpu)
 
 	err = _cpu_up(cpu, 0);
 
-	if (cpu_online(cpu))
-		cpu_set(cpu, cpu_active_map);
-
 out:
 	cpu_maps_update_done();
 	return err;
diff --git a/kernel/dma-coherent.c b/kernel/dma-coherent.c
index 91e96950cd5..c1d4d5b4c61 100644
--- a/kernel/dma-coherent.c
+++ b/kernel/dma-coherent.c
@@ -92,7 +92,7 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
 EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
 
 /**
- * Try to allocate memory from the per-device coherent area.
+ * dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area
  *
  * @dev:	device from which we allocate memory
  * @size:	size of requested memory area
@@ -100,11 +100,11 @@ EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
  * @ret:	This pointer will be filled with the virtual address
  * 		to allocated area.
  *
- * This function should be only called from per-arch %dma_alloc_coherent()
+ * This function should be only called from per-arch dma_alloc_coherent()
  * to support allocation from per-device coherent memory pools.
  *
  * Returns 0 if dma_alloc_coherent should continue with allocating from
- * generic memory areas, or !0 if dma_alloc_coherent should return %ret.
+ * generic memory areas, or !0 if dma_alloc_coherent should return @ret.
  */
 int dma_alloc_from_coherent(struct device *dev, ssize_t size,
 				       dma_addr_t *dma_handle, void **ret)
@@ -126,7 +126,7 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size,
 }
 
 /**
- * Try to free the memory allocated from per-device coherent memory pool.
+ * dma_release_from_coherent() - try to free the memory allocated from per-device coherent memory pool
  * @dev:	device from which the memory was allocated
  * @order:	the order of pages allocated
  * @vaddr:	virtual address of allocated pages
@@ -135,7 +135,7 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size,
  * coherent memory pool and if so, releases that memory.
  *
  * Returns 1 if we correctly released the memory, or 0 if
- * %dma_release_coherent() should proceed with releasing memory from
+ * dma_release_coherent() should proceed with releasing memory from
  * generic pools.
  */
 int dma_release_from_coherent(struct device *dev, int order, void *vaddr)
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 6c6d35d68ee..a09dd29c2fd 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -8,6 +8,7 @@
 
 #include <linux/irq.h>
 #include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <linux/interrupt.h>
 
 #include "internals.h"
@@ -16,23 +17,18 @@ static struct proc_dir_entry *root_irq_dir;
 
 #ifdef CONFIG_SMP
 
-static int irq_affinity_read_proc(char *page, char **start, off_t off,
-				  int count, int *eof, void *data)
+static int irq_affinity_proc_show(struct seq_file *m, void *v)
 {
-	struct irq_desc *desc = irq_desc + (long)data;
+	struct irq_desc *desc = irq_desc + (long)m->private;
 	cpumask_t *mask = &desc->affinity;
-	int len;
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
 	if (desc->status & IRQ_MOVE_PENDING)
 		mask = &desc->pending_mask;
 #endif
-	len = cpumask_scnprintf(page, count, *mask);
-
-	if (count - len < 2)
-		return -EINVAL;
-	len += sprintf(page + len, "\n");
-	return len;
+	seq_cpumask(m, mask);
+	seq_putc(m, '\n');
+	return 0;
 }
 
 #ifndef is_affinity_mask_valid
@@ -40,11 +36,12 @@ static int irq_affinity_read_proc(char *page, char **start, off_t off,
 #endif
 
 int no_irq_affinity;
-static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
-				   unsigned long count, void *data)
+static ssize_t irq_affinity_proc_write(struct file *file,
+		const char __user *buffer, size_t count, loff_t *pos)
 {
-	unsigned int irq = (int)(long)data, full_count = count, err;
+	unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data;
 	cpumask_t new_value;
+	int err;
 
 	if (!irq_desc[irq].chip->set_affinity || no_irq_affinity ||
 	    irq_balancing_disabled(irq))
@@ -65,28 +62,38 @@ static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
 	if (!cpus_intersects(new_value, cpu_online_map))
 		/* Special case for empty set - allow the architecture
 		   code to set default SMP affinity. */
-		return irq_select_affinity(irq) ? -EINVAL : full_count;
+		return irq_select_affinity(irq) ? -EINVAL : count;
 
 	irq_set_affinity(irq, new_value);
 
-	return full_count;
+	return count;
 }
 
-static int default_affinity_read(char *page, char **start, off_t off,
-				  int count, int *eof, void *data)
+static int irq_affinity_proc_open(struct inode *inode, struct file *file)
 {
-	int len = cpumask_scnprintf(page, count, irq_default_affinity);
-	if (count - len < 2)
-		return -EINVAL;
-	len += sprintf(page + len, "\n");
-	return len;
+	return single_open(file, irq_affinity_proc_show, PDE(inode)->data);
 }
 
-static int default_affinity_write(struct file *file, const char __user *buffer,
-				   unsigned long count, void *data)
+static const struct file_operations irq_affinity_proc_fops = {
+	.open		= irq_affinity_proc_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.write		= irq_affinity_proc_write,
+};
+
+static int default_affinity_show(struct seq_file *m, void *v)
+{
+	seq_cpumask(m, &irq_default_affinity);
+	seq_putc(m, '\n');
+	return 0;
+}
+
+static ssize_t default_affinity_write(struct file *file,
+		const char __user *buffer, size_t count, loff_t *ppos)
 {
-	unsigned int full_count = count, err;
 	cpumask_t new_value;
+	int err;
 
 	err = cpumask_parse_user(buffer, count, new_value);
 	if (err)
@@ -105,8 +112,21 @@ static int default_affinity_write(struct file *file, const char __user *buffer,
 
 	irq_default_affinity = new_value;
 
-	return full_count;
+	return count;
 }
+
+static int default_affinity_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, default_affinity_show, NULL);
+}
+
+static const struct file_operations default_affinity_proc_fops = {
+	.open		= default_affinity_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.write		= default_affinity_write,
+};
 #endif
 
 static int irq_spurious_read(char *page, char **start, off_t off,
@@ -178,16 +198,9 @@ void register_irq_proc(unsigned int irq)
 	irq_desc[irq].dir = proc_mkdir(name, root_irq_dir);
 
 #ifdef CONFIG_SMP
-	{
-		/* create /proc/irq/<irq>/smp_affinity */
-		entry = create_proc_entry("smp_affinity", 0600, irq_desc[irq].dir);
-
-		if (entry) {
-			entry->data = (void *)(long)irq;
-			entry->read_proc = irq_affinity_read_proc;
-			entry->write_proc = irq_affinity_write_proc;
-		}
-	}
+	/* create /proc/irq/<irq>/smp_affinity */
+	proc_create_data("smp_affinity", 0600, irq_desc[irq].dir,
+			 &irq_affinity_proc_fops, (void *)(long)irq);
 #endif
 
 	entry = create_proc_entry("spurious", 0444, irq_desc[irq].dir);
@@ -208,15 +221,8 @@ void unregister_handler_proc(unsigned int irq, struct irqaction *action)
 void register_default_affinity_proc(void)
 {
 #ifdef CONFIG_SMP
-	struct proc_dir_entry *entry;
-
-	/* create /proc/irq/default_smp_affinity */
-	entry = create_proc_entry("default_smp_affinity", 0600, root_irq_dir);
-	if (entry) {
-		entry->data = NULL;
-		entry->read_proc  = default_affinity_read;
-		entry->write_proc = default_affinity_write;
-	}
+	proc_create("irq/default_smp_affinity", 0600, NULL,
+		    &default_affinity_proc_fops);
 #endif
 }
 
diff --git a/kernel/kexec.c b/kernel/kexec.c
index c8a4370e2a3..59f3f0df35d 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -12,7 +12,7 @@
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/kexec.h>
-#include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <linux/list.h>
 #include <linux/highmem.h>
 #include <linux/syscalls.h>
@@ -77,7 +77,7 @@ int kexec_should_crash(struct task_struct *p)
  *
  * The code for the transition from the current kernel to the
  * the new kernel is placed in the control_code_buffer, whose size
- * is given by KEXEC_CONTROL_CODE_SIZE.  In the best case only a single
+ * is given by KEXEC_CONTROL_PAGE_SIZE.  In the best case only a single
  * page of memory is necessary, but some architectures require more.
  * Because this memory must be identity mapped in the transition from
  * virtual to physical addresses it must live in the range
@@ -242,7 +242,7 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
 	 */
 	result = -ENOMEM;
 	image->control_code_page = kimage_alloc_control_pages(image,
-					   get_order(KEXEC_CONTROL_CODE_SIZE));
+					   get_order(KEXEC_CONTROL_PAGE_SIZE));
 	if (!image->control_code_page) {
 		printk(KERN_ERR "Could not allocate control_code_buffer\n");
 		goto out;
@@ -317,7 +317,7 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
 	 */
 	result = -ENOMEM;
 	image->control_code_page = kimage_alloc_control_pages(image,
-					   get_order(KEXEC_CONTROL_CODE_SIZE));
+					   get_order(KEXEC_CONTROL_PAGE_SIZE));
 	if (!image->control_code_page) {
 		printk(KERN_ERR "Could not allocate control_code_buffer\n");
 		goto out;
@@ -924,19 +924,14 @@ static int kimage_load_segment(struct kimage *image,
  */
 struct kimage *kexec_image;
 struct kimage *kexec_crash_image;
-/*
- * A home grown binary mutex.
- * Nothing can wait so this mutex is safe to use
- * in interrupt context :)
- */
-static int kexec_lock;
+
+static DEFINE_MUTEX(kexec_mutex);
 
 asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
 				struct kexec_segment __user *segments,
 				unsigned long flags)
 {
 	struct kimage **dest_image, *image;
-	int locked;
 	int result;
 
