20 files changed, 159 insertions, 119 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index 0f8f8b0bc1bf..60c302cfb4d3 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -197,9 +197,9 @@ x509.genkey:
         @echo >>x509.genkey "x509_extensions = myexts"
         @echo >>x509.genkey
         @echo >>x509.genkey "[ req_distinguished_name ]"
-        @echo >>x509.genkey "O = Magrathea"
-        @echo >>x509.genkey "CN = Glacier signing key"
-        @echo >>x509.genkey "emailAddress = slartibartfast@magrathea.h2g2"
+        @echo >>x509.genkey "#O = Unspecified company"
+        @echo >>x509.genkey "CN = Build time autogenerated kernel key"
+        @echo >>x509.genkey "#emailAddress = unspecified.user@unspecified.company"
         @echo >>x509.genkey
         @echo >>x509.genkey "[ myexts ]"
         @echo >>x509.genkey "basicConstraints=critical,CA:FALSE"
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 4139a0f8b558..54f0e7fcd0e2 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -357,8 +357,8 @@ select_insn:
         ALU64_MOD_X:
                 if (unlikely(SRC == 0))
                         return 0;
-                tmp = DST;
-                DST = do_div(tmp, SRC);
+                div64_u64_rem(DST, SRC, &tmp);
+                DST = tmp;
                 CONT;
         ALU_MOD_X:
                 if (unlikely(SRC == 0))
@@ -367,8 +367,8 @@ select_insn:
                 DST = do_div(tmp, (u32) SRC);
                 CONT;
         ALU64_MOD_K:
-                tmp = DST;
-                DST = do_div(tmp, IMM);
+                div64_u64_rem(DST, IMM, &tmp);
+                DST = tmp;
                 CONT;
         ALU_MOD_K:
                 tmp = (u32) DST;
@@ -377,7 +377,7 @@ select_insn:
         ALU64_DIV_X:
                 if (unlikely(SRC == 0))
                         return 0;
-                do_div(DST, SRC);
+                DST = div64_u64(DST, SRC);
                 CONT;
         ALU_DIV_X:
                 if (unlikely(SRC == 0))
@@ -387,7 +387,7 @@ select_insn:
                 DST = (u32) tmp;
                 CONT;
         ALU64_DIV_K:
-                do_div(DST, IMM);
+                DST = div64_u64(DST, IMM);
                 CONT;
         ALU_DIV_K:
                 tmp = (u32) DST;
diff --git a/kernel/compat.c b/kernel/compat.c
index 24f00610c575..333d364be29d 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -912,7 +912,8 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
                          * bitmap. We must however ensure the end of the
                          * kernel bitmap is zeroed.
                          */
-                        if (nr_compat_longs-- > 0) {
+                        if (nr_compat_longs) {
+                                nr_compat_longs--;
                                 if (__get_user(um, umask))
                                         return -EFAULT;
                         } else {
@@ -954,7 +955,8 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
                          * We dont want to write past the end of the userspace
                          * bitmap.
                          */
-                        if (nr_compat_longs-- > 0) {
+                        if (nr_compat_longs) {
+                                nr_compat_longs--;
                                 if (__put_user(um, umask))
                                         return -EFAULT;
                         }
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 81aa3a4ece9f..eddf1ed4155e 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -913,10 +913,30 @@ static void put_ctx(struct perf_event_context *ctx)
  * Those places that change perf_event::ctx will hold both
  * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
  *
- * Lock ordering is by mutex address. There is one other site where
- * perf_event_context::mutex nests and that is put_event(). But remember that
- * that is a parent<->child context relation, and migration does not affect
- * children, therefore these two orderings should not interact.
+ * Lock ordering is by mutex address. There are two other sites where
+ * perf_event_context::mutex nests and those are:
+ *
+ *  - perf_event_exit_task_context()    [ child , 0 ]
+ *      __perf_event_exit_task()
+ *        sync_child_event()
+ *          put_event()                 [ parent, 1 ]
+ *
+ *  - perf_event_init_context()         [ parent, 0 ]
+ *      inherit_task_group()
+ *        inherit_group()
+ *          inherit_event()
+ *            perf_event_alloc()
+ *              perf_init_event()
+ *                perf_try_init_event() [ child , 1 ]
+ *
+ * While it appears there is an obvious deadlock here -- the parent and child
+ * nesting levels are inverted between the two. This is in fact safe because
+ * life-time rules separate them. That is an exiting task cannot fork, and a
+ * spawning task cannot (yet) exit.
+ *
+ * But remember that that these are parent<->child context relations, and
+ * migration does not affect children, therefore these two orderings should not
+ * interact.
  *
  * The change in perf_event::ctx does not affect children (as claimed above)
  * because the sys_perf_event_open() case will install a new event and break
@@ -3422,7 +3442,6 @@ static void free_event_rcu(struct rcu_head *head)
         if (event->ns)
                 put_pid_ns(event->ns);
         perf_event_free_filter(event);
-        perf_event_free_bpf_prog(event);
         kfree(event);
 }
 
