Merge tag 'kvm-arm-for-4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-next

KVM/ARM changes for Linux v4.5

- Complete rewrite of the arm64 world switch in C, hopefully
  paving the way for more sharing with the 32bit code, better
  maintainability and easier integration of new features.
  Also smaller and slightly faster in some cases...
- Support for 16bit VM identifiers
- Various cleanups

30 files changed, 356 insertions, 213 deletions

diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 3f4c99e06c6b..b0799bced518 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -28,11 +28,17 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr)
 	    attr->value_size == 0)
 		return ERR_PTR(-EINVAL);
 
+	if (attr->value_size >= 1 << (KMALLOC_SHIFT_MAX - 1))
+		/* if value_size is bigger, the user space won't be able to
+		 * access the elements.
+		 */
+		return ERR_PTR(-E2BIG);
+
 	elem_size = round_up(attr->value_size, 8);
 
 	/* check round_up into zero and u32 overflow */
 	if (elem_size == 0 ||
-	    attr->max_entries > (U32_MAX - sizeof(*array)) / elem_size)
+	    attr->max_entries > (U32_MAX - PAGE_SIZE - sizeof(*array)) / elem_size)
 		return ERR_PTR(-ENOMEM);
 
 	array_size = sizeof(*array) + attr->max_entries * elem_size;
@@ -105,7 +111,7 @@ static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
 		/* all elements already exist */
 		return -EEXIST;
 
-	memcpy(array->value + array->elem_size * index, value, array->elem_size);
+	memcpy(array->value + array->elem_size * index, value, map->value_size);
 	return 0;
 }
 
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 19909b22b4f8..34777b3746fa 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -64,12 +64,35 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 		 */
 		goto free_htab;
 
-	err = -ENOMEM;
+	if (htab->map.value_size >= (1 << (KMALLOC_SHIFT_MAX - 1)) -
+	    MAX_BPF_STACK - sizeof(struct htab_elem))
+		/* if value_size is bigger, the user space won't be able to
+		 * access the elements via bpf syscall. This check also makes
+		 * sure that the elem_size doesn't overflow and it's
+		 * kmalloc-able later in htab_map_update_elem()
+		 */
+		goto free_htab;
+
+	htab->elem_size = sizeof(struct htab_elem) +
+			  round_up(htab->map.key_size, 8) +
+			  htab->map.value_size;
+
 	/* prevent zero size kmalloc and check for u32 overflow */
 	if (htab->n_buckets == 0 ||
 	    htab->n_buckets > U32_MAX / sizeof(struct hlist_head))
 		goto free_htab;
 
+	if ((u64) htab->n_buckets * sizeof(struct hlist_head) +
+	    (u64) htab->elem_size * htab->map.max_entries >=
+	    U32_MAX - PAGE_SIZE)
+		/* make sure page count doesn't overflow */
+		goto free_htab;
+
+	htab->map.pages = round_up(htab->n_buckets * sizeof(struct hlist_head) +
+				   htab->elem_size * htab->map.max_entries,
+				   PAGE_SIZE) >> PAGE_SHIFT;
+
+	err = -ENOMEM;
 	htab->buckets = kmalloc_array(htab->n_buckets, sizeof(struct hlist_head),
 				      GFP_USER | __GFP_NOWARN);
 
@@ -85,13 +108,6 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 	raw_spin_lock_init(&htab->lock);
 	htab->count = 0;
 
-	htab->elem_size = sizeof(struct htab_elem) +
-			  round_up(htab->map.key_size, 8) +
-			  htab->map.value_size;
-
-	htab->map.pages = round_up(htab->n_buckets * sizeof(struct hlist_head) +
-				   htab->elem_size * htab->map.max_entries,
-				   PAGE_SIZE) >> PAGE_SHIFT;
 	return &htab->map;
 
 free_htab:
@@ -222,7 +238,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
 	WARN_ON_ONCE(!rcu_read_lock_held());
 
 	/* allocate new element outside of lock */
-	l_new = kmalloc(htab->elem_size, GFP_ATOMIC);
+	l_new = kmalloc(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN);
 	if (!l_new)
 		return -ENOMEM;
 
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index be6d726e31c9..5a8a797d50b7 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -34,7 +34,7 @@ static void *bpf_any_get(void *raw, enum bpf_type type)
 		atomic_inc(&((struct bpf_prog *)raw)->aux->refcnt);
 		break;
 	case BPF_TYPE_MAP:
-		atomic_inc(&((struct bpf_map *)raw)->refcnt);
+		bpf_map_inc(raw, true);
 		break;
 	default:
 		WARN_ON_ONCE(1);
@@ -51,7 +51,7 @@ static void bpf_any_put(void *raw, enum bpf_type type)
 		bpf_prog_put(raw);
 		break;
 	case BPF_TYPE_MAP:
-		bpf_map_put(raw);
+		bpf_map_put_with_uref(raw);
 		break;
 	default:
 		WARN_ON_ONCE(1);
@@ -64,7 +64,7 @@ static void *bpf_fd_probe_obj(u32 ufd, enum bpf_type *type)
 	void *raw;
 
 	*type = BPF_TYPE_MAP;
-	raw = bpf_map_get(ufd);
+	raw = bpf_map_get_with_uref(ufd);
 	if (IS_ERR(raw)) {
 		*type = BPF_TYPE_PROG;
 		raw = bpf_prog_get(ufd);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0d3313d02a7e..3b39550d8485 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -82,6 +82,14 @@ static void bpf_map_free_deferred(struct work_struct *work)
 	map->ops->map_free(map);
 }
 
+static void bpf_map_put_uref(struct bpf_map *map)
+{
+	if (atomic_dec_and_test(&map->usercnt)) {
+		if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
+			bpf_fd_array_map_clear(map);
+	}
+}
+
 /* decrement map refcnt and schedule it for freeing via workqueue
  * (unrelying map implementation ops->map_free() might sleep)
  */
@@ -93,17 +101,15 @@ void bpf_map_put(struct bpf_map *map)
 	}
 }
 
-static int bpf_map_release(struct inode *inode, struct file *filp)
+void bpf_map_put_with_uref(struct bpf_map *map)
 {
-	struct bpf_map *map = filp->private_data;
-
-	if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
-		/* prog_array stores refcnt-ed bpf_prog pointers
-		 * release them all when user space closes prog_array_fd
-		 */
-		bpf_fd_array_map_clear(map);
-
+	bpf_map_put_uref(map);
 	bpf_map_put(map);
+}
+
+static int bpf_map_release(struct inode *inode, struct file *filp)
+{
+	bpf_map_put_with_uref(filp->private_data);
 	return 0;
 }
 