 	/* We only trust the superuser with rebooting the system. */
@@ -972,8 +967,7 @@ asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
 	 *
 	 * KISS: always take the mutex.
 	 */
-	locked = xchg(&kexec_lock, 1);
-	if (locked)
+	if (!mutex_trylock(&kexec_mutex))
 		return -EBUSY;
 
 	dest_image = &kexec_image;
@@ -1015,8 +1009,7 @@ asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
 	image = xchg(dest_image, image);
 
 out:
-	locked = xchg(&kexec_lock, 0); /* Release the mutex */
-	BUG_ON(!locked);
+	mutex_unlock(&kexec_mutex);
 	kimage_free(image);
 
 	return result;
@@ -1063,10 +1056,7 @@ asmlinkage long compat_sys_kexec_load(unsigned long entry,
 
 void crash_kexec(struct pt_regs *regs)
 {
-	int locked;
-
-
-	/* Take the kexec_lock here to prevent sys_kexec_load
+	/* Take the kexec_mutex here to prevent sys_kexec_load
 	 * running on one cpu from replacing the crash kernel
 	 * we are using after a panic on a different cpu.
 	 *
@@ -1074,8 +1064,7 @@ void crash_kexec(struct pt_regs *regs)
 	 * of memory the xchg(&kexec_crash_image) would be
 	 * sufficient.  But since I reuse the memory...
 	 */
-	locked = xchg(&kexec_lock, 1);
-	if (!locked) {
+	if (mutex_trylock(&kexec_mutex)) {
 		if (kexec_crash_image) {
 			struct pt_regs fixed_regs;
 			crash_setup_regs(&fixed_regs, regs);
@@ -1083,8 +1072,7 @@ void crash_kexec(struct pt_regs *regs)
 			machine_crash_shutdown(&fixed_regs);
 			machine_kexec(kexec_crash_image);
 		}
-		locked = xchg(&kexec_lock, 0);
-		BUG_ON(!locked);
+		mutex_unlock(&kexec_mutex);
 	}
 }
 
@@ -1426,25 +1414,23 @@ static int __init crash_save_vmcoreinfo_init(void)
 
 module_init(crash_save_vmcoreinfo_init)
 
-/**
- *	kernel_kexec - reboot the system
- *
- *	Move into place and start executing a preloaded standalone
- *	executable.  If nothing was preloaded return an error.
+/*
+ * Move into place and start executing a preloaded standalone
+ * executable.  If nothing was preloaded return an error.
  */
 int kernel_kexec(void)
 {
 	int error = 0;
 
-	if (xchg(&kexec_lock, 1))
+	if (!mutex_trylock(&kexec_mutex))
 		return -EBUSY;
 	if (!kexec_image) {
 		error = -EINVAL;
 		goto Unlock;
 	}
 
-	if (kexec_image->preserve_context) {
 #ifdef CONFIG_KEXEC_JUMP
+	if (kexec_image->preserve_context) {
 		mutex_lock(&pm_mutex);
 		pm_prepare_console();
 		error = freeze_processes();
@@ -1459,6 +1445,7 @@ int kernel_kexec(void)
 		error = disable_nonboot_cpus();
 		if (error)
 			goto Resume_devices;
+		device_pm_lock();
 		local_irq_disable();
 		/* At this point, device_suspend() has been called,
 		 * but *not* device_power_down(). We *must*
@@ -1470,26 +1457,22 @@ int kernel_kexec(void)
 		error = device_power_down(PMSG_FREEZE);
 		if (error)
 			goto Enable_irqs;
-		save_processor_state();
+	} else
 #endif
-	} else {
-		blocking_notifier_call_chain(&reboot_notifier_list,
-					     SYS_RESTART, NULL);
-		system_state = SYSTEM_RESTART;
-		device_shutdown();
-		sysdev_shutdown();
+	{
+		kernel_restart_prepare(NULL);
 		printk(KERN_EMERG "Starting new kernel\n");
 		machine_shutdown();
 	}
 
 	machine_kexec(kexec_image);
 
-	if (kexec_image->preserve_context) {
 #ifdef CONFIG_KEXEC_JUMP
-		restore_processor_state();
+	if (kexec_image->preserve_context) {
 		device_power_up(PMSG_RESTORE);
  Enable_irqs:
 		local_irq_enable();
+		device_pm_unlock();
 		enable_nonboot_cpus();
  Resume_devices:
 		device_resume(PMSG_RESTORE);
@@ -1499,11 +1482,10 @@ int kernel_kexec(void)
  Restore_console:
 		pm_restore_console();
 		mutex_unlock(&pm_mutex);
-#endif
 	}
+#endif
 
  Unlock:
-	xchg(&kexec_lock, 0);
-
+	mutex_unlock(&kexec_mutex);
 	return error;
 }
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index d38a6436297..3bfb1877a00 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -124,6 +124,15 @@ static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
 unsigned long nr_lock_classes;
 static struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
 
+static inline struct lock_class *hlock_class(struct held_lock *hlock)
+{
+	if (!hlock->class_idx) {
+		DEBUG_LOCKS_WARN_ON(1);
+		return NULL;
+	}
+	return lock_classes + hlock->class_idx - 1;
+}
+
 #ifdef CONFIG_LOCK_STAT
 static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);
 
@@ -222,7 +231,7 @@ static void lock_release_holdtime(struct held_lock *hlock)
 
 	holdtime = sched_clock() - hlock->holdtime_stamp;
 
-	stats = get_lock_stats(hlock->class);
+	stats = get_lock_stats(hlock_class(hlock));
 	if (hlock->read)
 		lock_time_inc(&stats->read_holdtime, holdtime);
 	else
@@ -372,6 +381,19 @@ unsigned int nr_process_chains;
 unsigned int max_lockdep_depth;
 unsigned int max_recursion_depth;
 
+static unsigned int lockdep_dependency_gen_id;
+
+static bool lockdep_dependency_visit(struct lock_class *source,
+				     unsigned int depth)
+{
+	if (!depth)
+		lockdep_dependency_gen_id++;
+	if (source->dep_gen_id == lockdep_dependency_gen_id)
+		return true;
+	source->dep_gen_id = lockdep_dependency_gen_id;
+	return false;
+}
+
 #ifdef CONFIG_DEBUG_LOCKDEP
 /*
  * We cannot printk in early bootup code. Not even early_printk()
@@ -505,7 +527,7 @@ static void print_lockdep_cache(struct lockdep_map *lock)
 
 static void print_lock(struct held_lock *hlock)
 {
-	print_lock_name(hlock->class);
+	print_lock_name(hlock_class(hlock));
 	printk(", at: ");
 	print_ip_sym(hlock->acquire_ip);
 }
@@ -558,6 +580,9 @@ static void print_lock_dependencies(struct lock_class *class, int depth)
 {
 	struct lock_list *entry;
 
+	if (lockdep_dependency_visit(class, depth))
+		return;
+
 	if (DEBUG_LOCKS_WARN_ON(depth >= 20))
 		return;
 
@@ -932,7 +957,7 @@ static noinline int print_circular_bug_tail(void)
 	if (debug_locks_silent)
 		return 0;
 
-	this.class = check_source->class;
+	this.class = hlock_class(check_source);
 	if (!save_trace(&this.trace))
 		return 0;
 
@@ -959,6 +984,67 @@ static int noinline print_infinite_recursion_bug(void)
 	return 0;
 }
 
+unsigned long __lockdep_count_forward_deps(struct lock_class *class,
+					   unsigned int depth)
+{
+	struct lock_list *entry;
+	unsigned long ret = 1;
+
+	if (lockdep_dependency_visit(class, depth))
+		return 0;
+
+	/*
+	 * Recurse this class's dependency list:
+	 */
+	list_for_each_entry(entry, &class->locks_after, entry)
+		ret += __lockdep_count_forward_deps(entry->class, depth + 1);
+
+	return ret;
+}
+
+unsigned long lockdep_count_forward_deps(struct lock_class *class)
+{
+	unsigned long ret, flags;
+
+	local_irq_save(flags);
+	__raw_spin_lock(&lockdep_lock);
+	ret = __lockdep_count_forward_deps(class, 0);
+	__raw_spin_unlock(&lockdep_lock);
+	local_irq_restore(flags);
+
+	return ret;
+}
+
+unsigned long __lockdep_count_backward_deps(struct lock_class *class,
+					    unsigned int depth)
+{
+	struct lock_list *entry;
+	unsigned long ret = 1;
+
+	if (lockdep_dependency_visit(class, depth))
+		return 0;
+	/*
+	 * Recurse this class's dependency list:
+	 */
+	list_for_each_entry(entry, &class->locks_before, entry)
+		ret += __lockdep_count_backward_deps(entry->class, depth + 1);
+
+	return ret;
+}
+
+unsigned long lockdep_count_backward_deps(struct lock_class *class)
+{
+	unsigned long ret, flags;
+
+	local_irq_save(flags);
+	__raw_spin_lock(&lockdep_lock);
+	ret = __lockdep_count_backward_deps(class, 0);
+	__raw_spin_unlock(&lockdep_lock);
+	local_irq_restore(flags);
+
+	return ret;
+}
+
 /*
  * Prove that the dependency graph starting at <entry> can not
  * lead to <target>. Print an error and return 0 if it does.
@@ -968,6 +1054,9 @@ check_noncircular(struct lock_class *source, unsigned int depth)
 {
 	struct lock_list *entry;
 
