Adding upstream version 5.10.216.upstream/5.10.216

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

35 files changed, 699 insertions, 384 deletions

diff --git a/kernel/async.c b/kernel/async.c
index 1746cd65e..5dba7461f 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -145,6 +145,39 @@ static void async_run_entry_fn(struct work_struct *work)
 	wake_up(&async_done);
 }
 
+static async_cookie_t __async_schedule_node_domain(async_func_t func,
+						   void *data, int node,
+						   struct async_domain *domain,
+						   struct async_entry *entry)
+{
+	async_cookie_t newcookie;
+	unsigned long flags;
+
+	INIT_LIST_HEAD(&entry->domain_list);
+	INIT_LIST_HEAD(&entry->global_list);
+	INIT_WORK(&entry->work, async_run_entry_fn);
+	entry->func = func;
+	entry->data = data;
+	entry->domain = domain;
+
+	spin_lock_irqsave(&async_lock, flags);
+
+	/* allocate cookie and queue */
+	newcookie = entry->cookie = next_cookie++;
+
+	list_add_tail(&entry->domain_list, &domain->pending);
+	if (domain->registered)
+		list_add_tail(&entry->global_list, &async_global_pending);
+
+	atomic_inc(&entry_count);
+	spin_unlock_irqrestore(&async_lock, flags);
+
+	/* schedule for execution */
+	queue_work_node(node, system_unbound_wq, &entry->work);
+
+	return newcookie;
+}
+
 /**
  * async_schedule_node_domain - NUMA specific version of async_schedule_domain
  * @func: function to execute asynchronously
@@ -186,29 +219,8 @@ async_cookie_t async_schedule_node_domain(async_func_t func, void *data,
 		func(data, newcookie);
 		return newcookie;
 	}
-	INIT_LIST_HEAD(&entry->domain_list);
-	INIT_LIST_HEAD(&entry->global_list);
-	INIT_WORK(&entry->work, async_run_entry_fn);
-	entry->func = func;
-	entry->data = data;
-	entry->domain = domain;
-
-	spin_lock_irqsave(&async_lock, flags);
-
-	/* allocate cookie and queue */
-	newcookie = entry->cookie = next_cookie++;
-
-	list_add_tail(&entry->domain_list, &domain->pending);
-	if (domain->registered)
-		list_add_tail(&entry->global_list, &async_global_pending);
-
-	atomic_inc(&entry_count);
-	spin_unlock_irqrestore(&async_lock, flags);
-
-	/* schedule for execution */
-	queue_work_node(node, system_unbound_wq, &entry->work);
 
-	return newcookie;
+	return __async_schedule_node_domain(func, data, node, domain, entry);
 }
 EXPORT_SYMBOL_GPL(async_schedule_node_domain);
 
@@ -232,6 +244,35 @@ async_cookie_t async_schedule_node(async_func_t func, void *data, int node)
 EXPORT_SYMBOL_GPL(async_schedule_node);
 
 /**
+ * async_schedule_dev_nocall - A simplified variant of async_schedule_dev()
+ * @func: function to execute asynchronously
+ * @dev: device argument to be passed to function
+ *
+ * @dev is used as both the argument for the function and to provide NUMA
+ * context for where to run the function.
+ *
+ * If the asynchronous execution of @func is scheduled successfully, return
+ * true. Otherwise, do nothing and return false, unlike async_schedule_dev()
+ * that will run the function synchronously then.
+ */
+bool async_schedule_dev_nocall(async_func_t func, struct device *dev)
+{
+	struct async_entry *entry;
+
+	entry = kzalloc(sizeof(struct async_entry), GFP_KERNEL);
+
+	/* Give up if there is no memory or too much work. */
+	if (!entry || atomic_read(&entry_count) > MAX_WORK) {
+		kfree(entry);
+		return false;
+	}
+
+	__async_schedule_node_domain(func, dev, dev_to_node(dev),
+				     &async_dfl_domain, entry);
+	return true;
+}
+
+/**
  * async_synchronize_full - synchronize all asynchronous function calls
  *
  * This function waits until all asynchronous function calls have been done.
diff --git a/kernel/audit.c b/kernel/audit.c
index aeec86ed4..2ab04e0a7 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -490,15 +490,19 @@ static void auditd_conn_free(struct rcu_head *rcu)
  * @pid: auditd PID
  * @portid: auditd netlink portid
  * @net: auditd network namespace pointer
+ * @skb: the netlink command from the audit daemon
+ * @ack: netlink ack flag, cleared if ack'd here
  *
  * Description:
  * This function will obtain and drop network namespace references as
  * necessary.  Returns zero on success, negative values on failure.
  */
-static int auditd_set(struct pid *pid, u32 portid, struct net *net)
+static int auditd_set(struct pid *pid, u32 portid, struct net *net,
+		      struct sk_buff *skb, bool *ack)
 {
 	unsigned long flags;
 	struct auditd_connection *ac_old, *ac_new;
+	struct nlmsghdr *nlh;
 
 	if (!pid || !net)
 		return -EINVAL;
@@ -510,6 +514,13 @@ static int auditd_set(struct pid *pid, u32 portid, struct net *net)
 	ac_new->portid = portid;
 	ac_new->net = get_net(net);
 
+	/* send the ack now to avoid a race with the queue backlog */
+	if (*ack) {
+		nlh = nlmsg_hdr(skb);
+		netlink_ack(skb, nlh, 0, NULL);
+		*ack = false;
+	}
+
 	spin_lock_irqsave(&auditd_conn_lock, flags);
 	ac_old = rcu_dereference_protected(auditd_conn,
 					   lockdep_is_held(&auditd_conn_lock));
@@ -1203,7 +1214,8 @@ static int audit_replace(struct pid *pid)
 	return auditd_send_unicast_skb(skb);
 }
 
-static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+			     bool *ack)
 {
 	u32			seq;
 	void			*data;
@@ -1296,7 +1308,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 				/* register a new auditd connection */
 				err = auditd_set(req_pid,
 						 NETLINK_CB(skb).portid,
-						 sock_net(NETLINK_CB(skb).sk));
+						 sock_net(NETLINK_CB(skb).sk),
+						 skb, ack);
 				if (audit_enabled != AUDIT_OFF)
 					audit_log_config_change("audit_pid",
 								new_pid,
@@ -1541,9 +1554,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
  * Parse the provided skb and deal with any messages that may be present,
  * malformed skbs are discarded.
  */
-static void audit_receive(struct sk_buff  *skb)
+static void audit_receive(struct sk_buff *skb)
 {
 	struct nlmsghdr *nlh;
+	bool ack;
 	/*
 	 * len MUST be signed for nlmsg_next to be able to dec it below 0
 	 * if the nlmsg_len was not aligned
@@ -1556,9 +1570,12 @@ static void audit_receive(struct sk_buff  *skb)
 
 	audit_ctl_lock();
 	while (nlmsg_ok(nlh, len)) {
-		err = audit_receive_msg(skb, nlh);
-		/* if err or if this message says it wants a response */
-		if (err || (nlh->nlmsg_flags & NLM_F_ACK))
+		ack = nlh->nlmsg_flags & NLM_F_ACK;
+		err = audit_receive_msg(skb, nlh, &ack);
+
+		/* send an ack if the user asked for one and audit_receive_msg
+		 * didn't already do it, or if there was an error. */
+		if (ack || err)
 			netlink_ack(skb, nlh, err, NULL);
 
 		nlh = nlmsg_next(nlh, &len);
diff --git a/kernel/bounds.c b/kernel/bounds.c
index 9795d75b0..a3e1d3dfa 100644
--- a/kernel/bounds.c
+++ b/kernel/bounds.c
@@ -19,7 +19,7 @@ int main(void)
 	DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS);
 	DEFINE(MAX_NR_ZONES, __MAX_NR_ZONES);
 #ifdef CONFIG_SMP
-	DEFINE(NR_CPUS_BITS, ilog2(CONFIG_NR_CPUS));
+	DEFINE(NR_CPUS_BITS, order_base_2(CONFIG_NR_CPUS));
 #endif
 	DEFINE(SPINLOCK_SIZE, sizeof(spinlock_t));
 	/* End of constants */
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index f241bda26..510233812 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -764,7 +764,7 @@ int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
 	}
 
 	if (old_ptr)
-		map->ops->map_fd_put_ptr(old_ptr);
+		map->ops->map_fd_put_ptr(map, old_ptr, true);
 	return 0;
 }
 
@@ -787,7 +787,7 @@ static int fd_array_map_delete_elem(struct bpf_map *map, void *key)
 	}
 
 	if (old_ptr) {
-		map->ops->map_fd_put_ptr(old_ptr);
+		map->ops->map_fd_put_ptr(map, old_ptr, true);
 		return 0;
 	} else {
 		return -ENOENT;
@@ -811,8 +811,9 @@ static void *prog_fd_array_get_ptr(struct bpf_map *map,
 	return prog;
 }
 
-static void prog_fd_array_put_ptr(void *ptr)
+static void prog_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
 {
+	/* bpf_prog is freed after one RCU or tasks trace grace period */
 	bpf_prog_put(ptr);
 }
 
@@ -1139,8 +1140,9 @@ err_out:
 	return ee;
 }
 
-static void perf_event_fd_array_put_ptr(void *ptr)
+static void perf_event_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
 {
+	/* bpf_perf_event is freed after one RCU grace period */
 	bpf_event_entry_free_rcu(ptr);
 }
 
@@ -1195,7 +1197,7 @@ static void *cgroup_fd_array_get_ptr(struct bpf_map *map,
 	return cgroup_get_from_fd(fd);
 }
 
-static void cgroup_fd_array_put_ptr(void *ptr)
+static void cgroup_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
 {
 	/* cgroup_put free cgrp after a rcu grace period */
 	cgroup_put(ptr);
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index c61a23b56..9a4378df4 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -229,7 +229,7 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu,
 				    void **frames, int n,
 				    struct xdp_cpumap_stats *stats)
 {
-	struct xdp_rxq_info rxq;
+	struct xdp_rxq_info rxq = {};
 	struct xdp_buff xdp;
 	int i, nframes = 0;
 
@@ -299,6 +299,7 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu,
 static int cpu_map_kthread_run(void *data)
 {
 	struct bpf_cpu_map_entry *rcpu = data;
+	unsigned long last_qs = jiffies;
 
 	set_current_state(TASK_INTERRUPTIBLE);
 
