Merge commit 'linus/master' into x86/urgent

6 files changed, 147 insertions, 26 deletions

diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 22b0a6eedf24..e49ea1c5232d 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -220,7 +220,7 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc,
 		/*
 		 * If we are seeing only the odd spurious IRQ caused by
 		 * bus asynchronicity then don't eventually trigger an error,
-		 * otherwise the couter becomes a doomsday timer for otherwise
+		 * otherwise the counter becomes a doomsday timer for otherwise
 		 * working systems
 		 */
 		if (time_after(jiffies, desc->last_unhandled + HZ/10))
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 6b7ddba1dd64..40a996ec39fa 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -476,7 +476,7 @@ static void perf_event_remove_from_context(struct perf_event *event)
 	if (!task) {
 		/*
 		 * Per cpu events are removed via an smp call and
-		 * the removal is always sucessful.
+		 * the removal is always successful.
 		 */
 		smp_call_function_single(event->cpu,
 					 __perf_event_remove_from_context,
@@ -845,7 +845,7 @@ perf_install_in_context(struct perf_event_context *ctx,
 	if (!task) {
 		/*
 		 * Per cpu events are installed via an smp call and
-		 * the install is always sucessful.
+		 * the install is always successful.
 		 */
 		smp_call_function_single(cpu, __perf_install_in_context,
 					 event, 1);
diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index dfdec524d1b7..3db49b9ca374 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/pm_qos_params.c
@@ -29,7 +29,6 @@
 
 #include <linux/pm_qos_params.h>
 #include <linux/sched.h>
-#include <linux/smp_lock.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
 #include <linux/time.h>
@@ -344,37 +343,33 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
 }
 EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
 
-#define PID_NAME_LEN sizeof("process_1234567890")
-static char name[PID_NAME_LEN];
+#define PID_NAME_LEN 32
 
 static int pm_qos_power_open(struct inode *inode, struct file *filp)
 {
 	int ret;
 	long pm_qos_class;
+	char name[PID_NAME_LEN];
 
-	lock_kernel();
 	pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
 	if (pm_qos_class >= 0) {
 		filp->private_data = (void *)pm_qos_class;
-		sprintf(name, "process_%d", current->pid);
+		snprintf(name, PID_NAME_LEN, "process_%d", current->pid);
 		ret = pm_qos_add_requirement(pm_qos_class, name,
 					PM_QOS_DEFAULT_VALUE);
-		if (ret >= 0) {
-			unlock_kernel();
+		if (ret >= 0)
 			return 0;
-		}
 	}
-	unlock_kernel();
-
 	return -EPERM;
 }
 
 static int pm_qos_power_release(struct inode *inode, struct file *filp)
 {
 	int pm_qos_class;
+	char name[PID_NAME_LEN];
 
 	pm_qos_class = (long)filp->private_data;
-	sprintf(name, "process_%d", current->pid);
+	snprintf(name, PID_NAME_LEN, "process_%d", current->pid);
 	pm_qos_remove_requirement(pm_qos_class, name);
 
 	return 0;
@@ -385,13 +380,14 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
 {
 	s32 value;
 	int pm_qos_class;
+	char name[PID_NAME_LEN];
 
 	pm_qos_class = (long)filp->private_data;
 	if (count != sizeof(s32))
 		return -EINVAL;
 	if (copy_from_user(&value, buf, sizeof(s32)))
 		return -EFAULT;
-	sprintf(name, "process_%d", current->pid);
+	snprintf(name, PID_NAME_LEN, "process_%d", current->pid);
 	pm_qos_update_requirement(pm_qos_class, name, value);
 
 	return  sizeof(s32);
diff --git a/kernel/sys.c b/kernel/sys.c
index 9968c5fb55b9..585d6cd10040 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -8,7 +8,6 @@
 #include <linux/mm.h>
 #include <linux/utsname.h>
 #include <linux/mman.h>
-#include <linux/smp_lock.h>
 #include <linux/notifier.h>
 #include <linux/reboot.h>
 #include <linux/prctl.h>
@@ -349,6 +348,9 @@ void kernel_power_off(void)
 	machine_power_off();
 }
 EXPORT_SYMBOL_GPL(kernel_power_off);
+
+static DEFINE_MUTEX(reboot_mutex);
+
 /*
  * Reboot system call: for obvious reasons only root may call it,
  * and even root needs to set up some magic numbers in the registers
@@ -381,7 +383,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
 	if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
 		cmd = LINUX_REBOOT_CMD_HALT;
 
