11 files changed, 159 insertions, 104 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index c6d14b8008..5b888c24e4 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -762,11 +762,8 @@ static void exit_notify(struct task_struct *tsk)
                 read_lock(&tasklist_lock);
                 spin_lock_irq(&tsk->sighand->siglock);
                 for (t = next_thread(tsk); t != tsk; t = next_thread(t))
-                        if (!signal_pending(t) && !(t->flags & PF_EXITING)) {
-                                recalc_sigpending_tsk(t);
-                                if (signal_pending(t))
-                                        signal_wake_up(t, 0);
-                        }
+                        if (!signal_pending(t) && !(t->flags & PF_EXITING))
+                                recalc_sigpending_and_wake(t);
                 spin_unlock_irq(&tsk->sighand->siglock);
                 read_unlock(&tasklist_lock);
         }
diff --git a/kernel/fork.c b/kernel/fork.c
index 87069cfc18..73ad5cda1b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -45,6 +45,7 @@
 #include <linux/acct.h>
 #include <linux/tsacct_kern.h>
 #include <linux/cn_proc.h>
+#include <linux/freezer.h>
 #include <linux/delayacct.h>
 #include <linux/taskstats_kern.h>
 #include <linux/random.h>
@@ -1405,7 +1406,9 @@ long do_fork(unsigned long clone_flags,
                 }
 
                 if (clone_flags & CLONE_VFORK) {
+                        freezer_do_not_count();
                         wait_for_completion(&vfork);
+                        freezer_count();
                         if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE)) {
                                 current->ptrace_message = nr;
                                 ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index b0d81aae47..bd9e272d55 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -135,6 +135,39 @@ report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret)
         }
 }
 
+static inline int try_misrouted_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret)
+{
+        struct irqaction *action;
+
+        if (!irqfixup)
+                return 0;
+
+        /* We didn't actually handle the IRQ - see if it was misrouted? */
+        if (action_ret == IRQ_NONE)
+                return 1;
+
+        /*
+         * But for 'irqfixup == 2' we also do it for handled interrupts if
+         * they are marked as IRQF_IRQPOLL (or for irq zero, which is the
+         * traditional PC timer interrupt.. Legacy)
+         */
+        if (irqfixup < 2)
+                return 0;
+
+        if (!irq)
+                return 1;
+
+        /*
+         * Since we don't get the descriptor lock, "action" can
+         * change under us.  We don't really care, but we don't
+         * want to follow a NULL pointer. So tell the compiler to
+         * just load it once by using a barrier.
+         */
+        action = desc->action;
+        barrier();
+        return action && (action->flags & IRQF_IRQPOLL);
+}
+
 void note_interrupt(unsigned int irq, struct irq_desc *desc,
                     irqreturn_t action_ret)
 {
@@ -144,15 +177,10 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc,
                         report_bad_irq(irq, desc, action_ret);
         }
 
-        if (unlikely(irqfixup)) {
-                /* Don't punish working computers */
-                if ((irqfixup == 2 && ((irq == 0) ||
-                                (desc->action->flags & IRQF_IRQPOLL))) ||
-                                action_ret == IRQ_NONE) {
-                        int ok = misrouted_irq(irq);
-                        if (action_ret == IRQ_NONE)
-                                desc->irqs_unhandled -= ok;
-                }
+        if (unlikely(try_misrouted_irq(irq, desc, action_ret))) {
+                int ok = misrouted_irq(irq);
+                if (action_ret == IRQ_NONE)
+                        desc->irqs_unhandled -= ok;
         }
 
         desc->irq_count++;
diff --git a/kernel/kthread.c b/kernel/kthread.c
index df8a8e8f6c..bbd51b81a3 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -70,7 +70,7 @@ static int kthread(void *_create)
         data = create->data;
 
         /* OK, tell user we're spawned, wait for stop or wakeup */
-        __set_current_state(TASK_INTERRUPTIBLE);
+        __set_current_state(TASK_UNINTERRUPTIBLE);
         complete(&create->started);
         schedule();
 
@@ -162,7 +162,10 @@ EXPORT_SYMBOL(kthread_create);
  */
 void kthread_bind(struct task_struct *k, unsigned int cpu)
 {
-        BUG_ON(k->state != TASK_INTERRUPTIBLE);
+        if (k->state != TASK_UNINTERRUPTIBLE) {
+                WARN_ON(1);
+                return;
+        }
         /* Must have done schedule() in kthread() before we set_task_cpu */
         wait_task_inactive(k);
         set_task_cpu(k, cpu);
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 0884193873..e0233d8422 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -31,16 +31,36 @@ static inline int freezeable(struct task_struct * p)
         return 1;
 }
 
