Merge branch 'master' into for-linus

13 files changed, 236 insertions, 121 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index bd295922887..9b42695f0d1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1407,14 +1407,11 @@ long do_fork(unsigned long clone_flags,
 		if (clone_flags & CLONE_VFORK) {
 			p->vfork_done = &vfork;
 			init_completion(&vfork);
-		} else if (!(clone_flags & CLONE_VM)) {
-			/*
-			 * vfork will do an exec which will call
-			 * set_task_comm()
-			 */
-			perf_counter_fork(p);
 		}
 
+		if (!(clone_flags & CLONE_THREAD))
+			perf_counter_fork(p);
+
 		audit_finish_fork(p);
 		tracehook_report_clone(regs, clone_flags, nr, p);
 
diff --git a/kernel/freezer.c b/kernel/freezer.c
index 2f4936cf708..bd1d42b17cb 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -44,12 +44,19 @@ void refrigerator(void)
 	recalc_sigpending(); /* We sent fake signal, clean it up */
 	spin_unlock_irq(&current->sighand->siglock);
 
+	/* prevent accounting of that task to load */
+	current->flags |= PF_FREEZING;
+
 	for (;;) {
 		set_current_state(TASK_UNINTERRUPTIBLE);
 		if (!frozen(current))
 			break;
 		schedule();
 	}
+
+	/* Remove the accounting blocker */
+	current->flags &= ~PF_FREEZING;
+
 	pr_debug("%s left refrigerator\n", current->comm);
 	__set_current_state(save);
 }
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 73468253143..e70ed5592eb 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -42,8 +42,7 @@ static inline void unregister_handler_proc(unsigned int irq,
 
 extern int irq_select_affinity_usr(unsigned int irq);
 
-extern void
-irq_set_thread_affinity(struct irq_desc *desc, const struct cpumask *cpumask);
+extern void irq_set_thread_affinity(struct irq_desc *desc);
 
 /*
  * Debugging printout:
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 50da6767290..61c679db468 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -80,14 +80,22 @@ int irq_can_set_affinity(unsigned int irq)
 	return 1;
 }
 
-void
-irq_set_thread_affinity(struct irq_desc *desc, const struct cpumask *cpumask)
+/**
+ *	irq_set_thread_affinity - Notify irq threads to adjust affinity
+ *	@desc:		irq descriptor which has affitnity changed
+ *
+ *	We just set IRQTF_AFFINITY and delegate the affinity setting
+ *	to the interrupt thread itself. We can not call
+ *	set_cpus_allowed_ptr() here as we hold desc->lock and this
+ *	code can be called from hard interrupt context.
+ */
+void irq_set_thread_affinity(struct irq_desc *desc)
 {
 	struct irqaction *action = desc->action;
 
 	while (action) {
 		if (action->thread)
-			set_cpus_allowed_ptr(action->thread, cpumask);
+			set_bit(IRQTF_AFFINITY, &action->thread_flags);
 		action = action->next;
 	}
 }
@@ -112,7 +120,7 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 	if (desc->status & IRQ_MOVE_PCNTXT) {
 		if (!desc->chip->set_affinity(irq, cpumask)) {
 			cpumask_copy(desc->affinity, cpumask);
-			irq_set_thread_affinity(desc, cpumask);
+			irq_set_thread_affinity(desc);
 		}
 	}
 	else {
@@ -122,7 +130,7 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 #else
 	if (!desc->chip->set_affinity(irq, cpumask)) {
 		cpumask_copy(desc->affinity, cpumask);
-		irq_set_thread_affinity(desc, cpumask);
+		irq_set_thread_affinity(desc);
 	}
 #endif
 	desc->status |= IRQ_AFFINITY_SET;
@@ -176,7 +184,7 @@ int irq_select_affinity_usr(unsigned int irq)
 	spin_lock_irqsave(&desc->lock, flags);
 	ret = setup_affinity(irq, desc);
 	if (!ret)
-		irq_set_thread_affinity(desc, desc->affinity);
+		irq_set_thread_affinity(desc);
 	spin_unlock_irqrestore(&desc->lock, flags);
 
 	return ret;
@@ -443,6 +451,39 @@ static int irq_wait_for_interrupt(struct irqaction *action)
 	return -1;
 }
 