@@ -322,10 +323,12 @@ static int cpu_map_kthread_run(void *data)
 			if (__ptr_ring_empty(rcpu->queue)) {
 				schedule();
 				sched = 1;
+				last_qs = jiffies;
 			} else {
 				__set_current_state(TASK_RUNNING);
 			}
 		} else {
+			rcu_softirq_qs_periodic(last_qs);
 			sched = cond_resched();
 		}
 
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 01149821d..07b5edb2c 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -109,8 +109,6 @@ static inline struct hlist_head *dev_map_index_hash(struct bpf_dtab *dtab,
 static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
 {
 	u32 valsize = attr->value_size;
-	u64 cost = 0;
-	int err;
 
 	/* check sanity of attributes. 2 value sizes supported:
 	 * 4 bytes: ifindex
@@ -131,25 +129,18 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
 	bpf_map_init_from_attr(&dtab->map, attr);
 
 	if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
-		dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries);
-
-		if (!dtab->n_buckets) /* Overflow check */
+		/* hash table size must be power of 2; roundup_pow_of_two() can
+		 * overflow into UB on 32-bit arches, so check that first
+		 */
+		if (dtab->map.max_entries > 1UL << 31)
 			return -EINVAL;
-		cost += (u64) sizeof(struct hlist_head) * dtab->n_buckets;
-	} else {
-		cost += (u64) dtab->map.max_entries * sizeof(struct bpf_dtab_netdev *);
-	}
 
-	/* if map size is larger than memlock limit, reject it */
-	err = bpf_map_charge_init(&dtab->map.memory, cost);
-	if (err)
-		return -EINVAL;
+		dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries);
 
-	if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
 		dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets,
 							   dtab->map.numa_node);
 		if (!dtab->dev_index_head)
-			goto free_charge;
+			return -ENOMEM;
 
 		spin_lock_init(&dtab->index_lock);
 	} else {
@@ -157,14 +148,10 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
 						      sizeof(struct bpf_dtab_netdev *),
 						      dtab->map.numa_node);
 		if (!dtab->netdev_map)
-			goto free_charge;
+			return -ENOMEM;
 	}
 
 	return 0;
-
-free_charge:
-	bpf_map_charge_finish(&dtab->map.memory);
-	return -ENOMEM;
 }
 
 static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 0ce445aad..72bc5f575 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -443,7 +443,13 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 							  num_possible_cpus());
 	}
 
-	/* hash table size must be power of 2 */
+	/* hash table size must be power of 2; roundup_pow_of_two() can overflow
+	 * into UB on 32-bit arches, so check that first
+	 */
+	err = -E2BIG;
+	if (htab->map.max_entries > 1UL << 31)
+		goto free_htab;
+
 	htab->n_buckets = roundup_pow_of_two(htab->map.max_entries);
 
 	htab->elem_size = sizeof(struct htab_elem) +
@@ -453,10 +459,8 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 	else
 		htab->elem_size += round_up(htab->map.value_size, 8);
 
-	err = -E2BIG;
-	/* prevent zero size kmalloc and check for u32 overflow */
-	if (htab->n_buckets == 0 ||
-	    htab->n_buckets > U32_MAX / sizeof(struct bucket))
+	/* check for u32 overflow */
+	if (htab->n_buckets > U32_MAX / sizeof(struct bucket))
 		goto free_htab;
 
 	cost = (u64) htab->n_buckets * sizeof(struct bucket) +
@@ -786,7 +790,7 @@ static void htab_put_fd_value(struct bpf_htab *htab, struct htab_elem *l)
 
 	if (map->ops->map_fd_put_ptr) {
 		ptr = fd_htab_map_get_ptr(map, l);
-		map->ops->map_fd_put_ptr(ptr);
+		map->ops->map_fd_put_ptr(map, ptr, true);
 	}
 }
 
@@ -2023,7 +2027,7 @@ static void fd_htab_map_free(struct bpf_map *map)
 		hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
 			void *ptr = fd_htab_map_get_ptr(map, l);
 
-			map->ops->map_fd_put_ptr(ptr);
+			map->ops->map_fd_put_ptr(map, ptr, false);
 		}
 	}
 
@@ -2064,7 +2068,7 @@ int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file,
 
 	ret = htab_map_update_elem(map, key, &ptr, map_flags);
 	if (ret)
-		map->ops->map_fd_put_ptr(ptr);
+		map->ops->map_fd_put_ptr(map, ptr, false);
 
 	return ret;
 }
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 0efe7c7bf..084ac7e42 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -278,13 +278,18 @@ static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
 
 static DEFINE_PER_CPU(unsigned long, irqsave_flags);
 
-notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
+static inline void __bpf_spin_lock_irqsave(struct bpf_spin_lock *lock)
 {
 	unsigned long flags;
 
 	local_irq_save(flags);
 	__bpf_spin_lock(lock);
 	__this_cpu_write(irqsave_flags, flags);
+}
+
+NOTRACE_BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
+{
+	__bpf_spin_lock_irqsave(lock);
 	return 0;
 }
 
@@ -295,13 +300,18 @@ const struct bpf_func_proto bpf_spin_lock_proto = {
 	.arg1_type	= ARG_PTR_TO_SPIN_LOCK,
 };
 
-notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
+static inline void __bpf_spin_unlock_irqrestore(struct bpf_spin_lock *lock)
 {
 	unsigned long flags;
 
 	flags = __this_cpu_read(irqsave_flags);
 	__bpf_spin_unlock(lock);
 	local_irq_restore(flags);
+}
+
+NOTRACE_BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
+{
+	__bpf_spin_unlock_irqrestore(lock);
 	return 0;
 }
 
@@ -322,9 +332,9 @@ void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
 	else
 		lock = dst + map->spin_lock_off;
 	preempt_disable();
-	____bpf_spin_lock(lock);
+	__bpf_spin_lock_irqsave(lock);
 	copy_map_value(map, dst, src);
-	____bpf_spin_unlock(lock);
+	__bpf_spin_unlock_irqrestore(lock);
 	preempt_enable();
 }
 
diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c
index 39ab0b68c..caa1a17cb 100644
--- a/kernel/bpf/map_in_map.c
+++ b/kernel/bpf/map_in_map.c
@@ -100,12 +100,17 @@ void *bpf_map_fd_get_ptr(struct bpf_map *map,
 	return inner_map;
 }
 
-void bpf_map_fd_put_ptr(void *ptr)
+void bpf_map_fd_put_ptr(struct bpf_map *map, void *ptr, bool need_defer)
 {
-	/* ptr->ops->map_free() has to go through one
-	 * rcu grace period by itself.
+	struct bpf_map *inner_map = ptr;
+
+	/* The inner map may still be used by both non-sleepable and sleepable
+	 * bpf program, so free it after one RCU grace period and one tasks
+	 * trace RCU grace period.
 	 */
-	bpf_map_put(ptr);
+	if (need_defer)
+		WRITE_ONCE(inner_map->free_after_mult_rcu_gp, true);
+	bpf_map_put(inner_map);
 }
 
 u32 bpf_map_fd_sys_lookup_elem(void *ptr)
diff --git a/kernel/bpf/map_in_map.h b/kernel/bpf/map_in_map.h
index bcb7534af..7d6160235 100644
--- a/kernel/bpf/map_in_map.h
+++ b/kernel/bpf/map_in_map.h
@@ -13,7 +13,7 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd);
 void bpf_map_meta_free(struct bpf_map *map_meta);
 void *bpf_map_fd_get_ptr(struct bpf_map *map, struct file *map_file,
 			 int ufd);
-void bpf_map_fd_put_ptr(void *ptr);
+void bpf_map_fd_put_ptr(struct bpf_map *map, void *ptr, bool need_defer);
 u32 bpf_map_fd_sys_lookup_elem(void *ptr);
 
 #endif
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index b8afea2ce..3ec76cb5f 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -115,11 +115,14 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
 	} else if (value_size / 8 > sysctl_perf_event_max_stack)
 		return ERR_PTR(-EINVAL);
 
-	/* hash table size must be power of 2 */
-	n_buckets = roundup_pow_of_two(attr->max_entries);
-	if (!n_buckets)
+	/* hash table size must be power of 2; roundup_pow_of_two() can overflow
+	 * into UB on 32-bit arches, so check that first
+	 */
+	if (attr->max_entries > 1UL << 31)
 		return ERR_PTR(-E2BIG);
 
+	n_buckets = roundup_pow_of_two(attr->max_entries);
+
 	cost = n_buckets * sizeof(struct stack_map_bucket *) + sizeof(*smap);
 	err = bpf_map_charge_init(&mem, cost + attr->max_entries *
 			   (sizeof(struct stack_map_bucket) + (u64)value_size));
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index aaad2dce2..e1bee8cd3 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -493,6 +493,25 @@ static void bpf_map_put_uref(struct bpf_map *map)
 	}
 }
 
+static void bpf_map_free_in_work(struct bpf_map *map)
+{
+	INIT_WORK(&map->work, bpf_map_free_deferred);
+	schedule_work(&map->work);
+}
+
+static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
+{
+	bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
+}
+
+static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu)
+{
+	if (rcu_trace_implies_rcu_gp())
+		bpf_map_free_rcu_gp(rcu);
+	else
+		call_rcu(rcu, bpf_map_free_rcu_gp);
+}
+
 /* decrement map refcnt and schedule it for freeing via workqueue
  * (unrelying map implementation ops->map_free() might sleep)
  */
@@ -502,8 +521,11 @@ static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
 		/* bpf_map_free_id() must be called first */
 		bpf_map_free_id(map, do_idr_lock);
 		btf_put(map->btf);
-		INIT_WORK(&map->work, bpf_map_free_deferred);
-		schedule_work(&map->work);
+
+		if (READ_ONCE(map->free_after_mult_rcu_gp))
+			call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp);
+		else
+			bpf_map_free_in_work(map);
 	}
 }
 
@@ -1285,6 +1307,9 @@ int generic_map_delete_batch(struct bpf_map *map,
 	if (!max_count)
 		return 0;
 
+	if (put_user(0, &uattr->batch.count))
+		return -EFAULT;
+
 	key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
 	if (!key)
 		return -ENOMEM;
@@ -1343,6 +1368,9 @@ int generic_map_update_batch(struct bpf_map *map,
 	if (!max_count)
 		return 0;
 