@@ -3553,6 +3572,8 @@ static void __free_event(struct perf_event *event)
                         put_callchain_buffers();
         }
 
+        perf_event_free_bpf_prog(event);
+
         if (event->destroy)
                 event->destroy(event);
 
@@ -3657,9 +3678,6 @@ static void perf_remove_from_owner(struct perf_event *event)
         }
 }
 
-/*
- * Called when the last reference to the file is gone.
- */
 static void put_event(struct perf_event *event)
 {
         struct perf_event_context *ctx;
@@ -3697,6 +3715,9 @@ int perf_event_release_kernel(struct perf_event *event)
 }
 EXPORT_SYMBOL_GPL(perf_event_release_kernel);
 
+/*
+ * Called when the last reference to the file is gone.
+ */
 static int perf_release(struct inode *inode, struct file *file)
 {
         put_event(file->private_data);
@@ -7364,7 +7385,12 @@ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
                 return -ENODEV;
 
         if (event->group_leader != event) {
-                ctx = perf_event_ctx_lock(event->group_leader);
+                /*
+                 * This ctx->mutex can nest when we're called through
+                 * inheritance. See the perf_event_ctx_lock_nested() comment.
+                 */
+                ctx = perf_event_ctx_lock_nested(event->group_leader,
+                                                 SINGLE_DEPTH_NESTING);
                 BUG_ON(!ctx);
         }
 
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 232f00f273cb..725c416085e3 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -493,6 +493,20 @@ int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
                         rb->aux_pages[rb->aux_nr_pages] = page_address(page++);
         }
 
+        /*
+         * In overwrite mode, PMUs that don't support SG may not handle more
+         * than one contiguous allocation, since they rely on PMI to do double
+         * buffering. In this case, the entire buffer has to be one contiguous
+         * chunk.
+         */
+        if ((event->pmu->capabilities & PERF_PMU_CAP_AUX_NO_SG) &&
+            overwrite) {
+                struct page *page = virt_to_page(rb->aux_pages[0]);
+
+                if (page_private(page) != max_order)
+                        goto out;
+        }
+
         rb->aux_priv = event->pmu->setup_aux(event->cpu, rb->aux_pages, nr_pages,
                                              overwrite);
         if (!rb->aux_priv)
diff --git a/kernel/irq/dummychip.c b/kernel/irq/dummychip.c
index 988dc58e8847..2feb6feca0cc 100644
--- a/kernel/irq/dummychip.c
+++ b/kernel/irq/dummychip.c
@@ -57,5 +57,6 @@ struct irq_chip dummy_irq_chip = {
         .irq_ack        = noop,
         .irq_mask       = noop,
         .irq_unmask     = noop,
+        .flags          = IRQCHIP_SKIP_SET_WAKE,
 };
 EXPORT_SYMBOL_GPL(dummy_irq_chip);
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 38c25b1f2fd5..7a36fdcca5bf 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -707,7 +707,7 @@ static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
         do {
                 unsigned long pfn, epfn, addr, eaddr;
 
-                pages = kimage_alloc_pages(GFP_KERNEL, order);
+                pages = kimage_alloc_pages(KEXEC_CONTROL_MEMORY_GFP, order);
                 if (!pages)
                         break;
                 pfn   = page_to_pfn(pages);
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index a0831e1b99f4..aaeae885d9af 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -3900,7 +3900,8 @@ static void zap_class(struct lock_class *class)
         list_del_rcu(&class->hash_entry);
         list_del_rcu(&class->lock_entry);
 
