25 files changed, 371 insertions, 174 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 8fe8c0cb137b..dee025f2f286 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2042,10 +2042,13 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
         struct cgroup *cgrp;
         struct cgroup_iter it;
         struct task_struct *tsk;
+
         /*
-         * Validate dentry by checking the superblock operations
+         * Validate dentry by checking the superblock operations,
+         * and make sure it's a directory.
          */
-        if (dentry->d_sb->s_op != &cgroup_ops)
+        if (dentry->d_sb->s_op != &cgroup_ops ||
+            !S_ISDIR(dentry->d_inode->i_mode))
                  goto err;
 
         ret = 0;
@@ -2475,10 +2478,7 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
                 mutex_unlock(&cgroup_mutex);
                 return -EBUSY;
         }
-
-        parent = cgrp->parent;
-        root = cgrp->root;
-        sb = root->sb;
+        mutex_unlock(&cgroup_mutex);
 
         /*
          * Call pre_destroy handlers of subsys. Notify subsystems
@@ -2486,7 +2486,14 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
          */
         cgroup_call_pre_destroy(cgrp);
 
-        if (cgroup_has_css_refs(cgrp)) {
+        mutex_lock(&cgroup_mutex);
+        parent = cgrp->parent;
+        root = cgrp->root;
+        sb = root->sb;
+
+        if (atomic_read(&cgrp->count)
+            || !list_empty(&cgrp->children)
+            || cgroup_has_css_refs(cgrp)) {
                 mutex_unlock(&cgroup_mutex);
                 return -EBUSY;
         }
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 5a732c5ef08b..8ea32e8d68b0 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -462,7 +462,7 @@ out:
  * It must be called by the arch code on the new cpu, before the new cpu
  * enables interrupts and before the "boot" cpu returns from __cpu_up().
  */
-void notify_cpu_starting(unsigned int cpu)
+void __cpuinit notify_cpu_starting(unsigned int cpu)
 {
         unsigned long val = CPU_STARTING;
 
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 3e00526f52ec..96c0ba13b8cd 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -36,6 +36,7 @@
 #include <linux/list.h>
 #include <linux/mempolicy.h>
 #include <linux/mm.h>
+#include <linux/memory.h>
 #include <linux/module.h>
 #include <linux/mount.h>
 #include <linux/namei.h>
@@ -584,10 +585,9 @@ static int generate_sched_domains(cpumask_t **domains,
         int i, j, k;            /* indices for partition finding loops */
         cpumask_t *doms;        /* resulting partition; i.e. sched domains */
         struct sched_domain_attr *dattr;  /* attributes for custom domains */
-        int ndoms;              /* number of sched domains in result */
+        int ndoms = 0;          /* number of sched domains in result */
         int nslot;              /* next empty doms[] cpumask_t slot */
 
-        ndoms = 0;
         doms = NULL;
         dattr = NULL;
         csa = NULL;
@@ -674,10 +674,8 @@ restart:
          * Convert <csn, csa> to <ndoms, doms> and populate cpu masks.
          */
         doms = kmalloc(ndoms * sizeof(cpumask_t), GFP_KERNEL);
-        if (!doms) {
-                ndoms = 0;
+        if (!doms)
                 goto done;
-        }
 
         /*
          * The rest of the code, including the scheduler, can deal with
@@ -732,6 +730,13 @@ restart:
 done:
         kfree(csa);
 
+        /*
+         * Fallback to the default domain if kmalloc() failed.
+         * See comments in partition_sched_domains().
+         */
+        if (doms == NULL)
+                ndoms = 1;
+
         *domains    = doms;
         *attributes = dattr;
         return ndoms;
@@ -2011,12 +2016,23 @@ static int cpuset_track_online_cpus(struct notifier_block *unused_nb,
  * Call this routine anytime after node_states[N_HIGH_MEMORY] changes.
  * See also the previous routine cpuset_track_online_cpus().
  */
-void cpuset_track_online_nodes(void)
+static int cpuset_track_online_nodes(struct notifier_block *self,
+                                unsigned long action, void *arg)
 {
         cgroup_lock();
-        top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
-        scan_for_empty_cpusets(&top_cpuset);
+        switch (action) {
+        case MEM_ONLINE:
+                top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
+                break;
+        case MEM_OFFLINE:
+                top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
+                scan_for_empty_cpusets(&top_cpuset);
+                break;
+        default:
+                break;
+        }
         cgroup_unlock();
+        return NOTIFY_OK;
 }
 #endif
 
@@ -2032,6 +2048,7 @@ void __init cpuset_init_smp(void)
         top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
 
         hotcpu_notifier(cpuset_track_online_cpus, 0);
+        hotplug_memory_notifier(cpuset_track_online_nodes, 10);
 }
 
 /**
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index c9767e641980..64c1c7253dae 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -25,6 +25,8 @@ static inline void unregister_handler_proc(unsigned int irq,
                                            struct irqaction *action) { }
 #endif
 