+#ifdef CONFIG_SMP
+/*
+ * Check whether we need to change the affinity of the interrupt thread.
+ */
+static void
+irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
+{
+	cpumask_var_t mask;
+
+	if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
+		return;
+
+	/*
+	 * In case we are out of memory we set IRQTF_AFFINITY again and
+	 * try again next time
+	 */
+	if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
+		set_bit(IRQTF_AFFINITY, &action->thread_flags);
+		return;
+	}
+
+	spin_lock_irq(&desc->lock);
+	cpumask_copy(mask, desc->affinity);
+	spin_unlock_irq(&desc->lock);
+
+	set_cpus_allowed_ptr(current, mask);
+	free_cpumask_var(mask);
+}
+#else
+static inline void
+irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
+#endif
+
 /*
  * Interrupt handler thread
  */
@@ -458,6 +499,8 @@ static int irq_thread(void *data)
 
 	while (!irq_wait_for_interrupt(action)) {
 
+		irq_thread_check_affinity(desc, action);
+
 		atomic_inc(&desc->threads_active);
 
 		spin_lock_irq(&desc->lock);
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index cfe767ca154..fcb6c96f262 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -45,7 +45,7 @@ void move_masked_irq(int irq)
 		   < nr_cpu_ids))
 		if (!desc->chip->set_affinity(irq, desc->pending_mask)) {
 			cpumask_copy(desc->affinity, desc->pending_mask);
-			irq_set_thread_affinity(desc, desc->pending_mask);
+			irq_set_thread_affinity(desc);
 		}
 
 	cpumask_clear(desc->pending_mask);
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 9b1a7de2697..eb8751aa041 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -180,10 +180,12 @@ EXPORT_SYMBOL(kthread_bind);
  * @k: thread created by kthread_create().
  *
  * Sets kthread_should_stop() for @k to return true, wakes it, and
- * waits for it to exit.  Your threadfn() must not call do_exit()
- * itself if you use this function!  This can also be called after
- * kthread_create() instead of calling wake_up_process(): the thread
- * will exit without calling threadfn().
+ * waits for it to exit. This can also be called after kthread_create()
+ * instead of calling wake_up_process(): the thread will exit without
+ * calling threadfn().
+ *
+ * If threadfn() may call do_exit() itself, the caller must ensure
+ * task_struct can't go away.
  *
  * Returns the result of threadfn(), or %-EINTR if wake_up_process()
  * was never called.
diff --git a/kernel/module.c b/kernel/module.c
index 0a049837008..fd141140355 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1068,7 +1068,8 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
 {
 	const unsigned long *crc;
 
-	if (!find_symbol("module_layout", NULL, &crc, true, false))
+	if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
+			 &crc, true, false))
 		BUG();
 	return check_version(sechdrs, versindex, "module_layout", mod, crc);
 }
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index a641eb753b8..95093104195 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -146,6 +146,28 @@ static void put_ctx(struct perf_counter_context *ctx)
 	}
 }
 
+static void unclone_ctx(struct perf_counter_context *ctx)
+{
+	if (ctx->parent_ctx) {
+		put_ctx(ctx->parent_ctx);
+		ctx->parent_ctx = NULL;
+	}
+}
+
+/*
+ * If we inherit counters we want to return the parent counter id
+ * to userspace.
+ */
+static u64 primary_counter_id(struct perf_counter *counter)
+{
+	u64 id = counter->id;
+
+	if (counter->parent)
+		id = counter->parent->id;
+
+	return id;
+}
+
 /*
  * Get the perf_counter_context for a task and lock it.
  * This has to cope with with the fact that until it is locked,
@@ -1288,7 +1310,6 @@ static void perf_counter_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu)
 #define MAX_INTERRUPTS (~0ULL)
 
 static void perf_log_throttle(struct perf_counter *counter, int enable);
-static void perf_log_period(struct perf_counter *counter, u64 period);
 
 static void perf_adjust_period(struct perf_counter *counter, u64 events)
 {
@@ -1307,8 +1328,6 @@ static void perf_adjust_period(struct perf_counter *counter, u64 events)
 	if (!sample_period)
 		sample_period = 1;
 
-	perf_log_period(counter, sample_period);
-
 	hwc->sample_period = sample_period;
 }
 