+	if (put_user(0, &uattr->batch.count))
+		return -EFAULT;
+
 	key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
 	if (!key)
 		return -ENOMEM;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index fce2345f6..25f8a8716 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3941,6 +3941,11 @@ static int check_stack_access_within_bounds(
 	err = check_stack_slot_within_bounds(min_off, state, type);
 	if (!err && max_off > 0)
 		err = -EINVAL; /* out of stack access into non-negative offsets */
+	if (!err && access_size < 0)
+		/* access_size should not be negative (or overflow an int); others checks
+		 * along the way should have prevented such an access.
+		 */
+		err = -EFAULT; /* invalid negative access size; integer overflow? */
 
 	if (err) {
 		if (tnum_is_const(reg->var_off)) {
diff --git a/kernel/cpu.c b/kernel/cpu.c
index abf717c4f..d84ba5a13 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -2600,7 +2600,8 @@ enum cpu_mitigations {
 };
 
 static enum cpu_mitigations cpu_mitigations __ro_after_init =
-	CPU_MITIGATIONS_AUTO;
+	IS_ENABLED(CONFIG_CPU_MITIGATIONS) ? CPU_MITIGATIONS_AUTO :
+					     CPU_MITIGATIONS_OFF;
 
 static int __init mitigations_parse_cmdline(char *arg)
 {
diff --git a/kernel/events/core.c b/kernel/events/core.c
index afedd008e..e0b47bed8 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6890,9 +6890,16 @@ static void perf_output_read_group(struct perf_output_handle *handle,
 {
 	struct perf_event *leader = event->group_leader, *sub;
 	u64 read_format = event->attr.read_format;
+	unsigned long flags;
 	u64 values[6];
 	int n = 0;
 
+	/*
+	 * Disabling interrupts avoids all counter scheduling
+	 * (context switches, timer based rotation and IPIs).
+	 */
+	local_irq_save(flags);
+
 	values[n++] = 1 + leader->nr_siblings;
 
 	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
@@ -6928,6 +6935,8 @@ static void perf_output_read_group(struct perf_output_handle *handle,
 
 		__output_copy(handle, values, n * sizeof(u64));
 	}
+
+	local_irq_restore(flags);
 }
 
 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
@@ -10855,9 +10864,30 @@ static DEVICE_ATTR_RW(perf_event_mux_interval_ms);
 static struct attribute *pmu_dev_attrs[] = {
 	&dev_attr_type.attr,
 	&dev_attr_perf_event_mux_interval_ms.attr,
+	&dev_attr_nr_addr_filters.attr,
+	NULL,
+};
+
+static umode_t pmu_dev_is_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct pmu *pmu = dev_get_drvdata(dev);
+
+	if (n == 2 && !pmu->nr_addr_filters)
+		return 0;
+
+	return a->mode;
+}
+
+static struct attribute_group pmu_dev_attr_group = {
+	.is_visible = pmu_dev_is_visible,
+	.attrs = pmu_dev_attrs,
+};
+
+static const struct attribute_group *pmu_dev_groups[] = {
+	&pmu_dev_attr_group,
 	NULL,
 };
-ATTRIBUTE_GROUPS(pmu_dev);
 
 static int pmu_bus_running;
 static struct bus_type pmu_bus = {
@@ -10893,18 +10923,11 @@ static int pmu_dev_alloc(struct pmu *pmu)
 	if (ret)
 		goto free_dev;
 
-	/* For PMUs with address filters, throw in an extra attribute: */
-	if (pmu->nr_addr_filters)
-		ret = device_create_file(pmu->dev, &dev_attr_nr_addr_filters);
-
-	if (ret)
-		goto del_dev;
-
-	if (pmu->attr_update)
+	if (pmu->attr_update) {
 		ret = sysfs_update_groups(&pmu->dev->kobj, pmu->attr_update);
-
-	if (ret)
-		goto del_dev;
+		if (ret)
+			goto del_dev;
+	}
 
 out:
 	return ret;
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 05d3e156a..dba6541c0 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1647,10 +1647,17 @@ static int check_kprobe_address_safe(struct kprobe *p,
 	jump_label_lock();
 	preempt_disable();
 
-	/* Ensure it is not in reserved area nor out of text */
-	if (!(core_kernel_text((unsigned long) p->addr) ||
-	    is_module_text_address((unsigned long) p->addr)) ||
-	    in_gate_area_no_mm((unsigned long) p->addr) ||
+	/* Ensure the address is in a text area, and find a module if exists. */
+	*probed_mod = NULL;
+	if (!core_kernel_text((unsigned long) p->addr)) {
+		*probed_mod = __module_text_address((unsigned long) p->addr);
+		if (!(*probed_mod)) {
+			ret = -EINVAL;
+			goto out;
+		}
+	}
+	/* Ensure it is not in reserved area. */
+	if (in_gate_area_no_mm((unsigned long) p->addr) ||
 	    within_kprobe_blacklist((unsigned long) p->addr) ||
 	    jump_label_text_reserved(p->addr, p->addr) ||
 	    static_call_text_reserved(p->addr, p->addr) ||
@@ -1660,8 +1667,7 @@ static int check_kprobe_address_safe(struct kprobe *p,
 		goto out;
 	}
 
-	/* Check if are we probing a module */
-	*probed_mod = __module_text_address((unsigned long) p->addr);
+	/* Get module refcount and reject __init functions for loaded modules. */
 	if (*probed_mod) {
 		/*
 		 * We must hold a refcount of the probed module while updating
diff --git a/kernel/panic.c b/kernel/panic.c
index bc39e2b27..30d8da0d4 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -427,6 +427,14 @@ void panic(const char *fmt, ...)
 
 	/* Do not scroll important messages printed above */
 	suppress_printk = 1;
+
+	/*
+	 * The final messages may not have been printed if in a context that
+	 * defers printing (such as NMI) and irq_work is not available.
+	 * Explicitly flush the kernel log buffer one last time.
+	 */
+	console_flush_on_panic(CONSOLE_FLUSH_PENDING);
+
 	local_irq_enable();
 	for (i = 0; ; i += PANIC_TIMER_STEP) {
 		touch_softlockup_watchdog();
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 4aa4d5d39..14e981c05 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -187,6 +187,7 @@ static int __init mem_sleep_default_setup(char *str)
 		if (mem_sleep_labels[state] &&
 		    !strcmp(str, mem_sleep_labels[state])) {
 			mem_sleep_default = state;
+			mem_sleep_current = state;
 			break;
 		}
 
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 25e7cb96b..b288aba80 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -603,11 +603,11 @@ static int crc32_threadfn(void *data)
 	unsigned i;
 
 	while (1) {
-		wait_event(d->go, atomic_read(&d->ready) ||
+		wait_event(d->go, atomic_read_acquire(&d->ready) ||
 		                  kthread_should_stop());
 		if (kthread_should_stop()) {
 			d->thr = NULL;
-			atomic_set(&d->stop, 1);
+			atomic_set_release(&d->stop, 1);
 			wake_up(&d->done);
 			break;
 		}
@@ -616,7 +616,7 @@ static int crc32_threadfn(void *data)
 		for (i = 0; i < d->run_threads; i++)
 			*d->crc32 = crc32_le(*d->crc32,
 			                     d->unc[i], *d->unc_len[i]);
-		atomic_set(&d->stop, 1);
+		atomic_set_release(&d->stop, 1);
 		wake_up(&d->done);
 	}
 	return 0;
@@ -646,12 +646,12 @@ static int lzo_compress_threadfn(void *data)
 	struct cmp_data *d = data;
 
 	while (1) {
-		wait_event(d->go, atomic_read(&d->ready) ||
+		wait_event(d->go, atomic_read_acquire(&d->ready) ||
 		                  kthread_should_stop());
 		if (kthread_should_stop()) {
 			d->thr = NULL;
 			d->ret = -1;
-			atomic_set(&d->stop, 1);
+			atomic_set_release(&d->stop, 1);
 			wake_up(&d->done);
 			break;
 		}
@@ -660,7 +660,7 @@ static int lzo_compress_threadfn(void *data)
 		d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 		                          d->cmp + LZO_HEADER, &d->cmp_len,
 		                          d->wrk);
-		atomic_set(&d->stop, 1);
+		atomic_set_release(&d->stop, 1);
 		wake_up(&d->done);
 	}
 	return 0;
@@ -798,7 +798,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
 
 			data[thr].unc_len = off;
 
-			atomic_set(&data[thr].ready, 1);
+			atomic_set_release(&data[thr].ready, 1);
 			wake_up(&data[thr].go);
 		}
 
@@ -806,12 +806,12 @@ static int save_image_lzo(struct swap_map_handle *handle,
 			break;
 
 		crc->run_threads = thr;
-		atomic_set(&crc->ready, 1);
+		atomic_set_release(&crc->ready, 1);
 		wake_up(&crc->go);
 
 		for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 			wait_event(data[thr].done,
-			           atomic_read(&data[thr].stop));
+				atomic_read_acquire(&data[thr].stop));
 			atomic_set(&data[thr].stop, 0);
 
 			ret = data[thr].ret;
@@ -850,7 +850,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
 			}
 		}
 
-		wait_event(crc->done, atomic_read(&crc->stop));
+		wait_event(crc->done, atomic_read_acquire(&crc->stop));
 		atomic_set(&crc->stop, 0);
 	}
 
@@ -1132,12 +1132,12 @@ static int lzo_decompress_threadfn(void *data)
 	struct dec_data *d = data;
 
 	while (1) {
-		wait_event(d->go, atomic_read(&d->ready) ||
+		wait_event(d->go, atomic_read_acquire(&d->ready) ||
 		                  kthread_should_stop());
 		if (kthread_should_stop()) {
 			d->thr = NULL;
 			d->ret = -1;
-			atomic_set(&d->stop, 1);
+			atomic_set_release(&d->stop, 1);
 			wake_up(&d->done);
 			break;
 		}
@@ -1150,7 +1150,7 @@ static int lzo_decompress_threadfn(void *data)
 			flush_icache_range((unsigned long)d->unc,
 					   (unsigned long)d->unc + d->unc_len);
 
-		atomic_set(&d->stop, 1);
+		atomic_set_release(&d->stop, 1);
 		wake_up(&d->done);
 	}
 	return 0;
@@ -1338,7 +1338,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
 		}
 
 		if (crc->run_threads) {
-			wait_event(crc->done, atomic_read(&crc->stop));
+			wait_event(crc->done, atomic_read_acquire(&crc->stop));
 			atomic_set(&crc->stop, 0);
 			crc->run_threads = 0;
 		}
@@ -1374,7 +1374,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
 					pg = 0;
 			}
 
-			atomic_set(&data[thr].ready, 1);
+			atomic_set_release(&data[thr].ready, 1);
 			wake_up(&data[thr].go);
 		}
 