+extern int irq_select_affinity_usr(unsigned int irq);
+
 /*
  * Debugging printout:
  */
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index c498a1b8c621..801addda3c43 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -82,24 +82,27 @@ int irq_can_set_affinity(unsigned int irq)
 int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
 {
         struct irq_desc *desc = irq_to_desc(irq);
+        unsigned long flags;
 
         if (!desc->chip->set_affinity)
                 return -EINVAL;
 
+        spin_lock_irqsave(&desc->lock, flags);
+
 #ifdef CONFIG_GENERIC_PENDING_IRQ
         if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
-                unsigned long flags;
-
-                spin_lock_irqsave(&desc->lock, flags);
                 desc->affinity = cpumask;
                 desc->chip->set_affinity(irq, cpumask);
-                spin_unlock_irqrestore(&desc->lock, flags);
-        } else
-                set_pending_irq(irq, cpumask);
+        } else {
+                desc->status |= IRQ_MOVE_PENDING;
+                desc->pending_mask = cpumask;
+        }
 #else
         desc->affinity = cpumask;
         desc->chip->set_affinity(irq, cpumask);
 #endif
+        desc->status |= IRQ_AFFINITY_SET;
+        spin_unlock_irqrestore(&desc->lock, flags);
         return 0;
 }
 
@@ -107,24 +110,59 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
 /*
  * Generic version of the affinity autoselector.
  */
-int irq_select_affinity(unsigned int irq)
+int do_irq_select_affinity(unsigned int irq, struct irq_desc *desc)
 {
         cpumask_t mask;
-        struct irq_desc *desc;
 
         if (!irq_can_set_affinity(irq))
                 return 0;
 
         cpus_and(mask, cpu_online_map, irq_default_affinity);
 
-        desc = irq_to_desc(irq);
+        /*
+         * Preserve an userspace affinity setup, but make sure that
+         * one of the targets is online.
+         */
+        if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) {
+                if (cpus_intersects(desc->affinity, cpu_online_map))
+                        mask = desc->affinity;
+                else
+                        desc->status &= ~IRQ_AFFINITY_SET;
+        }
+
         desc->affinity = mask;
         desc->chip->set_affinity(irq, mask);
 
         return 0;
 }
+#else
+static inline int do_irq_select_affinity(unsigned int irq, struct irq_desc *d)
+{
+        return irq_select_affinity(irq);
+}
 #endif
 
+/*
+ * Called when affinity is set via /proc/irq
+ */
+int irq_select_affinity_usr(unsigned int irq)
+{
+        struct irq_desc *desc = irq_to_desc(irq);
+        unsigned long flags;
+        int ret;
+
+        spin_lock_irqsave(&desc->lock, flags);
+        ret = do_irq_select_affinity(irq, desc);
+        spin_unlock_irqrestore(&desc->lock, flags);
+
+        return ret;
+}
+
+#else
+static inline int do_irq_select_affinity(int irq, struct irq_desc *desc)
+{
+        return 0;
+}
 #endif
 
 /**
@@ -327,7 +365,7 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
                  * IRQF_TRIGGER_* but the PIC does not support multiple
                  * flow-types?
                  */
-                pr_warning("No set_type function for IRQ %d (%s)\n", irq,
+                pr_debug("No set_type function for IRQ %d (%s)\n", irq,
                                 chip ? (chip->name ? : "unknown") : "unknown");
                 return 0;
         }
@@ -445,8 +483,12 @@ __setup_irq(unsigned int irq, struct irq_desc * desc, struct irqaction *new)
                         /* Undo nested disables: */
                         desc->depth = 1;
 
+                /* Exclude IRQ from balancing if requested */
+                if (new->flags & IRQF_NOBALANCING)
+                        desc->status |= IRQ_NO_BALANCING;
+
                 /* Set default affinity mask once everything is setup */
-                irq_select_affinity(irq);
+                do_irq_select_affinity(irq, desc);
 
         } else if ((new->flags & IRQF_TRIGGER_MASK)
                         && (new->flags & IRQF_TRIGGER_MASK)
@@ -459,10 +501,6 @@ __setup_irq(unsigned int irq, struct irq_desc * desc, struct irqaction *new)
 
         *p = new;
 
-        /* Exclude IRQ from balancing */
-        if (new->flags & IRQF_NOBALANCING)
-                desc->status |= IRQ_NO_BALANCING;
-
         /* Reset broken irq detection when installing new handler */
         desc->irq_count = 0;
         desc->irqs_unhandled = 0;
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index 90b920d3f52b..9db681d95814 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -1,17 +1,6 @@
 
