Merging upstream version 4.19.282.

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

30 files changed, 408 insertions, 77 deletions

diff --git a/kernel/acct.c b/kernel/acct.c
index 81f9831a7..6d98aed40 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -331,6 +331,8 @@ static comp_t encode_comp_t(unsigned long value)
 		exp++;
 	}
 
+	if (exp > (((comp_t) ~0U) >> MANTSIZE))
+		return (comp_t) ~0U;
 	/*
 	 * Clean it up and polish it off.
 	 */
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index cbbd0168f..285101772 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -32,6 +32,7 @@
 #include <linux/kallsyms.h>
 #include <linux/rcupdate.h>
 #include <linux/perf_event.h>
+#include <linux/nospec.h>
 
 #include <asm/barrier.h>
 #include <asm/unaligned.h>
@@ -602,7 +603,7 @@ static int __init bpf_jit_charge_init(void)
 {
 	/* Only used as heuristic here to derive limit. */
 	bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
-	bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 2,
+	bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 1,
 					    PAGE_SIZE), LONG_MAX);
 	return 0;
 }
@@ -1373,9 +1374,7 @@ out:
 		 * reuse preexisting logic from Spectre v1 mitigation that
 		 * happens to produce the required code on x86 for v4 as well.
 		 */
-#ifdef CONFIG_X86
 		barrier_nospec();
-#endif
 		CONT;
 #define LDST(SIZEOP, SIZE)						\
 	STX_MEM_##SIZEOP:						\
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 694ee0b1f..61f3a31ab 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1012,7 +1012,9 @@ static int check_stack_write(struct bpf_verifier_env *env,
 		bool sanitize = reg && is_spillable_regtype(reg->type);
 
 		for (i = 0; i < size; i++) {
-			if (state->stack[spi].slot_type[i] == STACK_INVALID) {
+			u8 type = state->stack[spi].slot_type[i];
+
+			if (type != STACK_MISC && type != STACK_ZERO) {
 				sanitize = true;
 				break;
 			}
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 616449762..c0ebb7080 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -13,6 +13,7 @@
 #include <linux/delayacct.h>
 #include <linux/pid_namespace.h>
 #include <linux/cgroupstats.h>
+#include <linux/cpu.h>
 
 #include <trace/events/cgroup.h>
 
@@ -55,6 +56,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
 	int retval = 0;
 
 	mutex_lock(&cgroup_mutex);
+	get_online_cpus();
 	percpu_down_write(&cgroup_threadgroup_rwsem);
 	for_each_root(root) {
 		struct cgroup *from_cgrp;
@@ -71,6 +73,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
 			break;
 	}
 	percpu_up_write(&cgroup_threadgroup_rwsem);
+	put_online_cpus();
 	mutex_unlock(&cgroup_mutex);
 
 	return retval;
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index a892a99eb..a8185cdb8 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -55,6 +55,7 @@
 #include <linux/nsproxy.h>
 #include <linux/file.h>
 #include <linux/sched/cputime.h>
+#include <linux/cpu.h>
 #include <net/sock.h>
 
 #define CREATE_TRACE_POINTS
@@ -2210,6 +2211,45 @@ int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
 EXPORT_SYMBOL_GPL(task_cgroup_path);
 
 /**
+ * cgroup_attach_lock - Lock for ->attach()
+ * @lock_threadgroup: whether to down_write cgroup_threadgroup_rwsem
+ *
+ * cgroup migration sometimes needs to stabilize threadgroups against forks and
+ * exits by write-locking cgroup_threadgroup_rwsem. However, some ->attach()
+ * implementations (e.g. cpuset), also need to disable CPU hotplug.
+ * Unfortunately, letting ->attach() operations acquire cpus_read_lock() can
+ * lead to deadlocks.
+ *
+ * Bringing up a CPU may involve creating and destroying tasks which requires
+ * read-locking threadgroup_rwsem, so threadgroup_rwsem nests inside
+ * cpus_read_lock(). If we call an ->attach() which acquires the cpus lock while
+ * write-locking threadgroup_rwsem, the locking order is reversed and we end up
+ * waiting for an on-going CPU hotplug operation which in turn is waiting for
+ * the threadgroup_rwsem to be released to create new tasks. For more details:
+ *
+ *   http://lkml.kernel.org/r/20220711174629.uehfmqegcwn2lqzu@wubuntu
+ *
+ * Resolve the situation by always acquiring cpus_read_lock() before optionally
+ * write-locking cgroup_threadgroup_rwsem. This allows ->attach() to assume that
+ * CPU hotplug is disabled on entry.
+ */
+static void cgroup_attach_lock(void)
+{
+	get_online_cpus();
+	percpu_down_write(&cgroup_threadgroup_rwsem);
+}
+
+/**
+ * cgroup_attach_unlock - Undo cgroup_attach_lock()
+ * @lock_threadgroup: whether to up_write cgroup_threadgroup_rwsem
+ */
+static void cgroup_attach_unlock(void)
+{
+	percpu_up_write(&cgroup_threadgroup_rwsem);
+	put_online_cpus();
+}
+
+/**
  * cgroup_migrate_add_task - add a migration target task to a migration context
  * @task: target task
  * @mgctx: target migration context
@@ -2694,7 +2734,7 @@ struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup)
 	if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
 		return ERR_PTR(-EINVAL);
 