@@ -1463,10 +1482,8 @@ static void perf_counter_enable_on_exec(struct task_struct *task)
 	/*
 	 * Unclone this context if we enabled any counter.
 	 */
-	if (enabled && ctx->parent_ctx) {
-		put_ctx(ctx->parent_ctx);
-		ctx->parent_ctx = NULL;
-	}
+	if (enabled)
+		unclone_ctx(ctx);
 
 	spin_unlock(&ctx->lock);
 
@@ -1526,7 +1543,6 @@ __perf_counter_init_context(struct perf_counter_context *ctx,
 
 static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
 {
-	struct perf_counter_context *parent_ctx;
 	struct perf_counter_context *ctx;
 	struct perf_cpu_context *cpuctx;
 	struct task_struct *task;
@@ -1586,11 +1602,7 @@ static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
  retry:
 	ctx = perf_lock_task_context(task, &flags);
 	if (ctx) {
-		parent_ctx = ctx->parent_ctx;
-		if (parent_ctx) {
-			put_ctx(parent_ctx);
-			ctx->parent_ctx = NULL;		/* no longer a clone */
-		}
+		unclone_ctx(ctx);
 		spin_unlock_irqrestore(&ctx->lock, flags);
 	}
 
@@ -1704,7 +1716,7 @@ perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count)
 		values[n++] = counter->total_time_running +
 			atomic64_read(&counter->child_total_time_running);
 	if (counter->attr.read_format & PERF_FORMAT_ID)
-		values[n++] = counter->id;
+		values[n++] = primary_counter_id(counter);
 	mutex_unlock(&counter->child_mutex);
 
 	if (count < n * sizeof(u64))
@@ -1811,8 +1823,6 @@ static int perf_counter_period(struct perf_counter *counter, u64 __user *arg)
 
 		counter->attr.sample_freq = value;
 	} else {
-		perf_log_period(counter, value);
-
 		counter->attr.sample_period = value;
 		counter->hw.sample_period = value;
 	}
@@ -2661,10 +2671,14 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
 	if (sample_type & PERF_SAMPLE_ID)
 		header.size += sizeof(u64);
 
+	if (sample_type & PERF_SAMPLE_STREAM_ID)
+		header.size += sizeof(u64);
+
 	if (sample_type & PERF_SAMPLE_CPU) {
 		header.size += sizeof(cpu_entry);
 
 		cpu_entry.cpu = raw_smp_processor_id();
+		cpu_entry.reserved = 0;
 	}
 
 	if (sample_type & PERF_SAMPLE_PERIOD)
@@ -2703,7 +2717,13 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
 	if (sample_type & PERF_SAMPLE_ADDR)
 		perf_output_put(&handle, data->addr);
 
-	if (sample_type & PERF_SAMPLE_ID)
+	if (sample_type & PERF_SAMPLE_ID) {
+		u64 id = primary_counter_id(counter);
+
+		perf_output_put(&handle, id);
+	}
+
+	if (sample_type & PERF_SAMPLE_STREAM_ID)
 		perf_output_put(&handle, counter->id);
 
 	if (sample_type & PERF_SAMPLE_CPU)
@@ -2726,7 +2746,7 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
 			if (sub != counter)
 				sub->pmu->read(sub);
 
-			group_entry.id = sub->id;
+			group_entry.id = primary_counter_id(sub);
 			group_entry.counter = atomic64_read(&sub->count);
 
 			perf_output_put(&handle, group_entry);
@@ -2786,15 +2806,8 @@ perf_counter_read_event(struct perf_counter *counter,
 	}
 
 	if (counter->attr.read_format & PERF_FORMAT_ID) {
-		u64 id;
-
 		event.header.size += sizeof(u64);
-		if (counter->parent)
-			id = counter->parent->id;
-		else
-			id = counter->id;
-
-		event.format[i++] = id;
+		event.format[i++] = primary_counter_id(counter);
 	}
 
 	ret = perf_output_begin(&handle, counter, event.header.size, 0, 0);
@@ -2895,8 +2908,11 @@ void perf_counter_fork(struct task_struct *task)
 		.event  = {
 			.header = {
 				.type = PERF_EVENT_FORK,
+				.misc = 0,
 				.size = sizeof(fork_event.event),
 			},
+			/* .pid  */
+			/* .ppid */
 		},
 	};
 
@@ -2968,8 +2984,10 @@ static void perf_counter_comm_event(struct perf_comm_event *comm_event)
 	struct perf_cpu_context *cpuctx;
 	struct perf_counter_context *ctx;
 	unsigned int size;
-	char *comm = comm_event->task->comm;
+	char comm[TASK_COMM_LEN];
 