 #include <linux/irq.h>
 
-void set_pending_irq(unsigned int irq, cpumask_t mask)
-{
-        struct irq_desc *desc = irq_to_desc(irq);
-        unsigned long flags;
-
-        spin_lock_irqsave(&desc->lock, flags);
-        desc->status |= IRQ_MOVE_PENDING;
-        desc->pending_mask = mask;
-        spin_unlock_irqrestore(&desc->lock, flags);
-}
-
 void move_masked_irq(int irq)
 {
         struct irq_desc *desc = irq_to_desc(irq);
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 4d161c70ba55..d257e7d6a8a4 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -62,7 +62,7 @@ static ssize_t irq_affinity_proc_write(struct file *file,
         if (!cpus_intersects(new_value, cpu_online_map))
                 /* Special case for empty set - allow the architecture
                    code to set default SMP affinity. */
-                return irq_select_affinity(irq) ? -EINVAL : count;
+                return irq_select_affinity_usr(irq) ? -EINVAL : count;
 
         irq_set_affinity(irq, new_value);
 
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 5072cf1685a2..7b8b0f21a5b1 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -304,17 +304,24 @@ int sprint_symbol(char *buffer, unsigned long address)
         char *modname;
         const char *name;
         unsigned long offset, size;
-        char namebuf[KSYM_NAME_LEN];
+        int len;
 
-        name = kallsyms_lookup(address, &size, &offset, &modname, namebuf);
+        name = kallsyms_lookup(address, &size, &offset, &modname, buffer);
         if (!name)
                 return sprintf(buffer, "0x%lx", address);
 
+        if (name != buffer)
+                strcpy(buffer, name);
+        len = strlen(buffer);
+        buffer += len;
+
         if (modname)
-                return sprintf(buffer, "%s+%#lx/%#lx [%s]", name, offset,
-                                size, modname);
+                len += sprintf(buffer, "+%#lx/%#lx [%s]",
+                                                offset, size, modname);
         else
-                return sprintf(buffer, "%s+%#lx/%#lx", name, offset, size);
+                len += sprintf(buffer, "+%#lx/%#lx", offset, size);
+
+        return len;
 }
 
 /* Look up a kernel symbol and print it to the kernel messages. */
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 06e157119d2b..46a404173db2 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3276,10 +3276,10 @@ void __init lockdep_info(void)
 {
         printk("Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar\n");
 
-        printk("... MAX_LOCKDEP_SUBCLASSES:    %lu\n", MAX_LOCKDEP_SUBCLASSES);
+        printk("... MAX_LOCKDEP_SUBCLASSES:  %lu\n", MAX_LOCKDEP_SUBCLASSES);
         printk("... MAX_LOCK_DEPTH:          %lu\n", MAX_LOCK_DEPTH);
         printk("... MAX_LOCKDEP_KEYS:        %lu\n", MAX_LOCKDEP_KEYS);
-        printk("... CLASSHASH_SIZE:           %lu\n", CLASSHASH_SIZE);
+        printk("... CLASSHASH_SIZE:          %lu\n", CLASSHASH_SIZE);
         printk("... MAX_LOCKDEP_ENTRIES:     %lu\n", MAX_LOCKDEP_ENTRIES);
         printk("... MAX_LOCKDEP_CHAINS:      %lu\n", MAX_LOCKDEP_CHAINS);
         printk("... CHAINHASH_SIZE:          %lu\n", CHAINHASH_SIZE);
diff --git a/kernel/panic.c b/kernel/panic.c
index 6513aac8e992..4d5088355bfe 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -167,6 +167,7 @@ static const struct tnt tnts[] = {
  *  'M' - System experienced a machine check exception.
  *  'B' - System has hit bad_page.
  *  'U' - Userspace-defined naughtiness.
+ *  'D' - Kernel has oopsed before
  *  'A' - ACPI table overridden.
  *  'W' - Taint on warning.
  *  'C' - modules from drivers/staging are loaded.
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 153dcb2639c3..895337b16a24 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1308,9 +1308,10 @@ static inline int task_cputime_expired(const struct task_cputime *sample,
  */
 static inline int fastpath_timer_check(struct task_struct *tsk)
 {
-        struct signal_struct *sig = tsk->signal;
+        struct signal_struct *sig;
 
-        if (unlikely(!sig))
+        /* tsk == current, ensure it is safe to use ->signal/sighand */
+        if (unlikely(tsk->exit_state))
                 return 0;
 
         if (!task_cputime_zero(&tsk->cputime_expires)) {
@@ -1323,6 +1324,8 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
                 if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
                         return 1;
         }
+
+        sig = tsk->signal;
         if (!task_cputime_zero(&sig->cputime_expires)) {
                 struct task_cputime group_sample;
 
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 19122cf6d827..b8f7ce9473e8 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -174,7 +174,7 @@ static void suspend_test_finish(const char *label)
          * has some performance issues.  The stack dump of a WARN_ON
          * is more likely to get the right attention than a printk...
          */
-        WARN_ON(msec > (TEST_SUSPEND_SECONDS * 1000));
+        WARN(msec > (TEST_SUSPEND_SECONDS * 1000), "Component: %s\n", label);
 }
 
 #else
diff --git a/kernel/profile.c b/kernel/profile.c
index 9830a037d8db..dc41827fbfee 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -351,7 +351,7 @@ out:
         put_cpu();
 }
 