-	percpu_down_write(&cgroup_threadgroup_rwsem);
+	cgroup_attach_lock();
 
 	rcu_read_lock();
 	if (pid) {
@@ -2725,7 +2765,7 @@ struct task_struct *cgroup_procs_write_start(char *buf, bool threadgroup)
 	goto out_unlock_rcu;
 
 out_unlock_threadgroup:
-	percpu_up_write(&cgroup_threadgroup_rwsem);
+	cgroup_attach_unlock();
 out_unlock_rcu:
 	rcu_read_unlock();
 	return tsk;
@@ -2740,7 +2780,7 @@ void cgroup_procs_write_finish(struct task_struct *task)
 	/* release reference from cgroup_procs_write_start() */
 	put_task_struct(task);
 
-	percpu_up_write(&cgroup_threadgroup_rwsem);
+	cgroup_attach_unlock();
 	for_each_subsys(ss, ssid)
 		if (ss->post_attach)
 			ss->post_attach();
@@ -2799,7 +2839,7 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
 
 	lockdep_assert_held(&cgroup_mutex);
 
-	percpu_down_write(&cgroup_threadgroup_rwsem);
+	cgroup_attach_lock();
 
 	/* look up all csses currently attached to @cgrp's subtree */
 	spin_lock_irq(&css_set_lock);
@@ -2830,7 +2870,7 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
 	ret = cgroup_migrate_execute(&mgctx);
 out_finish:
 	cgroup_migrate_finish(&mgctx);
-	percpu_up_write(&cgroup_threadgroup_rwsem);
+	cgroup_attach_unlock();
 	return ret;
 }
 
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index dcd5755b1..3067d3e5a 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -830,8 +830,8 @@ static void rebuild_sched_domains_locked(void)
 	cpumask_var_t *doms;
 	int ndoms;
 
+	lockdep_assert_cpus_held();
 	lockdep_assert_held(&cpuset_mutex);
-	get_online_cpus();
 
 	/*
 	 * We have raced with CPU hotplug. Don't do anything to avoid
@@ -839,15 +839,13 @@ static void rebuild_sched_domains_locked(void)
 	 * Anyways, hotplug work item will rebuild sched domains.
 	 */
 	if (!cpumask_equal(top_cpuset.effective_cpus, cpu_active_mask))
-		goto out;
+		return;
 
 	/* Generate domain masks and attrs */
 	ndoms = generate_sched_domains(&doms, &attr);
 
 	/* Have scheduler rebuild the domains */
 	partition_sched_domains(ndoms, doms, attr);
-out:
-	put_online_cpus();
 }
 #else /* !CONFIG_SMP */
 static void rebuild_sched_domains_locked(void)
@@ -857,9 +855,11 @@ static void rebuild_sched_domains_locked(void)
 
 void rebuild_sched_domains(void)
 {
+	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
 	rebuild_sched_domains_locked();
 	mutex_unlock(&cpuset_mutex);
+	put_online_cpus();
 }
 
 /**
@@ -1504,7 +1504,9 @@ static void cpuset_cancel_attach(struct cgroup_taskset *tset)
 	cs = css_cs(css);
 
 	mutex_lock(&cpuset_mutex);
-	css_cs(css)->attach_in_progress--;
+	cs->attach_in_progress--;
+	if (!cs->attach_in_progress)
+		wake_up(&cpuset_attach_wq);
 	mutex_unlock(&cpuset_mutex);
 }
 
@@ -1528,13 +1530,9 @@ static void cpuset_attach(struct cgroup_taskset *tset)
 	cgroup_taskset_first(tset, &css);
 	cs = css_cs(css);
 
+	lockdep_assert_cpus_held();     /* see cgroup_attach_lock() */
 	mutex_lock(&cpuset_mutex);
 
-	/*
-	 * It should hold cpus lock because a cpu offline event can
-	 * cause set_cpus_allowed_ptr() failed.
-	 */
-	get_online_cpus();
 	/* prepare for attach */
 	if (cs == &top_cpuset)
 		cpumask_copy(cpus_attach, cpu_possible_mask);
@@ -1553,7 +1551,6 @@ static void cpuset_attach(struct cgroup_taskset *tset)
 		cpuset_change_task_nodemask(task, &cpuset_attach_nodemask_to);
 		cpuset_update_task_spread_flag(cs, task);
 	}
-       put_online_cpus();
 
 	/*
 	 * Change mm for all threadgroup leaders. This is expensive and may
@@ -1617,6 +1614,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
 	cpuset_filetype_t type = cft->private;
 	int retval = 0;
 
+	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
 	if (!is_cpuset_online(cs)) {
 		retval = -ENODEV;
@@ -1654,6 +1652,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
 	}
 out_unlock:
 	mutex_unlock(&cpuset_mutex);
+	put_online_cpus();
 	return retval;
 }
 
@@ -1664,6 +1663,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
 	cpuset_filetype_t type = cft->private;
 	int retval = -ENODEV;
 
+	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
 	if (!is_cpuset_online(cs))
 		goto out_unlock;
@@ -1678,6 +1678,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
 	}
 out_unlock:
 	mutex_unlock(&cpuset_mutex);
+	put_online_cpus();
 	return retval;
 }
 
@@ -1716,6 +1717,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
 	kernfs_break_active_protection(of->kn);
 	flush_work(&cpuset_hotplug_work);
 