+	memset(comm, 0, sizeof(comm));
+	strncpy(comm, comm_event->task->comm, sizeof(comm));
 	size = ALIGN(strlen(comm)+1, sizeof(u64));
 
 	comm_event->comm = comm;
@@ -3004,8 +3022,16 @@ void perf_counter_comm(struct task_struct *task)
 
 	comm_event = (struct perf_comm_event){
 		.task	= task,
+		/* .comm      */
+		/* .comm_size */
 		.event  = {
-			.header = { .type = PERF_EVENT_COMM, },
+			.header = {
+				.type = PERF_EVENT_COMM,
+				.misc = 0,
+				/* .size */
+			},
+			/* .pid */
+			/* .tid */
 		},
 	};
 
@@ -3088,8 +3114,15 @@ static void perf_counter_mmap_event(struct perf_mmap_event *mmap_event)
 	char *buf = NULL;
 	const char *name;
 
+	memset(tmp, 0, sizeof(tmp));
+
 	if (file) {
-		buf = kzalloc(PATH_MAX, GFP_KERNEL);
+		/*
+		 * d_path works from the end of the buffer backwards, so we
+		 * need to add enough zero bytes after the string to handle
+		 * the 64bit alignment we do later.
+		 */
+		buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL);
 		if (!buf) {
 			name = strncpy(tmp, "//enomem", sizeof(tmp));
 			goto got_name;
@@ -3100,9 +3133,11 @@ static void perf_counter_mmap_event(struct perf_mmap_event *mmap_event)
 			goto got_name;
 		}
 	} else {
-		name = arch_vma_name(mmap_event->vma);
-		if (name)
+		if (arch_vma_name(mmap_event->vma)) {
+			name = strncpy(tmp, arch_vma_name(mmap_event->vma),
+				       sizeof(tmp));
 			goto got_name;
+		}
 
 		if (!vma->vm_mm) {
 			name = strncpy(tmp, "[vdso]", sizeof(tmp));
@@ -3147,8 +3182,16 @@ void __perf_counter_mmap(struct vm_area_struct *vma)
 
 	mmap_event = (struct perf_mmap_event){
 		.vma	= vma,
+		/* .file_name */
+		/* .file_size */
 		.event  = {
-			.header = { .type = PERF_EVENT_MMAP, },
+			.header = {
+				.type = PERF_EVENT_MMAP,
+				.misc = 0,
+				/* .size */
+			},
+			/* .pid */
+			/* .tid */
 			.start  = vma->vm_start,
 			.len    = vma->vm_end - vma->vm_start,
 			.pgoff  = vma->vm_pgoff,
@@ -3159,49 +3202,6 @@ void __perf_counter_mmap(struct vm_area_struct *vma)
 }
 
 /*
- * Log sample_period changes so that analyzing tools can re-normalize the
- * event flow.
- */
-
-struct freq_event {
-	struct perf_event_header	header;
-	u64				time;
-	u64				id;
-	u64				period;
-};
-
-static void perf_log_period(struct perf_counter *counter, u64 period)
-{
-	struct perf_output_handle handle;
-	struct freq_event event;
-	int ret;
-
-	if (counter->hw.sample_period == period)
-		return;
-
-	if (counter->attr.sample_type & PERF_SAMPLE_PERIOD)
-		return;
-
-	event = (struct freq_event) {
-		.header = {
-			.type = PERF_EVENT_PERIOD,
-			.misc = 0,
-			.size = sizeof(event),
-		},
-		.time = sched_clock(),
-		.id = counter->id,
-		.period = period,
-	};
-
-	ret = perf_output_begin(&handle, counter, sizeof(event), 1, 0);
-	if (ret)
-		return;
-
-	perf_output_put(&handle, event);
-	perf_output_end(&handle);
-}
-
-/*
  * IRQ throttle logging
  */
 
@@ -3214,16 +3214,21 @@ static void perf_log_throttle(struct perf_counter *counter, int enable)
 		struct perf_event_header	header;
 		u64				time;
 		u64				id;
+		u64				stream_id;
 	} throttle_event = {
 		.header = {
-			.type = PERF_EVENT_THROTTLE + 1,
+			.type = PERF_EVENT_THROTTLE,
 			.misc = 0,
 			.size = sizeof(throttle_event),
 		},
-		.time	= sched_clock(),
-		.id	= counter->id,
+		.time		= sched_clock(),
+		.id		= primary_counter_id(counter),
+		.stream_id	= counter->id,
 	};
 