+	if (lockdep_dependency_visit(source, depth))
+		return 1;
+
 	debug_atomic_inc(&nr_cyclic_check_recursions);
 	if (depth > max_recursion_depth)
 		max_recursion_depth = depth;
@@ -977,7 +1066,7 @@ check_noncircular(struct lock_class *source, unsigned int depth)
 	 * Check this lock's dependency list:
 	 */
 	list_for_each_entry(entry, &source->locks_after, entry) {
-		if (entry->class == check_target->class)
+		if (entry->class == hlock_class(check_target))
 			return print_circular_bug_header(entry, depth+1);
 		debug_atomic_inc(&nr_cyclic_checks);
 		if (!check_noncircular(entry->class, depth+1))
@@ -1011,6 +1100,9 @@ find_usage_forwards(struct lock_class *source, unsigned int depth)
 	struct lock_list *entry;
 	int ret;
 
+	if (lockdep_dependency_visit(source, depth))
+		return 1;
+
 	if (depth > max_recursion_depth)
 		max_recursion_depth = depth;
 	if (depth >= RECURSION_LIMIT)
@@ -1050,6 +1142,9 @@ find_usage_backwards(struct lock_class *source, unsigned int depth)
 	struct lock_list *entry;
 	int ret;
 
+	if (lockdep_dependency_visit(source, depth))
+		return 1;
+
 	if (!__raw_spin_is_locked(&lockdep_lock))
 		return DEBUG_LOCKS_WARN_ON(1);
 
@@ -1064,6 +1159,11 @@ find_usage_backwards(struct lock_class *source, unsigned int depth)
 		return 2;
 	}
 
+	if (!source && debug_locks_off_graph_unlock()) {
+		WARN_ON(1);
+		return 0;
+	}
+
 	/*
 	 * Check this lock's dependency list:
 	 */
@@ -1103,9 +1203,9 @@ print_bad_irq_dependency(struct task_struct *curr,
 	printk("\nand this task is already holding:\n");
 	print_lock(prev);
 	printk("which would create a new lock dependency:\n");
-	print_lock_name(prev->class);
+	print_lock_name(hlock_class(prev));
 	printk(" ->");
-	print_lock_name(next->class);
+	print_lock_name(hlock_class(next));
 	printk("\n");
 
 	printk("\nbut this new dependency connects a %s-irq-safe lock:\n",
@@ -1146,12 +1246,12 @@ check_usage(struct task_struct *curr, struct held_lock *prev,
 
 	find_usage_bit = bit_backwards;
 	/* fills in <backwards_match> */
-	ret = find_usage_backwards(prev->class, 0);
+	ret = find_usage_backwards(hlock_class(prev), 0);
 	if (!ret || ret == 1)
 		return ret;
 
 	find_usage_bit = bit_forwards;
-	ret = find_usage_forwards(next->class, 0);
+	ret = find_usage_forwards(hlock_class(next), 0);
 	if (!ret || ret == 1)
 		return ret;
 	/* ret == 2 */
@@ -1272,18 +1372,32 @@ check_deadlock(struct task_struct *curr, struct held_lock *next,
 	       struct lockdep_map *next_instance, int read)
 {
 	struct held_lock *prev;
+	struct held_lock *nest = NULL;
 	int i;
 
 	for (i = 0; i < curr->lockdep_depth; i++) {
 		prev = curr->held_locks + i;
-		if (prev->class != next->class)
+
+		if (prev->instance == next->nest_lock)
+			nest = prev;
+
+		if (hlock_class(prev) != hlock_class(next))
 			continue;
+
 		/*
 		 * Allow read-after-read recursion of the same
 		 * lock class (i.e. read_lock(lock)+read_lock(lock)):
 		 */
 		if ((read == 2) && prev->read)
 			return 2;
+
+		/*
+		 * We're holding the nest_lock, which serializes this lock's
+		 * nesting behaviour.
+		 */
+		if (nest)
+			return 2;
+
 		return print_deadlock_bug(curr, prev, next);
 	}
 	return 1;
@@ -1329,7 +1443,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
 	 */
 	check_source = next;
 	check_target = prev;
-	if (!(check_noncircular(next->class, 0)))
+	if (!(check_noncircular(hlock_class(next), 0)))
 		return print_circular_bug_tail();
 
 	if (!check_prev_add_irq(curr, prev, next))
@@ -1353,8 +1467,8 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
 	 *  chains - the second one will be new, but L1 already has
 	 *  L2 added to its dependency list, due to the first chain.)
 	 */
-	list_for_each_entry(entry, &prev->class->locks_after, entry) {
-		if (entry->class == next->class) {
+	list_for_each_entry(entry, &hlock_class(prev)->locks_after, entry) {
+		if (entry->class == hlock_class(next)) {
 			if (distance == 1)
 				entry->distance = 1;
 			return 2;
@@ -1365,26 +1479,28 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
 	 * Ok, all validations passed, add the new lock
 	 * to the previous lock's dependency list:
 	 */
-	ret = add_lock_to_list(prev->class, next->class,
-			       &prev->class->locks_after, next->acquire_ip, distance);
+	ret = add_lock_to_list(hlock_class(prev), hlock_class(next),
+			       &hlock_class(prev)->locks_after,
+			       next->acquire_ip, distance);
 
 	if (!ret)
 		return 0;
 
-	ret = add_lock_to_list(next->class, prev->class,
-			       &next->class->locks_before, next->acquire_ip, distance);
+	ret = add_lock_to_list(hlock_class(next), hlock_class(prev),
+			       &hlock_class(next)->locks_before,
+			       next->acquire_ip, distance);
 	if (!ret)
 		return 0;
 
 	/*
 	 * Debugging printouts:
 	 */
-	if (verbose(prev->class) || verbose(next->class)) {
+	if (verbose(hlock_class(prev)) || verbose(hlock_class(next))) {
 		graph_unlock();
 		printk("\n new dependency: ");
-		print_lock_name(prev->class);
+		print_lock_name(hlock_class(prev));
 		printk(" => ");
-		print_lock_name(next->class);
+		print_lock_name(hlock_class(next));
 		printk("\n");
 		dump_stack();
 		return graph_lock();
@@ -1481,7 +1597,7 @@ static inline int lookup_chain_cache(struct task_struct *curr,
 				     struct held_lock *hlock,
 				     u64 chain_key)
 {
-	struct lock_class *class = hlock->class;
+	struct lock_class *class = hlock_class(hlock);
 	struct list_head *hash_head = chainhashentry(chain_key);
 	struct lock_chain *chain;
 	struct held_lock *hlock_curr, *hlock_next;
@@ -1554,7 +1670,7 @@ cache_hit:
 	if (likely(cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) {
 		chain->base = cn;
 		for (j = 0; j < chain->depth - 1; j++, i++) {
-			int lock_id = curr->held_locks[i].class - lock_classes;
+			int lock_id = curr->held_locks[i].class_idx - 1;
 			chain_hlocks[chain->base + j] = lock_id;
 		}
 		chain_hlocks[chain->base + j] = class - lock_classes;
@@ -1643,14 +1759,13 @@ static void check_chain_key(struct task_struct *curr)
 		hlock = curr->held_locks + i;
 		if (chain_key != hlock->prev_chain_key) {
 			debug_locks_off();
-			printk("hm#1, depth: %u [%u], %016Lx != %016Lx\n",
+			WARN(1, "hm#1, depth: %u [%u], %016Lx != %016Lx\n",
 				curr->lockdep_depth, i,
 				(unsigned long long)chain_key,
 				(unsigned long long)hlock->prev_chain_key);
-			WARN_ON(1);
 			return;
 		}
-		id = hlock->class - lock_classes;
+		id = hlock->class_idx - 1;
 		if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS))
 			return;
 
