Merge tag 'v5.4-rc7' into perf/core, to pick up fixes

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

kernel/bpf/cgroup.c

@@ -1311,12 +1311,12 @@ static bool sysctl_is_valid_access(int off, int size, enum bpf_access_type type,
 		return false;
 
 	switch (off) {
-	case offsetof(struct bpf_sysctl, write):
+	case bpf_ctx_range(struct bpf_sysctl, write):
 		if (type != BPF_READ)
 			return false;
 		bpf_ctx_record_field_size(info, size_default);
 		return bpf_ctx_narrow_access_ok(off, size, size_default);
-	case offsetof(struct bpf_sysctl, file_pos):
+	case bpf_ctx_range(struct bpf_sysctl, file_pos):
 		if (type == BPF_READ) {
 			bpf_ctx_record_field_size(info, size_default);
 			return bpf_ctx_narrow_access_ok(off, size, size_default);

kernel/bpf/core.c

@@ -502,7 +502,7 @@ int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
 	return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
 }
 
-void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
+static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
 {
 	int i;
 

kernel/bpf/devmap.c

@@ -128,7 +128,7 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
 
 		if (!dtab->n_buckets) /* Overflow check */
 			return -EINVAL;
-		cost += sizeof(struct hlist_head) * dtab->n_buckets;
+		cost += (u64) sizeof(struct hlist_head) * dtab->n_buckets;
 	}
 
 	/* if map size is larger than memlock limit, reject it */
@@ -719,6 +719,32 @@ const struct bpf_map_ops dev_map_hash_ops = {
 	.map_check_btf = map_check_no_btf,
 };
 
+static void dev_map_hash_remove_netdev(struct bpf_dtab *dtab,
+				       struct net_device *netdev)
+{
+	unsigned long flags;
+	u32 i;
+
+	spin_lock_irqsave(&dtab->index_lock, flags);
+	for (i = 0; i < dtab->n_buckets; i++) {
+		struct bpf_dtab_netdev *dev;
+		struct hlist_head *head;
+		struct hlist_node *next;
+
+		head = dev_map_index_hash(dtab, i);
+
+		hlist_for_each_entry_safe(dev, next, head, index_hlist) {
+			if (netdev != dev->dev)
+				continue;
+
+			dtab->items--;
+			hlist_del_rcu(&dev->index_hlist);
+			call_rcu(&dev->rcu, __dev_map_entry_free);
+		}
+	}
+	spin_unlock_irqrestore(&dtab->index_lock, flags);
+}
+
 static int dev_map_notification(struct notifier_block *notifier,
 				ulong event, void *ptr)
 {
@@ -735,6 +761,11 @@ static int dev_map_notification(struct notifier_block *notifier,
 		 */
 		rcu_read_lock();
 		list_for_each_entry_rcu(dtab, &dev_map_list, list) {
+			if (dtab->map.map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+				dev_map_hash_remove_netdev(dtab, netdev);
+				continue;
+			}
+
 			for (i = 0; i < dtab->map.max_entries; i++) {
 				struct bpf_dtab_netdev *dev, *odev;
 

kernel/bpf/syscall.c

@@ -126,7 +126,7 @@ static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
 	return map;
 }
 
-void *bpf_map_area_alloc(size_t size, int numa_node)
+void *bpf_map_area_alloc(u64 size, int numa_node)
 {
 	/* We really just want to fail instead of triggering OOM killer
 	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
@@ -141,6 +141,9 @@ void *bpf_map_area_alloc(size_t size, int numa_node)
 	const gfp_t flags = __GFP_NOWARN | __GFP_ZERO;
 	void *area;
 
+	if (size >= SIZE_MAX)
+		return NULL;
+
 	if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
 		area = kmalloc_node(size, GFP_USER | __GFP_NORETRY | flags,
 				    numa_node);
@@ -197,7 +200,7 @@ static void bpf_uncharge_memlock(struct user_struct *user, u32 pages)
 		atomic_long_sub(pages, &user->locked_vm);
 }
 
-int bpf_map_charge_init(struct bpf_map_memory *mem, size_t size)
+int bpf_map_charge_init(struct bpf_map_memory *mem, u64 size)
 {
 	u32 pages = round_up(size, PAGE_SIZE) >> PAGE_SHIFT;
 	struct user_struct *user;
@@ -1326,24 +1329,32 @@ static void __bpf_prog_put_rcu(struct rcu_head *rcu)
 {
 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
 