@@ -1393,7 +1393,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
 
 		for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 			wait_event(data[thr].done,
-			           atomic_read(&data[thr].stop));
+				atomic_read_acquire(&data[thr].stop));
 			atomic_set(&data[thr].stop, 0);
 
 			ret = data[thr].ret;
@@ -1424,7 +1424,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
 				ret = snapshot_write_next(snapshot);
 				if (ret <= 0) {
 					crc->run_threads = thr + 1;
-					atomic_set(&crc->ready, 1);
+					atomic_set_release(&crc->ready, 1);
 					wake_up(&crc->go);
 					goto out_finish;
 				}
@@ -1432,13 +1432,13 @@ static int load_image_lzo(struct swap_map_handle *handle,
 		}
 
 		crc->run_threads = thr;
-		atomic_set(&crc->ready, 1);
+		atomic_set_release(&crc->ready, 1);
 		wake_up(&crc->go);
 	}
 
 out_finish:
 	if (crc->run_threads) {
-		wait_event(crc->done, atomic_read(&crc->stop));
+		wait_event(crc->done, atomic_read_acquire(&crc->stop));
 		atomic_set(&crc->stop, 0);
 	}
 	stop = ktime_get();
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 17a310dcb..a8af93cbc 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1866,6 +1866,12 @@ static int console_trylock_spinning(void)
 	 */
 	mutex_acquire(&console_lock_dep_map, 0, 1, _THIS_IP_);
 
+	/*
+	 * Update @console_may_schedule for trylock because the previous
+	 * owner may have been schedulable.
+	 */
+	console_may_schedule = 0;
+
 	return 1;
 }
 
@@ -2684,6 +2690,21 @@ static int __init keep_bootcon_setup(char *str)
 
 early_param("keep_bootcon", keep_bootcon_setup);
 
+static int console_call_setup(struct console *newcon, char *options)
+{
+	int err;
+
+	if (!newcon->setup)
+		return 0;
+
+	/* Synchronize with possible boot console. */
+	console_lock();
+	err = newcon->setup(newcon, options);
+	console_unlock();
+
+	return err;
+}
+
 /*
  * This is called by register_console() to try to match
  * the newly registered console with any of the ones selected
@@ -2693,7 +2714,8 @@ early_param("keep_bootcon", keep_bootcon_setup);
  * Care need to be taken with consoles that are statically
  * enabled such as netconsole
  */
-static int try_enable_new_console(struct console *newcon, bool user_specified)
+static int try_enable_preferred_console(struct console *newcon,
+					bool user_specified)
 {
 	struct console_cmdline *c;
 	int i, err;
@@ -2718,8 +2740,8 @@ static int try_enable_new_console(struct console *newcon, bool user_specified)
 			if (_braille_register_console(newcon, c))
 				return 0;
 
-			if (newcon->setup &&
-			    (err = newcon->setup(newcon, c->options)) != 0)
+			err = console_call_setup(newcon, c->options);
+			if (err)
 				return err;
 		}
 		newcon->flags |= CON_ENABLED;
@@ -2741,6 +2763,23 @@ static int try_enable_new_console(struct console *newcon, bool user_specified)
 	return -ENOENT;
 }
 
+/* Try to enable the console unconditionally */
+static void try_enable_default_console(struct console *newcon)
+{
+	if (newcon->index < 0)
+		newcon->index = 0;
+
+	if (console_call_setup(newcon, NULL) != 0)
+		return;
+
+	newcon->flags |= CON_ENABLED;
+
+	if (newcon->device) {
+		newcon->flags |= CON_CONSDEV;
+		has_preferred_console = true;
+	}
+}
+
 /*
  * The console driver calls this routine during kernel initialization
  * to register the console printing procedure with printk() and to
@@ -2797,25 +2836,15 @@ void register_console(struct console *newcon)
 	 *	didn't select a console we take the first one
 	 *	that registers here.
 	 */
-	if (!has_preferred_console) {
-		if (newcon->index < 0)
-			newcon->index = 0;
-		if (newcon->setup == NULL ||
-		    newcon->setup(newcon, NULL) == 0) {
-			newcon->flags |= CON_ENABLED;
-			if (newcon->device) {
-				newcon->flags |= CON_CONSDEV;
-				has_preferred_console = true;
-			}
-		}
-	}
+	if (!has_preferred_console)
+		try_enable_default_console(newcon);
 
 	/* See if this console matches one we selected on the command line */
-	err = try_enable_new_console(newcon, true);
+	err = try_enable_preferred_console(newcon, true);
 
 	/* If not, try to match against the platform default(s) */
 	if (err == -ENOENT)
-		err = try_enable_new_console(newcon, false);
+		err = try_enable_preferred_console(newcon, false);
 
 	/* printk() messages are not printed to the Braille console. */
 	if (err || newcon->flags & CON_BRL)
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index c5624ab05..105fdc2bb 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -1015,6 +1015,8 @@ static void rcu_tasks_trace_postscan(struct list_head *hop)
 
 	// Wait for late-stage exiting tasks to finish exiting.
 	// These might have passed the call to exit_tasks_rcu_finish().
+
+	// If you remove the following line, update rcu_trace_implies_rcu_gp()!!!
 	synchronize_rcu();
 	// Any tasks that exit after this point will set ->trc_reader_checked.
 }
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index cc7cd512e..1b7c3bdba 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -34,6 +34,8 @@
 	| MEMBARRIER_PRIVATE_EXPEDITED_SYNC_CORE_BITMASK		\
 	| MEMBARRIER_PRIVATE_EXPEDITED_RSEQ_BITMASK)
 
+static DEFINE_MUTEX(membarrier_ipi_mutex);
+
 static void ipi_mb(void *info)
 {
 	smp_mb();	/* IPIs should be serializing but paranoid. */
@@ -119,6 +121,7 @@ static int membarrier_global_expedited(void)
 	if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
 		return -ENOMEM;
 
+	mutex_lock(&membarrier_ipi_mutex);
 	cpus_read_lock();
 	rcu_read_lock();
 	for_each_online_cpu(cpu) {
@@ -165,6 +168,8 @@ static int membarrier_global_expedited(void)
 	 * rq->curr modification in scheduler.
 	 */
 	smp_mb();	/* exit from system call is not a mb */
+	mutex_unlock(&membarrier_ipi_mutex);
+
 	return 0;
 }
 
@@ -208,6 +213,7 @@ static int membarrier_private_expedited(int flags, int cpu_id)
 	if (cpu_id < 0 && !zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
 		return -ENOMEM;
 
+	mutex_lock(&membarrier_ipi_mutex);
 	cpus_read_lock();
 
 	if (cpu_id >= 0) {
@@ -280,6 +286,7 @@ out:
 	 * rq->curr modification in scheduler.
 	 */
 	smp_mb();	/* exit from system call is not a mb */
+	mutex_unlock(&membarrier_ipi_mutex);
 
 	return 0;
 }
@@ -321,6 +328,7 @@ static int sync_runqueues_membarrier_state(struct mm_struct *mm)
 	 * between threads which are users of @mm has its membarrier state
 	 * updated.
 	 */
+	mutex_lock(&membarrier_ipi_mutex);
 	cpus_read_lock();
 	rcu_read_lock();
 	for_each_online_cpu(cpu) {
@@ -337,6 +345,7 @@ static int sync_runqueues_membarrier_state(struct mm_struct *mm)
 
 	free_cpumask_var(tmpmask);
 	cpus_read_unlock();
+	mutex_unlock(&membarrier_ipi_mutex);
 
 	return 0;
 }
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index f690f901b..1289991c9 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -8,7 +8,7 @@
 #include "pelt.h"
 
 int sched_rr_timeslice = RR_TIMESLICE;
-int sysctl_sched_rr_timeslice = (MSEC_PER_SEC / HZ) * RR_TIMESLICE;
+int sysctl_sched_rr_timeslice = (MSEC_PER_SEC * RR_TIMESLICE) / HZ;
 /* More than 4 hours if BW_SHIFT equals 20. */
 static const u64 max_rt_runtime = MAX_BW;
 
@@ -2727,9 +2727,6 @@ static int sched_rt_global_constraints(void)
 
 static int sched_rt_global_validate(void)
 {
-	if (sysctl_sched_rt_period <= 0)
-		return -EINVAL;
-
 	if ((sysctl_sched_rt_runtime != RUNTIME_INF) &&
 		((sysctl_sched_rt_runtime > sysctl_sched_rt_period) ||
 		 ((u64)sysctl_sched_rt_runtime *
@@ -2760,7 +2757,7 @@ int sched_rt_handler(struct ctl_table *table, int write, void *buffer,
 	old_period = sysctl_sched_rt_period;
 	old_runtime = sysctl_sched_rt_runtime;
 
-	ret = proc_dointvec(table, write, buffer, lenp, ppos);
+	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 
 	if (!ret && write) {
 		ret = sched_rt_global_validate();
@@ -2804,6 +2801,9 @@ int sched_rr_handler(struct ctl_table *table, int write, void *buffer,
 		sched_rr_timeslice =
 			sysctl_sched_rr_timeslice <= 0 ? RR_TIMESLICE :
 			msecs_to_jiffies(sysctl_sched_rr_timeslice);
+
+		if (sysctl_sched_rr_timeslice <= 0)
+			sysctl_sched_rr_timeslice = jiffies_to_msecs(RR_TIMESLICE);
 	}
 	mutex_unlock(&mutex);
 
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 305f0eca1..0b0331346 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -29,6 +29,9 @@
 #include <linux/syscalls.h>
 #include <linux/sysctl.h>
 