-static int __devinit profile_cpu_callback(struct notifier_block *info,
+static int __cpuinit profile_cpu_callback(struct notifier_block *info,
                                         unsigned long action, void *__cpu)
 {
         int node, cpu = (unsigned long)__cpu;
@@ -544,7 +544,7 @@ static const struct file_operations proc_profile_operations = {
 };
 
 #ifdef CONFIG_SMP
-static void __init profile_nop(void *unused)
+static inline void profile_nop(void *unused)
 {
 }
 
@@ -596,7 +596,7 @@ out_cleanup:
 #define create_hash_tables()                    ({ 0; })
 #endif
 
-int create_proc_profile(void)
+int __ref create_proc_profile(void) /* false positive from hotcpu_notifier */
 {
         struct proc_dir_entry *entry;
 
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index f764b8806955..ca2df68faf76 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -629,7 +629,7 @@ int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data)
         return (copied == sizeof(data)) ? 0 : -EIO;
 }
 
-#if defined CONFIG_COMPAT && defined __ARCH_WANT_COMPAT_SYS_PTRACE
+#if defined CONFIG_COMPAT
 #include <linux/compat.h>
 
 int compat_ptrace_request(struct task_struct *child, compat_long_t request,
@@ -726,4 +726,4 @@ asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
         unlock_kernel();
         return ret;
 }
-#endif  /* CONFIG_COMPAT && __ARCH_WANT_COMPAT_SYS_PTRACE */
+#endif  /* CONFIG_COMPAT */
diff --git a/kernel/relay.c b/kernel/relay.c
index 8d13a7855c08..32b0befdcb6a 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -400,7 +400,7 @@ void relay_reset(struct rchan *chan)
         }
 
         mutex_lock(&relay_channels_mutex);
-        for_each_online_cpu(i)
+        for_each_possible_cpu(i)
                 if (chan->buf[i])
                         __relay_reset(chan->buf[i], 0);
         mutex_unlock(&relay_channels_mutex);
@@ -611,10 +611,9 @@ struct rchan *relay_open(const char *base_filename,
         return chan;
 
 free_bufs:
-        for_each_online_cpu(i) {
-                if (!chan->buf[i])
-                        break;
-                relay_close_buf(chan->buf[i]);
+        for_each_possible_cpu(i) {
+                if (chan->buf[i])
+                        relay_close_buf(chan->buf[i]);
         }
 
         kref_put(&chan->kref, relay_destroy_channel);
diff --git a/kernel/sched.c b/kernel/sched.c
index 204d0662b438..993bc74a290c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1455,9 +1455,10 @@ static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
 static unsigned long cpu_avg_load_per_task(int cpu)
 {
         struct rq *rq = cpu_rq(cpu);
+        unsigned long nr_running = ACCESS_ONCE(rq->nr_running);
 
-        if (rq->nr_running)
-                rq->avg_load_per_task = rq->load.weight / rq->nr_running;
+        if (nr_running)
+                rq->avg_load_per_task = rq->load.weight / nr_running;
         else
                 rq->avg_load_per_task = 0;
 
@@ -7805,13 +7806,14 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
  *
  * The passed in 'doms_new' should be kmalloc'd. This routine takes
  * ownership of it and will kfree it when done with it. If the caller
- * failed the kmalloc call, then it can pass in doms_new == NULL,
- * and partition_sched_domains() will fallback to the single partition
- * 'fallback_doms', it also forces the domains to be rebuilt.
+ * failed the kmalloc call, then it can pass in doms_new == NULL &&
+ * ndoms_new == 1, and partition_sched_domains() will fallback to
+ * the single partition 'fallback_doms', it also forces the domains
+ * to be rebuilt.
  *
- * If doms_new==NULL it will be replaced with cpu_online_map.
- * ndoms_new==0 is a special case for destroying existing domains.
- * It will not create the default domain.
+ * If doms_new == NULL it will be replaced with cpu_online_map.
+ * ndoms_new == 0 is a special case for destroying existing domains,
+ * and it will not create the default domain.
  *
  * Call with hotplug lock held
  */
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 48ecc51e7701..26ed8e3d1c15 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -423,10 +423,11 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
 #undef __P
 
         {
+                unsigned int this_cpu = raw_smp_processor_id();
                 u64 t0, t1;
 
-                t0 = sched_clock();
-                t1 = sched_clock();
+                t0 = cpu_clock(this_cpu);
+                t1 = cpu_clock(this_cpu);
                 SEQ_printf(m, "%-35s:%21Ld\n",
                            "clock-delta", (long long)(t1-t0));
         }
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index ee71bec1da66..7dbf72a2b02c 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -298,9 +298,11 @@ static inline void account_group_user_time(struct task_struct *tsk,
 {
         struct signal_struct *sig;
 