@@ -142,6 +148,7 @@ static int map_create(union bpf_attr *attr)
 		return PTR_ERR(map);
 
 	atomic_set(&map->refcnt, 1);
+	atomic_set(&map->usercnt, 1);
 
 	err = bpf_map_charge_memlock(map);
 	if (err)
@@ -174,7 +181,14 @@ struct bpf_map *__bpf_map_get(struct fd f)
 	return f.file->private_data;
 }
 
-struct bpf_map *bpf_map_get(u32 ufd)
+void bpf_map_inc(struct bpf_map *map, bool uref)
+{
+	atomic_inc(&map->refcnt);
+	if (uref)
+		atomic_inc(&map->usercnt);
+}
+
+struct bpf_map *bpf_map_get_with_uref(u32 ufd)
 {
 	struct fd f = fdget(ufd);
 	struct bpf_map *map;
@@ -183,7 +197,7 @@ struct bpf_map *bpf_map_get(u32 ufd)
 	if (IS_ERR(map))
 		return map;
 
-	atomic_inc(&map->refcnt);
+	bpf_map_inc(map, true);
 	fdput(f);
 
 	return map;
@@ -226,7 +240,7 @@ static int map_lookup_elem(union bpf_attr *attr)
 		goto free_key;
 
 	err = -ENOMEM;
-	value = kmalloc(map->value_size, GFP_USER);
+	value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN);
 	if (!value)
 		goto free_key;
 
@@ -285,7 +299,7 @@ static int map_update_elem(union bpf_attr *attr)
 		goto free_key;
 
 	err = -ENOMEM;
-	value = kmalloc(map->value_size, GFP_USER);
+	value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN);
 	if (!value)
 		goto free_key;
 
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index c6073056badf..a7945d10b378 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2021,8 +2021,7 @@ static int replace_map_fd_with_map_ptr(struct verifier_env *env)
 			 * will be used by the valid program until it's unloaded
 			 * and all maps are released in free_bpf_prog_info()
 			 */
-			atomic_inc(&map->refcnt);
-
+			bpf_map_inc(map, false);
 			fdput(f);
 next_insn:
 			insn++;
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index f1603c153890..470f6536b9e8 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -98,6 +98,12 @@ static DEFINE_SPINLOCK(css_set_lock);
 static DEFINE_SPINLOCK(cgroup_idr_lock);
 
 /*
+ * Protects cgroup_file->kn for !self csses.  It synchronizes notifications
+ * against file removal/re-creation across css hiding.
+ */
+static DEFINE_SPINLOCK(cgroup_file_kn_lock);
+
+/*
  * Protects cgroup_subsys->release_agent_path.  Modifying it also requires
  * cgroup_mutex.  Reading requires either cgroup_mutex or this spinlock.
  */
@@ -754,9 +760,11 @@ static void put_css_set_locked(struct css_set *cset)
 	if (!atomic_dec_and_test(&cset->refcount))
 		return;
 
-	/* This css_set is dead. unlink it and release cgroup refcounts */
-	for_each_subsys(ss, ssid)
+	/* This css_set is dead. unlink it and release cgroup and css refs */
+	for_each_subsys(ss, ssid) {
 		list_del(&cset->e_cset_node[ssid]);
+		css_put(cset->subsys[ssid]);
+	}
 	hash_del(&cset->hlist);
 	css_set_count--;
 
@@ -1056,9 +1064,13 @@ static struct css_set *find_css_set(struct css_set *old_cset,
 	key = css_set_hash(cset->subsys);
 	hash_add(css_set_table, &cset->hlist, key);
 
-	for_each_subsys(ss, ssid)
+	for_each_subsys(ss, ssid) {
+		struct cgroup_subsys_state *css = cset->subsys[ssid];
+
 		list_add_tail(&cset->e_cset_node[ssid],
-			      &cset->subsys[ssid]->cgroup->e_csets[ssid]);
+			      &css->cgroup->e_csets[ssid]);
+		css_get(css);
+	}
 
 	spin_unlock_bh(&css_set_lock);
 
@@ -1393,6 +1405,16 @@ static void cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft)
 	char name[CGROUP_FILE_NAME_MAX];
 
 	lockdep_assert_held(&cgroup_mutex);
+
+	if (cft->file_offset) {
+		struct cgroup_subsys_state *css = cgroup_css(cgrp, cft->ss);
+		struct cgroup_file *cfile = (void *)css + cft->file_offset;
+
+		spin_lock_irq(&cgroup_file_kn_lock);
+		cfile->kn = NULL;
+		spin_unlock_irq(&cgroup_file_kn_lock);
+	}
+
 	kernfs_remove_by_name(cgrp->kn, cgroup_file_name(cgrp, cft, name));
 }
 
@@ -1856,7 +1878,6 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
 
 	INIT_LIST_HEAD(&cgrp->self.sibling);
 	INIT_LIST_HEAD(&cgrp->self.children);
-	INIT_LIST_HEAD(&cgrp->self.files);
 	INIT_LIST_HEAD(&cgrp->cset_links);
 	INIT_LIST_HEAD(&cgrp->pidlists);
 	mutex_init(&cgrp->pidlist_mutex);
@@ -2216,6 +2237,9 @@ struct cgroup_taskset {
 	struct list_head	src_csets;
 	struct list_head	dst_csets;
 
+	/* the subsys currently being processed */
+	int			ssid;
+
 	/*
 	 * Fields for cgroup_taskset_*() iteration.
 	 *
@@ -2278,25 +2302,29 @@ static void cgroup_taskset_add(struct task_struct *task,
 /**
  * cgroup_taskset_first - reset taskset and return the first task
  * @tset: taskset of interest
+ * @dst_cssp: output variable for the destination css
  *
  * @tset iteration is initialized and the first task is returned.
  */
-struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset)
+struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset,
+					 struct cgroup_subsys_state **dst_cssp)
 {
 	tset->cur_cset = list_first_entry(tset->csets, struct css_set, mg_node);
 	tset->cur_task = NULL;
 
-	return cgroup_taskset_next(tset);
+	return cgroup_taskset_next(tset, dst_cssp);
 }
 
 /**
  * cgroup_taskset_next - iterate to the next task in taskset
  * @tset: taskset of interest
+ * @dst_cssp: output variable for the destination css
  *
  * Return the next task in @tset.  Iteration must have been initialized
  * with cgroup_taskset_first().
  */
-struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset)
+struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset,
+					struct cgroup_subsys_state **dst_cssp)
 {
 	struct css_set *cset = tset->cur_cset;
 	struct task_struct *task = tset->cur_task;
@@ -2311,6 +2339,18 @@ struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset)
 		if (&task->cg_list != &cset->mg_tasks) {
 			tset->cur_cset = cset;
 			tset->cur_task = task;
+
+			/*
+			 * This function may be called both before and
+			 * after cgroup_taskset_migrate().  The two cases
+			 * can be distinguished by looking at whether @cset
+			 * has its ->mg_dst_cset set.
+			 */
+			if (cset->mg_dst_cset)
+				*dst_cssp = cset->mg_dst_cset->subsys[tset->ssid];
+			else
+				*dst_cssp = cset->subsys[tset->ssid];
+
 			return task;
 		}
 