-        class->key = NULL;
+        RCU_INIT_POINTER(class->key, NULL);
+        RCU_INIT_POINTER(class->name, NULL);
 }
 
 static inline int within(const void *addr, void *start, unsigned long size)
diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index ef43ac4bafb5..d83d798bef95 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -426,10 +426,12 @@ static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
 
 static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
 {
-        char name[39];
-        struct lock_class *class;
+        struct lockdep_subclass_key *ckey;
         struct lock_class_stats *stats;
+        struct lock_class *class;
+        const char *cname;
         int i, namelen;
+        char name[39];
 
         class = data->class;
         stats = &data->stats;
@@ -440,15 +442,25 @@ static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
         if (class->subclass)
                 namelen -= 2;
 
-        if (!class->name) {
+        rcu_read_lock_sched();
+        cname = rcu_dereference_sched(class->name);
+        ckey  = rcu_dereference_sched(class->key);
+
+        if (!cname && !ckey) {
+                rcu_read_unlock_sched();
+                return;
+
+        } else if (!cname) {
                 char str[KSYM_NAME_LEN];
                 const char *key_name;
 
-                key_name = __get_key_name(class->key, str);
+                key_name = __get_key_name(ckey, str);
                 snprintf(name, namelen, "%s", key_name);
         } else {
-                snprintf(name, namelen, "%s", class->name);
+                snprintf(name, namelen, "%s", cname);
         }
+        rcu_read_unlock_sched();
+
         namelen = strlen(name);
         if (class->name_version > 1) {
                 snprintf(name+namelen, 3, "#%d", class->name_version);
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index b73279367087..b025295f4966 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -265,15 +265,17 @@ struct task_struct *rt_mutex_get_top_task(struct task_struct *task)
 }
 
 /*
- * Called by sched_setscheduler() to check whether the priority change
- * is overruled by a possible priority boosting.
+ * Called by sched_setscheduler() to get the priority which will be
+ * effective after the change.
  */
-int rt_mutex_check_prio(struct task_struct *task, int newprio)
+int rt_mutex_get_effective_prio(struct task_struct *task, int newprio)
 {
         if (!task_has_pi_waiters(task))
-                return 0;
+                return newprio;
 
-        return task_top_pi_waiter(task)->task->prio <= newprio;
+        if (task_top_pi_waiter(task)->task->prio <= newprio)
+                return task_top_pi_waiter(task)->task->prio;
+        return newprio;
 }
 
 /*
diff --git a/kernel/module.c b/kernel/module.c
index 42a1d2afb217..cfc9e843a924 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3370,6 +3370,9 @@ static int load_module(struct load_info *info, const char __user *uargs,
         module_bug_cleanup(mod);
         mutex_unlock(&module_mutex);
 
+        blocking_notifier_call_chain(&module_notify_list,
+                                     MODULE_STATE_GOING, mod);
+
         /* we can't deallocate the module until we clear memory protection */
         unset_module_init_ro_nx(mod);
         unset_module_core_ro_nx(mod);
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 233165da782f..8cf7304b2867 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -162,11 +162,14 @@ static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp);
 static int kthread_prio = CONFIG_RCU_KTHREAD_PRIO;
 module_param(kthread_prio, int, 0644);
 
-/* Delay in jiffies for grace-period initialization delays. */
-static int gp_init_delay = IS_ENABLED(CONFIG_RCU_TORTURE_TEST_SLOW_INIT)
-                                ? CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY
-                                : 0;
+/* Delay in jiffies for grace-period initialization delays, debug only. */
+#ifdef CONFIG_RCU_TORTURE_TEST_SLOW_INIT
+static int gp_init_delay = CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY;
 module_param(gp_init_delay, int, 0644);
+#else /* #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_INIT */
+static const int gp_init_delay;
+#endif /* #else #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_INIT */
+#define PER_RCU_NODE_PERIOD 10  /* Number of grace periods between delays. */
 