-        sig = tsk->signal;
-        if (unlikely(!sig))
+        /* tsk == current, ensure it is safe to use ->signal */
+        if (unlikely(tsk->exit_state))
                 return;
+
+        sig = tsk->signal;
         if (sig->cputime.totals) {
                 struct task_cputime *times;
 
@@ -325,9 +327,11 @@ static inline void account_group_system_time(struct task_struct *tsk,
 {
         struct signal_struct *sig;
 
-        sig = tsk->signal;
-        if (unlikely(!sig))
+        /* tsk == current, ensure it is safe to use ->signal */
+        if (unlikely(tsk->exit_state))
                 return;
+
+        sig = tsk->signal;
         if (sig->cputime.totals) {
                 struct task_cputime *times;
 
@@ -353,8 +357,11 @@ static inline void account_group_exec_runtime(struct task_struct *tsk,
         struct signal_struct *sig;
 
         sig = tsk->signal;
+        /* see __exit_signal()->task_rq_unlock_wait() */
+        barrier();
         if (unlikely(!sig))
                 return;
+
         if (sig->cputime.totals) {
                 struct task_cputime *times;
 
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index a77b27b11b04..e14a23281707 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -31,7 +31,7 @@ cond_syscall(sys_socketpair);
 cond_syscall(sys_bind);
 cond_syscall(sys_listen);
 cond_syscall(sys_accept);
-cond_syscall(sys_paccept);
+cond_syscall(sys_accept4);
 cond_syscall(sys_connect);
 cond_syscall(sys_getsockname);
 cond_syscall(sys_getpeername);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 511031381c33..9d52b57310af 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -176,6 +176,9 @@ extern struct ctl_table random_table[];
 #ifdef CONFIG_INOTIFY_USER
 extern struct ctl_table inotify_table[];
 #endif
+#ifdef CONFIG_EPOLL
+extern struct ctl_table epoll_table[];
+#endif
 
 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 int sysctl_legacy_va_layout;
@@ -1325,6 +1328,13 @@ static struct ctl_table fs_table[] = {
                 .child          = inotify_table,
         },
 #endif  
+#ifdef CONFIG_EPOLL
+        {
+                .procname       = "epoll",
+                .mode           = 0555,
+                .child          = epoll_table,
+        },
+#endif
 #endif
         {
                 .ctl_name       = KERN_SETUID_DUMPABLE,
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 4a39d24568c8..78db083390f0 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -185,7 +185,6 @@ enum {
 };
 
 static int ftrace_filtered;
-static int tracing_on;
 
 static LIST_HEAD(ftrace_new_addrs);
 
@@ -327,96 +326,89 @@ ftrace_record_ip(unsigned long ip)
 
 static int
 __ftrace_replace_code(struct dyn_ftrace *rec,
-                      unsigned char *old, unsigned char *new, int enable)
+                      unsigned char *nop, int enable)
 {
         unsigned long ip, fl;
+        unsigned char *call, *old, *new;
 
         ip = rec->ip;
 
-        if (ftrace_filtered && enable) {
+        /*
+         * If this record is not to be traced and
+         * it is not enabled then do nothing.
+         *
+         * If this record is not to be traced and
+         * it is enabled then disabled it.
+         *
+         */
+        if (rec->flags & FTRACE_FL_NOTRACE) {
+                if (rec->flags & FTRACE_FL_ENABLED)
+                        rec->flags &= ~FTRACE_FL_ENABLED;
+                else
+                        return 0;
+
+        } else if (ftrace_filtered && enable) {
                 /*
-                 * If filtering is on:
-                 *
-                 * If this record is set to be filtered and
-                 * is enabled then do nothing.
-                 *
-                 * If this record is set to be filtered and
-                 * it is not enabled, enable it.
-                 *
-                 * If this record is not set to be filtered
-                 * and it is not enabled do nothing.
-                 *
-                 * If this record is set not to trace then
-                 * do nothing.
-                 *
-                 * If this record is set not to trace and
-                 * it is enabled then disable it.
-                 *
-                 * If this record is not set to be filtered and
-                 * it is enabled, disable it.
+                 * Filtering is on:
                  */
 
-                fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE |
-                                   FTRACE_FL_ENABLED);
+                fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
 
-                if ((fl ==  (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) ||
-                    (fl ==  (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) ||
-                    !fl || (fl == FTRACE_FL_NOTRACE))
+                /* Record is filtered and enabled, do nothing */
+                if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
                         return 0;
 