@@ -1662,11 +1777,10 @@ static void check_chain_key(struct task_struct *curr)
 	}
 	if (chain_key != curr->curr_chain_key) {
 		debug_locks_off();
-		printk("hm#2, depth: %u [%u], %016Lx != %016Lx\n",
+		WARN(1, "hm#2, depth: %u [%u], %016Lx != %016Lx\n",
 			curr->lockdep_depth, i,
 			(unsigned long long)chain_key,
 			(unsigned long long)curr->curr_chain_key);
-		WARN_ON(1);
 	}
 #endif
 }
@@ -1695,7 +1809,7 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this,
 	print_lock(this);
 
 	printk("{%s} state was registered at:\n", usage_str[prev_bit]);
-	print_stack_trace(this->class->usage_traces + prev_bit, 1);
+	print_stack_trace(hlock_class(this)->usage_traces + prev_bit, 1);
 
 	print_irqtrace_events(curr);
 	printk("\nother info that might help us debug this:\n");
@@ -1714,7 +1828,7 @@ static inline int
 valid_state(struct task_struct *curr, struct held_lock *this,
 	    enum lock_usage_bit new_bit, enum lock_usage_bit bad_bit)
 {
-	if (unlikely(this->class->usage_mask & (1 << bad_bit)))
+	if (unlikely(hlock_class(this)->usage_mask & (1 << bad_bit)))
 		return print_usage_bug(curr, this, bad_bit, new_bit);
 	return 1;
 }
@@ -1753,7 +1867,7 @@ print_irq_inversion_bug(struct task_struct *curr, struct lock_class *other,
 	lockdep_print_held_locks(curr);
 
 	printk("\nthe first lock's dependencies:\n");
-	print_lock_dependencies(this->class, 0);
+	print_lock_dependencies(hlock_class(this), 0);
 
 	printk("\nthe second lock's dependencies:\n");
 	print_lock_dependencies(other, 0);
@@ -1776,7 +1890,7 @@ check_usage_forwards(struct task_struct *curr, struct held_lock *this,
 
 	find_usage_bit = bit;
 	/* fills in <forwards_match> */
-	ret = find_usage_forwards(this->class, 0);
+	ret = find_usage_forwards(hlock_class(this), 0);
 	if (!ret || ret == 1)
 		return ret;
 
@@ -1795,7 +1909,7 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this,
 
 	find_usage_bit = bit;
 	/* fills in <backwards_match> */
-	ret = find_usage_backwards(this->class, 0);
+	ret = find_usage_backwards(hlock_class(this), 0);
 	if (!ret || ret == 1)
 		return ret;
 
@@ -1861,7 +1975,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
 				LOCK_ENABLED_HARDIRQS_READ, "hard-read"))
 			return 0;
 #endif
-		if (hardirq_verbose(this->class))
+		if (hardirq_verbose(hlock_class(this)))
 			ret = 2;
 		break;
 	case LOCK_USED_IN_SOFTIRQ:
@@ -1886,7 +2000,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
 				LOCK_ENABLED_SOFTIRQS_READ, "soft-read"))
 			return 0;
 #endif
-		if (softirq_verbose(this->class))
+		if (softirq_verbose(hlock_class(this)))
 			ret = 2;
 		break;
 	case LOCK_USED_IN_HARDIRQ_READ:
@@ -1899,7 +2013,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
 		if (!check_usage_forwards(curr, this,
 					  LOCK_ENABLED_HARDIRQS, "hard"))
 			return 0;
-		if (hardirq_verbose(this->class))
+		if (hardirq_verbose(hlock_class(this)))
 			ret = 2;
 		break;
 	case LOCK_USED_IN_SOFTIRQ_READ:
@@ -1912,7 +2026,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
 		if (!check_usage_forwards(curr, this,
 					  LOCK_ENABLED_SOFTIRQS, "soft"))
 			return 0;
-		if (softirq_verbose(this->class))
+		if (softirq_verbose(hlock_class(this)))
 			ret = 2;
 		break;
 	case LOCK_ENABLED_HARDIRQS:
@@ -1938,7 +2052,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
 				   LOCK_USED_IN_HARDIRQ_READ, "hard-read"))
 			return 0;
 #endif
-		if (hardirq_verbose(this->class))
+		if (hardirq_verbose(hlock_class(this)))
 			ret = 2;
 		break;
 	case LOCK_ENABLED_SOFTIRQS:
@@ -1964,7 +2078,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
 				   LOCK_USED_IN_SOFTIRQ_READ, "soft-read"))
 			return 0;
 #endif
-		if (softirq_verbose(this->class))
+		if (softirq_verbose(hlock_class(this)))
 			ret = 2;
 		break;
 	case LOCK_ENABLED_HARDIRQS_READ:
@@ -1979,7 +2093,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
 					   LOCK_USED_IN_HARDIRQ, "hard"))
 			return 0;
 #endif
-		if (hardirq_verbose(this->class))
+		if (hardirq_verbose(hlock_class(this)))
 			ret = 2;
 		break;
 	case LOCK_ENABLED_SOFTIRQS_READ:
@@ -1994,7 +2108,7 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
 					   LOCK_USED_IN_SOFTIRQ, "soft"))
 			return 0;
 #endif
-		if (softirq_verbose(this->class))
+		if (softirq_verbose(hlock_class(this)))
 			ret = 2;
 		break;
 	default:
@@ -2310,7 +2424,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
 	 * If already set then do not dirty the cacheline,
 	 * nor do any checks:
 	 */
-	if (likely(this->class->usage_mask & new_mask))
+	if (likely(hlock_class(this)->usage_mask & new_mask))
 		return 1;
 
 	if (!graph_lock())
@@ -2318,14 +2432,14 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
 	/*
 	 * Make sure we didnt race:
 	 */
-	if (unlikely(this->class->usage_mask & new_mask)) {
+	if (unlikely(hlock_class(this)->usage_mask & new_mask)) {
 		graph_unlock();
 		return 1;
 	}
 
-	this->class->usage_mask |= new_mask;
+	hlock_class(this)->usage_mask |= new_mask;
 
-	if (!save_trace(this->class->usage_traces + new_bit))
+	if (!save_trace(hlock_class(this)->usage_traces + new_bit))
 		return 0;
 
 	switch (new_bit) {
@@ -2405,7 +2519,7 @@ EXPORT_SYMBOL_GPL(lockdep_init_map);
  */
 static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 			  int trylock, int read, int check, int hardirqs_off,
-			  unsigned long ip)
+			  struct lockdep_map *nest_lock, unsigned long ip)
 {
 	struct task_struct *curr = current;
 	struct lock_class *class = NULL;
@@ -2459,14 +2573,16 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 		return 0;
 
 	hlock = curr->held_locks + depth;
-
-	hlock->class = class;
+	if (DEBUG_LOCKS_WARN_ON(!class))
+		return 0;
+	hlock->class_idx = class - lock_classes + 1;
 	hlock->acquire_ip = ip;
 	hlock->instance = lock;
+	hlock->nest_lock = nest_lock;
 	hlock->trylock = trylock;
 	hlock->read = read;
 	hlock->check = check;
-	hlock->hardirqs_off = hardirqs_off;
+	hlock->hardirqs_off = !!hardirqs_off;
 #ifdef CONFIG_LOCK_STAT
 	hlock->waittime_stamp = 0;
 	hlock->holdtime_stamp = sched_clock();
@@ -2574,6 +2690,55 @@ static int check_unlock(struct task_struct *curr, struct lockdep_map *lock,
 	return 1;
 }
 
+static int
+__lock_set_subclass(struct lockdep_map *lock,
+		    unsigned int subclass, unsigned long ip)
+{
+	struct task_struct *curr = current;
+	struct held_lock *hlock, *prev_hlock;
+	struct lock_class *class;
+	unsigned int depth;
+	int i;
+
+	depth = curr->lockdep_depth;
+	if (DEBUG_LOCKS_WARN_ON(!depth))
+		return 0;
+
+	prev_hlock = NULL;
+	for (i = depth-1; i >= 0; i--) {
+		hlock = curr->held_locks + i;
+		/*
+		 * We must not cross into another context:
+		 */
+		if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
+			break;
+		if (hlock->instance == lock)
+			goto found_it;
+		prev_hlock = hlock;
+	}
+	return print_unlock_inbalance_bug(curr, lock, ip);
+
+found_it:
+	class = register_lock_class(lock, subclass, 0);
+	hlock->class_idx = class - lock_classes + 1;
+
+	curr->lockdep_depth = i;
+	curr->curr_chain_key = hlock->prev_chain_key;
+
+	for (; i < depth; i++) {
+		hlock = curr->held_locks + i;
+		if (!__lock_acquire(hlock->instance,
+			hlock_class(hlock)->subclass, hlock->trylock,
+				hlock->read, hlock->check, hlock->hardirqs_off,
+				hlock->nest_lock, hlock->acquire_ip))
+			return 0;
+	}
+
+	if (DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth))
+		return 0;
+	return 1;
+}
+
 /*
  * Remove the lock to the list of currently held locks in a
  * potentially non-nested (out of order) manner. This is a
@@ -2624,9 +2789,9 @@ found_it:
 	for (i++; i < depth; i++) {
 		hlock = curr->held_locks + i;
 		if (!__lock_acquire(hlock->instance,
-			hlock->class->subclass, hlock->trylock,
+			hlock_class(hlock)->subclass, hlock->trylock,
 				hlock->read, hlock->check, hlock->hardirqs_off,
-				hlock->acquire_ip))
+				hlock->nest_lock, hlock->acquire_ip))
 			return 0;
 	}
 
@@ -2669,7 +2834,7 @@ static int lock_release_nested(struct task_struct *curr,
 
 #ifdef CONFIG_DEBUG_LOCKDEP
 	hlock->prev_chain_key = 0;
-	hlock->class = NULL;
+	hlock->class_idx = 0;
 	hlock->acquire_ip = 0;
 	hlock->irq_context = 0;
 #endif
@@ -2738,18 +2903,36 @@ static void check_flags(unsigned long flags)
 #endif
 }
 