+	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
 	if (!is_cpuset_online(cs))
 		goto out_unlock;
@@ -1741,6 +1743,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
 	free_trial_cpuset(trialcs);
 out_unlock:
 	mutex_unlock(&cpuset_mutex);
+	put_online_cpus();
 	kernfs_unbreak_active_protection(of->kn);
 	css_put(&cs->css);
 	flush_workqueue(cpuset_migrate_mm_wq);
@@ -1985,6 +1988,7 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
 	if (!parent)
 		return 0;
 
+	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
 
 	set_bit(CS_ONLINE, &cs->flags);
@@ -2035,6 +2039,7 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
 	spin_unlock_irq(&callback_lock);
 out_unlock:
 	mutex_unlock(&cpuset_mutex);
+	put_online_cpus();
 	return 0;
 }
 
@@ -2048,6 +2053,7 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css)
 {
 	struct cpuset *cs = css_cs(css);
 
+	get_online_cpus();
 	mutex_lock(&cpuset_mutex);
 
 	if (is_sched_load_balance(cs))
@@ -2057,6 +2063,7 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css)
 	clear_bit(CS_ONLINE, &cs->flags);
 
 	mutex_unlock(&cpuset_mutex);
+	put_online_cpus();
 }
 
 static void cpuset_css_free(struct cgroup_subsys_state *css)
diff --git a/kernel/compat.c b/kernel/compat.c
index e4548a9e9..5f320b0db 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -307,7 +307,7 @@ COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t,  pid, unsigned int, len,
 	if (len & (sizeof(compat_ulong_t)-1))
 		return -EINVAL;
 
-	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
+	if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
 		return -ENOMEM;
 
 	ret = sched_getaffinity(pid, mask);
diff --git a/kernel/events/core.c b/kernel/events/core.c
index ba66ea3ca..72ed3f3d0 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9682,13 +9682,15 @@ static int pmu_dev_alloc(struct pmu *pmu)
 
 	pmu->dev->groups = pmu->attr_groups;
 	device_initialize(pmu->dev);
-	ret = dev_set_name(pmu->dev, "%s", pmu->name);
-	if (ret)
-		goto free_dev;
 
 	dev_set_drvdata(pmu->dev, pmu);
 	pmu->dev->bus = &pmu_bus;
 	pmu->dev->release = pmu_dev_release;
+
+	ret = dev_set_name(pmu->dev, "%s", pmu->name);
+	if (ret)
+		goto free_dev;
+
 	ret = device_add(pmu->dev);
 	if (ret)
 		goto free_dev;
@@ -10429,7 +10431,7 @@ perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
 	/*
 	 * If its not a per-cpu rb, it must be the same task.
 	 */
-	if (output_event->cpu == -1 && output_event->ctx != event->ctx)
+	if (output_event->cpu == -1 && output_event->hw.target != event->hw.target)
 		goto out;
 
 	/*
diff --git a/kernel/exit.c b/kernel/exit.c
index 908e7a33e..02360ec3b 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -62,12 +62,59 @@
 #include <linux/random.h>
 #include <linux/rcuwait.h>
 #include <linux/compat.h>
+#include <linux/sysfs.h>
 
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
 #include <asm/pgtable.h>
 #include <asm/mmu_context.h>
 
+/*
+ * The default value should be high enough to not crash a system that randomly
+ * crashes its kernel from time to time, but low enough to at least not permit
+ * overflowing 32-bit refcounts or the ldsem writer count.
+ */
+static unsigned int oops_limit = 10000;
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table kern_exit_table[] = {
+	{
+		.procname       = "oops_limit",
+		.data           = &oops_limit,
+		.maxlen         = sizeof(oops_limit),
+		.mode           = 0644,
+		.proc_handler   = proc_douintvec,
+	},
+	{ }
+};
+
+static __init int kernel_exit_sysctls_init(void)
+{
+	register_sysctl_init("kernel", kern_exit_table);
+	return 0;
+}
+late_initcall(kernel_exit_sysctls_init);
+#endif
+
+static atomic_t oops_count = ATOMIC_INIT(0);
+
+#ifdef CONFIG_SYSFS
+static ssize_t oops_count_show(struct kobject *kobj, struct kobj_attribute *attr,
+			       char *page)
+{
+	return sysfs_emit(page, "%d\n", atomic_read(&oops_count));
+}
+
+static struct kobj_attribute oops_count_attr = __ATTR_RO(oops_count);
+
+static __init int kernel_exit_sysfs_init(void)
+{
+	sysfs_add_file_to_group(kernel_kobj, &oops_count_attr.attr, NULL);
+	return 0;
+}
+late_initcall(kernel_exit_sysfs_init);
+#endif
+
 static void __unhash_process(struct task_struct *p, bool group_dead)
 {
 	nr_threads--;
@@ -922,6 +969,31 @@ void __noreturn do_exit(long code)
 }
 EXPORT_SYMBOL_GPL(do_exit);
 