+	kvfree(aux->func_info);
 	free_used_maps(aux);
 	bpf_prog_uncharge_memlock(aux->prog);
 	security_bpf_prog_free(aux);
 	bpf_prog_free(aux->prog);
 }
 
+static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
+{
+	bpf_prog_kallsyms_del_all(prog);
+	btf_put(prog->aux->btf);
+	bpf_prog_free_linfo(prog);
+
+	if (deferred)
+		call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
+	else
+		__bpf_prog_put_rcu(&prog->aux->rcu);
+}
+
 static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
 {
 	if (atomic_dec_and_test(&prog->aux->refcnt)) {
 		perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
 		/* bpf_prog_free_id() must be called first */
 		bpf_prog_free_id(prog, do_idr_lock);
-		bpf_prog_kallsyms_del_all(prog);
-		btf_put(prog->aux->btf);
-		kvfree(prog->aux->func_info);
-		bpf_prog_free_linfo(prog);
-
-		call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
+		__bpf_prog_put_noref(prog, true);
 	}
 }
 
@@ -1741,11 +1752,12 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
 	return err;
 
 free_used_maps:
-	bpf_prog_free_linfo(prog);
-	kvfree(prog->aux->func_info);
-	btf_put(prog->aux->btf);
-	bpf_prog_kallsyms_del_subprogs(prog);
-	free_used_maps(prog->aux);
+	/* In case we have subprogs, we need to wait for a grace
+	 * period before we can tear down JIT memory since symbols
+	 * are already exposed under kallsyms.
+	 */
+	__bpf_prog_put_noref(prog, prog->aux->func_cnt);
+	return err;
 free_prog:
 	bpf_prog_uncharge_memlock(prog);
 free_prog_sec:

kernel/cgroup/cpuset.c

@@ -798,7 +798,8 @@ static int generate_sched_domains(cpumask_var_t **domains,
 		    cpumask_subset(cp->cpus_allowed, top_cpuset.effective_cpus))
 			continue;
 
-		if (is_sched_load_balance(cp))
+		if (is_sched_load_balance(cp) &&
+		    !cpumask_empty(cp->effective_cpus))
 			csa[csn++] = cp;
 
 		/* skip @cp's subtree if not a partition root */

kernel/fork.c

@@ -2561,7 +2561,35 @@ noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
 	return 0;
 }
 
-static bool clone3_args_valid(const struct kernel_clone_args *kargs)
+/**
+ * clone3_stack_valid - check and prepare stack
+ * @kargs: kernel clone args
+ *
+ * Verify that the stack arguments userspace gave us are sane.
+ * In addition, set the stack direction for userspace since it's easy for us to
+ * determine.
+ */
+static inline bool clone3_stack_valid(struct kernel_clone_args *kargs)
+{
+	if (kargs->stack == 0) {
+		if (kargs->stack_size > 0)
+			return false;
+	} else {
+		if (kargs->stack_size == 0)
+			return false;
+
+		if (!access_ok((void __user *)kargs->stack, kargs->stack_size))
+			return false;
+
+#if !defined(CONFIG_STACK_GROWSUP) && !defined(CONFIG_IA64)
+		kargs->stack += kargs->stack_size;
+#endif
+	}
+
+	return true;
+}
+
+static bool clone3_args_valid(struct kernel_clone_args *kargs)
 {
 	/*
 	 * All lower bits of the flag word are taken.
@@ -2581,6 +2609,9 @@ static bool clone3_args_valid(const struct kernel_clone_args *kargs)
 	    kargs->exit_signal)
 		return false;
 
+	if (!clone3_stack_valid(kargs))
+		return false;
+
 	return true;
 }
 

kernel/irq/irqdomain.c

@@ -51,7 +51,7 @@ EXPORT_SYMBOL_GPL(irqchip_fwnode_ops);
  * @type:	Type of irqchip_fwnode. See linux/irqdomain.h
  * @name:	Optional user provided domain name
  * @id:		Optional user provided id if name != NULL
- * @data:	Optional user-provided data
+ * @pa:		Optional user-provided physical address
  *
  * Allocate a struct irqchip_fwid, and return a poiner to the embedded
  * fwnode_handle (or NULL on failure).

kernel/sched/core.c

@@ -1073,6 +1073,7 @@ uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id)
 	task_rq_unlock(rq, p, &rf);
 }
 