+void
+lock_set_subclass(struct lockdep_map *lock,
+		  unsigned int subclass, unsigned long ip)
+{
+	unsigned long flags;
+
+	if (unlikely(current->lockdep_recursion))
+		return;
+
+	raw_local_irq_save(flags);
+	current->lockdep_recursion = 1;
+	check_flags(flags);
+	if (__lock_set_subclass(lock, subclass, ip))
+		check_chain_key(current);
+	current->lockdep_recursion = 0;
+	raw_local_irq_restore(flags);
+}
+
+EXPORT_SYMBOL_GPL(lock_set_subclass);
+
 /*
  * We are not always called with irqs disabled - do that here,
  * and also avoid lockdep recursion:
  */
 void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
-			  int trylock, int read, int check, unsigned long ip)
+			  int trylock, int read, int check,
+			  struct lockdep_map *nest_lock, unsigned long ip)
 {
 	unsigned long flags;
 
-	if (unlikely(!lock_stat && !prove_locking))
-		return;
-
 	if (unlikely(current->lockdep_recursion))
 		return;
 
@@ -2758,7 +2941,7 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 
 	current->lockdep_recursion = 1;
 	__lock_acquire(lock, subclass, trylock, read, check,
-		       irqs_disabled_flags(flags), ip);
+		       irqs_disabled_flags(flags), nest_lock, ip);
 	current->lockdep_recursion = 0;
 	raw_local_irq_restore(flags);
 }
@@ -2770,9 +2953,6 @@ void lock_release(struct lockdep_map *lock, int nested,
 {
 	unsigned long flags;
 
-	if (unlikely(!lock_stat && !prove_locking))
-		return;
-
 	if (unlikely(current->lockdep_recursion))
 		return;
 
@@ -2845,9 +3025,9 @@ __lock_contended(struct lockdep_map *lock, unsigned long ip)
 found_it:
 	hlock->waittime_stamp = sched_clock();
 
-	point = lock_contention_point(hlock->class, ip);
+	point = lock_contention_point(hlock_class(hlock), ip);
 
-	stats = get_lock_stats(hlock->class);
+	stats = get_lock_stats(hlock_class(hlock));
 	if (point < ARRAY_SIZE(stats->contention_point))
 		stats->contention_point[i]++;
 	if (lock->cpu != smp_processor_id())
@@ -2893,7 +3073,7 @@ found_it:
 		hlock->holdtime_stamp = now;
 	}
 
-	stats = get_lock_stats(hlock->class);
+	stats = get_lock_stats(hlock_class(hlock));
 	if (waittime) {
 		if (hlock->read)
 			lock_time_inc(&stats->read_waittime, waittime);
@@ -2988,6 +3168,7 @@ static void zap_class(struct lock_class *class)
 	list_del_rcu(&class->hash_entry);
 	list_del_rcu(&class->lock_entry);
 
+	class->key = NULL;
 }
 
 static inline int within(const void *addr, void *start, unsigned long size)
diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h
index c3600a091a2..56b196932c0 100644
--- a/kernel/lockdep_internals.h
+++ b/kernel/lockdep_internals.h
@@ -17,9 +17,6 @@
  */
 #define MAX_LOCKDEP_ENTRIES	8192UL
 
-#define MAX_LOCKDEP_KEYS_BITS	11
-#define MAX_LOCKDEP_KEYS	(1UL << MAX_LOCKDEP_KEYS_BITS)
-
 #define MAX_LOCKDEP_CHAINS_BITS	14
 #define MAX_LOCKDEP_CHAINS	(1UL << MAX_LOCKDEP_CHAINS_BITS)
 
@@ -53,6 +50,22 @@ extern unsigned int nr_process_chains;
 extern unsigned int max_lockdep_depth;
 extern unsigned int max_recursion_depth;
 
+#ifdef CONFIG_PROVE_LOCKING
+extern unsigned long lockdep_count_forward_deps(struct lock_class *);
+extern unsigned long lockdep_count_backward_deps(struct lock_class *);
+#else
+static inline unsigned long
+lockdep_count_forward_deps(struct lock_class *class)
+{
+	return 0;
+}
+static inline unsigned long
+lockdep_count_backward_deps(struct lock_class *class)
+{
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_DEBUG_LOCKDEP
 /*
  * Various lockdep statistics:
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index 9b0e940e254..4b194d34d77 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -63,34 +63,6 @@ static void l_stop(struct seq_file *m, void *v)
 {
 }
 
-static unsigned long count_forward_deps(struct lock_class *class)
-{
-	struct lock_list *entry;
-	unsigned long ret = 1;
-
-	/*
-	 * Recurse this class's dependency list:
-	 */
-	list_for_each_entry(entry, &class->locks_after, entry)
-		ret += count_forward_deps(entry->class);
-
-	return ret;
-}
-
-static unsigned long count_backward_deps(struct lock_class *class)
-{
-	struct lock_list *entry;
-	unsigned long ret = 1;
-
-	/*
-	 * Recurse this class's dependency list:
-	 */
-	list_for_each_entry(entry, &class->locks_before, entry)
-		ret += count_backward_deps(entry->class);
-
-	return ret;
-}
-
 static void print_name(struct seq_file *m, struct lock_class *class)
 {
 	char str[128];
@@ -110,7 +82,6 @@ static void print_name(struct seq_file *m, struct lock_class *class)
 
 static int l_show(struct seq_file *m, void *v)
 {
-	unsigned long nr_forward_deps, nr_backward_deps;
 	struct lock_class *class = v;
 	struct lock_list *entry;
 	char c1, c2, c3, c4;
@@ -124,11 +95,10 @@ static int l_show(struct seq_file *m, void *v)
 #ifdef CONFIG_DEBUG_LOCKDEP
 	seq_printf(m, " OPS:%8ld", class->ops);
 #endif
-	nr_forward_deps = count_forward_deps(class);
-	seq_printf(m, " FD:%5ld", nr_forward_deps);
-
-	nr_backward_deps = count_backward_deps(class);
-	seq_printf(m, " BD:%5ld", nr_backward_deps);
+#ifdef CONFIG_PROVE_LOCKING
+	seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class));
+	seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class));
+#endif
 
 	get_usage_chars(class, &c1, &c2, &c3, &c4);
 	seq_printf(m, " %c%c%c%c", c1, c2, c3, c4);
@@ -229,6 +199,9 @@ static int lc_show(struct seq_file *m, void *v)
 
 	for (i = 0; i < chain->depth; i++) {
 		class = lock_chain_get_class(chain, i);
+		if (!class->key)
+			continue;
+
 		seq_printf(m, "[%p] ", class->key);
 		print_name(m, class);
 		seq_puts(m, "\n");
@@ -350,7 +323,9 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
 		if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
 			nr_hardirq_read_unsafe++;
 
-		sum_forward_deps += count_forward_deps(class);
+#ifdef CONFIG_PROVE_LOCKING
+		sum_forward_deps += lockdep_count_forward_deps(class);
+#endif
 	}
 #ifdef CONFIG_DEBUG_LOCKDEP
 	DEBUG_LOCKS_WARN_ON(debug_atomic_read(&nr_unused_locks) != nr_unused);
diff --git a/kernel/module.c b/kernel/module.c
index 61d212120df..08864d257eb 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2288,7 +2288,7 @@ sys_init_module(void __user *umod,
 
 	/* Start the module */
 	if (mod->init != NULL)
-		ret = mod->init();
+		ret = do_one_initcall(mod->init);
 	if (ret < 0) {
 		/* Init routine failed: abort.  Try to protect us from
                    buggy refcounters. */
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 9a21681aa80..e36d5798cbf 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -289,21 +289,29 @@ void do_schedule_next_timer(struct siginfo *info)
 		else
 			schedule_next_timer(timr);
 
-		info->si_overrun = timr->it_overrun_last;
+		info->si_overrun += timr->it_overrun_last;
 	}
 
 	if (timr)
 		unlock_timer(timr, flags);
 }
 
-int posix_timer_event(struct k_itimer *timr,int si_private)
+int posix_timer_event(struct k_itimer *timr, int si_private)
 {
-	memset(&timr->sigq->info, 0, sizeof(siginfo_t));
+	/*
+	 * FIXME: if ->sigq is queued we can race with
+	 * dequeue_signal()->do_schedule_next_timer().
+	 *
+	 * If dequeue_signal() sees the "right" value of
+	 * si_sys_private it calls do_schedule_next_timer().
+	 * We re-queue ->sigq and drop ->it_lock().
+	 * do_schedule_next_timer() locks the timer
+	 * and re-schedules it while ->sigq is pending.
+	 * Not really bad, but not that we want.
+	 */
 	timr->sigq->info.si_sys_private = si_private;
-	/* Send signal to the process that owns this timer.*/
 
 	timr->sigq->info.si_signo = timr->it_sigev_signo;
-	timr->sigq->info.si_errno = 0;
 	timr->sigq->info.si_code = SI_TIMER;
 	timr->sigq->info.si_tid = timr->it_id;
 	timr->sigq->info.si_value = timr->it_sigev_value;
@@ -435,6 +443,7 @@ static struct k_itimer * alloc_posix_timer(void)
 		kmem_cache_free(posix_timers_cache, tmr);
 		tmr = NULL;
 	}
+	memset(&tmr->sigq->info, 0, sizeof(siginfo_t));
 	return tmr;
 }
 
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 082b3fcb32a..356699a96d5 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -140,7 +140,7 @@ int __ptrace_may_access(struct task_struct *task, unsigned int mode)
 	if (!dumpable && !capable(CAP_SYS_PTRACE))
 		return -EPERM;
 