@@ -2346,7 +2386,8 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
 	/* check that we can legitimately attach to the cgroup */
 	for_each_e_css(css, i, dst_cgrp) {
 		if (css->ss->can_attach) {
-			ret = css->ss->can_attach(css, tset);
+			tset->ssid = i;
+			ret = css->ss->can_attach(tset);
 			if (ret) {
 				failed_css = css;
 				goto out_cancel_attach;
@@ -2379,9 +2420,12 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
 	 */
 	tset->csets = &tset->dst_csets;
 
-	for_each_e_css(css, i, dst_cgrp)
-		if (css->ss->attach)
-			css->ss->attach(css, tset);
+	for_each_e_css(css, i, dst_cgrp) {
+		if (css->ss->attach) {
+			tset->ssid = i;
+			css->ss->attach(tset);
+		}
+	}
 
 	ret = 0;
 	goto out_release_tset;
@@ -2390,8 +2434,10 @@ out_cancel_attach:
 	for_each_e_css(css, i, dst_cgrp) {
 		if (css == failed_css)
 			break;
-		if (css->ss->cancel_attach)
-			css->ss->cancel_attach(css, tset);
+		if (css->ss->cancel_attach) {
+			tset->ssid = i;
+			css->ss->cancel_attach(tset);
+		}
 	}
 out_release_tset:
 	spin_lock_bh(&css_set_lock);
@@ -3313,9 +3359,9 @@ static int cgroup_add_file(struct cgroup_subsys_state *css, struct cgroup *cgrp,
 	if (cft->file_offset) {
 		struct cgroup_file *cfile = (void *)css + cft->file_offset;
 
-		kernfs_get(kn);
+		spin_lock_irq(&cgroup_file_kn_lock);
 		cfile->kn = kn;
-		list_add(&cfile->node, &css->files);
+		spin_unlock_irq(&cgroup_file_kn_lock);
 	}
 
 	return 0;
@@ -3553,6 +3599,22 @@ int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts)
 }
 
 /**
+ * cgroup_file_notify - generate a file modified event for a cgroup_file
+ * @cfile: target cgroup_file
+ *
+ * @cfile must have been obtained by setting cftype->file_offset.
+ */
+void cgroup_file_notify(struct cgroup_file *cfile)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&cgroup_file_kn_lock, flags);
+	if (cfile->kn)
+		kernfs_notify(cfile->kn);
+	spin_unlock_irqrestore(&cgroup_file_kn_lock, flags);
+}
+
+/**
  * cgroup_task_count - count the number of tasks in a cgroup.
  * @cgrp: the cgroup in question
  *
@@ -4613,13 +4675,9 @@ static void css_free_work_fn(struct work_struct *work)
 		container_of(work, struct cgroup_subsys_state, destroy_work);
 	struct cgroup_subsys *ss = css->ss;
 	struct cgroup *cgrp = css->cgroup;
-	struct cgroup_file *cfile;
 
 	percpu_ref_exit(&css->refcnt);
 
-	list_for_each_entry(cfile, &css->files, node)
-		kernfs_put(cfile->kn);
-
 	if (ss) {
 		/* css free path */
 		int id = css->id;
@@ -4724,7 +4782,6 @@ static void init_and_link_css(struct cgroup_subsys_state *css,
 	css->ss = ss;
 	INIT_LIST_HEAD(&css->sibling);
 	INIT_LIST_HEAD(&css->children);
-	INIT_LIST_HEAD(&css->files);
 	css->serial_nr = css_serial_nr_next++;
 
 	if (cgroup_parent(cgrp)) {
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index f1b30ad5dc6d..2d3df82c54f2 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -155,12 +155,10 @@ static void freezer_css_free(struct cgroup_subsys_state *css)
  * @freezer->lock.  freezer_attach() makes the new tasks conform to the
  * current state and all following state changes can see the new tasks.
  */
-static void freezer_attach(struct cgroup_subsys_state *new_css,
-			   struct cgroup_taskset *tset)
+static void freezer_attach(struct cgroup_taskset *tset)
 {
-	struct freezer *freezer = css_freezer(new_css);
 	struct task_struct *task;
-	bool clear_frozen = false;
+	struct cgroup_subsys_state *new_css;
 
 	mutex_lock(&freezer_mutex);
 
@@ -174,22 +172,21 @@ static void freezer_attach(struct cgroup_subsys_state *new_css,
 	 * current state before executing the following - !frozen tasks may
 	 * be visible in a FROZEN cgroup and frozen tasks in a THAWED one.
 	 */
-	cgroup_taskset_for_each(task, tset) {
+	cgroup_taskset_for_each(task, new_css, tset) {
+		struct freezer *freezer = css_freezer(new_css);
+
 		if (!(freezer->state & CGROUP_FREEZING)) {
 			__thaw_task(task);
 		} else {
 			freeze_task(task);
-			freezer->state &= ~CGROUP_FROZEN;
-			clear_frozen = true;
+			/* clear FROZEN and propagate upwards */
+			while (freezer && (freezer->state & CGROUP_FROZEN)) {
+				freezer->state &= ~CGROUP_FROZEN;
+				freezer = parent_freezer(freezer);
+			}
 		}
 	}
 
-	/* propagate FROZEN clearing upwards */
-	while (clear_frozen && (freezer = parent_freezer(freezer))) {
-		freezer->state &= ~CGROUP_FROZEN;
-		clear_frozen = freezer->state & CGROUP_FREEZING;
-	}
-
 	mutex_unlock(&freezer_mutex);
 }
 
diff --git a/kernel/cgroup_pids.c b/kernel/cgroup_pids.c
index cdd8df4e991c..b50d5a167fda 100644
--- a/kernel/cgroup_pids.c
+++ b/kernel/cgroup_pids.c
@@ -106,7 +106,7 @@ static void pids_uncharge(struct pids_cgroup *pids, int num)
 {
 	struct pids_cgroup *p;
 
-	for (p = pids; p; p = parent_pids(p))
+	for (p = pids; parent_pids(p); p = parent_pids(p))
 		pids_cancel(p, num);
 }
 
@@ -123,7 +123,7 @@ static void pids_charge(struct pids_cgroup *pids, int num)
 {
 	struct pids_cgroup *p;
 