+/* Not exposed in headers: strictly internal use only. */
+#define SECCOMP_MODE_DEAD	(SECCOMP_MODE_FILTER + 1)
+
 #ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
 #include <asm/syscall.h>
 #endif
@@ -795,6 +798,7 @@ static void __secure_computing_strict(int this_syscall)
 #ifdef SECCOMP_DEBUG
 	dump_stack();
 #endif
+	current->seccomp.mode = SECCOMP_MODE_DEAD;
 	seccomp_log(this_syscall, SIGKILL, SECCOMP_RET_KILL_THREAD, true);
 	do_exit(SIGKILL);
 }
@@ -1023,6 +1027,7 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
 	case SECCOMP_RET_KILL_THREAD:
 	case SECCOMP_RET_KILL_PROCESS:
 	default:
+		current->seccomp.mode = SECCOMP_MODE_DEAD;
 		seccomp_log(this_syscall, SIGSYS, action, true);
 		/* Dump core only if this is the last remaining thread. */
 		if (action != SECCOMP_RET_KILL_THREAD ||
@@ -1075,6 +1080,11 @@ int __secure_computing(const struct seccomp_data *sd)
 		return 0;
 	case SECCOMP_MODE_FILTER:
 		return __seccomp_filter(this_syscall, sd, false);
+	/* Surviving SECCOMP_RET_KILL_* must be proactively impossible. */
+	case SECCOMP_MODE_DEAD:
+		WARN_ON_ONCE(1);
+		do_exit(SIGKILL);
+		return -1;
 	default:
 		BUG();
 	}
diff --git a/kernel/sys.c b/kernel/sys.c
index bff14910b..efc213ae4 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1736,74 +1736,87 @@ void getrusage(struct task_struct *p, int who, struct rusage *r)
 	struct task_struct *t;
 	unsigned long flags;
 	u64 tgutime, tgstime, utime, stime;
-	unsigned long maxrss = 0;
+	unsigned long maxrss;
+	struct mm_struct *mm;
+	struct signal_struct *sig = p->signal;
+	unsigned int seq = 0;
 
-	memset((char *)r, 0, sizeof (*r));
+retry:
+	memset(r, 0, sizeof(*r));
 	utime = stime = 0;
+	maxrss = 0;
 
 	if (who == RUSAGE_THREAD) {
 		task_cputime_adjusted(current, &utime, &stime);
 		accumulate_thread_rusage(p, r);
-		maxrss = p->signal->maxrss;
-		goto out;
+		maxrss = sig->maxrss;
+		goto out_thread;
 	}
 
-	if (!lock_task_sighand(p, &flags))
-		return;
+	flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq);
 
 	switch (who) {
 	case RUSAGE_BOTH:
 	case RUSAGE_CHILDREN:
-		utime = p->signal->cutime;
-		stime = p->signal->cstime;
-		r->ru_nvcsw = p->signal->cnvcsw;
-		r->ru_nivcsw = p->signal->cnivcsw;
-		r->ru_minflt = p->signal->cmin_flt;
-		r->ru_majflt = p->signal->cmaj_flt;
-		r->ru_inblock = p->signal->cinblock;
-		r->ru_oublock = p->signal->coublock;
-		maxrss = p->signal->cmaxrss;
+		utime = sig->cutime;
+		stime = sig->cstime;
+		r->ru_nvcsw = sig->cnvcsw;
+		r->ru_nivcsw = sig->cnivcsw;
+		r->ru_minflt = sig->cmin_flt;
+		r->ru_majflt = sig->cmaj_flt;
+		r->ru_inblock = sig->cinblock;
+		r->ru_oublock = sig->coublock;
+		maxrss = sig->cmaxrss;
 
 		if (who == RUSAGE_CHILDREN)
 			break;
 		fallthrough;
 
 	case RUSAGE_SELF:
-		thread_group_cputime_adjusted(p, &tgutime, &tgstime);
-		utime += tgutime;
-		stime += tgstime;
-		r->ru_nvcsw += p->signal->nvcsw;
-		r->ru_nivcsw += p->signal->nivcsw;
-		r->ru_minflt += p->signal->min_flt;
-		r->ru_majflt += p->signal->maj_flt;
-		r->ru_inblock += p->signal->inblock;
-		r->ru_oublock += p->signal->oublock;
-		if (maxrss < p->signal->maxrss)
-			maxrss = p->signal->maxrss;
-		t = p;
-		do {
+		r->ru_nvcsw += sig->nvcsw;
+		r->ru_nivcsw += sig->nivcsw;
+		r->ru_minflt += sig->min_flt;
+		r->ru_majflt += sig->maj_flt;
+		r->ru_inblock += sig->inblock;
+		r->ru_oublock += sig->oublock;
+		if (maxrss < sig->maxrss)
+			maxrss = sig->maxrss;
+
+		rcu_read_lock();
+		__for_each_thread(sig, t)
 			accumulate_thread_rusage(t, r);
-		} while_each_thread(p, t);
+		rcu_read_unlock();
+
 		break;
 
 	default:
 		BUG();
 	}
-	unlock_task_sighand(p, &flags);
 
-out:
-	r->ru_utime = ns_to_kernel_old_timeval(utime);
-	r->ru_stime = ns_to_kernel_old_timeval(stime);
+	if (need_seqretry(&sig->stats_lock, seq)) {
+		seq = 1;
+		goto retry;
+	}
+	done_seqretry_irqrestore(&sig->stats_lock, seq, flags);
 
-	if (who != RUSAGE_CHILDREN) {
-		struct mm_struct *mm = get_task_mm(p);
+	if (who == RUSAGE_CHILDREN)
+		goto out_children;
 
-		if (mm) {
-			setmax_mm_hiwater_rss(&maxrss, mm);
-			mmput(mm);
-		}
+	thread_group_cputime_adjusted(p, &tgutime, &tgstime);
+	utime += tgutime;
+	stime += tgstime;
+
+out_thread:
+	mm = get_task_mm(p);
+	if (mm) {
+		setmax_mm_hiwater_rss(&maxrss, mm);
+		mmput(mm);
 	}
+
+out_children:
 	r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
+	r->ru_utime = ns_to_kernel_old_timeval(utime);
+	r->ru_stime = ns_to_kernel_old_timeval(stime);
 }
 
 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index a45f0dd10..99a191901 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1859,6 +1859,8 @@ static struct ctl_table kern_table[] = {
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler	= sched_rt_handler,
+		.extra1		= SYSCTL_ONE,
+		.extra2		= SYSCTL_INT_MAX,
 	},
 	{
 		.procname	= "sched_rt_runtime_us",
@@ -1866,6 +1868,8 @@ static struct ctl_table kern_table[] = {
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= sched_rt_handler,
+		.extra1		= SYSCTL_NEG_ONE,
+		.extra2		= SYSCTL_INT_MAX,
 	},
 	{
 		.procname	= "sched_deadline_period_max_us",
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 86e0fbe58..754e93edb 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -118,6 +118,7 @@ static DECLARE_WORK(watchdog_work, clocksource_watchdog_work);
 static DEFINE_SPINLOCK(watchdog_lock);
 static int watchdog_running;
 static atomic_t watchdog_reset_pending;
+static int64_t watchdog_max_interval;
 
 static inline void clocksource_watchdog_lock(unsigned long *flags)
 {
@@ -136,6 +137,7 @@ static void __clocksource_change_rating(struct clocksource *cs, int rating);
  * Interval: 0.5sec.
  */
 #define WATCHDOG_INTERVAL (HZ >> 1)
+#define WATCHDOG_INTERVAL_MAX_NS ((2 * WATCHDOG_INTERVAL) * (NSEC_PER_SEC / HZ))
 
 static void clocksource_watchdog_work(struct work_struct *work)
 {
@@ -324,8 +326,8 @@ static inline void clocksource_reset_watchdog(void)
 static void clocksource_watchdog(struct timer_list *unused)
 {
 	u64 csnow, wdnow, cslast, wdlast, delta;
+	int64_t wd_nsec, cs_nsec, interval;
 	int next_cpu, reset_pending;
-	int64_t wd_nsec, cs_nsec;
 	struct clocksource *cs;
 	enum wd_read_status read_ret;
 	unsigned long extra_wait = 0;
@@ -395,6 +397,27 @@ static void clocksource_watchdog(struct timer_list *unused)
 		if (atomic_read(&watchdog_reset_pending))
 			continue;
 
+		/*
+		 * The processing of timer softirqs can get delayed (usually
+		 * on account of ksoftirqd not getting to run in a timely
+		 * manner), which causes the watchdog interval to stretch.
+		 * Skew detection may fail for longer watchdog intervals
+		 * on account of fixed margins being used.
+		 * Some clocksources, e.g. acpi_pm, cannot tolerate
+		 * watchdog intervals longer than a few seconds.
+		 */
+		interval = max(cs_nsec, wd_nsec);
+		if (unlikely(interval > WATCHDOG_INTERVAL_MAX_NS)) {
+			if (system_state > SYSTEM_SCHEDULING &&
+			    interval > 2 * watchdog_max_interval) {
+				watchdog_max_interval = interval;
+				pr_warn("Long readout interval, skipping watchdog check: cs_nsec: %lld wd_nsec: %lld\n",
+					cs_nsec, wd_nsec);
+			}
+			watchdog_timer.expires = jiffies;
+			continue;
+		}
+
 		/* Check the deviation from the watchdog clocksource. */
 		md = cs->uncertainty_margin + watchdog->uncertainty_margin;
 		if (abs(cs_nsec - wd_nsec) > md) {
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index ede09dda3..2b2a6e292 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -980,6 +980,7 @@ static int enqueue_hrtimer(struct hrtimer *timer,
 			   enum hrtimer_mode mode)
 {
 	debug_activate(timer, mode);
+	WARN_ON_ONCE(!base->cpu_base->online);
 
 	base->cpu_base->active_bases |= 1 << base->index;
 
@@ -2078,6 +2079,7 @@ int hrtimers_prepare_cpu(unsigned int cpu)
 	cpu_base->softirq_next_timer = NULL;
 	cpu_base->expires_next = KTIME_MAX;
 	cpu_base->softirq_expires_next = KTIME_MAX;
+	cpu_base->online = 1;
 	hrtimer_cpu_base_init_expiry_lock(cpu_base);
 	return 0;
 }
@@ -2145,6 +2147,7 @@ int hrtimers_cpu_dying(unsigned int dying_cpu)
 	smp_call_function_single(ncpu, retrigger_next_event, NULL, 0);
 
 	raw_spin_unlock(&new_base->lock);
+	old_base->online = 0;
 	raw_spin_unlock(&old_base->lock);
 
 	return 0;
@@ -2161,7 +2164,7 @@ void __init hrtimers_init(void)
 /**
  * schedule_hrtimeout_range_clock - sleep until timeout
  * @expires:	timeout value (ktime_t)
- * @delta:	slack in expires timeout (ktime_t)
+ * @delta:	slack in expires timeout (ktime_t) for SCHED_OTHER tasks
  * @mode:	timer mode
  * @clock_id:	timer clock to be used
  */
@@ -2188,6 +2191,13 @@ schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta,
 		return -EINTR;
 	}
 