+void __noreturn make_task_dead(int signr)
+{
+	/*
+	 * Take the task off the cpu after something catastrophic has
+	 * happened.
+	 */
+	unsigned int limit;
+
+	/*
+	 * Every time the system oopses, if the oops happens while a reference
+	 * to an object was held, the reference leaks.
+	 * If the oops doesn't also leak memory, repeated oopsing can cause
+	 * reference counters to wrap around (if they're not using refcount_t).
+	 * This means that repeated oopsing can make unexploitable-looking bugs
+	 * exploitable through repeated oopsing.
+	 * To make sure this can't happen, place an upper bound on how often the
+	 * kernel may oops without panic().
+	 */
+	limit = READ_ONCE(oops_limit);
+	if (atomic_inc_return(&oops_count) >= limit && limit)
+		panic("Oopsed too often (kernel.oops_limit is %d)", limit);
+
+	do_exit(signr);
+}
+
 void complete_and_exit(struct completion *comp, long code)
 {
 	if (comp)
diff --git a/kernel/gcov/gcc_4_7.c b/kernel/gcov/gcc_4_7.c
index bb6ccf456..1c2bd1f23 100644
--- a/kernel/gcov/gcc_4_7.c
+++ b/kernel/gcov/gcc_4_7.c
@@ -85,6 +85,7 @@ struct gcov_fn_info {
  * @version: gcov version magic indicating the gcc version used for compilation
  * @next: list head for a singly-linked list
  * @stamp: uniquifying time stamp
+ * @checksum: unique object checksum
  * @filename: name of the associated gcov data file
  * @merge: merge functions (null for unused counter type)
  * @n_functions: number of instrumented functions
@@ -97,6 +98,10 @@ struct gcov_info {
 	unsigned int version;
 	struct gcov_info *next;
 	unsigned int stamp;
+ /* Since GCC 12.1 a checksum field is added. */
+#if (__GNUC__ >= 12)
+	unsigned int checksum;
+#endif
 	const char *filename;
 	void (*merge[GCOV_COUNTERS])(gcov_type *, unsigned int);
 	unsigned int n_functions;
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 1e42fc2ad..3ebe231a5 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -494,6 +494,9 @@ void irq_domain_disassociate(struct irq_domain *domain, unsigned int irq)
 		return;
 
 	hwirq = irq_data->hwirq;
+
+	mutex_lock(&irq_domain_mutex);
+
 	irq_set_status_flags(irq, IRQ_NOREQUEST);
 
 	/* remove chip and handler */
@@ -513,10 +516,12 @@ void irq_domain_disassociate(struct irq_domain *domain, unsigned int irq)
 
 	/* Clear reverse map for this hwirq */
 	irq_domain_clear_mapping(domain, hwirq);
+
+	mutex_unlock(&irq_domain_mutex);
 }
 
-int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
-			 irq_hw_number_t hwirq)
+static int irq_domain_associate_locked(struct irq_domain *domain, unsigned int virq,
+				       irq_hw_number_t hwirq)
 {
 	struct irq_data *irq_data = irq_get_irq_data(virq);
 	int ret;
@@ -529,7 +534,6 @@ int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
 	if (WARN(irq_data->domain, "error: virq%i is already associated", virq))
 		return -EINVAL;
 
-	mutex_lock(&irq_domain_mutex);
 	irq_data->hwirq = hwirq;
 	irq_data->domain = domain;
 	if (domain->ops->map) {
@@ -546,7 +550,6 @@ int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
 			}
 			irq_data->domain = NULL;
 			irq_data->hwirq = 0;
-			mutex_unlock(&irq_domain_mutex);
 			return ret;
 		}
 
@@ -557,12 +560,23 @@ int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
 
 	domain->mapcount++;
 	irq_domain_set_mapping(domain, hwirq, irq_data);
-	mutex_unlock(&irq_domain_mutex);
 
 	irq_clear_status_flags(virq, IRQ_NOREQUEST);
 
 	return 0;
 }
+
+int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
+			 irq_hw_number_t hwirq)
+{
+	int ret;
+
+	mutex_lock(&irq_domain_mutex);
+	ret = irq_domain_associate_locked(domain, virq, hwirq);
+	mutex_unlock(&irq_domain_mutex);
+
+	return ret;
+}
 EXPORT_SYMBOL_GPL(irq_domain_associate);
 
 void irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base,
@@ -818,13 +832,8 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
 	}
 
 	irq_data = irq_get_irq_data(virq);
-	if (!irq_data) {
-		if (irq_domain_is_hierarchy(domain))
-			irq_domain_free_irqs(virq, 1);
-		else
-			irq_dispose_mapping(virq);
+	if (WARN_ON(!irq_data))
 		return 0;
-	}
 
 	/* Store trigger type */
 	irqd_set_trigger_type(irq_data, type);
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 33aba4e2e..e1fb6453e 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -418,8 +418,8 @@ static inline int kprobe_optready(struct kprobe *p)
 	return 0;
 }
 
-/* Return true(!0) if the kprobe is disarmed. Note: p must be on hash list */
-static inline int kprobe_disarmed(struct kprobe *p)
+/* Return true if the kprobe is disarmed. Note: p must be on hash list */
+bool kprobe_disarmed(struct kprobe *p)
 {
 	struct optimized_kprobe *op;
 
@@ -626,7 +626,7 @@ void wait_for_kprobe_optimizer(void)
 	mutex_unlock(&kprobe_mutex);
 }
 
-static bool optprobe_queued_unopt(struct optimized_kprobe *op)
+bool optprobe_queued_unopt(struct optimized_kprobe *op)
 {
 	struct optimized_kprobe *_op;
 
diff --git a/kernel/module.c b/kernel/module.c
index 42a604401..6ec0b2e0f 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3478,7 +3478,8 @@ static bool finished_loading(const char *name)
 	sched_annotate_sleep();
 	mutex_lock(&module_mutex);
 	mod = find_module_all(name, strlen(name), true);
-	ret = !mod || mod->state == MODULE_STATE_LIVE;
+	ret = !mod || mod->state == MODULE_STATE_LIVE
+		|| mod->state == MODULE_STATE_GOING;
 	mutex_unlock(&module_mutex);
 
 	return ret;
@@ -3632,20 +3633,35 @@ static int add_unformed_module(struct module *mod)
 
 	mod->state = MODULE_STATE_UNFORMED;
 