+	if (enable)
+		throttle_event.header.type = PERF_EVENT_UNTHROTTLE;
+
 	ret = perf_output_begin(&handle, counter, sizeof(throttle_event), 1, 0);
 	if (ret)
 		return;
@@ -3671,7 +3676,7 @@ static const struct pmu perf_ops_task_clock = {
 void perf_tpcounter_event(int event_id)
 {
 	struct perf_sample_data data = {
-		.regs = get_irq_regs();
+		.regs = get_irq_regs(),
 		.addr = 0,
 	};
 
@@ -3687,16 +3692,12 @@ extern void ftrace_profile_disable(int);
 
 static void tp_perf_counter_destroy(struct perf_counter *counter)
 {
-	ftrace_profile_disable(perf_event_id(&counter->attr));
+	ftrace_profile_disable(counter->attr.config);
 }
 
 static const struct pmu *tp_perf_counter_init(struct perf_counter *counter)
 {
-	int event_id = perf_event_id(&counter->attr);
-	int ret;
-
-	ret = ftrace_profile_enable(event_id);
-	if (ret)
+	if (ftrace_profile_enable(counter->attr.config))
 		return NULL;
 
 	counter->destroy = tp_perf_counter_destroy;
@@ -4255,15 +4256,12 @@ void perf_counter_exit_task(struct task_struct *child)
 	 */
 	spin_lock(&child_ctx->lock);
 	child->perf_counter_ctxp = NULL;
-	if (child_ctx->parent_ctx) {
-		/*
-		 * This context is a clone; unclone it so it can't get
-		 * swapped to another process while we're removing all
-		 * the counters from it.
-		 */
-		put_ctx(child_ctx->parent_ctx);
-		child_ctx->parent_ctx = NULL;
-	}
+	/*
+	 * If this context is a clone; unclone it so it can't get
+	 * swapped to another process while we're removing all
+	 * the counters from it.
+	 */
+	unclone_ctx(child_ctx);
 	spin_unlock(&child_ctx->lock);
 	local_irq_restore(flags);
 
diff --git a/kernel/sched.c b/kernel/sched.c
index 98972d366fd..1b59e265273 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -7289,6 +7289,7 @@ static void migrate_dead_tasks(unsigned int dead_cpu)
 static void calc_global_load_remove(struct rq *rq)
 {
 	atomic_long_sub(rq->calc_load_active, &calc_load_tasks);
+	rq->calc_load_active = 0;
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
@@ -7515,6 +7516,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 		task_rq_unlock(rq, &flags);
 		get_task_struct(p);
 		cpu_rq(cpu)->migration_thread = p;
+		rq->calc_load_update = calc_load_update;
 		break;
 
 	case CPU_ONLINE:
@@ -7525,8 +7527,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 		/* Update our root-domain */
 		rq = cpu_rq(cpu);
 		spin_lock_irqsave(&rq->lock, flags);
-		rq->calc_load_update = calc_load_update;
-		rq->calc_load_active = 0;
 		if (rq->rd) {
 			BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
 
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 7c248dc30f4..9ffb2b2ceba 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -266,6 +266,12 @@ static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime)
 	return min_vruntime;
 }
 
+static inline int entity_before(struct sched_entity *a,
+				struct sched_entity *b)
+{
+	return (s64)(a->vruntime - b->vruntime) < 0;
+}
+
 static inline s64 entity_key(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
 	return se->vruntime - cfs_rq->min_vruntime;
@@ -1017,7 +1023,7 @@ static void yield_task_fair(struct rq *rq)
 	/*
 	 * Already in the rightmost position?
 	 */
-	if (unlikely(!rightmost || rightmost->vruntime < se->vruntime))
+	if (unlikely(!rightmost || entity_before(rightmost, se)))
 		return;
 
 	/*
@@ -1713,7 +1719,7 @@ static void task_new_fair(struct rq *rq, struct task_struct *p)
 