-	for (p = pids; p; p = parent_pids(p))
+	for (p = pids; parent_pids(p); p = parent_pids(p))
 		atomic64_add(num, &p->counter);
 }
 
@@ -140,7 +140,7 @@ static int pids_try_charge(struct pids_cgroup *pids, int num)
 {
 	struct pids_cgroup *p, *q;
 
-	for (p = pids; p; p = parent_pids(p)) {
+	for (p = pids; parent_pids(p); p = parent_pids(p)) {
 		int64_t new = atomic64_add_return(num, &p->counter);
 
 		/*
@@ -162,13 +162,13 @@ revert:
 	return -EAGAIN;
 }
 
-static int pids_can_attach(struct cgroup_subsys_state *css,
-			   struct cgroup_taskset *tset)
+static int pids_can_attach(struct cgroup_taskset *tset)
 {
-	struct pids_cgroup *pids = css_pids(css);
 	struct task_struct *task;
+	struct cgroup_subsys_state *dst_css;
 
-	cgroup_taskset_for_each(task, tset) {
+	cgroup_taskset_for_each(task, dst_css, tset) {
+		struct pids_cgroup *pids = css_pids(dst_css);
 		struct cgroup_subsys_state *old_css;
 		struct pids_cgroup *old_pids;
 
@@ -187,13 +187,13 @@ static int pids_can_attach(struct cgroup_subsys_state *css,
 	return 0;
 }
 
-static void pids_cancel_attach(struct cgroup_subsys_state *css,
-			       struct cgroup_taskset *tset)
+static void pids_cancel_attach(struct cgroup_taskset *tset)
 {
-	struct pids_cgroup *pids = css_pids(css);
 	struct task_struct *task;
+	struct cgroup_subsys_state *dst_css;
 
-	cgroup_taskset_for_each(task, tset) {
+	cgroup_taskset_for_each(task, dst_css, tset) {
+		struct pids_cgroup *pids = css_pids(dst_css);
 		struct cgroup_subsys_state *old_css;
 		struct pids_cgroup *old_pids;
 
@@ -205,65 +205,28 @@ static void pids_cancel_attach(struct cgroup_subsys_state *css,
 	}
 }
 
+/*
+ * task_css_check(true) in pids_can_fork() and pids_cancel_fork() relies
+ * on threadgroup_change_begin() held by the copy_process().
+ */
 static int pids_can_fork(struct task_struct *task, void **priv_p)
 {
 	struct cgroup_subsys_state *css;
 	struct pids_cgroup *pids;
-	int err;
 
-	/*
-	 * Use the "current" task_css for the pids subsystem as the tentative
-	 * css. It is possible we will charge the wrong hierarchy, in which
-	 * case we will forcefully revert/reapply the charge on the right
-	 * hierarchy after it is committed to the task proper.
-	 */
-	css = task_get_css(current, pids_cgrp_id);
+	css = task_css_check(current, pids_cgrp_id, true);
 	pids = css_pids(css);
-
-	err = pids_try_charge(pids, 1);
-	if (err)
-		goto err_css_put;
-
-	*priv_p = css;
-	return 0;
-
-err_css_put:
-	css_put(css);
-	return err;
+	return pids_try_charge(pids, 1);
 }
 
 static void pids_cancel_fork(struct task_struct *task, void *priv)
 {
-	struct cgroup_subsys_state *css = priv;
-	struct pids_cgroup *pids = css_pids(css);
-
-	pids_uncharge(pids, 1);
-	css_put(css);
-}
-
-static void pids_fork(struct task_struct *task, void *priv)
-{
 	struct cgroup_subsys_state *css;
-	struct cgroup_subsys_state *old_css = priv;
 	struct pids_cgroup *pids;
-	struct pids_cgroup *old_pids = css_pids(old_css);
 
-	css = task_get_css(task, pids_cgrp_id);
+	css = task_css_check(current, pids_cgrp_id, true);
 	pids = css_pids(css);
-
-	/*
-	 * If the association has changed, we have to revert and reapply the
-	 * charge/uncharge on the wrong hierarchy to the current one. Since
-	 * the association can only change due to an organisation event, its
-	 * okay for us to ignore the limit in this case.
-	 */
-	if (pids != old_pids) {
-		pids_uncharge(old_pids, 1);
-		pids_charge(pids, 1);
-	}
-
-	css_put(css);
-	css_put(old_css);
+	pids_uncharge(pids, 1);
 }
 
 static void pids_free(struct task_struct *task)
@@ -335,6 +298,7 @@ static struct cftype pids_files[] = {
 	{
 		.name = "current",
 		.read_s64 = pids_current_read,
+		.flags = CFTYPE_NOT_ON_ROOT,
 	},
 	{ }	/* terminate */
 };
@@ -346,7 +310,6 @@ struct cgroup_subsys pids_cgrp_subsys = {
 	.cancel_attach 	= pids_cancel_attach,
 	.can_fork	= pids_can_fork,
 	.cancel_fork	= pids_cancel_fork,
-	.fork		= pids_fork,
 	.free		= pids_free,
 	.legacy_cftypes	= pids_files,
 	.dfl_cftypes	= pids_files,
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 10ae73611d80..02a8ea5c9963 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1429,15 +1429,16 @@ static int fmeter_getrate(struct fmeter *fmp)
 static struct cpuset *cpuset_attach_old_cs;
 
 /* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */
-static int cpuset_can_attach(struct cgroup_subsys_state *css,
-			     struct cgroup_taskset *tset)
+static int cpuset_can_attach(struct cgroup_taskset *tset)
 {
-	struct cpuset *cs = css_cs(css);
+	struct cgroup_subsys_state *css;
+	struct cpuset *cs;
 	struct task_struct *task;
 	int ret;
 
 	/* used later by cpuset_attach() */
-	cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset));
+	cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset, &css));
+	cs = css_cs(css);
 
 	mutex_lock(&cpuset_mutex);
 
@@ -1447,7 +1448,7 @@ static int cpuset_can_attach(struct cgroup_subsys_state *css,
 	    (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)))
 		goto out_unlock;
 
-	cgroup_taskset_for_each(task, tset) {
+	cgroup_taskset_for_each(task, css, tset) {
 		ret = task_can_attach(task, cs->cpus_allowed);
 		if (ret)
 			goto out_unlock;
@@ -1467,9 +1468,14 @@ out_unlock:
 	return ret;
 }
 