-	return security_ptrace(current, task, mode);
+	return security_ptrace_may_access(task, mode);
 }
 
 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
@@ -499,8 +499,7 @@ repeat:
 			goto repeat;
 		}
 
-		ret = security_ptrace(current->parent, current,
-				      PTRACE_MODE_ATTACH);
+		ret = security_ptrace_traceme(current->parent);
 
 		/*
 		 * Set the ptrace bit in the process ptrace flags.
diff --git a/kernel/sched.c b/kernel/sched.c
index 04160d277e7..9a1ddb84e26 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -600,7 +600,6 @@ struct rq {
 	/* BKL stats */
 	unsigned int bkl_count;
 #endif
-	struct lock_class_key rq_lock_key;
 };
 
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
@@ -809,9 +808,9 @@ const_debug unsigned int sysctl_sched_nr_migrate = 32;
 
 /*
  * ratelimit for updating the group shares.
- * default: 0.5ms
+ * default: 0.25ms
  */
-const_debug unsigned int sysctl_sched_shares_ratelimit = 500000;
+unsigned int sysctl_sched_shares_ratelimit = 250000;
 
 /*
  * period over which we measure -rt task cpu usage in us.
@@ -834,7 +833,7 @@ static inline u64 global_rt_period(void)
 
 static inline u64 global_rt_runtime(void)
 {
-	if (sysctl_sched_rt_period < 0)
+	if (sysctl_sched_rt_runtime < 0)
 		return RUNTIME_INF;
 
 	return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
@@ -2759,10 +2758,10 @@ static void double_rq_lock(struct rq *rq1, struct rq *rq2)
 	} else {
 		if (rq1 < rq2) {
 			spin_lock(&rq1->lock);
-			spin_lock(&rq2->lock);
+			spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
 		} else {
 			spin_lock(&rq2->lock);
-			spin_lock(&rq1->lock);
+			spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
 		}
 	}
 	update_rq_clock(rq1);
@@ -2805,14 +2804,21 @@ static int double_lock_balance(struct rq *this_rq, struct rq *busiest)
 		if (busiest < this_rq) {
 			spin_unlock(&this_rq->lock);
 			spin_lock(&busiest->lock);
-			spin_lock(&this_rq->lock);
+			spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING);
 			ret = 1;
 		} else
-			spin_lock(&busiest->lock);
+			spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING);
 	}
 	return ret;
 }
 
+static void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
+	__releases(busiest->lock)
+{
+	spin_unlock(&busiest->lock);
+	lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
+}
+
 /*
  * If dest_cpu is allowed for this process, migrate the task to it.
  * This is accomplished by forcing the cpu_allowed mask to only
@@ -3637,7 +3643,7 @@ redo:
 		ld_moved = move_tasks(this_rq, this_cpu, busiest,
 					imbalance, sd, CPU_NEWLY_IDLE,
 					&all_pinned);
-		spin_unlock(&busiest->lock);
+		double_unlock_balance(this_rq, busiest);
 
 		if (unlikely(all_pinned)) {
 			cpu_clear(cpu_of(busiest), *cpus);
@@ -3752,7 +3758,7 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu)
 		else
 			schedstat_inc(sd, alb_failed);
 	}
-	spin_unlock(&target_rq->lock);
+	double_unlock_balance(busiest_rq, target_rq);
 }
 
 #ifdef CONFIG_NO_HZ
@@ -4663,6 +4669,52 @@ int __sched wait_for_completion_killable(struct completion *x)
 }
 EXPORT_SYMBOL(wait_for_completion_killable);
 
+/**
+ *	try_wait_for_completion - try to decrement a completion without blocking
+ *	@x:	completion structure
+ *
+ *	Returns: 0 if a decrement cannot be done without blocking
+ *		 1 if a decrement succeeded.
+ *
+ *	If a completion is being used as a counting completion,
+ *	attempt to decrement the counter without blocking. This
+ *	enables us to avoid waiting if the resource the completion
+ *	is protecting is not available.
+ */
+bool try_wait_for_completion(struct completion *x)
+{
+	int ret = 1;
+
+	spin_lock_irq(&x->wait.lock);
+	if (!x->done)
+		ret = 0;
+	else
+		x->done--;
+	spin_unlock_irq(&x->wait.lock);
+	return ret;
+}
+EXPORT_SYMBOL(try_wait_for_completion);
+
+/**
+ *	completion_done - Test to see if a completion has any waiters
+ *	@x:	completion structure
+ *
+ *	Returns: 0 if there are waiters (wait_for_completion() in progress)
+ *		 1 if there are no waiters.
+ *
+ */
+bool completion_done(struct completion *x)
+{
+	int ret = 1;
+
+	spin_lock_irq(&x->wait.lock);
+	if (!x->done)
+		ret = 0;
+	spin_unlock_irq(&x->wait.lock);
+	return ret;
+}
+EXPORT_SYMBOL(completion_done);
+
 static long __sched
 sleep_on_common(wait_queue_head_t *q, int state, long timeout)
 {
@@ -5734,6 +5786,8 @@ static inline void sched_init_granularity(void)
 		sysctl_sched_latency = limit;
 
 	sysctl_sched_wakeup_granularity *= factor;
+
+	sysctl_sched_shares_ratelimit *= factor;
 }
 
 #ifdef CONFIG_SMP
@@ -8000,7 +8054,6 @@ void __init sched_init(void)
 
 		rq = cpu_rq(i);
 		spin_lock_init(&rq->lock);
-		lockdep_set_class(&rq->lock, &rq->rq_lock_key);
 		rq->nr_running = 0;
 		init_cfs_rq(&rq->cfs, rq);
 		init_rt_rq(&rq->rt, rq);
@@ -8457,8 +8510,8 @@ struct task_group *sched_create_group(struct task_group *parent)
 	WARN_ON(!parent); /* root should already exist */
 
 	tg->parent = parent;
-	list_add_rcu(&tg->siblings, &parent->children);
 	INIT_LIST_HEAD(&tg->children);
+	list_add_rcu(&tg->siblings, &parent->children);
 	spin_unlock_irqrestore(&task_group_lock, flags);
 
 	return tg;
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index 22ed55d1167..204991a0bfa 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -32,13 +32,19 @@
 #include <linux/ktime.h>
 #include <linux/module.h>
 
+/*
+ * Scheduler clock - returns current time in nanosec units.
+ * This is default implementation.
+ * Architectures and sub-architectures can override this.
+ */
+unsigned long long __attribute__((weak)) sched_clock(void)
+{
+	return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
+}
 
-#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
+static __read_mostly int sched_clock_running;
 
-#define MULTI_SHIFT 15
-/* Max is double, Min is 1/2 */
-#define MAX_MULTI (2LL << MULTI_SHIFT)
-#define MIN_MULTI (1LL << (MULTI_SHIFT-1))
+#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
 
 struct sched_clock_data {
 	/*
@@ -49,14 +55,9 @@ struct sched_clock_data {
 	raw_spinlock_t		lock;
 
 	unsigned long		tick_jiffies;
-	u64			prev_raw;
 	u64			tick_raw;
 	u64			tick_gtod;
 	u64			clock;
-	s64			multi;
-#ifdef CONFIG_NO_HZ
-	int			check_max;
-#endif
 };
 
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct sched_clock_data, sched_clock_data);
@@ -71,8 +72,6 @@ static inline struct sched_clock_data *cpu_sdc(int cpu)
 	return &per_cpu(sched_clock_data, cpu);
 }
 
-static __read_mostly int sched_clock_running;
-
 void sched_clock_init(void)
 {
 	u64 ktime_now = ktime_to_ns(ktime_get());
@@ -84,90 +83,39 @@ void sched_clock_init(void)
 
 		scd->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
 		scd->tick_jiffies = now_jiffies;
-		scd->prev_raw = 0;
 		scd->tick_raw = 0;
 		scd->tick_gtod = ktime_now;
 		scd->clock = ktime_now;
-		scd->multi = 1 << MULTI_SHIFT;
-#ifdef CONFIG_NO_HZ
-		scd->check_max = 1;
-#endif
 	}
 
 	sched_clock_running = 1;
 }
 
-#ifdef CONFIG_NO_HZ
-/*
- * The dynamic ticks makes the delta jiffies inaccurate. This
- * prevents us from checking the maximum time update.
- * Disable the maximum check during stopped ticks.
- */
-void sched_clock_tick_stop(int cpu)
-{
-	struct sched_clock_data *scd = cpu_sdc(cpu);
-
-	scd->check_max = 0;
-}
-
-void sched_clock_tick_start(int cpu)
-{
-	struct sched_clock_data *scd = cpu_sdc(cpu);
-
-	scd->check_max = 1;
-}
-
-static int check_max(struct sched_clock_data *scd)
-{
-	return scd->check_max;
-}
-#else
-static int check_max(struct sched_clock_data *scd)
-{
-	return 1;
-}
-#endif /* CONFIG_NO_HZ */
-
 /*
  * update the percpu scd from the raw @now value
  *
  *  - filter out backward motion
  *  - use jiffies to generate a min,max window to clip the raw values
  */
-static void __update_sched_clock(struct sched_clock_data *scd, u64 now, u64 *time)
+static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now)
 {
 	unsigned long now_jiffies = jiffies;
 	long delta_jiffies = now_jiffies - scd->tick_jiffies;
 	u64 clock = scd->clock;
 	u64 min_clock, max_clock;
-	s64 delta = now - scd->prev_raw;
+	s64 delta = now - scd->tick_raw;
 