-                /*
-                 * If it is enabled disable it,
-                 * otherwise enable it!
-                 */
-                if (fl & FTRACE_FL_ENABLED) {
-                        /* swap new and old */
-                        new = old;
-                        old = ftrace_call_replace(ip, FTRACE_ADDR);
+                /* Record is not filtered and is not enabled do nothing */
+                if (!fl)
+                        return 0;
+
+                /* Record is not filtered but enabled, disable it */
+                if (fl == FTRACE_FL_ENABLED)
                         rec->flags &= ~FTRACE_FL_ENABLED;
-                } else {
-                        new = ftrace_call_replace(ip, FTRACE_ADDR);
+                else
+                /* Otherwise record is filtered but not enabled, enable it */
                         rec->flags |= FTRACE_FL_ENABLED;
-                }
         } else {
+                /* Disable or not filtered */
 
                 if (enable) {
-                        /*
-                         * If this record is set not to trace and is
-                         * not enabled, do nothing.
-                         */
-                        fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED);
-                        if (fl == FTRACE_FL_NOTRACE)
-                                return 0;
-
-                        new = ftrace_call_replace(ip, FTRACE_ADDR);
-                } else
-                        old = ftrace_call_replace(ip, FTRACE_ADDR);
-
-                if (enable) {
+                        /* if record is enabled, do nothing */
                         if (rec->flags & FTRACE_FL_ENABLED)
                                 return 0;
+
                         rec->flags |= FTRACE_FL_ENABLED;
+
                 } else {
+
+                        /* if record is not enabled do nothing */
                         if (!(rec->flags & FTRACE_FL_ENABLED))
                                 return 0;
+
                         rec->flags &= ~FTRACE_FL_ENABLED;
                 }
         }
 
+        call = ftrace_call_replace(ip, FTRACE_ADDR);
+
+        if (rec->flags & FTRACE_FL_ENABLED) {
+                old = nop;
+                new = call;
+        } else {
+                old = call;
+                new = nop;
+        }
+
         return ftrace_modify_code(ip, old, new);
 }
 
 static void ftrace_replace_code(int enable)
 {
         int i, failed;
-        unsigned char *new = NULL, *old = NULL;
+        unsigned char *nop = NULL;
         struct dyn_ftrace *rec;
         struct ftrace_page *pg;
 
-        if (enable)
-                old = ftrace_nop_replace();
-        else
-                new = ftrace_nop_replace();
+        nop = ftrace_nop_replace();
 
         for (pg = ftrace_pages_start; pg; pg = pg->next) {
                 for (i = 0; i < pg->index; i++) {
@@ -434,7 +426,7 @@ static void ftrace_replace_code(int enable)
                                 unfreeze_record(rec);
                         }
 
-                        failed = __ftrace_replace_code(rec, old, new, enable);
+                        failed = __ftrace_replace_code(rec, nop, enable);
                         if (failed && (rec->flags & FTRACE_FL_CONVERTED)) {
                                 rec->flags |= FTRACE_FL_FAILED;
                                 if ((system_state == SYSTEM_BOOTING) ||
@@ -506,13 +498,10 @@ static int __ftrace_modify_code(void *data)
 {
         int *command = data;
 
-        if (*command & FTRACE_ENABLE_CALLS) {
+        if (*command & FTRACE_ENABLE_CALLS)
                 ftrace_replace_code(1);
-                tracing_on = 1;
-        } else if (*command & FTRACE_DISABLE_CALLS) {
+        else if (*command & FTRACE_DISABLE_CALLS)
                 ftrace_replace_code(0);
-                tracing_on = 0;
-        }
 
         if (*command & FTRACE_UPDATE_TRACE_FUNC)
                 ftrace_update_ftrace_func(ftrace_trace_function);
@@ -538,8 +527,7 @@ static void ftrace_startup(void)
 
         mutex_lock(&ftrace_start_lock);
         ftrace_start++;
-        if (ftrace_start == 1)
-                command |= FTRACE_ENABLE_CALLS;
+        command |= FTRACE_ENABLE_CALLS;
 
         if (saved_ftrace_func != ftrace_trace_function) {
                 saved_ftrace_func = ftrace_trace_function;
@@ -677,7 +665,7 @@ static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
 
         cnt = num_to_init / ENTRIES_PER_PAGE;
         pr_info("ftrace: allocating %ld entries in %d pages\n",
-                num_to_init, cnt);
+                num_to_init, cnt + 1);
 
         for (i = 0; i < cnt; i++) {
                 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
@@ -738,6 +726,9 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
                     ((iter->flags & FTRACE_ITER_FAILURES) &&
                      !(rec->flags & FTRACE_FL_FAILED)) ||
 
+                    ((iter->flags & FTRACE_ITER_FILTER) &&
+                     !(rec->flags & FTRACE_FL_FILTER)) ||
+
                     ((iter->flags & FTRACE_ITER_NOTRACE) &&
                      !(rec->flags & FTRACE_FL_NOTRACE))) {
                         rec = NULL;
@@ -757,13 +748,11 @@ static void *t_start(struct seq_file *m, loff_t *pos)
         void *p = NULL;
         loff_t l = -1;
 