 	/* 'curr' will be NULL if the child belongs to a different group */
 	if (sysctl_sched_child_runs_first && this_cpu == task_cpu(p) &&
-			curr && curr->vruntime < se->vruntime) {
+			curr && entity_before(curr, se)) {
 		/*
 		 * Upon rescheduling, sched_class::put_prev_task() will place
 		 * 'current' within the tree based on its new key value.
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 3a94905fa5d..eb5e131a048 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -345,7 +345,9 @@ void open_softirq(int nr, void (*action)(struct softirq_action *))
 	softirq_vec[nr].action = action;
 }
 
-/* Tasklets */
+/*
+ * Tasklets
+ */
 struct tasklet_head
 {
 	struct tasklet_struct *head;
@@ -493,6 +495,66 @@ void tasklet_kill(struct tasklet_struct *t)
 
 EXPORT_SYMBOL(tasklet_kill);
 
+/*
+ * tasklet_hrtimer
+ */
+
+/*
+ * The trampoline is called when the hrtimer expires. If this is
+ * called from the hrtimer interrupt then we schedule the tasklet as
+ * the timer callback function expects to run in softirq context. If
+ * it's called in softirq context anyway (i.e. high resolution timers
+ * disabled) then the hrtimer callback is called right away.
+ */
+static enum hrtimer_restart __hrtimer_tasklet_trampoline(struct hrtimer *timer)
+{
+	struct tasklet_hrtimer *ttimer =
+		container_of(timer, struct tasklet_hrtimer, timer);
+
+	if (hrtimer_is_hres_active(timer)) {
+		tasklet_hi_schedule(&ttimer->tasklet);
+		return HRTIMER_NORESTART;
+	}
+	return ttimer->function(timer);
+}
+
+/*
+ * Helper function which calls the hrtimer callback from
+ * tasklet/softirq context
+ */
+static void __tasklet_hrtimer_trampoline(unsigned long data)
+{
+	struct tasklet_hrtimer *ttimer = (void *)data;
+	enum hrtimer_restart restart;
+
+	restart = ttimer->function(&ttimer->timer);
+	if (restart != HRTIMER_NORESTART)
+		hrtimer_restart(&ttimer->timer);
+}
+
+/**
+ * tasklet_hrtimer_init - Init a tasklet/hrtimer combo for softirq callbacks
+ * @ttimer:	 tasklet_hrtimer which is initialized
+ * @function:	 hrtimer callback funtion which gets called from softirq context
+ * @which_clock: clock id (CLOCK_MONOTONIC/CLOCK_REALTIME)
+ * @mode:	 hrtimer mode (HRTIMER_MODE_ABS/HRTIMER_MODE_REL)
+ */
+void tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
+			  enum hrtimer_restart (*function)(struct hrtimer *),
+			  clockid_t which_clock, enum hrtimer_mode mode)
+{
+	hrtimer_init(&ttimer->timer, which_clock, mode);
+	ttimer->timer.function = __hrtimer_tasklet_trampoline;
+	tasklet_init(&ttimer->tasklet, __tasklet_hrtimer_trampoline,
+		     (unsigned long)ttimer);
+	ttimer->function = function;
+}
+EXPORT_SYMBOL_GPL(tasklet_hrtimer_init);
+
+/*
+ * Remote softirq bits
+ */
+
 DEFINE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
 EXPORT_PER_CPU_SYMBOL(softirq_work_list);
 
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 592bf584d1d..7466cb81125 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -513,7 +513,7 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
 	 * Check to make sure we don't switch to a non-highres capable
 	 * clocksource if the tick code is in oneshot mode (highres or nohz)
 	 */
-	if (tick_oneshot_mode_active() &&
+	if (tick_oneshot_mode_active() && ovr &&
 	    !(ovr->flags & CLOCK_SOURCE_VALID_FOR_HRES)) {
 		printk(KERN_WARNING "%s clocksource is not HRT compatible. "
 			"Cannot switch while in HRT/NOHZ mode\n", ovr->name);
diff --git a/kernel/timer.c b/kernel/timer.c
index 0b36b9e5cc8..a7f07d5a624 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -714,7 +714,7 @@ int mod_timer(struct timer_list *timer, unsigned long expires)
 	 * networking code - if the timer is re-modified
 	 * to be the same thing then just return:
 	 */
-	if (timer->expires == expires && timer_pending(timer))
+	if (timer_pending(timer) && timer->expires == expires)
 		return 1;
 
 	return __mod_timer(timer, expires, false, TIMER_NOT_PINNED);