-	lock_kernel();
+	mutex_lock(&reboot_mutex);
 	switch (cmd) {
 	case LINUX_REBOOT_CMD_RESTART:
 		kernel_restart(NULL);
@@ -397,20 +399,18 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
 
 	case LINUX_REBOOT_CMD_HALT:
 		kernel_halt();
-		unlock_kernel();
 		do_exit(0);
 		panic("cannot halt");
 
 	case LINUX_REBOOT_CMD_POWER_OFF:
 		kernel_power_off();
-		unlock_kernel();
 		do_exit(0);
 		break;
 
 	case LINUX_REBOOT_CMD_RESTART2:
 		if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
-			unlock_kernel();
-			return -EFAULT;
+			ret = -EFAULT;
+			break;
 		}
 		buffer[sizeof(buffer) - 1] = '\0';
 
@@ -433,7 +433,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
 		ret = -EINVAL;
 		break;
 	}
-	unlock_kernel();
+	mutex_unlock(&reboot_mutex);
 	return ret;
 }
 
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index d422c7b2236b..e85c23404d34 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -677,7 +677,7 @@ sysfs_show_current_clocksources(struct sys_device *dev,
  * @count:	length of buffer
  *
  * Takes input from sysfs interface for manually overriding the default
- * clocksource selction.
+ * clocksource selection.
  */
 static ssize_t sysfs_override_clocksource(struct sys_device *dev,
 					  struct sysdev_attribute *attr,
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 67e526b6ae81..dee48658805c 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -68,6 +68,116 @@ struct workqueue_struct {
 #endif
 };
 
+#ifdef CONFIG_DEBUG_OBJECTS_WORK
+
+static struct debug_obj_descr work_debug_descr;
+
+/*
+ * fixup_init is called when:
+ * - an active object is initialized
+ */
+static int work_fixup_init(void *addr, enum debug_obj_state state)
+{
+	struct work_struct *work = addr;
+
+	switch (state) {
+	case ODEBUG_STATE_ACTIVE:
+		cancel_work_sync(work);
+		debug_object_init(work, &work_debug_descr);
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+/*
+ * fixup_activate is called when:
+ * - an active object is activated
+ * - an unknown object is activated (might be a statically initialized object)
+ */
+static int work_fixup_activate(void *addr, enum debug_obj_state state)
+{
+	struct work_struct *work = addr;
+
+	switch (state) {
+
+	case ODEBUG_STATE_NOTAVAILABLE:
+		/*
+		 * This is not really a fixup. The work struct was
+		 * statically initialized. We just make sure that it
+		 * is tracked in the object tracker.
+		 */
+		if (test_bit(WORK_STRUCT_STATIC, work_data_bits(work))) {
+			debug_object_init(work, &work_debug_descr);
+			debug_object_activate(work, &work_debug_descr);
+			return 0;
+		}
+		WARN_ON_ONCE(1);
+		return 0;
+
+	case ODEBUG_STATE_ACTIVE:
+		WARN_ON(1);
+
+	default:
+		return 0;
+	}
+}
+
+/*
+ * fixup_free is called when:
+ * - an active object is freed
+ */
+static int work_fixup_free(void *addr, enum debug_obj_state state)
+{
+	struct work_struct *work = addr;
+
+	switch (state) {
+	case ODEBUG_STATE_ACTIVE:
+		cancel_work_sync(work);
+		debug_object_free(work, &work_debug_descr);
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+static struct debug_obj_descr work_debug_descr = {
+	.name		= "work_struct",
+	.fixup_init	= work_fixup_init,
+	.fixup_activate	= work_fixup_activate,
+	.fixup_free	= work_fixup_free,
+};
+
+static inline void debug_work_activate(struct work_struct *work)
+{
+	debug_object_activate(work, &work_debug_descr);
+}
+
+static inline void debug_work_deactivate(struct work_struct *work)
+{
+	debug_object_deactivate(work, &work_debug_descr);
+}
+
+void __init_work(struct work_struct *work, int onstack)
+{
+	if (onstack)
+		debug_object_init_on_stack(work, &work_debug_descr);
+	else
+		debug_object_init(work, &work_debug_descr);
+}
+EXPORT_SYMBOL_GPL(__init_work);
+
+void destroy_work_on_stack(struct work_struct *work)
+{
+	debug_object_free(work, &work_debug_descr);
+}
+EXPORT_SYMBOL_GPL(destroy_work_on_stack);
+
+#else
+static inline void debug_work_activate(struct work_struct *work) { }
+static inline void debug_work_deactivate(struct work_struct *work) { }
+#endif
+
 /* Serializes the accesses to the list of workqueues. */
 static DEFINE_SPINLOCK(workqueue_lock);
 static LIST_HEAD(workqueues);
@@ -145,6 +255,7 @@ static void __queue_work(struct cpu_workqueue_struct *cwq,
 {
 	unsigned long flags;
 