+/*
+ * freezing is complete, mark current process as frozen
+ */
+static inline void frozen_process(void)
+{
+        if (!unlikely(current->flags & PF_NOFREEZE)) {
+                current->flags |= PF_FROZEN;
+                wmb();
+        }
+        clear_tsk_thread_flag(current, TIF_FREEZE);
+}
+
 /* Refrigerator is place where frozen processes are stored :-). */
 void refrigerator(void)
 {
         /* Hmm, should we be allowed to suspend when there are realtime
            processes around? */
         long save;
+
+        task_lock(current);
+        if (freezing(current)) {
+                frozen_process();
+                task_unlock(current);
+        } else {
+                task_unlock(current);
+                return;
+        }
         save = current->state;
         pr_debug("%s entered refrigerator\n", current->comm);
 
-        frozen_process(current);
         spin_lock_irq(&current->sighand->siglock);
         recalc_sigpending(); /* We sent fake signal, clean it up */
         spin_unlock_irq(&current->sighand->siglock);
@@ -81,7 +101,7 @@ static void cancel_freezing(struct task_struct *p)
                 pr_debug("  clean up: %s\n", p->comm);
                 do_not_freeze(p);
                 spin_lock_irqsave(&p->sighand->siglock, flags);
-                recalc_sigpending_tsk(p);
+                recalc_sigpending_and_wake(p);
                 spin_unlock_irqrestore(&p->sighand->siglock, flags);
         }
 }
@@ -112,22 +132,12 @@ static unsigned int try_to_freeze_tasks(int freeze_user_space)
                                 cancel_freezing(p);
                                 continue;
                         }
-                        if (is_user_space(p)) {
-                                if (!freeze_user_space)
-                                        continue;
-
-                                /* Freeze the task unless there is a vfork
-                                 * completion pending
-                                 */
-                                if (!p->vfork_done)
-                                        freeze_process(p);
-                        } else {
-                                if (freeze_user_space)
-                                        continue;
-
-                                freeze_process(p);
-                        }
-                        todo++;
+                        if (freeze_user_space && !is_user_space(p))
+                                continue;
+
+                        freeze_process(p);
+                        if (!freezer_should_skip(p))
+                                todo++;
                 } while_each_thread(g, p);
                 read_unlock(&tasklist_lock);
                 yield();                        /* Yield is okay here */
@@ -149,13 +159,16 @@ static unsigned int try_to_freeze_tasks(int freeze_user_space)
                                 TIMEOUT / HZ, todo);
                 read_lock(&tasklist_lock);
                 do_each_thread(g, p) {
-                        if (is_user_space(p) == !freeze_user_space)
+                        if (freeze_user_space && !is_user_space(p))
                                 continue;
 
-                        if (freezeable(p) && !frozen(p))
+                        task_lock(p);
+                        if (freezeable(p) && !frozen(p) &&
+                            !freezer_should_skip(p))
                                 printk(KERN_ERR " %s\n", p->comm);
 
                         cancel_freezing(p);
+                        task_unlock(p);
                 } while_each_thread(g, p);
                 read_unlock(&tasklist_lock);
         }
@@ -200,9 +213,7 @@ static void thaw_tasks(int thaw_user_space)
                 if (is_user_space(p) == !thaw_user_space)
                         continue;
 
-                if (!thaw_process(p))
-                        printk(KERN_WARNING " Strange, %s not stopped\n",
-                                p->comm );
+                thaw_process(p);
         } while_each_thread(g, p);
         read_unlock(&tasklist_lock);
 }
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index b8b235cc19..8b1a1b8371 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -584,7 +584,7 @@ int swsusp_check(void)
         resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
         if (!IS_ERR(resume_bdev)) {
                 set_blocksize(resume_bdev, PAGE_SIZE);
-                memset(swsusp_header, 0, sizeof(PAGE_SIZE));
+                memset(swsusp_header, 0, PAGE_SIZE);
                 error = bio_read_page(swsusp_resume_block,
                                         swsusp_header, NULL);
                 if (error)
diff --git a/kernel/sched.c b/kernel/sched.c
index 799d23b4e3..13cdab3b4c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4775,9 +4775,7 @@ int __sched cond_resched_softirq(void)
         BUG_ON(!in_softirq());
 
         if (need_resched() && system_state == SYSTEM_RUNNING) {
-                raw_local_irq_disable();
-                _local_bh_enable();
-                raw_local_irq_enable();
+                local_bh_enable();
                 __cond_resched();
                 local_bh_disable();
                 return 1;
diff --git a/kernel/signal.c b/kernel/signal.c
index 364fc95bf9..acdfc0549c 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -96,15 +96,27 @@ static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked)
 