-        if (*pos != iter->pos) {
-                for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l))
-                        ;
-        } else {
-                l = *pos;
-                p = t_next(m, p, &l);
-        }
+        if (*pos > iter->pos)
+                *pos = iter->pos;
+
+        l = *pos;
+        p = t_next(m, p, &l);
 
         return p;
 }
@@ -774,15 +763,21 @@ static void t_stop(struct seq_file *m, void *p)
 
 static int t_show(struct seq_file *m, void *v)
 {
+        struct ftrace_iterator *iter = m->private;
         struct dyn_ftrace *rec = v;
         char str[KSYM_SYMBOL_LEN];
+        int ret = 0;
 
         if (!rec)
                 return 0;
 
         kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
 
-        seq_printf(m, "%s\n", str);
+        ret = seq_printf(m, "%s\n", str);
+        if (ret < 0) {
+                iter->pos--;
+                iter->idx--;
+        }
 
         return 0;
 }
@@ -808,7 +803,7 @@ ftrace_avail_open(struct inode *inode, struct file *file)
                 return -ENOMEM;
 
         iter->pg = ftrace_pages_start;
-        iter->pos = -1;
+        iter->pos = 0;
 
         ret = seq_open(file, &show_ftrace_seq_ops);
         if (!ret) {
@@ -895,7 +890,7 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
 
         if (file->f_mode & FMODE_READ) {
                 iter->pg = ftrace_pages_start;
-                iter->pos = -1;
+                iter->pos = 0;
                 iter->flags = enable ? FTRACE_ITER_FILTER :
                         FTRACE_ITER_NOTRACE;
 
@@ -1186,7 +1181,7 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
 
         mutex_lock(&ftrace_sysctl_lock);
         mutex_lock(&ftrace_start_lock);
-        if (iter->filtered && ftrace_start && ftrace_enabled)
+        if (ftrace_start && ftrace_enabled)
                 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
         mutex_unlock(&ftrace_start_lock);
         mutex_unlock(&ftrace_sysctl_lock);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 2f76193c3489..668bbb5ef2bd 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -16,14 +16,49 @@
 #include <linux/list.h>
 #include <linux/fs.h>
 
+#include "trace.h"
+
+/* Global flag to disable all recording to ring buffers */
+static int ring_buffers_off __read_mostly;
+
+/**
+ * tracing_on - enable all tracing buffers
+ *
+ * This function enables all tracing buffers that may have been
+ * disabled with tracing_off.
+ */
+void tracing_on(void)
+{
+        ring_buffers_off = 0;
+}
+
+/**
+ * tracing_off - turn off all tracing buffers
+ *
+ * This function stops all tracing buffers from recording data.
+ * It does not disable any overhead the tracers themselves may
+ * be causing. This function simply causes all recording to
+ * the ring buffers to fail.
+ */
+void tracing_off(void)
+{
+        ring_buffers_off = 1;
+}
+
 /* Up this if you want to test the TIME_EXTENTS and normalization */
 #define DEBUG_SHIFT 0
 
 /* FIXME!!! */
 u64 ring_buffer_time_stamp(int cpu)
 {
+        u64 time;
+
+        preempt_disable_notrace();
         /* shift to debug/test normalization and TIME_EXTENTS */
-        return sched_clock() << DEBUG_SHIFT;
+        time = sched_clock() << DEBUG_SHIFT;
+        preempt_enable_notrace();
+
+        return time;
 }
 
 void ring_buffer_normalize_time_stamp(int cpu, u64 *ts)
@@ -503,6 +538,12 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
         LIST_HEAD(pages);
         int i, cpu;
 
+        /*
+         * Always succeed at resizing a non-existent buffer:
+         */
+        if (!buffer)
+                return size;
+
         size = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
         size *= BUF_PAGE_SIZE;
         buffer_size = buffer->pages * BUF_PAGE_SIZE;
@@ -576,6 +617,7 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
                 list_del_init(&page->list);
                 free_buffer_page(page);
         }
+        mutex_unlock(&buffer->mutex);
         return -ENOMEM;
 }
 
@@ -1133,6 +1175,9 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer,
         struct ring_buffer_event *event;
         int cpu, resched;
 
+        if (ring_buffers_off)
+                return NULL;
+
         if (atomic_read(&buffer->record_disabled))
                 return NULL;
 
@@ -1170,7 +1215,7 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer,
 
  out:
         if (resched)
-                preempt_enable_notrace();
+                preempt_enable_no_resched_notrace();
         else
                 preempt_enable_notrace();
         return NULL;
@@ -1249,6 +1294,9 @@ int ring_buffer_write(struct ring_buffer *buffer,
         int ret = -EBUSY;
         int cpu, resched;
 
+        if (ring_buffers_off)
+                return -EBUSY;
+
         if (atomic_read(&buffer->record_disabled))
                 return -EBUSY;
 
@@ -2070,3 +2118,69 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
         return 0;
 }
 