+	/*
+	 * Override any slack passed by the user if under
+	 * rt contraints.
+	 */
+	if (rt_task(current))
+		delta = 0;
+
 	hrtimer_init_sleeper_on_stack(&t, clock_id, mode);
 	hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
 	hrtimer_sleeper_start_expires(&t, mode);
@@ -2207,7 +2217,7 @@ EXPORT_SYMBOL_GPL(schedule_hrtimeout_range_clock);
 /**
  * schedule_hrtimeout_range - sleep until timeout
  * @expires:	timeout value (ktime_t)
- * @delta:	slack in expires timeout (ktime_t)
+ * @delta:	slack in expires timeout (ktime_t) for SCHED_OTHER tasks
  * @mode:	timer mode
  *
  * Make the current task sleep until the given expiry time has
@@ -2215,7 +2225,8 @@ EXPORT_SYMBOL_GPL(schedule_hrtimeout_range_clock);
  * the current task state has been set (see set_current_state()).
  *
  * The @delta argument gives the kernel the freedom to schedule the
- * actual wakeup to a time that is both power and performance friendly.
+ * actual wakeup to a time that is both power and performance friendly
+ * for regular (non RT/DL) tasks.
  * The kernel give the normal best effort behavior for "@expires+@delta",
  * but may decide to fire the timer earlier, but no earlier than @expires.
  *
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index bc00ab011..d1693c269 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -1440,6 +1440,7 @@ void tick_cancel_sched_timer(int cpu)
 {
 	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
 	ktime_t idle_sleeptime, iowait_sleeptime;
+	unsigned long idle_calls, idle_sleeps;
 
 # ifdef CONFIG_HIGH_RES_TIMERS
 	if (ts->sched_timer.base)
@@ -1448,9 +1449,13 @@ void tick_cancel_sched_timer(int cpu)
 
 	idle_sleeptime = ts->idle_sleeptime;
 	iowait_sleeptime = ts->iowait_sleeptime;
+	idle_calls = ts->idle_calls;
+	idle_sleeps = ts->idle_sleeps;
 	memset(ts, 0, sizeof(*ts));
 	ts->idle_sleeptime = idle_sleeptime;
 	ts->iowait_sleeptime = iowait_sleeptime;
+	ts->idle_calls = idle_calls;
+	ts->idle_sleeps = idle_sleeps;
 }
 #endif
 
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index d9b48f7a3..629a07e6a 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1167,13 +1167,15 @@ static int adjust_historical_crosststamp(struct system_time_snapshot *history,
 }
 
 /*
- * cycle_between - true if test occurs chronologically between before and after
+ * timestamp_in_interval - true if ts is chronologically in [start, end]
+ *
+ * True if ts occurs chronologically at or after start, and before or at end.
  */
-static bool cycle_between(u64 before, u64 test, u64 after)
+static bool timestamp_in_interval(u64 start, u64 end, u64 ts)
 {
-	if (test > before && test < after)
+	if (ts >= start && ts <= end)
 		return true;
-	if (test < before && before > after)
+	if (start > end && (ts >= start || ts <= end))
 		return true;
 	return false;
 }
@@ -1233,7 +1235,7 @@ int get_device_system_crosststamp(int (*get_time_fn)
 		 */
 		now = tk_clock_read(&tk->tkr_mono);
 		interval_start = tk->tkr_mono.cycle_last;
-		if (!cycle_between(interval_start, cycles, now)) {
+		if (!timestamp_in_interval(interval_start, now, cycles)) {
 			clock_was_set_seq = tk->clock_was_set_seq;
 			cs_was_changed_seq = tk->cs_was_changed_seq;
 			cycles = interval_start;
@@ -1246,10 +1248,8 @@ int get_device_system_crosststamp(int (*get_time_fn)
 				      tk_core.timekeeper.offs_real);
 		base_raw = tk->tkr_raw.base;
 
-		nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono,
-						     system_counterval.cycles);
-		nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw,
-						    system_counterval.cycles);
+		nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, cycles);
+		nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, cycles);
 	} while (read_seqcount_retry(&tk_core.seq, seq));
 
 	xtstamp->sys_realtime = ktime_add_ns(base_real, nsec_real);
@@ -1264,13 +1264,13 @@ int get_device_system_crosststamp(int (*get_time_fn)
 		bool discontinuity;
 
 		/*
-		 * Check that the counter value occurs after the provided
+		 * Check that the counter value is not before the provided
 		 * history reference and that the history doesn't cross a
 		 * clocksource change
 		 */
 		if (!history_begin ||
-		    !cycle_between(history_begin->cycles,
-				   system_counterval.cycles, cycles) ||
+		    !timestamp_in_interval(history_begin->cycles,
+					   cycles, system_counterval.cycles) ||
 		    history_begin->cs_was_changed_seq != cs_was_changed_seq)
 			return -EINVAL;
 		partial_history_cycles = cycles - system_counterval.cycles;
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index e87e638c3..c135cefa4 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1030,7 +1030,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires, unsigned int option
 		/*
 		 * We are trying to schedule the timer on the new base.
 		 * However we can't change timer's base while it is running,
-		 * otherwise del_timer_sync() can't detect that the timer's
+		 * otherwise timer_delete_sync() can't detect that the timer's
 		 * handler yet has not finished. This also guarantees that the
 		 * timer is serialized wrt itself.
 		 */
@@ -1068,14 +1068,16 @@ out_unlock:
 }
 
 /**
- * mod_timer_pending - modify a pending timer's timeout
- * @timer: the pending timer to be modified
- * @expires: new timeout in jiffies
+ * mod_timer_pending - Modify a pending timer's timeout
+ * @timer:	The pending timer to be modified
+ * @expires:	New absolute timeout in jiffies
  *
- * mod_timer_pending() is the same for pending timers as mod_timer(),
- * but will not re-activate and modify already deleted timers.
+ * mod_timer_pending() is the same for pending timers as mod_timer(), but
+ * will not activate inactive timers.
  *
- * It is useful for unserialized use of timers.
+ * Return:
+ * * %0 - The timer was inactive and not modified
+ * * %1 - The timer was active and requeued to expire at @expires
  */
 int mod_timer_pending(struct timer_list *timer, unsigned long expires)
 {
@@ -1084,24 +1086,27 @@ int mod_timer_pending(struct timer_list *timer, unsigned long expires)
 EXPORT_SYMBOL(mod_timer_pending);
 
 /**
- * mod_timer - modify a timer's timeout
- * @timer: the timer to be modified
- * @expires: new timeout in jiffies
- *
- * mod_timer() is a more efficient way to update the expire field of an
- * active timer (if the timer is inactive it will be activated)
+ * mod_timer - Modify a timer's timeout
+ * @timer:	The timer to be modified
+ * @expires:	New absolute timeout in jiffies
  *
  * mod_timer(timer, expires) is equivalent to:
  *
  *     del_timer(timer); timer->expires = expires; add_timer(timer);
  *
+ * mod_timer() is more efficient than the above open coded sequence. In
+ * case that the timer is inactive, the del_timer() part is a NOP. The
+ * timer is in any case activated with the new expiry time @expires.
+ *
  * Note that if there are multiple unserialized concurrent users of the
  * same timer, then mod_timer() is the only safe way to modify the timeout,
  * since add_timer() cannot modify an already running timer.
  *
- * The function returns whether it has modified a pending timer or not.
- * (ie. mod_timer() of an inactive timer returns 0, mod_timer() of an
- * active timer returns 1.)
+ * Return:
+ * * %0 - The timer was inactive and started
+ * * %1 - The timer was active and requeued to expire at @expires or
+ *	  the timer was active and not modified because @expires did
+ *	  not change the effective expiry time
  */
 int mod_timer(struct timer_list *timer, unsigned long expires)
 {
@@ -1112,11 +1117,18 @@ EXPORT_SYMBOL(mod_timer);
 /**
  * timer_reduce - Modify a timer's timeout if it would reduce the timeout
  * @timer:	The timer to be modified
- * @expires:	New timeout in jiffies
+ * @expires:	New absolute timeout in jiffies
  *
  * timer_reduce() is very similar to mod_timer(), except that it will only
- * modify a running timer if that would reduce the expiration time (it will
- * start a timer that isn't running).
+ * modify an enqueued timer if that would reduce the expiration time. If
+ * @timer is not enqueued it starts the timer.
+ *
+ * Return:
+ * * %0 - The timer was inactive and started
+ * * %1 - The timer was active and requeued to expire at @expires or
+ *	  the timer was active and not modified because @expires
+ *	  did not change the effective expiry time such that the
+ *	  timer would expire earlier than already scheduled
  */
 int timer_reduce(struct timer_list *timer, unsigned long expires)
 {
@@ -1125,18 +1137,21 @@ int timer_reduce(struct timer_list *timer, unsigned long expires)
 EXPORT_SYMBOL(timer_reduce);
 
 /**
- * add_timer - start a timer
- * @timer: the timer to be added
+ * add_timer - Start a timer
+ * @timer:	The timer to be started
  *
- * The kernel will do a ->function(@timer) callback from the
- * timer interrupt at the ->expires point in the future. The
- * current time is 'jiffies'.
+ * Start @timer to expire at @timer->expires in the future. @timer->expires
+ * is the absolute expiry time measured in 'jiffies'. When the timer expires
+ * timer->function(timer) will be invoked from soft interrupt context.
  *
- * The timer's ->expires, ->function fields must be set prior calling this
- * function.
+ * The @timer->expires and @timer->function fields must be set prior
+ * to calling this function.
  *
- * Timers with an ->expires field in the past will be executed in the next
- * timer tick.
+ * If @timer->expires is already in the past @timer will be queued to
+ * expire at the next timer tick.
+ *
+ * This can only operate on an inactive timer. Attempts to invoke this on
+ * an active timer are rejected with a warning.
  */
 void add_timer(struct timer_list *timer)
 {
@@ -1146,11 +1161,13 @@ void add_timer(struct timer_list *timer)
 EXPORT_SYMBOL(add_timer);
 
 /**
- * add_timer_on - start a timer on a particular CPU
- * @timer: the timer to be added
- * @cpu: the CPU to start it on
+ * add_timer_on - Start a timer on a particular CPU
+ * @timer:	The timer to be started
+ * @cpu:	The CPU to start it on
+ *
+ * Same as add_timer() except that it starts the timer on the given CPU.
  *
- * This is not very scalable on SMP. Double adds are not possible.
+ * See add_timer() for further details.
  */
 void add_timer_on(struct timer_list *timer, int cpu)
 {
@@ -1185,15 +1202,18 @@ void add_timer_on(struct timer_list *timer, int cpu)
 EXPORT_SYMBOL_GPL(add_timer_on);
 