+#ifdef CONFIG_UCLAMP_TASK_GROUP
 static inline void
 uclamp_update_active_tasks(struct cgroup_subsys_state *css,
 			   unsigned int clamps)
@@ -1091,7 +1092,6 @@ uclamp_update_active_tasks(struct cgroup_subsys_state *css,
 	css_task_iter_end(&it);
 }
 
-#ifdef CONFIG_UCLAMP_TASK_GROUP
 static void cpu_util_update_eff(struct cgroup_subsys_state *css);
 static void uclamp_update_root_tg(void)
 {
@@ -3929,13 +3929,22 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 	}
 
 restart:
+#ifdef CONFIG_SMP
 	/*
-	 * Ensure that we put DL/RT tasks before the pick loop, such that they
-	 * can PULL higher prio tasks when we lower the RQ 'priority'.
+	 * We must do the balancing pass before put_next_task(), such
+	 * that when we release the rq->lock the task is in the same
+	 * state as before we took rq->lock.
+	 *
+	 * We can terminate the balance pass as soon as we know there is
+	 * a runnable task of @class priority or higher.
 	 */
-	prev->sched_class->put_prev_task(rq, prev, rf);
-	if (!rq->nr_running)
-		newidle_balance(rq, rf);
+	for_class_range(class, prev->sched_class, &idle_sched_class) {
+		if (class->balance(rq, prev, rf))
+			break;
+	}
+#endif
+
+	put_prev_task(rq, prev);
 
 	for_each_class(class) {
 		p = class->pick_next_task(rq, NULL, NULL);
@@ -6201,7 +6210,7 @@ static struct task_struct *__pick_migrate_task(struct rq *rq)
 	for_each_class(class) {
 		next = class->pick_next_task(rq, NULL, NULL);
 		if (next) {
-			next->sched_class->put_prev_task(rq, next, NULL);
+			next->sched_class->put_prev_task(rq, next);
 			return next;
 		}
 	}

kernel/sched/deadline.c

@@ -1691,6 +1691,22 @@ static void check_preempt_equal_dl(struct rq *rq, struct task_struct *p)
 	resched_curr(rq);
 }
 
+static int balance_dl(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
+{
+	if (!on_dl_rq(&p->dl) && need_pull_dl_task(rq, p)) {
+		/*
+		 * This is OK, because current is on_cpu, which avoids it being
+		 * picked for load-balance and preemption/IRQs are still
+		 * disabled avoiding further scheduler activity on it and we've
+		 * not yet started the picking loop.
+		 */
+		rq_unpin_lock(rq, rf);
+		pull_dl_task(rq);
+		rq_repin_lock(rq, rf);
+	}
+
+	return sched_stop_runnable(rq) || sched_dl_runnable(rq);
+}
 #endif /* CONFIG_SMP */
 
 /*
@@ -1758,45 +1774,28 @@ static struct task_struct *
 pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 {
 	struct sched_dl_entity *dl_se;
+	struct dl_rq *dl_rq = &rq->dl;
 	struct task_struct *p;
-	struct dl_rq *dl_rq;
 
 	WARN_ON_ONCE(prev || rf);
 
-	dl_rq = &rq->dl;
-
-	if (unlikely(!dl_rq->dl_nr_running))
+	if (!sched_dl_runnable(rq))
 		return NULL;
 
 	dl_se = pick_next_dl_entity(rq, dl_rq);
 	BUG_ON(!dl_se);
-
 	p = dl_task_of(dl_se);
-
 	set_next_task_dl(rq, p);
-
 	return p;
 }
 
-static void put_prev_task_dl(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
+static void put_prev_task_dl(struct rq *rq, struct task_struct *p)
 {
 	update_curr_dl(rq);
 
 	update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 1);
 	if (on_dl_rq(&p->dl) && p->nr_cpus_allowed > 1)
 		enqueue_pushable_dl_task(rq, p);
-
-	if (rf && !on_dl_rq(&p->dl) && need_pull_dl_task(rq, p)) {
-		/*
-		 * This is OK, because current is on_cpu, which avoids it being
-		 * picked for load-balance and preemption/IRQs are still
-		 * disabled avoiding further scheduler activity on it and we've
-		 * not yet started the picking loop.
-		 */
-		rq_unpin_lock(rq, rf);
-		pull_dl_task(rq);
-		rq_repin_lock(rq, rf);
-	}
 }
 