-static void cpuset_cancel_attach(struct cgroup_subsys_state *css,
-				 struct cgroup_taskset *tset)
+static void cpuset_cancel_attach(struct cgroup_taskset *tset)
 {
+	struct cgroup_subsys_state *css;
+	struct cpuset *cs;
+
+	cgroup_taskset_first(tset, &css);
+	cs = css_cs(css);
+
 	mutex_lock(&cpuset_mutex);
 	css_cs(css)->attach_in_progress--;
 	mutex_unlock(&cpuset_mutex);
@@ -1482,16 +1488,19 @@ static void cpuset_cancel_attach(struct cgroup_subsys_state *css,
  */
 static cpumask_var_t cpus_attach;
 
-static void cpuset_attach(struct cgroup_subsys_state *css,
-			  struct cgroup_taskset *tset)
+static void cpuset_attach(struct cgroup_taskset *tset)
 {
 	/* static buf protected by cpuset_mutex */
 	static nodemask_t cpuset_attach_nodemask_to;
 	struct task_struct *task;
 	struct task_struct *leader;
-	struct cpuset *cs = css_cs(css);
+	struct cgroup_subsys_state *css;
+	struct cpuset *cs;
 	struct cpuset *oldcs = cpuset_attach_old_cs;
 
+	cgroup_taskset_first(tset, &css);
+	cs = css_cs(css);
+
 	mutex_lock(&cpuset_mutex);
 
 	/* prepare for attach */
@@ -1502,7 +1511,7 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
 
 	guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
 
-	cgroup_taskset_for_each(task, tset) {
+	cgroup_taskset_for_each(task, css, tset) {
 		/*
 		 * can_attach beforehand should guarantee that this doesn't
 		 * fail.  TODO: have a better way to handle failure here
@@ -1518,7 +1527,7 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
 	 * sleep and should be moved outside migration path proper.
 	 */
 	cpuset_attach_nodemask_to = cs->effective_mems;
-	cgroup_taskset_for_each_leader(leader, tset) {
+	cgroup_taskset_for_each_leader(leader, css, tset) {
 		struct mm_struct *mm = get_task_mm(leader);
 
 		if (mm) {
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index d659487254d5..9c418002b8c1 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -3,7 +3,7 @@
  *
  *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
  *  Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
- *  Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *  Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
  *  Copyright  ©  2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
  *
  * For licensing details see kernel-base/COPYING
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 36babfd20648..ef2d6ea10736 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3,7 +3,7 @@
  *
  *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
  *  Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
- *  Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *  Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
  *  Copyright  ©  2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
  *
  * For licensing details see kernel-base/COPYING
@@ -435,7 +435,7 @@ static inline void update_cgrp_time_from_event(struct perf_event *event)
 	if (!is_cgroup_event(event))
 		return;
 
-	cgrp = perf_cgroup_from_task(current);
+	cgrp = perf_cgroup_from_task(current, event->ctx);
 	/*
 	 * Do not update time when cgroup is not active
 	 */
@@ -458,7 +458,7 @@ perf_cgroup_set_timestamp(struct task_struct *task,
 	if (!task || !ctx->nr_cgroups)
 		return;
 
-	cgrp = perf_cgroup_from_task(task);
+	cgrp = perf_cgroup_from_task(task, ctx);
 	info = this_cpu_ptr(cgrp->info);
 	info->timestamp = ctx->timestamp;
 }
@@ -489,7 +489,6 @@ static void perf_cgroup_switch(struct task_struct *task, int mode)
 	 * we reschedule only in the presence of cgroup
 	 * constrained events.
 	 */
-	rcu_read_lock();
 
 	list_for_each_entry_rcu(pmu, &pmus, entry) {
 		cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
@@ -522,8 +521,10 @@ static void perf_cgroup_switch(struct task_struct *task, int mode)
 				 * set cgrp before ctxsw in to allow
 				 * event_filter_match() to not have to pass
 				 * task around
+				 * we pass the cpuctx->ctx to perf_cgroup_from_task()
+				 * because cgorup events are only per-cpu
 				 */
-				cpuctx->cgrp = perf_cgroup_from_task(task);
+				cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx);
 				cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);
 			}
 			perf_pmu_enable(cpuctx->ctx.pmu);
@@ -531,8 +532,6 @@ static void perf_cgroup_switch(struct task_struct *task, int mode)
 		}
 	}
 
-	rcu_read_unlock();
-
 	local_irq_restore(flags);
 }
 
@@ -542,17 +541,20 @@ static inline void perf_cgroup_sched_out(struct task_struct *task,
 	struct perf_cgroup *cgrp1;
 	struct perf_cgroup *cgrp2 = NULL;
 
+	rcu_read_lock();
 	/*
 	 * we come here when we know perf_cgroup_events > 0
+	 * we do not need to pass the ctx here because we know
+	 * we are holding the rcu lock
 	 */
-	cgrp1 = perf_cgroup_from_task(task);
+	cgrp1 = perf_cgroup_from_task(task, NULL);
 
 	/*
 	 * next is NULL when called from perf_event_enable_on_exec()
 	 * that will systematically cause a cgroup_switch()
 	 */
 	if (next)
-		cgrp2 = perf_cgroup_from_task(next);
+		cgrp2 = perf_cgroup_from_task(next, NULL);
 
 	/*
 	 * only schedule out current cgroup events if we know
@@ -561,6 +563,8 @@ static inline void perf_cgroup_sched_out(struct task_struct *task,
 	 */
 	if (cgrp1 != cgrp2)
 		perf_cgroup_switch(task, PERF_CGROUP_SWOUT);
+
+	rcu_read_unlock();
 }
 
 static inline void perf_cgroup_sched_in(struct task_struct *prev,
@@ -569,13 +573,16 @@ static inline void perf_cgroup_sched_in(struct task_struct *prev,
 	struct perf_cgroup *cgrp1;
 	struct perf_cgroup *cgrp2 = NULL;
 
+	rcu_read_lock();
 	/*
 	 * we come here when we know perf_cgroup_events > 0
+	 * we do not need to pass the ctx here because we know
+	 * we are holding the rcu lock
 	 */
-	cgrp1 = perf_cgroup_from_task(task);
+	cgrp1 = perf_cgroup_from_task(task, NULL);
 
 	/* prev can never be NULL */
-	cgrp2 = perf_cgroup_from_task(prev);
+	cgrp2 = perf_cgroup_from_task(prev, NULL);
 
 	/*
 	 * only need to schedule in cgroup events if we are changing
@@ -584,6 +591,8 @@ static inline void perf_cgroup_sched_in(struct task_struct *prev,
 	 */
 	if (cgrp1 != cgrp2)
 		perf_cgroup_switch(task, PERF_CGROUP_SWIN);
+
+	rcu_read_unlock();
 }
 
 static inline int perf_cgroup_connect(int fd, struct perf_event *event,
@@ -4216,7 +4225,14 @@ retry:
 		goto retry;
 	}
 