 #define PENDING(p,b) has_pending_signals(&(p)->signal, (b))
 
-fastcall void recalc_sigpending_tsk(struct task_struct *t)
+static int recalc_sigpending_tsk(struct task_struct *t)
 {
         if (t->signal->group_stop_count > 0 ||
             (freezing(t)) ||
             PENDING(&t->pending, &t->blocked) ||
-            PENDING(&t->signal->shared_pending, &t->blocked))
+            PENDING(&t->signal->shared_pending, &t->blocked)) {
                 set_tsk_thread_flag(t, TIF_SIGPENDING);
-        else
-                clear_tsk_thread_flag(t, TIF_SIGPENDING);
+                return 1;
+        }
+        clear_tsk_thread_flag(t, TIF_SIGPENDING);
+        return 0;
+}
+
+/*
+ * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up.
+ * This is superfluous when called on current, the wakeup is a harmless no-op.
+ */
+void recalc_sigpending_and_wake(struct task_struct *t)
+{
+        if (recalc_sigpending_tsk(t))
+                signal_wake_up(t, 0);
 }
 
 void recalc_sigpending(void)
@@ -744,7 +756,7 @@ force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
                 action->sa.sa_handler = SIG_DFL;
                 if (blocked) {
                         sigdelset(&t->blocked, sig);
-                        recalc_sigpending_tsk(t);
+                        recalc_sigpending_and_wake(t);
                 }
         }
         ret = specific_send_sig_info(sig, info, t);
@@ -2273,7 +2285,7 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
                         rm_from_queue_full(&mask, &t->signal->shared_pending);
                         do {
                                 rm_from_queue_full(&mask, &t->pending);
-                                recalc_sigpending_tsk(t);
+                                recalc_sigpending_and_wake(t);
                                 t = next_thread(t);
                         } while (t != current);
                 }
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index eadfce2fff..8001d37071 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -243,11 +243,18 @@ void tick_broadcast_on_off(unsigned long reason, int *oncpu)
 {
         int cpu = get_cpu();
 
-        if (cpu == *oncpu)
-                tick_do_broadcast_on_off(&reason);
-        else
-                smp_call_function_single(*oncpu, tick_do_broadcast_on_off,
-                                         &reason, 1, 1);
+        if (!cpu_isset(*oncpu, cpu_online_map)) {
+                printk(KERN_ERR "tick-braodcast: ignoring broadcast for "
+                       "offline CPU #%d\n", *oncpu);
+        } else {
+
+                if (cpu == *oncpu)
+                        tick_do_broadcast_on_off(&reason);
+                else
+                        smp_call_function_single(*oncpu,
+                                                 tick_do_broadcast_on_off,
+                                                 &reason, 1, 1);
+        }
         put_cpu();
 }
 
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 3483e6cb95..3e7ebc4646 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -167,9 +167,15 @@ void tick_nohz_stop_sched_tick(void)
                 goto end;
 
         cpu = smp_processor_id();
-        if (unlikely(local_softirq_pending()))
-                printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
-                       local_softirq_pending());
+        if (unlikely(local_softirq_pending())) {
+                static int ratelimit;
+
+                if (ratelimit < 10) {
+                        printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
+                               local_softirq_pending());
+                        ratelimit++;
+                }
+        }
 
         now = ktime_get();
         /*
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index fb56fedd5c..3bebf73be9 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -47,7 +47,6 @@ struct cpu_workqueue_struct {
 
         struct workqueue_struct *wq;
         struct task_struct *thread;
-        int should_stop;
 
         int run_depth;          /* Detect run_workqueue() recursion depth */
 } ____cacheline_aligned;
@@ -71,7 +70,13 @@ static LIST_HEAD(workqueues);
 
 static int singlethread_cpu __read_mostly;
 static cpumask_t cpu_singlethread_map __read_mostly;
-/* optimization, we could use cpu_possible_map */
+/*
+ * _cpu_down() first removes CPU from cpu_online_map, then CPU_DEAD
+ * flushes cwq->worklist. This means that flush_workqueue/wait_on_work
+ * which comes in between can't use for_each_online_cpu(). We could
+ * use cpu_possible_map, the cpumask below is more a documentation
+ * than optimization.
+ */
 static cpumask_t cpu_populated_map __read_mostly;
 