 /**
- * del_timer - deactivate a timer.
- * @timer: the timer to be deactivated
- *
- * del_timer() deactivates a timer - this works on both active and inactive
- * timers.
- *
- * The function returns whether it has deactivated a pending timer or not.
- * (ie. del_timer() of an inactive timer returns 0, del_timer() of an
- * active timer returns 1.)
+ * del_timer - Deactivate a timer.
+ * @timer:	The timer to be deactivated
+ *
+ * The function only deactivates a pending timer, but contrary to
+ * timer_delete_sync() it does not take into account whether the timer's
+ * callback function is concurrently executed on a different CPU or not.
+ * It neither prevents rearming of the timer. If @timer can be rearmed
+ * concurrently then the return value of this function is meaningless.
+ *
+ * Return:
+ * * %0 - The timer was not pending
+ * * %1 - The timer was pending and deactivated
  */
 int del_timer(struct timer_list *timer)
 {
@@ -1215,10 +1235,19 @@ EXPORT_SYMBOL(del_timer);
 
 /**
  * try_to_del_timer_sync - Try to deactivate a timer
- * @timer: timer to delete
+ * @timer:	Timer to deactivate
+ *
+ * This function tries to deactivate a timer. On success the timer is not
+ * queued and the timer callback function is not running on any CPU.
+ *
+ * This function does not guarantee that the timer cannot be rearmed right
+ * after dropping the base lock. That needs to be prevented by the calling
+ * code if necessary.
  *
- * This function tries to deactivate a timer. Upon successful (ret >= 0)
- * exit the timer is not queued and the handler is not running on any CPU.
+ * Return:
+ * * %0  - The timer was not pending
+ * * %1  - The timer was pending and deactivated
+ * * %-1 - The timer callback function is running on a different CPU
  */
 int try_to_del_timer_sync(struct timer_list *timer)
 {
@@ -1312,25 +1341,20 @@ static inline void timer_sync_wait_running(struct timer_base *base) { }
 static inline void del_timer_wait_running(struct timer_list *timer) { }
 #endif
 
-#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT)
 /**
- * del_timer_sync - deactivate a timer and wait for the handler to finish.
- * @timer: the timer to be deactivated
- *
- * This function only differs from del_timer() on SMP: besides deactivating
- * the timer it also makes sure the handler has finished executing on other
- * CPUs.
+ * timer_delete_sync - Deactivate a timer and wait for the handler to finish.
+ * @timer:	The timer to be deactivated
  *
  * Synchronization rules: Callers must prevent restarting of the timer,
  * otherwise this function is meaningless. It must not be called from
  * interrupt contexts unless the timer is an irqsafe one. The caller must
- * not hold locks which would prevent completion of the timer's
- * handler. The timer's handler must not call add_timer_on(). Upon exit the
- * timer is not queued and the handler is not running on any CPU.
+ * not hold locks which would prevent completion of the timer's callback
+ * function. The timer's handler must not call add_timer_on(). Upon exit
+ * the timer is not queued and the handler is not running on any CPU.
  *
- * Note: For !irqsafe timers, you must not hold locks that are held in
- *   interrupt context while calling this function. Even if the lock has
- *   nothing to do with the timer in question.  Here's why::
+ * For !irqsafe timers, the caller must not hold locks that are held in
+ * interrupt context. Even if the lock has nothing to do with the timer in
+ * question.  Here's why::
  *
  *    CPU0                             CPU1
  *    ----                             ----
@@ -1340,16 +1364,23 @@ static inline void del_timer_wait_running(struct timer_list *timer) { }
  *    spin_lock_irq(somelock);
  *                                     <IRQ>
  *                                        spin_lock(somelock);
- *    del_timer_sync(mytimer);
+ *    timer_delete_sync(mytimer);
  *    while (base->running_timer == mytimer);
  *
- * Now del_timer_sync() will never return and never release somelock.
- * The interrupt on the other CPU is waiting to grab somelock but
- * it has interrupted the softirq that CPU0 is waiting to finish.
+ * Now timer_delete_sync() will never return and never release somelock.
+ * The interrupt on the other CPU is waiting to grab somelock but it has
+ * interrupted the softirq that CPU0 is waiting to finish.
+ *
+ * This function cannot guarantee that the timer is not rearmed again by
+ * some concurrent or preempting code, right after it dropped the base
+ * lock. If there is the possibility of a concurrent rearm then the return
+ * value of the function is meaningless.
  *
- * The function returns whether it has deactivated a pending timer or not.
+ * Return:
+ * * %0	- The timer was not pending
+ * * %1	- The timer was pending and deactivated
  */
-int del_timer_sync(struct timer_list *timer)
+int timer_delete_sync(struct timer_list *timer)
 {
 	int ret;
 
@@ -1382,8 +1413,7 @@ int del_timer_sync(struct timer_list *timer)
 
 	return ret;
 }
-EXPORT_SYMBOL(del_timer_sync);
-#endif
+EXPORT_SYMBOL(timer_delete_sync);
 
 static void call_timer_fn(struct timer_list *timer,
 			  void (*fn)(struct timer_list *),
@@ -1405,8 +1435,8 @@ static void call_timer_fn(struct timer_list *timer,
 #endif
 	/*
 	 * Couple the lock chain with the lock chain at
-	 * del_timer_sync() by acquiring the lock_map around the fn()
-	 * call here and in del_timer_sync().
+	 * timer_delete_sync() by acquiring the lock_map around the fn()
+	 * call here and in timer_delete_sync().
 	 */
 	lock_map_acquire(&lockdep_map);
 
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 041b91c2b..2df8e13a2 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -415,7 +415,6 @@ struct rb_irq_work {
 	struct irq_work			work;
 	wait_queue_head_t		waiters;
 	wait_queue_head_t		full_waiters;
-	long				wait_index;
 	bool				waiters_pending;
 	bool				full_waiters_pending;
 	bool				wakeup_full;
@@ -832,8 +831,19 @@ static void rb_wake_up_waiters(struct irq_work *work)
 
 	wake_up_all(&rbwork->waiters);
 	if (rbwork->full_waiters_pending || rbwork->wakeup_full) {
+		/* Only cpu_buffer sets the above flags */
+		struct ring_buffer_per_cpu *cpu_buffer =
+			container_of(rbwork, struct ring_buffer_per_cpu, irq_work);
+
+		/* Called from interrupt context */
+		raw_spin_lock(&cpu_buffer->reader_lock);
 		rbwork->wakeup_full = false;
 		rbwork->full_waiters_pending = false;
+
+		/* Waking up all waiters, they will reset the shortest full */
+		cpu_buffer->shortest_full = 0;
+		raw_spin_unlock(&cpu_buffer->reader_lock);
+
 		wake_up_all(&rbwork->full_waiters);
 	}
 }
@@ -862,14 +872,41 @@ void ring_buffer_wake_waiters(struct trace_buffer *buffer, int cpu)
 		rbwork = &cpu_buffer->irq_work;
 	}
 
-	rbwork->wait_index++;
-	/* make sure the waiters see the new index */
-	smp_wmb();
-
 	/* This can be called in any context */
 	irq_work_queue(&rbwork->work);
 }
 
+static bool rb_watermark_hit(struct trace_buffer *buffer, int cpu, int full)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	bool ret = false;
+
+	/* Reads of all CPUs always waits for any data */
+	if (cpu == RING_BUFFER_ALL_CPUS)
+		return !ring_buffer_empty(buffer);
+
+	cpu_buffer = buffer->buffers[cpu];
+
+	if (!ring_buffer_empty_cpu(buffer, cpu)) {
+		unsigned long flags;
+		bool pagebusy;
+
+		if (!full)
+			return true;
+
+		raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+		pagebusy = cpu_buffer->reader_page == cpu_buffer->commit_page;
+		ret = !pagebusy && full_hit(buffer, cpu, full);
+
+		if (!ret && (!cpu_buffer->shortest_full ||
+			     cpu_buffer->shortest_full > full)) {
+		    cpu_buffer->shortest_full = full;
+		}
+		raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+	}
+	return ret;
+}
+
 /**
  * ring_buffer_wait - wait for input to the ring buffer
  * @buffer: buffer to wait on
@@ -885,7 +922,6 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full)
 	struct ring_buffer_per_cpu *cpu_buffer;
 	DEFINE_WAIT(wait);
 	struct rb_irq_work *work;
-	long wait_index;
 	int ret = 0;
 
 	/*
@@ -904,81 +940,54 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full)
 		work = &cpu_buffer->irq_work;
 	}
 
-	wait_index = READ_ONCE(work->wait_index);
-
-	while (true) {
-		if (full)
-			prepare_to_wait(&work->full_waiters, &wait, TASK_INTERRUPTIBLE);
-		else
-			prepare_to_wait(&work->waiters, &wait, TASK_INTERRUPTIBLE);
-
-		/*
-		 * The events can happen in critical sections where
-		 * checking a work queue can cause deadlocks.
-		 * After adding a task to the queue, this flag is set
-		 * only to notify events to try to wake up the queue
-		 * using irq_work.
-		 *
-		 * We don't clear it even if the buffer is no longer
-		 * empty. The flag only causes the next event to run
-		 * irq_work to do the work queue wake up. The worse
-		 * that can happen if we race with !trace_empty() is that
-		 * an event will cause an irq_work to try to wake up
-		 * an empty queue.
-		 *
-		 * There's no reason to protect this flag either, as
-		 * the work queue and irq_work logic will do the necessary
-		 * synchronization for the wake ups. The only thing
-		 * that is necessary is that the wake up happens after
-		 * a task has been queued. It's OK for spurious wake ups.
-		 */
-		if (full)
-			work->full_waiters_pending = true;
-		else
-			work->waiters_pending = true;
-
-		if (signal_pending(current)) {
-			ret = -EINTR;
-			break;
-		}
-
-		if (cpu == RING_BUFFER_ALL_CPUS && !ring_buffer_empty(buffer))
-			break;
-
-		if (cpu != RING_BUFFER_ALL_CPUS &&
-		    !ring_buffer_empty_cpu(buffer, cpu)) {
-			unsigned long flags;
-			bool pagebusy;
-			bool done;
-
-			if (!full)
-				break;
-
-			raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
-			pagebusy = cpu_buffer->reader_page == cpu_buffer->commit_page;
-			done = !pagebusy && full_hit(buffer, cpu, full);
+	if (full)
+		prepare_to_wait(&work->full_waiters, &wait, TASK_INTERRUPTIBLE);
+	else
+		prepare_to_wait(&work->waiters, &wait, TASK_INTERRUPTIBLE);
 