-	__perf_event_period(&pe);
+	if (event->attr.freq) {
+		event->attr.sample_freq = value;
+	} else {
+		event->attr.sample_period = value;
+		event->hw.sample_period = value;
+	}
+
+	local64_set(&event->hw.period_left, 0);
 	raw_spin_unlock_irq(&ctx->lock);
 
 	return 0;
@@ -5667,6 +5683,17 @@ perf_event_aux_ctx(struct perf_event_context *ctx,
 }
 
 static void
+perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data,
+			struct perf_event_context *task_ctx)
+{
+	rcu_read_lock();
+	preempt_disable();
+	perf_event_aux_ctx(task_ctx, output, data);
+	preempt_enable();
+	rcu_read_unlock();
+}
+
+static void
 perf_event_aux(perf_event_aux_output_cb output, void *data,
 	       struct perf_event_context *task_ctx)
 {
@@ -5675,14 +5702,23 @@ perf_event_aux(perf_event_aux_output_cb output, void *data,
 	struct pmu *pmu;
 	int ctxn;
 
+	/*
+	 * If we have task_ctx != NULL we only notify
+	 * the task context itself. The task_ctx is set
+	 * only for EXIT events before releasing task
+	 * context.
+	 */
+	if (task_ctx) {
+		perf_event_aux_task_ctx(output, data, task_ctx);
+		return;
+	}
+
 	rcu_read_lock();
 	list_for_each_entry_rcu(pmu, &pmus, entry) {
 		cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
 		if (cpuctx->unique_pmu != pmu)
 			goto next;
 		perf_event_aux_ctx(&cpuctx->ctx, output, data);
-		if (task_ctx)
-			goto next;
 		ctxn = pmu->task_ctx_nr;
 		if (ctxn < 0)
 			goto next;
@@ -5692,12 +5728,6 @@ perf_event_aux(perf_event_aux_output_cb output, void *data,
 next:
 		put_cpu_ptr(pmu->pmu_cpu_context);
 	}
-
-	if (task_ctx) {
-		preempt_disable();
-		perf_event_aux_ctx(task_ctx, output, data);
-		preempt_enable();
-	}
 	rcu_read_unlock();
 }
 
@@ -8787,10 +8817,8 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
 	struct perf_event_context *child_ctx, *clone_ctx = NULL;
 	unsigned long flags;
 
-	if (likely(!child->perf_event_ctxp[ctxn])) {
-		perf_event_task(child, NULL, 0);
+	if (likely(!child->perf_event_ctxp[ctxn]))
 		return;
-	}
 
 	local_irq_save(flags);
 	/*
@@ -8874,6 +8902,14 @@ void perf_event_exit_task(struct task_struct *child)
 
 	for_each_task_context_nr(ctxn)
 		perf_event_exit_task_context(child, ctxn);
+
+	/*
+	 * The perf_event_exit_task_context calls perf_event_task
+	 * with child's task_ctx, which generates EXIT events for
+	 * child contexts and sets child->perf_event_ctxp[] to NULL.
+	 * At this point we need to send EXIT events to cpu contexts.
+	 */
+	perf_event_task(child, NULL, 0);
 }
 
 static void perf_free_event(struct perf_event *event,
@@ -9452,16 +9488,18 @@ static void perf_cgroup_css_free(struct cgroup_subsys_state *css)
 static int __perf_cgroup_move(void *info)
 {
 	struct task_struct *task = info;
+	rcu_read_lock();
 	perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN);
+	rcu_read_unlock();
 	return 0;
 }
 
-static void perf_cgroup_attach(struct cgroup_subsys_state *css,
-			       struct cgroup_taskset *tset)
+static void perf_cgroup_attach(struct cgroup_taskset *tset)
 {
 	struct task_struct *task;
+	struct cgroup_subsys_state *css;
 
-	cgroup_taskset_for_each(task, tset)
+	cgroup_taskset_for_each(task, css, tset)
 		task_function_call(task, __perf_cgroup_move, task);
 }
 
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index b5d1ea79c595..adfdc0536117 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -3,7 +3,7 @@
  *
  *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
  *  Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
- *  Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *  Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
  *  Copyright  ©  2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
  *
  * For licensing details see kernel-base/COPYING
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 4e5e9798aa0c..7dad84913abf 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -19,7 +19,7 @@
  * Authors:
  *	Srikar Dronamraju
  *	Jim Keniston
- * Copyright (C) 2011-2012 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ * Copyright (C) 2011-2012 Red Hat, Inc., Peter Zijlstra
  */
 
 #include <linux/kernel.h>
diff --git a/kernel/fork.c b/kernel/fork.c
index f97f2c449f5c..fce002ee3ddf 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1368,8 +1368,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	p->real_start_time = ktime_get_boot_ns();
 	p->io_context = NULL;
 	p->audit_context = NULL;
-	if (clone_flags & CLONE_THREAD)
-		threadgroup_change_begin(current);
+	threadgroup_change_begin(current);
 	cgroup_fork(p);
 #ifdef CONFIG_NUMA
 	p->mempolicy = mpol_dup(p->mempolicy);
@@ -1610,8 +1609,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 
 	proc_fork_connector(p);
 	cgroup_post_fork(p, cgrp_ss_priv);
-	if (clone_flags & CLONE_THREAD)
-		threadgroup_change_end(current);
+	threadgroup_change_end(current);
 	perf_event_fork(p);
 
 	trace_task_newtask(p, clone_flags);
@@ -1652,8 +1650,7 @@ bad_fork_cleanup_policy:
 	mpol_put(p->mempolicy);
 bad_fork_cleanup_threadgroup_lock:
 #endif
-	if (clone_flags & CLONE_THREAD)
-		threadgroup_change_end(current);
+	threadgroup_change_end(current);
 	delayacct_tsk_free(p);
 bad_fork_cleanup_count:
 	atomic_dec(&p->cred->user->processes);
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index cbf9fb899d92..bcf107ce0854 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2010 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ * Copyright (C) 2010 Red Hat, Inc., Peter Zijlstra
  *
  * Provides a framework for enqueueing and running callbacks from hardirq
  * context. The enqueueing is NMI-safe.
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index f7dd15d537f9..05254eeb4b4e 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -2,7 +2,7 @@
  * jump label support
  *
  * Copyright (C) 2009 Jason Baron <jbaron@redhat.com>
- * Copyright (C) 2011 Peter Zijlstra <pzijlstr@redhat.com>
+ * Copyright (C) 2011 Peter Zijlstra
  *
  */
 #include <linux/memory.h>
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index deae3907ac1e..60ace56618f6 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -6,7 +6,7 @@
  * Started by Ingo Molnar:
  *
  *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
- *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
  *
  * this code maps all the lock dependencies as they occur in a live kernel
  * and will warn about the following classes of locking bugs:
diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index d83d798bef95..dbb61a302548 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -6,7 +6,7 @@
  * Started by Ingo Molnar:
  *
  *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
- *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
  *
  * Code for /proc/lockdep and /proc/lockdep_stats:
  *
diff --git a/kernel/pid.c b/kernel/pid.c
index ca368793808e..78b3d9f80d44 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -467,7 +467,7 @@ struct pid *get_task_pid(struct task_struct *task, enum pid_type type)
 	rcu_read_lock();
 	if (type != PIDTYPE_PID)
 		task = task->group_leader;
-	pid = get_pid(task->pids[type].pid);
+	pid = get_pid(rcu_dereference(task->pids[type].pid));
 	rcu_read_unlock();
 	return pid;
 }
@@ -528,7 +528,7 @@ pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
 	if (likely(pid_alive(task))) {
 		if (type != PIDTYPE_PID)
 			task = task->group_leader;
-		nr = pid_nr_ns(task->pids[type].pid, ns);
+		nr = pid_nr_ns(rcu_dereference(task->pids[type].pid), ns);
 	}
 	rcu_read_unlock();
 
diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index c0a205101c23..caf4041f5b0a 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -1,7 +1,7 @@
 /*
  * sched_clock for unstable cpu clocks
  *
- *  Copyright (C) 2008 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *  Copyright (C) 2008 Red Hat, Inc., Peter Zijlstra
  *
  *  Updates and enhancements:
  *    Copyright (C) 2008 Red Hat, Inc. Steven Rostedt <srostedt@redhat.com>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4d568ac9319e..732e993b564b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1947,13 +1947,38 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
 
 #ifdef CONFIG_SMP
 	/*
+	 * Ensure we load p->on_cpu _after_ p->on_rq, otherwise it would be
+	 * possible to, falsely, observe p->on_cpu == 0.
+	 *
+	 * One must be running (->on_cpu == 1) in order to remove oneself
+	 * from the runqueue.
+	 *
+	 *  [S] ->on_cpu = 1;	[L] ->on_rq
+	 *      UNLOCK rq->lock
+	 *			RMB
+	 *      LOCK   rq->lock
+	 *  [S] ->on_rq = 0;    [L] ->on_cpu
+	 *
+	 * Pairs with the full barrier implied in the UNLOCK+LOCK on rq->lock
+	 * from the consecutive calls to schedule(); the first switching to our
+	 * task, the second putting it to sleep.
+	 */
+	smp_rmb();
+
+	/*
 	 * If the owning (remote) cpu is still in the middle of schedule() with
 	 * this task as prev, wait until its done referencing the task.
 	 */
 	while (p->on_cpu)
 		cpu_relax();
 	/*
-	 * Pairs with the smp_wmb() in finish_lock_switch().
+	 * Combined with the control dependency above, we have an effective
+	 * smp_load_acquire() without the need for full barriers.
+	 *
+	 * Pairs with the smp_store_release() in finish_lock_switch().
+	 *
+	 * This ensures that tasks getting woken will be fully ordered against
+	 * their previous state and preserve Program Order.
 	 */
 	smp_rmb();
 
@@ -2039,7 +2064,6 @@ out:
  */
 int wake_up_process(struct task_struct *p)
 {
-	WARN_ON(task_is_stopped_or_traced(p));
 	return try_to_wake_up(p, TASK_NORMAL, 0);
 }
 EXPORT_SYMBOL(wake_up_process);
@@ -5847,13 +5871,13 @@ static int init_rootdomain(struct root_domain *rd)
 {
 	memset(rd, 0, sizeof(*rd));
 
-	if (!alloc_cpumask_var(&rd->span, GFP_KERNEL))
+	if (!zalloc_cpumask_var(&rd->span, GFP_KERNEL))
 		goto out;
-	if (!alloc_cpumask_var(&rd->online, GFP_KERNEL))
+	if (!zalloc_cpumask_var(&rd->online, GFP_KERNEL))
 		goto free_span;
-	if (!alloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL))
+	if (!zalloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL))
 		goto free_online;
-	if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
+	if (!zalloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
 		goto free_dlo_mask;
 
 	init_dl_bw(&rd->dl_bw);
@@ -8217,12 +8241,12 @@ static void cpu_cgroup_fork(struct task_struct *task, void *private)
 	sched_move_task(task);
 }
 
-static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css,
-				 struct cgroup_taskset *tset)
+static int cpu_cgroup_can_attach(struct cgroup_taskset *tset)
 {
 	struct task_struct *task;
+	struct cgroup_subsys_state *css;
 
-	cgroup_taskset_for_each(task, tset) {
+	cgroup_taskset_for_each(task, css, tset) {
 #ifdef CONFIG_RT_GROUP_SCHED
 		if (!sched_rt_can_attach(css_tg(css), task))
 			return -EINVAL;
@@ -8235,12 +8259,12 @@ static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css,
 	return 0;
 }
 
-static void cpu_cgroup_attach(struct cgroup_subsys_state *css,
-			      struct cgroup_taskset *tset)
+static void cpu_cgroup_attach(struct cgroup_taskset *tset)
 {
 	struct task_struct *task;
+	struct cgroup_subsys_state *css;
 
-	cgroup_taskset_for_each(task, tset)
+	cgroup_taskset_for_each(task, css, tset)
 		sched_move_task(task);
 }
 
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 26a54461bf59..05de80b48586 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -788,6 +788,9 @@ cputime_t task_gtime(struct task_struct *t)
 	unsigned int seq;
 	cputime_t gtime;
 
+	if (!context_tracking_is_enabled())
+		return t->gtime;
+
 	do {
 		seq = read_seqbegin(&t->vtime_seqlock);
 
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f04fda8f669c..90e26b11deaa 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -17,7 +17,7 @@
  *  Copyright (C) 2007, Thomas Gleixner <tglx@linutronix.de>
  *
  *  Adaptive scheduling granularity, math enhancements by Peter Zijlstra
- *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
  */
 
 #include <linux/latencytop.h>
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index e3cc16312046..8ec86abe0ea1 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -64,7 +64,7 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
 	raw_spin_unlock(&rt_b->rt_runtime_lock);
 }
 
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) && defined(HAVE_RT_PUSH_IPI)
 static void push_irq_work_func(struct irq_work *work);
 #endif
 