 /* If it's single threaded, it isn't in the list of workqueues. */
@@ -272,24 +277,6 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq)
         spin_unlock_irq(&cwq->lock);
 }
 
-/*
- * NOTE: the caller must not touch *cwq if this func returns true
- */
-static int cwq_should_stop(struct cpu_workqueue_struct *cwq)
-{
-        int should_stop = cwq->should_stop;
-
-        if (unlikely(should_stop)) {
-                spin_lock_irq(&cwq->lock);
-                should_stop = cwq->should_stop && list_empty(&cwq->worklist);
-                if (should_stop)
-                        cwq->thread = NULL;
-                spin_unlock_irq(&cwq->lock);
-        }
-
-        return should_stop;
-}
-
 static int worker_thread(void *__cwq)
 {
         struct cpu_workqueue_struct *cwq = __cwq;
@@ -302,14 +289,15 @@ static int worker_thread(void *__cwq)
 
         for (;;) {
                 prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE);
-                if (!freezing(current) && !cwq->should_stop
-                    && list_empty(&cwq->worklist))
+                if (!freezing(current) &&
+                    !kthread_should_stop() &&
+                    list_empty(&cwq->worklist))
                         schedule();
                 finish_wait(&cwq->more_work, &wait);
 
                 try_to_freeze();
 
-                if (cwq_should_stop(cwq))
+                if (kthread_should_stop())
                         break;
 
                 run_workqueue(cwq);
@@ -340,18 +328,21 @@ static void insert_wq_barrier(struct cpu_workqueue_struct *cwq,
         insert_work(cwq, &barr->work, tail);
 }
 
-static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq)
+static int flush_cpu_workqueue(struct cpu_workqueue_struct *cwq)
 {
+        int active;
+
         if (cwq->thread == current) {
                 /*
                  * Probably keventd trying to flush its own queue. So simply run
                  * it by hand rather than deadlocking.
                  */
                 run_workqueue(cwq);
+                active = 1;
         } else {
                 struct wq_barrier barr;
-                int active = 0;
 
+                active = 0;
                 spin_lock_irq(&cwq->lock);
                 if (!list_empty(&cwq->worklist) || cwq->current_work != NULL) {
                         insert_wq_barrier(cwq, &barr, 1);
@@ -362,6 +353,8 @@ static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq)
                 if (active)
                         wait_for_completion(&barr.done);
         }
+
+        return active;
 }
 
 /**
@@ -674,7 +667,6 @@ static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu)
                 return PTR_ERR(p);
 
         cwq->thread = p;
-        cwq->should_stop = 0;
 
         return 0;
 }
@@ -740,29 +732,27 @@ EXPORT_SYMBOL_GPL(__create_workqueue);
 
 static void cleanup_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu)
 {
-        struct wq_barrier barr;
-        int alive = 0;
-
-        spin_lock_irq(&cwq->lock);
-        if (cwq->thread != NULL) {
-                insert_wq_barrier(cwq, &barr, 1);
-                cwq->should_stop = 1;
-                alive = 1;
-        }
-        spin_unlock_irq(&cwq->lock);
+        /*
+         * Our caller is either destroy_workqueue() or CPU_DEAD,
+         * workqueue_mutex protects cwq->thread
+         */
+        if (cwq->thread == NULL)
+                return;
 
-        if (alive) {
-                wait_for_completion(&barr.done);
+        /*
+         * If the caller is CPU_DEAD the single flush_cpu_workqueue()
+         * is not enough, a concurrent flush_workqueue() can insert a
+         * barrier after us.
+         * When ->worklist becomes empty it is safe to exit because no
+         * more work_structs can be queued on this cwq: flush_workqueue
+         * checks list_empty(), and a "normal" queue_work() can't use
+         * a dead CPU.
+         */
+        while (flush_cpu_workqueue(cwq))
+                ;
 
-                while (unlikely(cwq->thread != NULL))
-                        cpu_relax();
-                /*
-                 * Wait until cwq->thread unlocks cwq->lock,
-                 * it won't touch *cwq after that.
-                 */
-                smp_rmb();
-                spin_unlock_wait(&cwq->lock);
-        }
+        kthread_stop(cwq->thread);
+        cwq->thread = NULL;
 }
 
 /**