 /*
@@ -2442,6 +2441,7 @@ const struct sched_class dl_sched_class = {
 	.set_next_task		= set_next_task_dl,
 
 #ifdef CONFIG_SMP
+	.balance		= balance_dl,
 	.select_task_rq		= select_task_rq_dl,
 	.migrate_task_rq	= migrate_task_rq_dl,
 	.set_cpus_allowed       = set_cpus_allowed_dl,

kernel/sched/fair.c

@@ -6570,6 +6570,15 @@ static void task_dead_fair(struct task_struct *p)
 {
 	remove_entity_load_avg(&p->se);
 }
+
+static int
+balance_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+{
+	if (rq->nr_running)
+		return 1;
+
+	return newidle_balance(rq, rf) != 0;
+}
 #endif /* CONFIG_SMP */
 
 static unsigned long wakeup_gran(struct sched_entity *se)
@@ -6746,7 +6755,7 @@ pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf
 	int new_tasks;
 
 again:
-	if (!cfs_rq->nr_running)
+	if (!sched_fair_runnable(rq))
 		goto idle;
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
@@ -6884,7 +6893,7 @@ idle:
 /*
  * Account for a descheduled task:
  */
-static void put_prev_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+static void put_prev_task_fair(struct rq *rq, struct task_struct *prev)
 {
 	struct sched_entity *se = &prev->se;
 	struct cfs_rq *cfs_rq;
@@ -10414,11 +10423,11 @@ const struct sched_class fair_sched_class = {
 	.check_preempt_curr	= check_preempt_wakeup,
 
 	.pick_next_task		= pick_next_task_fair,
-
 	.put_prev_task		= put_prev_task_fair,
 	.set_next_task          = set_next_task_fair,
 
 #ifdef CONFIG_SMP
+	.balance		= balance_fair,
 	.select_task_rq		= select_task_rq_fair,
 	.migrate_task_rq	= migrate_task_rq_fair,
 

kernel/sched/idle.c

@@ -365,6 +365,12 @@ select_task_rq_idle(struct task_struct *p, int cpu, int sd_flag, int flags)
 {
 	return task_cpu(p); /* IDLE tasks as never migrated */
 }
+
+static int
+balance_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+{
+	return WARN_ON_ONCE(1);
+}
 #endif
 
 /*
@@ -375,7 +381,7 @@ static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int fl
 	resched_curr(rq);
 }
 
-static void put_prev_task_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
 {
 }
 
@@ -460,6 +466,7 @@ const struct sched_class idle_sched_class = {
 	.set_next_task          = set_next_task_idle,
 
 #ifdef CONFIG_SMP
+	.balance		= balance_idle,
 	.select_task_rq		= select_task_rq_idle,
 	.set_cpus_allowed	= set_cpus_allowed_common,
 #endif

kernel/sched/rt.c

@@ -1469,6 +1469,22 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
 	resched_curr(rq);
 }
 
+static int balance_rt(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
+{
+	if (!on_rt_rq(&p->rt) && need_pull_rt_task(rq, p)) {
+		/*
+		 * This is OK, because current is on_cpu, which avoids it being
+		 * picked for load-balance and preemption/IRQs are still
+		 * disabled avoiding further scheduler activity on it and we've
+		 * not yet started the picking loop.
+		 */
+		rq_unpin_lock(rq, rf);
+		pull_rt_task(rq);
+		rq_repin_lock(rq, rf);
+	}
+
+	return sched_stop_runnable(rq) || sched_dl_runnable(rq) || sched_rt_runnable(rq);
+}
 #endif /* CONFIG_SMP */
 
 /*
@@ -1552,21 +1568,18 @@ static struct task_struct *
 pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 {
 	struct task_struct *p;
-	struct rt_rq *rt_rq = &rq->rt;
 
 	WARN_ON_ONCE(prev || rf);
 
-	if (!rt_rq->rt_queued)
+	if (!sched_rt_runnable(rq))
 		return NULL;
 
 	p = _pick_next_task_rt(rq);
-
 	set_next_task_rt(rq, p);
-
 	return p;
 }
 
-static void put_prev_task_rt(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
+static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
 {
 	update_curr_rt(rq);
 