 	WARN_ON_ONCE(!irqs_disabled());
-
-	/*
-	 * At schedule tick the clock can be just under the gtod. We don't
-	 * want to push it too prematurely.
-	 */
-	min_clock = scd->tick_gtod + (delta_jiffies * TICK_NSEC);
-	if (min_clock > TICK_NSEC)
-		min_clock -= TICK_NSEC / 2;
+	min_clock = scd->tick_gtod + delta_jiffies * TICK_NSEC;
 
 	if (unlikely(delta < 0)) {
 		clock++;
 		goto out;
 	}
 
-	/*
-	 * The clock must stay within a jiffie of the gtod.
-	 * But since we may be at the start of a jiffy or the end of one
-	 * we add another jiffy buffer.
-	 */
-	max_clock = scd->tick_gtod + (2 + delta_jiffies) * TICK_NSEC;
-
-	delta *= scd->multi;
-	delta >>= MULTI_SHIFT;
+	max_clock = min_clock + TICK_NSEC;
 
-	if (unlikely(clock + delta > max_clock) && check_max(scd)) {
+	if (unlikely(clock + delta > max_clock)) {
 		if (clock < max_clock)
 			clock = max_clock;
 		else
@@ -180,12 +128,10 @@ static void __update_sched_clock(struct sched_clock_data *scd, u64 now, u64 *tim
 	if (unlikely(clock < min_clock))
 		clock = min_clock;
 
-	if (time)
-		*time = clock;
-	else {
-		scd->prev_raw = now;
-		scd->clock = clock;
-	}
+	scd->tick_jiffies = now_jiffies;
+	scd->clock = clock;
+
+	return clock;
 }
 
 static void lock_double_clock(struct sched_clock_data *data1,
@@ -203,7 +149,7 @@ static void lock_double_clock(struct sched_clock_data *data1,
 u64 sched_clock_cpu(int cpu)
 {
 	struct sched_clock_data *scd = cpu_sdc(cpu);
-	u64 now, clock;
+	u64 now, clock, this_clock, remote_clock;
 
 	if (unlikely(!sched_clock_running))
 		return 0ull;
@@ -212,43 +158,44 @@ u64 sched_clock_cpu(int cpu)
 	now = sched_clock();
 
 	if (cpu != raw_smp_processor_id()) {
-		/*
-		 * in order to update a remote cpu's clock based on our
-		 * unstable raw time rebase it against:
-		 *   tick_raw		(offset between raw counters)
-		 *   tick_gotd          (tick offset between cpus)
-		 */
 		struct sched_clock_data *my_scd = this_scd();
 
 		lock_double_clock(scd, my_scd);
 
-		now -= my_scd->tick_raw;
-		now += scd->tick_raw;
+		this_clock = __update_sched_clock(my_scd, now);
+		remote_clock = scd->clock;
 
-		now += my_scd->tick_gtod;
-		now -= scd->tick_gtod;
+		/*
+		 * Use the opportunity that we have both locks
+		 * taken to couple the two clocks: we take the
+		 * larger time as the latest time for both
+		 * runqueues. (this creates monotonic movement)
+		 */
+		if (likely(remote_clock < this_clock)) {
+			clock = this_clock;
+			scd->clock = clock;
+		} else {
+			/*
+			 * Should be rare, but possible:
+			 */
+			clock = remote_clock;
+			my_scd->clock = remote_clock;
+		}
 
 		__raw_spin_unlock(&my_scd->lock);
-
-		__update_sched_clock(scd, now, &clock);
-
-		__raw_spin_unlock(&scd->lock);
-
 	} else {
 		__raw_spin_lock(&scd->lock);
-		__update_sched_clock(scd, now, NULL);
-		clock = scd->clock;
-		__raw_spin_unlock(&scd->lock);
+		clock = __update_sched_clock(scd, now);
 	}
 
+	__raw_spin_unlock(&scd->lock);
+
 	return clock;
 }
 
 void sched_clock_tick(void)
 {
 	struct sched_clock_data *scd = this_scd();
-	unsigned long now_jiffies = jiffies;
-	s64 mult, delta_gtod, delta_raw;
 	u64 now, now_gtod;
 
 	if (unlikely(!sched_clock_running))
@@ -260,29 +207,14 @@ void sched_clock_tick(void)
 	now = sched_clock();
 
 	__raw_spin_lock(&scd->lock);
-	__update_sched_clock(scd, now, NULL);
+	__update_sched_clock(scd, now);
 	/*
 	 * update tick_gtod after __update_sched_clock() because that will
 	 * already observe 1 new jiffy; adding a new tick_gtod to that would
 	 * increase the clock 2 jiffies.
 	 */
-	delta_gtod = now_gtod - scd->tick_gtod;
-	delta_raw = now - scd->tick_raw;
-
-	if ((long)delta_raw > 0) {
-		mult = delta_gtod << MULTI_SHIFT;
-		do_div(mult, delta_raw);
-		scd->multi = mult;
-		if (scd->multi > MAX_MULTI)
-			scd->multi = MAX_MULTI;
-		else if (scd->multi < MIN_MULTI)
-			scd->multi = MIN_MULTI;
-	} else
-		scd->multi = 1 << MULTI_SHIFT;
-
 	scd->tick_raw = now;
 	scd->tick_gtod = now_gtod;
-	scd->tick_jiffies = now_jiffies;
 	__raw_spin_unlock(&scd->lock);
 }
 
@@ -301,7 +233,6 @@ EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event);
 void sched_clock_idle_wakeup_event(u64 delta_ns)
 {
 	struct sched_clock_data *scd = this_scd();
-	u64 now = sched_clock();
 
 	/*
 	 * Override the previous timestamp and ignore all
@@ -310,27 +241,30 @@ void sched_clock_idle_wakeup_event(u64 delta_ns)
 	 * rq clock:
 	 */
 	__raw_spin_lock(&scd->lock);
-	scd->prev_raw = now;
 	scd->clock += delta_ns;
-	scd->multi = 1 << MULTI_SHIFT;
 	__raw_spin_unlock(&scd->lock);
 
 	touch_softlockup_watchdog();
 }
 EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
 
-#endif
+#else /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
 
-/*
- * Scheduler clock - returns current time in nanosec units.
- * This is default implementation.
- * Architectures and sub-architectures can override this.
- */
-unsigned long long __attribute__((weak)) sched_clock(void)
+void sched_clock_init(void)
 {
-	return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
+	sched_clock_running = 1;
 }
 
+u64 sched_clock_cpu(int cpu)
+{
+	if (unlikely(!sched_clock_running))
+		return 0;
+
+	return sched_clock();
+}
+
+#endif
+
 unsigned long long cpu_clock(int cpu)
 {
 	unsigned long long clock;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index cf2cd6ce4cb..fb8994c6d4b 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -899,7 +899,7 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p)
 		 * doesn't make sense. Rely on vruntime for fairness.
 		 */
 		if (rq->curr != p)
-			delta = max(10000LL, delta);
+			delta = max_t(s64, 10000LL, delta);
 
 		hrtick_start(rq, delta);
 	}
@@ -1442,18 +1442,23 @@ __load_balance_iterator(struct cfs_rq *cfs_rq, struct list_head *next)
 	struct task_struct *p = NULL;
 	struct sched_entity *se;
 
-	while (next != &cfs_rq->tasks) {
+	if (next == &cfs_rq->tasks)
+		return NULL;
+
+	/* Skip over entities that are not tasks */
+	do {
 		se = list_entry(next, struct sched_entity, group_node);
 		next = next->next;
+	} while (next != &cfs_rq->tasks && !entity_is_task(se));
 
-		/* Skip over entities that are not tasks */
-		if (entity_is_task(se)) {
-			p = task_of(se);
-			break;
-		}
-	}
+	if (next == &cfs_rq->tasks)
+		return NULL;
 
 	cfs_rq->balance_iterator = next;
+
+	if (entity_is_task(se))
+		p = task_of(se);
+
 	return p;
 }
 
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 908c04f9dad..998ba54b454 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -298,7 +298,7 @@ static void __disable_runtime(struct rq *rq)
 			struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
 			s64 diff;
 
-			if (iter == rt_rq)
+			if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF)
 				continue;
 
 			spin_lock(&iter->rt_runtime_lock);
@@ -861,6 +861,8 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
 #define RT_MAX_TRIES 3
 
 static int double_lock_balance(struct rq *this_rq, struct rq *busiest);
+static void double_unlock_balance(struct rq *this_rq, struct rq *busiest);
+
 static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep);
 
 static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
@@ -1022,7 +1024,7 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
 			break;
 
 		/* try again */
-		spin_unlock(&lowest_rq->lock);
+		double_unlock_balance(rq, lowest_rq);
 		lowest_rq = NULL;
 	}
 
@@ -1091,7 +1093,7 @@ static int push_rt_task(struct rq *rq)
 
 	resched_task(lowest_rq->curr);
 
-	spin_unlock(&lowest_rq->lock);
+	double_unlock_balance(rq, lowest_rq);
 
 	ret = 1;
 out:
@@ -1197,7 +1199,7 @@ static int pull_rt_task(struct rq *this_rq)
 