 /*
  * Track the rcutorture test sequence number and the update version
@@ -1843,9 +1846,8 @@ static int rcu_gp_init(struct rcu_state *rsp)
                 raw_spin_unlock_irq(&rnp->lock);
                 cond_resched_rcu_qs();
                 ACCESS_ONCE(rsp->gp_activity) = jiffies;
-                if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_SLOW_INIT) &&
-                    gp_init_delay > 0 &&
-                    !(rsp->gpnum % (rcu_num_nodes * 10)))
+                if (gp_init_delay > 0 &&
+                    !(rsp->gpnum % (rcu_num_nodes * PER_RCU_NODE_PERIOD)))
                         schedule_timeout_uninterruptible(gp_init_delay);
         }
 
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index f9123a82cbb6..123673291ffb 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1016,13 +1016,6 @@ void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
                 rq_clock_skip_update(rq, true);
 }
 
-static ATOMIC_NOTIFIER_HEAD(task_migration_notifier);
-
-void register_task_migration_notifier(struct notifier_block *n)
-{
-        atomic_notifier_chain_register(&task_migration_notifier, n);
-}
-
 #ifdef CONFIG_SMP
 void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 {
@@ -1053,18 +1046,10 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
         trace_sched_migrate_task(p, new_cpu);
 
         if (task_cpu(p) != new_cpu) {
-                struct task_migration_notifier tmn;
-
                 if (p->sched_class->migrate_task_rq)
                         p->sched_class->migrate_task_rq(p, new_cpu);
                 p->se.nr_migrations++;
                 perf_sw_event_sched(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 0);
-
-                tmn.task = p;
-                tmn.from_cpu = task_cpu(p);
-                tmn.to_cpu = new_cpu;
-
-                atomic_notifier_call_chain(&task_migration_notifier, 0, &tmn);
         }
 
         __set_task_cpu(p, new_cpu);
@@ -3315,15 +3300,18 @@ static void __setscheduler_params(struct task_struct *p,
 
 /* Actually do priority change: must hold pi & rq lock. */
 static void __setscheduler(struct rq *rq, struct task_struct *p,
-                           const struct sched_attr *attr)
+                           const struct sched_attr *attr, bool keep_boost)
 {
         __setscheduler_params(p, attr);
 
         /*
-         * If we get here, there was no pi waiters boosting the
-         * task. It is safe to use the normal prio.
+         * Keep a potential priority boosting if called from
+         * sched_setscheduler().
          */
-        p->prio = normal_prio(p);
+        if (keep_boost)
+                p->prio = rt_mutex_get_effective_prio(p, normal_prio(p));
+        else
+                p->prio = normal_prio(p);
 
         if (dl_prio(p->prio))
                 p->sched_class = &dl_sched_class;
@@ -3423,7 +3411,7 @@ static int __sched_setscheduler(struct task_struct *p,
         int newprio = dl_policy(attr->sched_policy) ? MAX_DL_PRIO - 1 :
                       MAX_RT_PRIO - 1 - attr->sched_priority;
         int retval, oldprio, oldpolicy = -1, queued, running;
-        int policy = attr->sched_policy;
+        int new_effective_prio, policy = attr->sched_policy;
         unsigned long flags;
         const struct sched_class *prev_class;
         struct rq *rq;
@@ -3605,15 +3593,14 @@ change:
         oldprio = p->prio;
 
         /*
-         * Special case for priority boosted tasks.
-         *
-         * If the new priority is lower or equal (user space view)
-         * than the current (boosted) priority, we just store the new
+         * Take priority boosted tasks into account. If the new
+         * effective priority is unchanged, we just store the new
          * normal parameters and do not touch the scheduler class and
          * the runqueue. This will be done when the task deboost
          * itself.
          */
-        if (rt_mutex_check_prio(p, newprio)) {
+        new_effective_prio = rt_mutex_get_effective_prio(p, newprio);
+        if (new_effective_prio == oldprio) {
                 __setscheduler_params(p, attr);
                 task_rq_unlock(rq, p, &flags);
                 return 0;
@@ -3627,7 +3614,7 @@ change:
                 put_prev_task(rq, p);
 
         prev_class = p->sched_class;
-        __setscheduler(rq, p, attr);
+        __setscheduler(rq, p, attr, true);
 
         if (running)
                 p->sched_class->set_curr_task(rq);
@@ -4402,10 +4389,7 @@ long __sched io_schedule_timeout(long timeout)
         long ret;
 
         current->in_iowait = 1;
-        if (old_iowait)
-                blk_schedule_flush_plug(current);
-        else
-                blk_flush_plug(current);
+        blk_schedule_flush_plug(current);
 
         delayacct_blkio_start();
         rq = raw_rq();
@@ -7012,27 +6996,23 @@ static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action,
         unsigned long flags;
         long cpu = (long)hcpu;
         struct dl_bw *dl_b;
+        bool overflow;
+        int cpus;
 