+	debug_work_activate(work);
 	spin_lock_irqsave(&cwq->lock, flags);
 	insert_work(cwq, work, &cwq->worklist);
 	spin_unlock_irqrestore(&cwq->lock, flags);
@@ -280,6 +391,7 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq)
 		struct lockdep_map lockdep_map = work->lockdep_map;
 #endif
 		trace_workqueue_execution(cwq->thread, work);
+		debug_work_deactivate(work);
 		cwq->current_work = work;
 		list_del_init(cwq->worklist.next);
 		spin_unlock_irq(&cwq->lock);
@@ -350,11 +462,18 @@ static void wq_barrier_func(struct work_struct *work)
 static void insert_wq_barrier(struct cpu_workqueue_struct *cwq,
 			struct wq_barrier *barr, struct list_head *head)
 {
-	INIT_WORK(&barr->work, wq_barrier_func);
+	/*
+	 * debugobject calls are safe here even with cwq->lock locked
+	 * as we know for sure that this will not trigger any of the
+	 * checks and call back into the fixup functions where we
+	 * might deadlock.
+	 */
+	INIT_WORK_ON_STACK(&barr->work, wq_barrier_func);
 	__set_bit(WORK_STRUCT_PENDING, work_data_bits(&barr->work));
 
 	init_completion(&barr->done);
 
+	debug_work_activate(&barr->work);
 	insert_work(cwq, &barr->work, head);
 }
 
@@ -372,8 +491,10 @@ static int flush_cpu_workqueue(struct cpu_workqueue_struct *cwq)
 	}
 	spin_unlock_irq(&cwq->lock);
 
-	if (active)
+	if (active) {
 		wait_for_completion(&barr.done);
+		destroy_work_on_stack(&barr.work);
+	}
 
 	return active;
 }
@@ -451,6 +572,7 @@ out:
 		return 0;
 
 	wait_for_completion(&barr.done);
+	destroy_work_on_stack(&barr.work);
 	return 1;
 }
 EXPORT_SYMBOL_GPL(flush_work);
@@ -485,6 +607,7 @@ static int try_to_grab_pending(struct work_struct *work)
 		 */
 		smp_rmb();
 		if (cwq == get_wq_data(work)) {
+			debug_work_deactivate(work);
 			list_del_init(&work->entry);
 			ret = 1;
 		}
@@ -507,8 +630,10 @@ static void wait_on_cpu_work(struct cpu_workqueue_struct *cwq,
 	}
 	spin_unlock_irq(&cwq->lock);
 
-	if (unlikely(running))
+	if (unlikely(running)) {
 		wait_for_completion(&barr.done);
+		destroy_work_on_stack(&barr.work);
+	}
 }
 
 static void wait_on_work(struct work_struct *work)