-again:
 	mutex_lock(&module_mutex);
 	old = find_module_all(mod->name, strlen(mod->name), true);
 	if (old != NULL) {
-		if (old->state != MODULE_STATE_LIVE) {
+		if (old->state == MODULE_STATE_COMING
+		    || old->state == MODULE_STATE_UNFORMED) {
 			/* Wait in case it fails to load. */
 			mutex_unlock(&module_mutex);
 			err = wait_event_interruptible(module_wq,
 					       finished_loading(mod->name));
 			if (err)
 				goto out_unlocked;
-			goto again;
+
+			/* The module might have gone in the meantime. */
+			mutex_lock(&module_mutex);
+			old = find_module_all(mod->name, strlen(mod->name),
+					      true);
 		}
-		err = -EEXIST;
+
+		/*
+		 * We are here only when the same module was being loaded. Do
+		 * not try to load it again right now. It prevents long delays
+		 * caused by serialized module load failures. It might happen
+		 * when more devices of the same type trigger load of
+		 * a particular module.
+		 */
+		if (old && old->state == MODULE_STATE_LIVE)
+			err = -EEXIST;
+		else
+			err = -EBUSY;
 		goto out;
 	}
 	mod_update_bounds(mod);
diff --git a/kernel/panic.c b/kernel/panic.c
index 8138a676f..982ecba28 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -29,6 +29,7 @@
 #include <linux/bug.h>
 #include <linux/ratelimit.h>
 #include <linux/debugfs.h>
+#include <linux/sysfs.h>
 #include <asm/sections.h>
 
 #define PANIC_TIMER_STEP 100
@@ -42,6 +43,7 @@ static int pause_on_oops_flag;
 static DEFINE_SPINLOCK(pause_on_oops_lock);
 bool crash_kexec_post_notifiers;
 int panic_on_warn __read_mostly;
+static unsigned int warn_limit __read_mostly;
 
 int panic_timeout = CONFIG_PANIC_TIMEOUT;
 EXPORT_SYMBOL_GPL(panic_timeout);
@@ -50,6 +52,45 @@ ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
 
 EXPORT_SYMBOL(panic_notifier_list);
 
+#ifdef CONFIG_SYSCTL
+static struct ctl_table kern_panic_table[] = {
+	{
+		.procname       = "warn_limit",
+		.data           = &warn_limit,
+		.maxlen         = sizeof(warn_limit),
+		.mode           = 0644,
+		.proc_handler   = proc_douintvec,
+	},
+	{ }
+};
+
+static __init int kernel_panic_sysctls_init(void)
+{
+	register_sysctl_init("kernel", kern_panic_table);
+	return 0;
+}
+late_initcall(kernel_panic_sysctls_init);
+#endif
+
+static atomic_t warn_count = ATOMIC_INIT(0);
+
+#ifdef CONFIG_SYSFS
+static ssize_t warn_count_show(struct kobject *kobj, struct kobj_attribute *attr,
+			       char *page)
+{
+	return sysfs_emit(page, "%d\n", atomic_read(&warn_count));
+}
+
+static struct kobj_attribute warn_count_attr = __ATTR_RO(warn_count);
+
+static __init int kernel_panic_sysfs_init(void)
+{
+	sysfs_add_file_to_group(kernel_kobj, &warn_count_attr.attr, NULL);
+	return 0;
+}
+late_initcall(kernel_panic_sysfs_init);
+#endif
+
 static long no_blink(int state)
 {
 	return 0;
@@ -125,6 +166,19 @@ void nmi_panic(struct pt_regs *regs, const char *msg)
 }
 EXPORT_SYMBOL(nmi_panic);
 
+void check_panic_on_warn(const char *origin)
+{
+	unsigned int limit;
+
+	if (panic_on_warn)
+		panic("%s: panic_on_warn set ...\n", origin);
+
+	limit = READ_ONCE(warn_limit);
+	if (atomic_inc_return(&warn_count) >= limit && limit)
+		panic("%s: system warned too often (kernel.warn_limit is %d)",
+		      origin, limit);
+}
+
 /**
  *	panic - halt the system
  *	@fmt: The text string to print
@@ -142,6 +196,16 @@ void panic(const char *fmt, ...)
 	int old_cpu, this_cpu;
 	bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
 
+	if (panic_on_warn) {
+		/*
+		 * This thread may hit another WARN() in the panic path.
+		 * Resetting this prevents additional WARN() from panicking the
+		 * system on this thread.  Other threads are blocked by the
+		 * panic_mutex in panic().
+		 */
+		panic_on_warn = 0;
+	}
+
 	/*
 	 * Disable local interrupts. This will prevent panic_smp_self_stop
 	 * from deadlocking the first cpu that invokes the panic, since
@@ -530,16 +594,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
 	if (args)
 		vprintk(args->fmt, args->args);
 