+static ssize_t
+rb_simple_read(struct file *filp, char __user *ubuf,
+               size_t cnt, loff_t *ppos)
+{
+        int *p = filp->private_data;
+        char buf[64];
+        int r;
+
+        /* !ring_buffers_off == tracing_on */
+        r = sprintf(buf, "%d\n", !*p);
+
+        return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t
+rb_simple_write(struct file *filp, const char __user *ubuf,
+                size_t cnt, loff_t *ppos)
+{
+        int *p = filp->private_data;
+        char buf[64];
+        long val;
+        int ret;
+
+        if (cnt >= sizeof(buf))
+                return -EINVAL;
+
+        if (copy_from_user(&buf, ubuf, cnt))
+                return -EFAULT;
+
+        buf[cnt] = 0;
+
+        ret = strict_strtoul(buf, 10, &val);
+        if (ret < 0)
+                return ret;
+
+        /* !ring_buffers_off == tracing_on */
+        *p = !val;
+
+        (*ppos)++;
+
+        return cnt;
+}
+
+static struct file_operations rb_simple_fops = {
+        .open           = tracing_open_generic,
+        .read           = rb_simple_read,
+        .write          = rb_simple_write,
+};
+
+
+static __init int rb_init_debugfs(void)
+{
+        struct dentry *d_tracer;
+        struct dentry *entry;
+
+        d_tracer = tracing_init_dentry();
+
+        entry = debugfs_create_file("tracing_on", 0644, d_tracer,
+                                    &ring_buffers_off, &rb_simple_fops);
+        if (!entry)
+                pr_warning("Could not create debugfs 'tracing_on' entry\n");
+
+        return 0;
+}
+
+fs_initcall(rb_init_debugfs);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ffe7c96fa09b..1ee9e4e454a0 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1936,6 +1936,7 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
                         ring_buffer_read_finish(iter->buffer_iter[cpu]);
         }
         mutex_unlock(&trace_types_lock);
+        kfree(iter);
 
         return ERR_PTR(-ENOMEM);
 }
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index f28484618ff0..e62cbf78eab6 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -18,12 +18,14 @@ struct header_iter {
 
 static struct trace_array *mmio_trace_array;
 static bool overrun_detected;
+static unsigned long prev_overruns;
 
 static void mmio_reset_data(struct trace_array *tr)
 {
         int cpu;
 
         overrun_detected = false;
+        prev_overruns = 0;
         tr->time_start = ftrace_now(tr->cpu);
 
         for_each_online_cpu(cpu)
@@ -128,16 +130,12 @@ static void mmio_close(struct trace_iterator *iter)
 
 static unsigned long count_overruns(struct trace_iterator *iter)
 {
-        int cpu;
         unsigned long cnt = 0;
-/* FIXME: */
-#if 0
-        for_each_online_cpu(cpu) {
-                cnt += iter->overrun[cpu];
-                iter->overrun[cpu] = 0;
-        }
-#endif
-        (void)cpu;
+        unsigned long over = ring_buffer_overruns(iter->tr->buffer);
+
+        if (over > prev_overruns)
+                cnt = over - prev_overruns;
+        prev_overruns = over;
         return cnt;
 }
 
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index be682b62fe58..3bdb44bde4b7 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -184,11 +184,16 @@ static struct file_operations stack_max_size_fops = {
 static void *
 t_next(struct seq_file *m, void *v, loff_t *pos)
 {
-        long i = (long)m->private;
+        long i;
 
         (*pos)++;
 
-        i++;
+        if (v == SEQ_START_TOKEN)
+                i = 0;
+        else {
+                i = *(long *)v;
+                i++;
+        }
 
         if (i >= max_stack_trace.nr_entries ||
             stack_dump_trace[i] == ULONG_MAX)
@@ -201,12 +206,15 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
 
 static void *t_start(struct seq_file *m, loff_t *pos)
 {
-        void *t = &m->private;
+        void *t = SEQ_START_TOKEN;
         loff_t l = 0;
 
         local_irq_disable();
         __raw_spin_lock(&max_stack_lock);
 
+        if (*pos == 0)
+                return SEQ_START_TOKEN;
+
         for (; t && l < *pos; t = t_next(m, t, &l))
                 ;
 
@@ -235,10 +243,10 @@ static int trace_lookup_stack(struct seq_file *m, long i)
 
 static int t_show(struct seq_file *m, void *v)
 {
-        long i = *(long *)v;
+        long i;
         int size;
 
-        if (i < 0) {
+        if (v == SEQ_START_TOKEN) {
                 seq_printf(m, "        Depth   Size      Location"
                            "    (%d entries)\n"
                            "        -----   ----      --------\n",
@@ -246,6 +254,8 @@ static int t_show(struct seq_file *m, void *v)
                 return 0;
         }
 
+        i = *(long *)v;
+
         if (i >= max_stack_trace.nr_entries ||
             stack_dump_trace[i] == ULONG_MAX)
                 return 0;
@@ -275,10 +285,6 @@ static int stack_trace_open(struct inode *inode, struct file *file)
         int ret;
 
         ret = seq_open(file, &stack_trace_seq_ops);
-        if (!ret) {
-                struct seq_file *m = file->private_data;
-                m->private = (void *)-1;
-        }
 
         return ret;
 }