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index efd3bfc7e347..b242775bf670 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1073,6 +1073,9 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
 	 * We must ensure this doesn't happen until the switch is completely
 	 * finished.
 	 *
+	 * In particular, the load of prev->state in finish_task_switch() must
+	 * happen before this.
+	 *
 	 * Pairs with the control dependency and rmb in try_to_wake_up().
 	 */
 	smp_store_release(&prev->on_cpu, 0);
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index 052e02672d12..f15d6b6a538a 100644
--- a/kernel/sched/wait.c
+++ b/kernel/sched/wait.c
@@ -392,7 +392,7 @@ __wait_on_bit(wait_queue_head_t *wq, struct wait_bit_queue *q,
 	do {
 		prepare_to_wait(wq, &q->wait, mode);
 		if (test_bit(q->key.bit_nr, q->key.flags))
-			ret = (*action)(&q->key);
+			ret = (*action)(&q->key, mode);
 	} while (test_bit(q->key.bit_nr, q->key.flags) && !ret);
 	finish_wait(wq, &q->wait);
 	return ret;
@@ -431,7 +431,7 @@ __wait_on_bit_lock(wait_queue_head_t *wq, struct wait_bit_queue *q,
 		prepare_to_wait_exclusive(wq, &q->wait, mode);
 		if (!test_bit(q->key.bit_nr, q->key.flags))
 			continue;
-		ret = action(&q->key);
+		ret = action(&q->key, mode);
 		if (!ret)
 			continue;
 		abort_exclusive_wait(wq, &q->wait, mode, &q->key);
@@ -581,44 +581,44 @@ void wake_up_atomic_t(atomic_t *p)
 }
 EXPORT_SYMBOL(wake_up_atomic_t);
 
-__sched int bit_wait(struct wait_bit_key *word)
+__sched int bit_wait(struct wait_bit_key *word, int mode)
 {
-	if (signal_pending_state(current->state, current))
-		return 1;
 	schedule();
+	if (signal_pending_state(mode, current))
+		return -EINTR;
 	return 0;
 }
 EXPORT_SYMBOL(bit_wait);
 
-__sched int bit_wait_io(struct wait_bit_key *word)
+__sched int bit_wait_io(struct wait_bit_key *word, int mode)
 {
-	if (signal_pending_state(current->state, current))
-		return 1;
 	io_schedule();
+	if (signal_pending_state(mode, current))
+		return -EINTR;
 	return 0;
 }
 EXPORT_SYMBOL(bit_wait_io);
 
-__sched int bit_wait_timeout(struct wait_bit_key *word)
+__sched int bit_wait_timeout(struct wait_bit_key *word, int mode)
 {
 	unsigned long now = READ_ONCE(jiffies);
-	if (signal_pending_state(current->state, current))
-		return 1;
 	if (time_after_eq(now, word->timeout))
 		return -EAGAIN;
 	schedule_timeout(word->timeout - now);
+	if (signal_pending_state(mode, current))
+		return -EINTR;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(bit_wait_timeout);
 
-__sched int bit_wait_io_timeout(struct wait_bit_key *word)
+__sched int bit_wait_io_timeout(struct wait_bit_key *word, int mode)
 {
 	unsigned long now = READ_ONCE(jiffies);
-	if (signal_pending_state(current->state, current))
-		return 1;
 	if (time_after_eq(now, word->timeout))
 		return -EAGAIN;
 	io_schedule_timeout(word->timeout - now);
+	if (signal_pending_state(mode, current))
+		return -EINTR;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(bit_wait_io_timeout);
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 867bc20e1ef1..a3bbaee77c58 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -531,7 +531,7 @@ static int __init cpu_stop_init(void)
 }
 early_initcall(cpu_stop_init);
 
-#ifdef CONFIG_STOP_MACHINE
+#if defined(CONFIG_SMP) || defined(CONFIG_HOTPLUG_CPU)
 
 static int __stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus)
 {
@@ -631,4 +631,4 @@ int stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data,
 	return ret ?: done.ret;
 }
 
-#endif	/* CONFIG_STOP_MACHINE */
+#endif	/* CONFIG_SMP || CONFIG_HOTPLUG_CPU */
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 75f1d05ea82d..9c6045a27ba3 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1887,12 +1887,6 @@ rb_event_index(struct ring_buffer_event *event)
 	return (addr & ~PAGE_MASK) - BUF_PAGE_HDR_SIZE;
 }
 
-static void rb_reset_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
-{
-	cpu_buffer->read_stamp = cpu_buffer->reader_page->page->time_stamp;
-	cpu_buffer->reader_page->read = 0;
-}
-
 static void rb_inc_iter(struct ring_buffer_iter *iter)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
@@ -2803,8 +2797,11 @@ rb_reserve_next_event(struct ring_buffer *buffer,
 
 	event = __rb_reserve_next(cpu_buffer, &info);
 
-	if (unlikely(PTR_ERR(event) == -EAGAIN))
+	if (unlikely(PTR_ERR(event) == -EAGAIN)) {
+		if (info.add_timestamp)
+			info.length -= RB_LEN_TIME_EXTEND;
 		goto again;
+	}
 
 	if (!event)
 		goto out_fail;
@@ -3626,7 +3623,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 
 	/* Finally update the reader page to the new head */
 	cpu_buffer->reader_page = reader;
-	rb_reset_reader_page(cpu_buffer);
+	cpu_buffer->reader_page->read = 0;
 
 	if (overwrite != cpu_buffer->last_overrun) {
 		cpu_buffer->lost_events = overwrite - cpu_buffer->last_overrun;
@@ -3636,6 +3633,10 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 	goto again;
 
  out:
+	/* Update the read_stamp on the first event */
+	if (reader && reader->read == 0)
+		cpu_buffer->read_stamp = reader->page->time_stamp;
+
 	arch_spin_unlock(&cpu_buffer->lock);
 	local_irq_restore(flags);
 
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index abfc903e741e..cc9f7a9319be 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -1,7 +1,7 @@
 /*
  * trace event based perf event profiling/tracing
  *
- * Copyright (C) 2009 Red Hat Inc, Peter Zijlstra <pzijlstr@redhat.com>
+ * Copyright (C) 2009 Red Hat Inc, Peter Zijlstra
  * Copyright (C) 2009-2010 Frederic Weisbecker <fweisbec@gmail.com>
  */
 
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 6bbc5f652355..4f6ef6912e00 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -582,6 +582,12 @@ static void __ftrace_clear_event_pids(struct trace_array *tr)
 	unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
 	unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
 
+	unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
+	unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
+
+	unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
+	unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
+
 	list_for_each_entry(file, &tr->events, list) {
 		clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
 	}
@@ -1729,6 +1735,16 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
 						 tr, INT_MAX);
 		register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
 						 tr, 0);
+
+		register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
+						     tr, INT_MAX);
+		register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
+						     tr, 0);
+
+		register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
+						 tr, INT_MAX);
+		register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
+						 tr, 0);
 	}
 
 	/*