-        switch (action & ~CPU_TASKS_FROZEN) {
+        switch (action) {
         case CPU_DOWN_PREPARE:
-                /* explicitly allow suspend */
-                if (!(action & CPU_TASKS_FROZEN)) {
-                        bool overflow;
-                        int cpus;
-
-                        rcu_read_lock_sched();
-                        dl_b = dl_bw_of(cpu);
+                rcu_read_lock_sched();
+                dl_b = dl_bw_of(cpu);
 
-                        raw_spin_lock_irqsave(&dl_b->lock, flags);
-                        cpus = dl_bw_cpus(cpu);
-                        overflow = __dl_overflow(dl_b, cpus, 0, 0);
-                        raw_spin_unlock_irqrestore(&dl_b->lock, flags);
+                raw_spin_lock_irqsave(&dl_b->lock, flags);
+                cpus = dl_bw_cpus(cpu);
+                overflow = __dl_overflow(dl_b, cpus, 0, 0);
+                raw_spin_unlock_irqrestore(&dl_b->lock, flags);
 
-                        rcu_read_unlock_sched();
+                rcu_read_unlock_sched();
 
-                        if (overflow)
-                                return notifier_from_errno(-EBUSY);
-                }
+                if (overflow)
+                        return notifier_from_errno(-EBUSY);
                 cpuset_update_active_cpus(false);
                 break;
         case CPU_DOWN_PREPARE_FROZEN:
@@ -7361,7 +7341,7 @@ static void normalize_task(struct rq *rq, struct task_struct *p)
         queued = task_on_rq_queued(p);
         if (queued)
                 dequeue_task(rq, p, 0);
-        __setscheduler(rq, p, &attr);
+        __setscheduler(rq, p, &attr, false);
         if (queued) {
                 enqueue_task(rq, p, 0);
                 resched_curr(rq);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index ffeaa4105e48..c2980e8733bc 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2181,7 +2181,7 @@ void task_numa_work(struct callback_head *work)
         }
         for (; vma; vma = vma->vm_next) {
                 if (!vma_migratable(vma) || !vma_policy_mof(vma) ||
-                        is_vm_hugetlb_page(vma)) {
+                        is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_MIXEDMAP)) {
                         continue;
                 }
 
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index deef1caa94c6..fefcb1fa5160 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -81,7 +81,6 @@ static void cpuidle_idle_call(void)
         struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
         struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
         int next_state, entered_state;
-        unsigned int broadcast;
         bool reflect;
 
         /*
@@ -150,17 +149,6 @@ static void cpuidle_idle_call(void)
                 goto exit_idle;
         }
 
-        broadcast = drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP;
-
-        /*
-         * Tell the time framework to switch to a broadcast timer
-         * because our local timer will be shutdown. If a local timer
-         * is used from another cpu as a broadcast timer, this call may
-         * fail if it is not available
-         */
-        if (broadcast && tick_broadcast_enter())
-                goto use_default;
-
         /* Take note of the planned idle state. */
         idle_set_state(this_rq(), &drv->states[next_state]);
 
@@ -174,8 +162,8 @@ static void cpuidle_idle_call(void)
         /* The cpu is no longer idle or about to enter idle. */
         idle_set_state(this_rq(), NULL);
 
-        if (broadcast)
-                tick_broadcast_exit();
+        if (entered_state == -EBUSY)
+                goto use_default;
 