-	if (panic_on_warn) {
-		/*
-		 * This thread may hit another WARN() in the panic path.
-		 * Resetting this prevents additional WARN() from panicking the
-		 * system on this thread.  Other threads are blocked by the
-		 * panic_mutex in panic().
-		 */
-		panic_on_warn = 0;
-		panic("panic_on_warn set ...\n");
-	}
+	check_panic_on_warn("kernel");
 
 	print_modules();
 
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 72770a551..fa6ae9ed2 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -577,7 +577,9 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
 				mask = leaf_node_cpu_bit(rnp, cpu);
 				if (!(rnp->expmask & mask))
 					continue;
+				preempt_disable(); // For smp_processor_id() in dump_cpu_task().
 				dump_cpu_task(cpu);
+				preempt_enable();
 			}
 		}
 		jiffies_stall = 3 * rcu_jiffies_till_stall_check() + 3;
diff --git a/kernel/relay.c b/kernel/relay.c
index 735cb208f..b7aa7df43 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -163,13 +163,13 @@ static struct rchan_buf *relay_create_buf(struct rchan *chan)
 {
 	struct rchan_buf *buf;
 
-	if (chan->n_subbufs > KMALLOC_MAX_SIZE / sizeof(size_t *))
+	if (chan->n_subbufs > KMALLOC_MAX_SIZE / sizeof(size_t))
 		return NULL;
 
 	buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL);
 	if (!buf)
 		return NULL;
-	buf->padding = kmalloc_array(chan->n_subbufs, sizeof(size_t *),
+	buf->padding = kmalloc_array(chan->n_subbufs, sizeof(size_t),
 				     GFP_KERNEL);
 	if (!buf->padding)
 		goto free_buf;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a03464249..8d5a9fa8a 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -741,6 +741,9 @@ static inline void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
 
 void activate_task(struct rq *rq, struct task_struct *p, int flags)
 {
+	if (task_on_rq_migrating(p))
+		flags |= ENQUEUE_MIGRATED;
+
 	if (task_contributes_to_load(p))
 		rq->nr_uninterruptible--;
 
@@ -3316,8 +3319,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
 		print_ip_sym(preempt_disable_ip);
 		pr_cont("\n");
 	}
-	if (panic_on_warn)
-		panic("scheduling while atomic\n");
+	check_panic_on_warn("scheduling while atomic");
 
 	dump_stack();
 	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
@@ -4951,14 +4953,14 @@ SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
 	if (len & (sizeof(unsigned long)-1))
 		return -EINVAL;
 
-	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
+	if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
 		return -ENOMEM;
 
 	ret = sched_getaffinity(pid, mask);
 	if (ret == 0) {
 		unsigned int retlen = min(len, cpumask_size());
 
-		if (copy_to_user(user_mask_ptr, mask, retlen))
+		if (copy_to_user(user_mask_ptr, cpumask_bits(mask), retlen))
 			ret = -EFAULT;
 		else
 			ret = retlen;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 84e7efda9..eb67f42fb 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3854,6 +3854,29 @@ static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se)
 #endif
 }
 
+static inline bool entity_is_long_sleeper(struct sched_entity *se)
+{
+	struct cfs_rq *cfs_rq;
+	u64 sleep_time;
+
+	if (se->exec_start == 0)
+		return false;
+
+	cfs_rq = cfs_rq_of(se);
+
+	sleep_time = rq_clock_task(rq_of(cfs_rq));
+
+	/* Happen while migrating because of clock task divergence */
+	if (sleep_time <= se->exec_start)
+		return false;
+
+	sleep_time -= se->exec_start;
+	if (sleep_time > ((1ULL << 63) / scale_load_down(NICE_0_LOAD)))
+		return true;
+
+	return false;
+}
+
 static void
 place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 {
@@ -3882,8 +3905,29 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 		vruntime -= thresh;
 	}
 
-	/* ensure we never gain time by being placed backwards. */
-	se->vruntime = max_vruntime(se->vruntime, vruntime);
+	/*
+	 * Pull vruntime of the entity being placed to the base level of
+	 * cfs_rq, to prevent boosting it if placed backwards.
+	 * However, min_vruntime can advance much faster than real time, with
+	 * the extreme being when an entity with the minimal weight always runs
+	 * on the cfs_rq. If the waking entity slept for a long time, its
+	 * vruntime difference from min_vruntime may overflow s64 and their
+	 * comparison may get inversed, so ignore the entity's original
+	 * vruntime in that case.
+	 * The maximal vruntime speedup is given by the ratio of normal to
+	 * minimal weight: scale_load_down(NICE_0_LOAD) / MIN_SHARES.
+	 * When placing a migrated waking entity, its exec_start has been set
+	 * from a different rq. In order to take into account a possible
+	 * divergence between new and prev rq's clocks task because of irq and
+	 * stolen time, we take an additional margin.
+	 * So, cutting off on the sleep time of
+	 *     2^63 / scale_load_down(NICE_0_LOAD) ~ 104 days
+	 * should be safe.
+	 */
+	if (entity_is_long_sleeper(se))
+		se->vruntime = vruntime;
+	else
+		se->vruntime = max_vruntime(se->vruntime, vruntime);
 }
 
 static void check_enqueue_throttle(struct cfs_rq *cfs_rq);
@@ -3978,6 +4022,9 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 
 	if (flags & ENQUEUE_WAKEUP)
 		place_entity(cfs_rq, se, 0);
+	/* Entity has migrated, no longer consider this task hot */
+	if (flags & ENQUEUE_MIGRATED)
+		se->exec_start = 0;
 
 	check_schedstat_required();
 	update_stats_enqueue(cfs_rq, se, flags);
@@ -6544,9 +6591,6 @@ static void migrate_task_rq_fair(struct task_struct *p, int new_cpu)
 	/* Tell new CPU we are migrated */
 	p->se.avg.last_update_time = 0;
 