@@ -1578,18 +1591,6 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p, struct rq_fla
 	 */
 	if (on_rt_rq(&p->rt) && p->nr_cpus_allowed > 1)
 		enqueue_pushable_task(rq, p);
-
-	if (rf && !on_rt_rq(&p->rt) && need_pull_rt_task(rq, p)) {
-		/*
-		 * This is OK, because current is on_cpu, which avoids it being
-		 * picked for load-balance and preemption/IRQs are still
-		 * disabled avoiding further scheduler activity on it and we've
-		 * not yet started the picking loop.
-		 */
-		rq_unpin_lock(rq, rf);
-		pull_rt_task(rq);
-		rq_repin_lock(rq, rf);
-	}
 }
 
 #ifdef CONFIG_SMP
@@ -2366,8 +2367,8 @@ const struct sched_class rt_sched_class = {
 	.set_next_task          = set_next_task_rt,
 
 #ifdef CONFIG_SMP
+	.balance		= balance_rt,
 	.select_task_rq		= select_task_rq_rt,
-
 	.set_cpus_allowed       = set_cpus_allowed_common,
 	.rq_online              = rq_online_rt,
 	.rq_offline             = rq_offline_rt,

kernel/sched/sched.h

@@ -1727,10 +1727,11 @@ struct sched_class {
 	struct task_struct * (*pick_next_task)(struct rq *rq,
 					       struct task_struct *prev,
 					       struct rq_flags *rf);
-	void (*put_prev_task)(struct rq *rq, struct task_struct *p, struct rq_flags *rf);
+	void (*put_prev_task)(struct rq *rq, struct task_struct *p);
 	void (*set_next_task)(struct rq *rq, struct task_struct *p);
 
 #ifdef CONFIG_SMP
+	int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
 	int  (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
 	void (*migrate_task_rq)(struct task_struct *p, int new_cpu);
 
@@ -1773,7 +1774,7 @@ struct sched_class {
 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
 {
 	WARN_ON_ONCE(rq->curr != prev);
-	prev->sched_class->put_prev_task(rq, prev, NULL);
+	prev->sched_class->put_prev_task(rq, prev);
 }
 
 static inline void set_next_task(struct rq *rq, struct task_struct *next)
@@ -1787,8 +1788,12 @@ static inline void set_next_task(struct rq *rq, struct task_struct *next)
 #else
 #define sched_class_highest (&dl_sched_class)
 #endif
+
+#define for_class_range(class, _from, _to) \
+	for (class = (_from); class != (_to); class = class->next)
+
 #define for_each_class(class) \
-   for (class = sched_class_highest; class; class = class->next)
+	for_class_range(class, sched_class_highest, NULL)
 
 extern const struct sched_class stop_sched_class;
 extern const struct sched_class dl_sched_class;
@@ -1796,6 +1801,25 @@ extern const struct sched_class rt_sched_class;
 extern const struct sched_class fair_sched_class;
 extern const struct sched_class idle_sched_class;
 
+static inline bool sched_stop_runnable(struct rq *rq)
+{
+	return rq->stop && task_on_rq_queued(rq->stop);
+}
+
+static inline bool sched_dl_runnable(struct rq *rq)
+{
+	return rq->dl.dl_nr_running > 0;
+}
+
+static inline bool sched_rt_runnable(struct rq *rq)
+{
+	return rq->rt.rt_queued > 0;
+}
+
+static inline bool sched_fair_runnable(struct rq *rq)
+{
+	return rq->cfs.nr_running > 0;
+}
 
 #ifdef CONFIG_SMP
 

kernel/sched/stop_task.c

@@ -15,6 +15,12 @@ select_task_rq_stop(struct task_struct *p, int cpu, int sd_flag, int flags)
 {
 	return task_cpu(p); /* stop tasks as never migrate */
 }
+
+static int
+balance_stop(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+{
+	return sched_stop_runnable(rq);
+}
 #endif /* CONFIG_SMP */
 
 static void
@@ -31,16 +37,13 @@ static void set_next_task_stop(struct rq *rq, struct task_struct *stop)
 static struct task_struct *
 pick_next_task_stop(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 {
-	struct task_struct *stop = rq->stop;
-
 	WARN_ON_ONCE(prev || rf);
 
-	if (!stop || !task_on_rq_queued(stop))
+	if (!sched_stop_runnable(rq))
 		return NULL;
 
-	set_next_task_stop(rq, stop);
-
-	return stop;
+	set_next_task_stop(rq, rq->stop);
+	return rq->stop;
 }
 
 static void
@@ -60,7 +63,7 @@ static void yield_task_stop(struct rq *rq)
 	BUG(); /* the stop task should never yield, its pointless. */
 }
 