 		}
  skip:
-		spin_unlock(&src_rq->lock);
+		double_unlock_balance(this_rq, src_rq);
 	}
 
 	return ret;
diff --git a/kernel/signal.c b/kernel/signal.c
index 954f77d7e3b..c539f60c6f4 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1304,6 +1304,7 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
 		q->info.si_overrun++;
 		goto out;
 	}
+	q->info.si_overrun = 0;
 
 	signalfd_notify(t, sig);
 	pending = group ? &t->signal->shared_pending : &t->pending;
diff --git a/kernel/smp.c b/kernel/smp.c
index 96fc7c0edc5..782e2b93e46 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -135,7 +135,8 @@ void generic_smp_call_function_interrupt(void)
 			 */
 			smp_wmb();
 			data->csd.flags &= ~CSD_FLAG_WAIT;
-		} else
+		}
+		if (data->csd.flags & CSD_FLAG_ALLOC)
 			call_rcu(&data->rcu_head, rcu_free_call_data);
 	}
 	rcu_read_unlock();
@@ -260,6 +261,42 @@ void __smp_call_function_single(int cpu, struct call_single_data *data)
 	generic_exec_single(cpu, data);
 }
 
+/* Dummy function */
+static void quiesce_dummy(void *unused)
+{
+}
+
+/*
+ * Ensure stack based data used in call function mask is safe to free.
+ *
+ * This is needed by smp_call_function_mask when using on-stack data, because
+ * a single call function queue is shared by all CPUs, and any CPU may pick up
+ * the data item on the queue at any time before it is deleted. So we need to
+ * ensure that all CPUs have transitioned through a quiescent state after
+ * this call.
+ *
+ * This is a very slow function, implemented by sending synchronous IPIs to
+ * all possible CPUs. For this reason, we have to alloc data rather than use
+ * stack based data even in the case of synchronous calls. The stack based
+ * data is then just used for deadlock/oom fallback which will be very rare.
+ *
+ * If a faster scheme can be made, we could go back to preferring stack based
+ * data -- the data allocation/free is non-zero cost.
+ */
+static void smp_call_function_mask_quiesce_stack(cpumask_t mask)
+{
+	struct call_single_data data;
+	int cpu;
+
+	data.func = quiesce_dummy;
+	data.info = NULL;
+
+	for_each_cpu_mask(cpu, mask) {
+		data.flags = CSD_FLAG_WAIT;
+		generic_exec_single(cpu, &data);
+	}
+}
+
 /**
  * smp_call_function_mask(): Run a function on a set of other CPUs.
  * @mask: The set of cpus to run on.
@@ -285,6 +322,7 @@ int smp_call_function_mask(cpumask_t mask, void (*func)(void *), void *info,
 	cpumask_t allbutself;
 	unsigned long flags;
 	int cpu, num_cpus;
+	int slowpath = 0;
 
 	/* Can deadlock when called with interrupts disabled */
 	WARN_ON(irqs_disabled());
@@ -306,15 +344,16 @@ int smp_call_function_mask(cpumask_t mask, void (*func)(void *), void *info,
 		return smp_call_function_single(cpu, func, info, wait);
 	}
 
-	if (!wait) {
-		data = kmalloc(sizeof(*data), GFP_ATOMIC);
-		if (data)
-			data->csd.flags = CSD_FLAG_ALLOC;
-	}
-	if (!data) {
+	data = kmalloc(sizeof(*data), GFP_ATOMIC);
+	if (data) {
+		data->csd.flags = CSD_FLAG_ALLOC;
+		if (wait)
+			data->csd.flags |= CSD_FLAG_WAIT;
+	} else {
 		data = &d;
 		data->csd.flags = CSD_FLAG_WAIT;
 		wait = 1;
+		slowpath = 1;
 	}
 
 	spin_lock_init(&data->lock);
@@ -331,8 +370,11 @@ int smp_call_function_mask(cpumask_t mask, void (*func)(void *), void *info,
 	arch_send_call_function_ipi(mask);
 
 	/* optionally wait for the CPUs to complete */
-	if (wait)
+	if (wait) {
 		csd_flag_wait(&data->csd);
+		if (unlikely(slowpath))
+			smp_call_function_mask_quiesce_stack(mask);
+	}
 
 	return 0;
 }
diff --git a/kernel/spinlock.c b/kernel/spinlock.c
index a1fb54c93cd..29ab20749dd 100644
--- a/kernel/spinlock.c
+++ b/kernel/spinlock.c
@@ -290,8 +290,8 @@ void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
 	spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
 	LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
 }
-
 EXPORT_SYMBOL(_spin_lock_nested);
+
 unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass)
 {
 	unsigned long flags;
@@ -311,9 +311,17 @@ unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclas
 #endif
 	return flags;
 }
-
 EXPORT_SYMBOL(_spin_lock_irqsave_nested);
 
+void __lockfunc _spin_lock_nest_lock(spinlock_t *lock,
+				     struct lockdep_map *nest_lock)
+{
+	preempt_disable();
+	spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
+	LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+}
+EXPORT_SYMBOL(_spin_lock_nest_lock);
+
 #endif
 
 void __lockfunc _spin_unlock(spinlock_t *lock)
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index e446c7c7d6a..af3c7cea258 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -65,7 +65,6 @@ static void ack_state(void)
 static int stop_cpu(struct stop_machine_data *smdata)
 {
 	enum stopmachine_state curstate = STOPMACHINE_NONE;
-	int uninitialized_var(ret);
 
 	/* Simple state machine */
 	do {
diff --git a/kernel/sys.c b/kernel/sys.c
index c01858090a9..3dacb00a7f7 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -274,7 +274,7 @@ void emergency_restart(void)
 }
 EXPORT_SYMBOL_GPL(emergency_restart);
 
-static void kernel_restart_prepare(char *cmd)
+void kernel_restart_prepare(char *cmd)
 {
 	blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
 	system_state = SYSTEM_RESTART;
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 825b4c00fe4..f5da526424a 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -289,7 +289,6 @@ void tick_nohz_stop_sched_tick(int inidle)
 			ts->tick_stopped = 1;
 			ts->idle_jiffies = last_jiffies;
 			rcu_enter_nohz();
-			sched_clock_tick_stop(cpu);
 		}
 
 		/*
@@ -392,7 +391,6 @@ void tick_nohz_restart_sched_tick(void)
 	select_nohz_load_balancer(0);
 	now = ktime_get();
 	tick_do_update_jiffies64(now);
-	sched_clock_tick_start(cpu);
 	cpu_clear(cpu, nohz_cpu_mask);
 
 	/*
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 4a26a1382df..4048e92aa04 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -290,11 +290,11 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq)
 
 		BUG_ON(get_wq_data(work) != cwq);
 		work_clear_pending(work);
-		lock_acquire(&cwq->wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
-		lock_acquire(&lockdep_map, 0, 0, 0, 2, _THIS_IP_);
+		lock_map_acquire(&cwq->wq->lockdep_map);
+		lock_map_acquire(&lockdep_map);
 		f(work);
-		lock_release(&lockdep_map, 1, _THIS_IP_);
-		lock_release(&cwq->wq->lockdep_map, 1, _THIS_IP_);
+		lock_map_release(&lockdep_map);
+		lock_map_release(&cwq->wq->lockdep_map);
 
 		if (unlikely(in_atomic() || lockdep_depth(current) > 0)) {
 			printk(KERN_ERR "BUG: workqueue leaked lock or atomic: "
@@ -413,8 +413,8 @@ void flush_workqueue(struct workqueue_struct *wq)
 	int cpu;
 
 	might_sleep();
-	lock_acquire(&wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
-	lock_release(&wq->lockdep_map, 1, _THIS_IP_);
+	lock_map_acquire(&wq->lockdep_map);
+	lock_map_release(&wq->lockdep_map);
 	for_each_cpu_mask_nr(cpu, *cpu_map)
 		flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu));
 }
@@ -441,8 +441,8 @@ int flush_work(struct work_struct *work)
 	if (!cwq)
 		return 0;
 
-	lock_acquire(&cwq->wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
-	lock_release(&cwq->wq->lockdep_map, 1, _THIS_IP_);
+	lock_map_acquire(&cwq->wq->lockdep_map);
+	lock_map_release(&cwq->wq->lockdep_map);
 
 	prev = NULL;
 	spin_lock_irq(&cwq->lock);
@@ -536,8 +536,8 @@ static void wait_on_work(struct work_struct *work)
 
 	might_sleep();
 
-	lock_acquire(&work->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
-	lock_release(&work->lockdep_map, 1, _THIS_IP_);
+	lock_map_acquire(&work->lockdep_map);
+	lock_map_release(&work->lockdep_map);
 
 	cwq = get_wq_data(work);
 	if (!cwq)
@@ -872,8 +872,8 @@ static void cleanup_workqueue_thread(struct cpu_workqueue_struct *cwq)
 	if (cwq->thread == NULL)
 		return;
 
-	lock_acquire(&cwq->wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_);
-	lock_release(&cwq->wq->lockdep_map, 1, _THIS_IP_);
+	lock_map_acquire(&cwq->wq->lockdep_map);
+	lock_map_release(&cwq->wq->lockdep_map);
 
 	flush_cpu_workqueue(cwq);
 	/*