-	/* We have migrated, no longer consider this task hot */
-	p->se.exec_start = 0;
-
 	update_scan_period(p, new_cpu);
 }
 
diff --git a/kernel/sys.c b/kernel/sys.c
index d0663f8e6..3548467f6 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1530,6 +1530,8 @@ int do_prlimit(struct task_struct *tsk, unsigned int resource,
 
 	if (resource >= RLIM_NLIMITS)
 		return -EINVAL;
+	resource = array_index_nospec(resource, RLIM_NLIMITS);
+
 	if (new_rlim) {
 		if (new_rlim->rlim_cur > new_rlim->rlim_max)
 			return -EINVAL;
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 6a2ba3988..56af8a97c 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -476,11 +476,35 @@ u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
 }
 EXPORT_SYMBOL_GPL(alarm_forward);
 
-u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
+static u64 __alarm_forward_now(struct alarm *alarm, ktime_t interval, bool throttle)
 {
 	struct alarm_base *base = &alarm_bases[alarm->type];
+	ktime_t now = base->gettime();
+
+	if (IS_ENABLED(CONFIG_HIGH_RES_TIMERS) && throttle) {
+		/*
+		 * Same issue as with posix_timer_fn(). Timers which are
+		 * periodic but the signal is ignored can starve the system
+		 * with a very small interval. The real fix which was
+		 * promised in the context of posix_timer_fn() never
+		 * materialized, but someone should really work on it.
+		 *
+		 * To prevent DOS fake @now to be 1 jiffie out which keeps
+		 * the overrun accounting correct but creates an
+		 * inconsistency vs. timer_gettime(2).
+		 */
+		ktime_t kj = NSEC_PER_SEC / HZ;
+
+		if (interval < kj)
+			now = ktime_add(now, kj);
+	}
+
+	return alarm_forward(alarm, now, interval);
+}
 
-	return alarm_forward(alarm, base->gettime(), interval);
+u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
+{
+	return __alarm_forward_now(alarm, interval, false);
 }
 EXPORT_SYMBOL_GPL(alarm_forward_now);
 
@@ -554,9 +578,10 @@ static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
 	if (posix_timer_event(ptr, si_private) && ptr->it_interval) {
 		/*
 		 * Handle ignored signals and rearm the timer. This will go
-		 * away once we handle ignored signals proper.
+		 * away once we handle ignored signals proper. Ensure that
+		 * small intervals cannot starve the system.
 		 */
-		ptr->it_overrun += alarm_forward_now(alarm, ptr->it_interval);
+		ptr->it_overrun += __alarm_forward_now(alarm, ptr->it_interval, true);
 		++ptr->it_requeue_pending;
 		ptr->it_active = 1;
 		result = ALARMTIMER_RESTART;
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 32ee24f51..8512f06f0 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1838,6 +1838,7 @@ SYSCALL_DEFINE2(nanosleep, struct __kernel_timespec __user *, rqtp,
 	if (!timespec64_valid(&tu))
 		return -EINVAL;
 
+	current->restart_block.fn = do_no_restart_syscall;
 	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
 	current->restart_block.nanosleep.rmtp = rmtp;
 	return hrtimer_nanosleep(&tu, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
@@ -1858,6 +1859,7 @@ COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp,
 	if (!timespec64_valid(&tu))
 		return -EINVAL;
 
+	current->restart_block.fn = do_no_restart_syscall;
 	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
 	current->restart_block.nanosleep.compat_rmtp = rmtp;
 	return hrtimer_nanosleep(&tu, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index 2c6847d5d..362c159fb 100644
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -144,6 +144,7 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
 		return -EINVAL;
 	if (flags & TIMER_ABSTIME)
 		rmtp = NULL;
+	current->restart_block.fn = do_no_restart_syscall;
 	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
 	current->restart_block.nanosleep.rmtp = rmtp;
 	return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
@@ -230,6 +231,7 @@ COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
 		return -EINVAL;
 	if (flags & TIMER_ABSTIME)
 		rmtp = NULL;
+	current->restart_block.fn = do_no_restart_syscall;
 	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
 	current->restart_block.nanosleep.compat_rmtp = rmtp;
 	return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 48758108e..1234868b3 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -1225,6 +1225,7 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
 		return -EINVAL;
 	if (flags & TIMER_ABSTIME)
 		rmtp = NULL;
+	current->restart_block.fn = do_no_restart_syscall;
 	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
 	current->restart_block.nanosleep.rmtp = rmtp;
 
@@ -1252,6 +1253,7 @@ COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
 		return -EINVAL;
 	if (flags & TIMER_ABSTIME)
 		rmtp = NULL;
+	current->restart_block.fn = do_no_restart_syscall;
 	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
 	current->restart_block.nanosleep.compat_rmtp = rmtp;
 