         /*
          * Give the governor an opportunity to reflect on the outcome
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 11dc22a6983b..637a09461c1d 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -117,11 +117,7 @@ static int __clockevents_set_state(struct clock_event_device *dev,
         /* Transition with new state-specific callbacks */
         switch (state) {
         case CLOCK_EVT_STATE_DETACHED:
-                /*
-                 * This is an internal state, which is guaranteed to go from
-                 * SHUTDOWN to DETACHED. No driver interaction required.
-                 */
-                return 0;
+                /* The clockevent device is getting replaced. Shut it down. */
 
         case CLOCK_EVT_STATE_SHUTDOWN:
                 return dev->set_state_shutdown(dev);
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 76d4bd962b19..93ef7190bdea 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -266,21 +266,23 @@ lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
 /*
  * Divide a ktime value by a nanosecond value
  */
-u64 __ktime_divns(const ktime_t kt, s64 div)
+s64 __ktime_divns(const ktime_t kt, s64 div)
 {
-        u64 dclc;
         int sft = 0;
+        s64 dclc;
+        u64 tmp;
 
         dclc = ktime_to_ns(kt);
+        tmp = dclc < 0 ? -dclc : dclc;
+
         /* Make sure the divisor is less than 2^32: */
         while (div >> 32) {
                 sft++;
                 div >>= 1;
         }
-        dclc >>= sft;
-        do_div(dclc, (unsigned long) div);
-
-        return dclc;
+        tmp >>= sft;
+        do_div(tmp, (unsigned long) div);
+        return dclc < 0 ? -tmp : tmp;
 }
 EXPORT_SYMBOL_GPL(__ktime_divns);
 #endif /* BITS_PER_LONG >= 64 */
diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c
index 13d945c0d03f..1b28df2d9104 100644
--- a/kernel/trace/ring_buffer_benchmark.c
+++ b/kernel/trace/ring_buffer_benchmark.c
@@ -450,7 +450,7 @@ static int __init ring_buffer_benchmark_init(void)
 
         if (producer_fifo >= 0) {
                 struct sched_param param = {
-                        .sched_priority = consumer_fifo
+                        .sched_priority = producer_fifo
                 };
                 sched_setscheduler(producer, SCHED_FIFO, &param);
         } else
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 692bf7184c8c..25a086bcb700 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -178,12 +178,13 @@ ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 EXPORT_SYMBOL(ftrace_print_hex_seq);
 
 const char *
-ftrace_print_array_seq(struct trace_seq *p, const void *buf, int buf_len,
+ftrace_print_array_seq(struct trace_seq *p, const void *buf, int count,
                        size_t el_size)
 {
         const char *ret = trace_seq_buffer_ptr(p);
         const char *prefix = "";
         void *ptr = (void *)buf;
+        size_t buf_len = count * el_size;
 
         trace_seq_putc(p, '{');
 
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 2316f50b07a4..581a68a04c64 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -41,6 +41,8 @@
 #define NMI_WATCHDOG_ENABLED      (1 << NMI_WATCHDOG_ENABLED_BIT)
 #define SOFT_WATCHDOG_ENABLED     (1 << SOFT_WATCHDOG_ENABLED_BIT)
 
+static DEFINE_MUTEX(watchdog_proc_mutex);
+
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 static unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED|NMI_WATCHDOG_ENABLED;
 #else
@@ -608,26 +610,36 @@ void watchdog_nmi_enable_all(void)
 {
         int cpu;
 
-        if (!watchdog_user_enabled)
-                return;
+        mutex_lock(&watchdog_proc_mutex);
+
+        if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
+                goto unlock;
 
         get_online_cpus();
         for_each_online_cpu(cpu)
                 watchdog_nmi_enable(cpu);
         put_online_cpus();
+
+unlock:
+        mutex_unlock(&watchdog_proc_mutex);
 }
 
 void watchdog_nmi_disable_all(void)
 {
         int cpu;
 
+        mutex_lock(&watchdog_proc_mutex);
+
         if (!watchdog_running)
-                return;
+                goto unlock;
 
         get_online_cpus();
         for_each_online_cpu(cpu)
                 watchdog_nmi_disable(cpu);
         put_online_cpus();
+
+unlock:
+        mutex_unlock(&watchdog_proc_mutex);
 }
 #else
 static int watchdog_nmi_enable(unsigned int cpu) { return 0; }
@@ -744,8 +756,6 @@ static int proc_watchdog_update(void)
 
 }
 
-static DEFINE_MUTEX(watchdog_proc_mutex);
-
 /*
  * common function for watchdog, nmi_watchdog and soft_watchdog parameter
  *