-static void put_prev_task_stop(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+static void put_prev_task_stop(struct rq *rq, struct task_struct *prev)
 {
 	struct task_struct *curr = rq->curr;
 	u64 delta_exec;
@@ -129,6 +132,7 @@ const struct sched_class stop_sched_class = {
 	.set_next_task          = set_next_task_stop,
 
 #ifdef CONFIG_SMP
+	.balance		= balance_stop,
 	.select_task_rq		= select_task_rq_stop,
 	.set_cpus_allowed	= set_cpus_allowed_common,
 #endif

kernel/sched/topology.c

@@ -1948,7 +1948,7 @@ next_level:
 static int
 build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *attr)
 {
-	enum s_alloc alloc_state;
+	enum s_alloc alloc_state = sa_none;
 	struct sched_domain *sd;
 	struct s_data d;
 	struct rq *rq = NULL;
@@ -1956,6 +1956,9 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att
 	struct sched_domain_topology_level *tl_asym;
 	bool has_asym = false;
 
+	if (WARN_ON(cpumask_empty(cpu_map)))
+		goto error;
+
 	alloc_state = __visit_domain_allocation_hell(&d, cpu_map);
 	if (alloc_state != sa_rootdomain)
 		goto error;
@@ -2026,7 +2029,7 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att
 	rcu_read_unlock();
 
 	if (has_asym)
-		static_branch_enable_cpuslocked(&sched_asym_cpucapacity);
+		static_branch_inc_cpuslocked(&sched_asym_cpucapacity);
 
 	if (rq && sched_debug_enabled) {
 		pr_info("root domain span: %*pbl (max cpu_capacity = %lu)\n",
@@ -2121,8 +2124,12 @@ int sched_init_domains(const struct cpumask *cpu_map)
  */
 static void detach_destroy_domains(const struct cpumask *cpu_map)
 {
+	unsigned int cpu = cpumask_any(cpu_map);
 	int i;
 
+	if (rcu_access_pointer(per_cpu(sd_asym_cpucapacity, cpu)))
+		static_branch_dec_cpuslocked(&sched_asym_cpucapacity);
+
 	rcu_read_lock();
 	for_each_cpu(i, cpu_map)
 		cpu_attach_domain(NULL, &def_root_domain, i);

kernel/stacktrace.c

@@ -141,7 +141,8 @@ unsigned int stack_trace_save_tsk(struct task_struct *tsk, unsigned long *store,
 	struct stacktrace_cookie c = {
 		.store	= store,
 		.size	= size,
-		.skip	= skipnr + 1,
+		/* skip this function if they are tracing us */
+		.skip	= skipnr + !!(current == tsk),
 	};
 
 	if (!try_get_task_stack(tsk))
@@ -298,7 +299,8 @@ unsigned int stack_trace_save_tsk(struct task_struct *task,
 	struct stack_trace trace = {
 		.entries	= store,
 		.max_entries	= size,
-		.skip		= skipnr + 1,
+		/* skip this function if they are tracing us */
+		.skip	= skipnr + !!(current == task),
 	};
 
 	save_stack_trace_tsk(task, &trace);

kernel/time/vsyscall.c

@@ -110,8 +110,7 @@ void update_vsyscall(struct timekeeper *tk)
 	nsec		= nsec + tk->wall_to_monotonic.tv_nsec;
 	vdso_ts->sec	+= __iter_div_u64_rem(nsec, NSEC_PER_SEC, &vdso_ts->nsec);
 
-	if (__arch_use_vsyscall(vdata))
-		update_vdso_data(vdata, tk);
+	update_vdso_data(vdata, tk);
 
 	__arch_update_vsyscall(vdata, tk);
 
@@ -124,10 +123,8 @@ void update_vsyscall_tz(void)
 {
 	struct vdso_data *vdata = __arch_get_k_vdso_data();
 
-	if (__arch_use_vsyscall(vdata)) {
-		vdata[CS_HRES_COARSE].tz_minuteswest = sys_tz.tz_minuteswest;
-		vdata[CS_HRES_COARSE].tz_dsttime = sys_tz.tz_dsttime;
-	}
+	vdata[CS_HRES_COARSE].tz_minuteswest = sys_tz.tz_minuteswest;
+	vdata[CS_HRES_COARSE].tz_dsttime = sys_tz.tz_dsttime;
 
 	__arch_sync_vdso_data(vdata);
 }