-			if (!cpu_buffer->shortest_full ||
-			    cpu_buffer->shortest_full > full)
-				cpu_buffer->shortest_full = full;
-			raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
-			if (done)
-				break;
-		}
+	/*
+	 * The events can happen in critical sections where
+	 * checking a work queue can cause deadlocks.
+	 * After adding a task to the queue, this flag is set
+	 * only to notify events to try to wake up the queue
+	 * using irq_work.
+	 *
+	 * We don't clear it even if the buffer is no longer
+	 * empty. The flag only causes the next event to run
+	 * irq_work to do the work queue wake up. The worse
+	 * that can happen if we race with !trace_empty() is that
+	 * an event will cause an irq_work to try to wake up
+	 * an empty queue.
+	 *
+	 * There's no reason to protect this flag either, as
+	 * the work queue and irq_work logic will do the necessary
+	 * synchronization for the wake ups. The only thing
+	 * that is necessary is that the wake up happens after
+	 * a task has been queued. It's OK for spurious wake ups.
+	 */
+	if (full)
+		work->full_waiters_pending = true;
+	else
+		work->waiters_pending = true;
 
-		schedule();
+	if (rb_watermark_hit(buffer, cpu, full))
+		goto out;
 
-		/* Make sure to see the new wait index */
-		smp_rmb();
-		if (wait_index != work->wait_index)
-			break;
+	if (signal_pending(current)) {
+		ret = -EINTR;
+		goto out;
 	}
 
+	schedule();
+ out:
 	if (full)
 		finish_wait(&work->full_waiters, &wait);
 	else
 		finish_wait(&work->waiters, &wait);
 
+	if (!ret && !rb_watermark_hit(buffer, cpu, full) && signal_pending(current))
+		ret = -EINTR;
+
 	return ret;
 }
 
@@ -1001,30 +1010,51 @@ __poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu,
 			  struct file *filp, poll_table *poll_table, int full)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
-	struct rb_irq_work *work;
+	struct rb_irq_work *rbwork;
 
 	if (cpu == RING_BUFFER_ALL_CPUS) {
-		work = &buffer->irq_work;
+		rbwork = &buffer->irq_work;
 		full = 0;
 	} else {
 		if (!cpumask_test_cpu(cpu, buffer->cpumask))
-			return -EINVAL;
+			return EPOLLERR;
 
 		cpu_buffer = buffer->buffers[cpu];
-		work = &cpu_buffer->irq_work;
+		rbwork = &cpu_buffer->irq_work;
 	}
 
 	if (full) {
-		poll_wait(filp, &work->full_waiters, poll_table);
-		work->full_waiters_pending = true;
+		unsigned long flags;
+
+		poll_wait(filp, &rbwork->full_waiters, poll_table);
+
+		raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
 		if (!cpu_buffer->shortest_full ||
 		    cpu_buffer->shortest_full > full)
 			cpu_buffer->shortest_full = full;
-	} else {
-		poll_wait(filp, &work->waiters, poll_table);
-		work->waiters_pending = true;
+		raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+		if (full_hit(buffer, cpu, full))
+			return EPOLLIN | EPOLLRDNORM;
+		/*
+		 * Only allow full_waiters_pending update to be seen after
+		 * the shortest_full is set. If the writer sees the
+		 * full_waiters_pending flag set, it will compare the
+		 * amount in the ring buffer to shortest_full. If the amount
+		 * in the ring buffer is greater than the shortest_full
+		 * percent, it will call the irq_work handler to wake up
+		 * this list. The irq_handler will reset shortest_full
+		 * back to zero. That's done under the reader_lock, but
+		 * the below smp_mb() makes sure that the update to
+		 * full_waiters_pending doesn't leak up into the above.
+		 */
+		smp_mb();
+		rbwork->full_waiters_pending = true;
+		return 0;
 	}
 
+	poll_wait(filp, &rbwork->waiters, poll_table);
+	rbwork->waiters_pending = true;
+
 	/*
 	 * There's a tight race between setting the waiters_pending and
 	 * checking if the ring buffer is empty.  Once the waiters_pending bit
@@ -1040,9 +1070,6 @@ __poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu,
 	 */
 	smp_mb();
 
-	if (full)
-		return full_hit(buffer, cpu, full) ? EPOLLIN | EPOLLRDNORM : 0;
-
 	if ((cpu == RING_BUFFER_ALL_CPUS && !ring_buffer_empty(buffer)) ||
 	    (cpu != RING_BUFFER_ALL_CPUS && !ring_buffer_empty_cpu(buffer, cpu)))
 		return EPOLLIN | EPOLLRDNORM;
@@ -4184,7 +4211,7 @@ int ring_buffer_iter_empty(struct ring_buffer_iter *iter)
 	cpu_buffer = iter->cpu_buffer;
 	reader = cpu_buffer->reader_page;
 	head_page = cpu_buffer->head_page;
-	commit_page = cpu_buffer->commit_page;
+	commit_page = READ_ONCE(cpu_buffer->commit_page);
 	commit_ts = commit_page->page->time_stamp;
 
 	/*
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 548f694fc..22e1e5711 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -39,6 +39,7 @@
 #include <linux/slab.h>
 #include <linux/ctype.h>
 #include <linux/init.h>
+#include <linux/kmemleak.h>
 #include <linux/poll.h>
 #include <linux/nmi.h>
 #include <linux/fs.h>
@@ -2239,7 +2240,7 @@ struct saved_cmdlines_buffer {
 	unsigned *map_cmdline_to_pid;
 	unsigned cmdline_num;
 	int cmdline_idx;
-	char *saved_cmdlines;
+	char saved_cmdlines[];
 };
 static struct saved_cmdlines_buffer *savedcmd;
 
@@ -2253,47 +2254,60 @@ static inline void set_cmdline(int idx, const char *cmdline)
 	strncpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN);
 }
 
-static int allocate_cmdlines_buffer(unsigned int val,
-				    struct saved_cmdlines_buffer *s)
+static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)
 {
+	int order = get_order(sizeof(*s) + s->cmdline_num * TASK_COMM_LEN);
+
+	kfree(s->map_cmdline_to_pid);
+	kmemleak_free(s);
+	free_pages((unsigned long)s, order);
+}
+
+static struct saved_cmdlines_buffer *allocate_cmdlines_buffer(unsigned int val)
+{
+	struct saved_cmdlines_buffer *s;
+	struct page *page;
+	int orig_size, size;
+	int order;
+
+	/* Figure out how much is needed to hold the given number of cmdlines */
+	orig_size = sizeof(*s) + val * TASK_COMM_LEN;
+	order = get_order(orig_size);
+	size = 1 << (order + PAGE_SHIFT);
+	page = alloc_pages(GFP_KERNEL, order);
+	if (!page)
+		return NULL;
+
+	s = page_address(page);
+	kmemleak_alloc(s, size, 1, GFP_KERNEL);
+	memset(s, 0, sizeof(*s));
+
+	/* Round up to actual allocation */
+	val = (size - sizeof(*s)) / TASK_COMM_LEN;
+	s->cmdline_num = val;
+
 	s->map_cmdline_to_pid = kmalloc_array(val,
 					      sizeof(*s->map_cmdline_to_pid),
 					      GFP_KERNEL);
-	if (!s->map_cmdline_to_pid)
-		return -ENOMEM;
-
-	s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);
-	if (!s->saved_cmdlines) {
-		kfree(s->map_cmdline_to_pid);
-		return -ENOMEM;
+	if (!s->map_cmdline_to_pid) {
+		free_saved_cmdlines_buffer(s);
+		return NULL;
 	}
 
 	s->cmdline_idx = 0;
-	s->cmdline_num = val;
 	memset(&s->map_pid_to_cmdline, NO_CMDLINE_MAP,
 	       sizeof(s->map_pid_to_cmdline));
 	memset(s->map_cmdline_to_pid, NO_CMDLINE_MAP,
 	       val * sizeof(*s->map_cmdline_to_pid));
 
-	return 0;
+	return s;
 }
 
 static int trace_create_savedcmd(void)
 {
-	int ret;
-
-	savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL);
-	if (!savedcmd)
-		return -ENOMEM;
+	savedcmd = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT);
 
-	ret = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT, savedcmd);
-	if (ret < 0) {
-		kfree(savedcmd);
-		savedcmd = NULL;
-		return -ENOMEM;
-	}
-
-	return 0;
+	return savedcmd ? 0 : -ENOMEM;
 }
 
 int is_tracing_stopped(void)
@@ -5603,26 +5617,14 @@ tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf,
 	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 }
 
-static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)
-{
-	kfree(s->saved_cmdlines);
-	kfree(s->map_cmdline_to_pid);
-	kfree(s);
-}
-
 static int tracing_resize_saved_cmdlines(unsigned int val)
 {
 	struct saved_cmdlines_buffer *s, *savedcmd_temp;
 
-	s = kmalloc(sizeof(*s), GFP_KERNEL);
+	s = allocate_cmdlines_buffer(val);
 	if (!s)
 		return -ENOMEM;
 
-	if (allocate_cmdlines_buffer(val, s) < 0) {
-		kfree(s);
-		return -ENOMEM;
-	}
-
 	preempt_disable();
 	arch_spin_lock(&trace_cmdline_lock);
 	savedcmd_temp = savedcmd;
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 643e0b199..eb81ad523 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -400,7 +400,8 @@ void *perf_trace_buf_alloc(int size, struct pt_regs **regs, int *rctxp)
 	BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long));
 
 	if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
-		      "perf buffer not large enough"))
+		      "perf buffer not large enough, wanted %d, have %d",
+		      size, PERF_MAX_TRACE_SIZE))
 		return NULL;
 
 	*rctxp = rctx = perf_swevent_get_recursion_context();
diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c
index 51a9d1185..d47641f97 100644
--- a/kernel/trace/tracing_map.c
+++ b/kernel/trace/tracing_map.c
@@ -574,7 +574,12 @@ __tracing_map_insert(struct tracing_map *map, void *key, bool lookup_only)
 				}
 
 				memcpy(elt->key, key, map->key_size);
-				entry->val = elt;
+				/*
+				 * Ensure the initialization is visible and
+				 * publish the elt.
+				 */
+				smp_wmb();
+				WRITE_ONCE(entry->val, elt);
 				atomic64_inc(&map->hits);
 
 				return entry->val;