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 75ea1a5be..113cbe1a2 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1594,7 +1594,8 @@ blk_trace_event_print_binary(struct trace_iterator *iter, int flags,
 
 static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
 {
-	if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
+	if ((iter->ent->type != TRACE_BLK) ||
+	    !(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
 		return TRACE_TYPE_UNHANDLED;
 
 	return print_one_line(iter, true);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 9c7795566..5c0463dbe 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1581,7 +1581,8 @@ unsigned long ftrace_location_range(unsigned long start, unsigned long end)
 	key.flags = end;	/* overload flags, as it is unsigned long */
 
 	for (pg = ftrace_pages_start; pg; pg = pg->next) {
-		if (end < pg->records[0].ip ||
+		if (pg->index == 0 ||
+		    end < pg->records[0].ip ||
 		    start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
 			continue;
 		rec = bsearch(&key, pg->records, pg->index,
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 5e5b0c067..37fade510 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2463,6 +2463,10 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
 		if (RB_WARN_ON(cpu_buffer,
 			       rb_is_reader_page(cpu_buffer->tail_page)))
 			return;
+		/*
+		 * No need for a memory barrier here, as the update
+		 * of the tail_page did it for this page.
+		 */
 		local_set(&cpu_buffer->commit_page->page->commit,
 			  rb_page_write(cpu_buffer->commit_page));
 		rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
@@ -2476,6 +2480,8 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
 	while (rb_commit_index(cpu_buffer) !=
 	       rb_page_write(cpu_buffer->commit_page)) {
 
+		/* Make sure the readers see the content of what is committed. */
+		smp_wmb();
 		local_set(&cpu_buffer->commit_page->page->commit,
 			  rb_page_write(cpu_buffer->commit_page));
 		RB_WARN_ON(cpu_buffer,
@@ -3841,7 +3847,12 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 
 	/*
 	 * Make sure we see any padding after the write update
-	 * (see rb_reset_tail())
+	 * (see rb_reset_tail()).
+	 *
+	 * In addition, a writer may be writing on the reader page
+	 * if the page has not been fully filled, so the read barrier
+	 * is also needed to make sure we see the content of what is
+	 * committed by the writer (see rb_set_commit_to_write()).
 	 */
 	smp_rmb();
 
@@ -4685,11 +4696,16 @@ EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page);
  */
 void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data)
 {
-	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+	struct ring_buffer_per_cpu *cpu_buffer;
 	struct buffer_data_page *bpage = data;
 	struct page *page = virt_to_page(bpage);
 	unsigned long flags;
 
+	if (!buffer || !buffer->buffers || !buffer->buffers[cpu])
+		return;
+
+	cpu_buffer = buffer->buffers[cpu];
+
 	/* If the page is still in use someplace else, we can't reuse it */
 	if (page_ref_count(page) > 1)
 		goto out;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5b7a6e9b0..98abff046 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5803,7 +5803,20 @@ waitagain:
 
 		ret = print_trace_line(iter);
 		if (ret == TRACE_TYPE_PARTIAL_LINE) {
-			/* don't print partial lines */
+			/*
+			 * If one print_trace_line() fills entire trace_seq in one shot,
+			 * trace_seq_to_user() will returns -EBUSY because save_len == 0,
+			 * In this case, we need to consume it, otherwise, loop will peek
+			 * this event next time, resulting in an infinite loop.
+			 */
+			if (save_len == 0) {
+				iter->seq.full = 0;
+				trace_seq_puts(&iter->seq, "[LINE TOO BIG]\n");
+				trace_consume(iter);
+				break;
+			}
+
+			/* In other cases, don't print partial lines */
 			iter->seq.seq.len = save_len;
 			break;
 		}
@@ -8661,6 +8674,8 @@ void __init early_trace_init(void)
 			static_key_enable(&tracepoint_printk_key.key);
 	}
 	tracer_alloc_buffers();
+
+	init_events();
 }
 
 void __init trace_init(void)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 74185fb04..0923d1b18 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1530,6 +1530,7 @@ extern void trace_event_enable_cmd_record(bool enable);
 extern void trace_event_enable_tgid_record(bool enable);
 
 extern int event_trace_init(void);
+extern int init_events(void);
 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
 extern int event_trace_del_tracer(struct trace_array *tr);
 
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 48f85dab9..455cf41ae 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1764,6 +1764,9 @@ static const char *hist_field_name(struct hist_field *field,
 {
 	const char *field_name = "";
 
+	if (WARN_ON_ONCE(!field))
+		return field_name;
+
 	if (level > 1)
 		return field_name;
 
@@ -2314,6 +2317,8 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
 		unsigned long fl = flags & ~HIST_FIELD_FL_LOG2;
 		hist_field->fn = hist_field_log2;
 		hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL);
+		if (!hist_field->operands[0])
+			goto free;
 		hist_field->size = hist_field->operands[0]->size;
 		hist_field->type = kstrdup(hist_field->operands[0]->type, GFP_KERNEL);
 		if (!hist_field->type)
@@ -5807,7 +5812,7 @@ enable:
 	/* Just return zero, not the number of registered triggers */
 	ret = 0;
  out:
-	if (ret == 0)
+	if (ret == 0 && glob[0])
 		hist_err_clear();
 
 	return ret;
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 6e6cc64fa..62015d62d 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -1395,7 +1395,7 @@ static struct trace_event *events[] __initdata = {
 	NULL
 };
 
-__init static int init_events(void)
+__init int init_events(void)
 {
 	struct trace_event *event;
 	int i, ret;
@@ -1413,4 +1413,3 @@ __init static int init_events(void)
 
 	return 0;
 }
-early_initcall(init_events);