4 files changed, 138 insertions, 58 deletions

diff --git a/kernel/params.c b/kernel/params.c
index 08107d181758..0da1411222b9 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -719,9 +719,7 @@ void destroy_params(const struct kernel_param *params, unsigned num)
                         params[i].ops->free(params[i].arg);
 }
 
-static void __init kernel_add_sysfs_param(const char *name,
-                                          struct kernel_param *kparam,
-                                          unsigned int name_skip)
+static struct module_kobject * __init locate_module_kobject(const char *name)
 {
         struct module_kobject *mk;
         struct kobject *kobj;
@@ -729,10 +727,7 @@ static void __init kernel_add_sysfs_param(const char *name,
 
         kobj = kset_find_obj(module_kset, name);
         if (kobj) {
-                /* We already have one.  Remove params so we can add more. */
                 mk = to_module_kobject(kobj);
-                /* We need to remove it before adding parameters. */
-                sysfs_remove_group(&mk->kobj, &mk->mp->grp);
         } else {
                 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
                 BUG_ON(!mk);
@@ -743,15 +738,36 @@ static void __init kernel_add_sysfs_param(const char *name,
                                            "%s", name);
                 if (err) {
                         kobject_put(&mk->kobj);
-                        printk(KERN_ERR "Module '%s' failed add to sysfs, "
-                               "error number %d\n", name, err);
-                        printk(KERN_ERR "The system will be unstable now.\n");
-                        return;
+                        printk(KERN_ERR
+                                "Module '%s' failed add to sysfs, error number %d\n",
+                                name, err);
+                        printk(KERN_ERR
+                                "The system will be unstable now.\n");
+                        return NULL;
                 }
-                /* So that exit path is even. */
+
+                /* So that we hold reference in both cases. */
                 kobject_get(&mk->kobj);
         }
 
+        return mk;
+}
+
+static void __init kernel_add_sysfs_param(const char *name,
+                                          struct kernel_param *kparam,
+                                          unsigned int name_skip)
+{
+        struct module_kobject *mk;
+        int err;
+
+        mk = locate_module_kobject(name);
+        if (!mk)
+                return;
+
+        /* We need to remove old parameters before adding more. */
+        if (mk->mp)
+                sysfs_remove_group(&mk->kobj, &mk->mp->grp);
+
         /* These should not fail at boot. */
         err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
         BUG_ON(err);
@@ -796,6 +812,32 @@ static void __init param_sysfs_builtin(void)
         }
 }
 
+ssize_t __modver_version_show(struct module_attribute *mattr,
+                              struct module *mod, char *buf)
+{
+        struct module_version_attribute *vattr =
+                container_of(mattr, struct module_version_attribute, mattr);
+
+        return sprintf(buf, "%s\n", vattr->version);
+}
+
+extern struct module_version_attribute __start___modver[], __stop___modver[];
+
+static void __init version_sysfs_builtin(void)
+{
+        const struct module_version_attribute *vattr;
+        struct module_kobject *mk;
+        int err;
+
+        for (vattr = __start___modver; vattr < __stop___modver; vattr++) {
+                mk = locate_module_kobject(vattr->module_name);
+                if (mk) {
+                        err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
+                        kobject_uevent(&mk->kobj, KOBJ_ADD);
+                        kobject_put(&mk->kobj);
+                }
+        }
+}
 
 /* module-related sysfs stuff */
 
@@ -875,6 +917,7 @@ static int __init param_sysfs_init(void)
         }
         module_sysfs_initialized = 1;
 
+        version_sysfs_builtin();
         param_sysfs_builtin();
 
         return 0;
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 84522c796987..126a302c481c 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2201,13 +2201,6 @@ find_lively_task_by_vpid(pid_t vpid)
         if (!task)
                 return ERR_PTR(-ESRCH);
 
-        /*
-         * Can't attach events to a dying task.
-         */
-        err = -ESRCH;
-        if (task->flags & PF_EXITING)
-                goto errout;
-
         /* Reuse ptrace permission checks for now. */
         err = -EACCES;
         if (!ptrace_may_access(task, PTRACE_MODE_READ))
@@ -2268,14 +2261,27 @@ retry:
 
                 get_ctx(ctx);
 
-                if (cmpxchg(&task->perf_event_ctxp[ctxn], NULL, ctx)) {
-                        /*
-                         * We raced with some other task; use
-                         * the context they set.
-                         */
+                err = 0;
+                mutex_lock(&task->perf_event_mutex);
+                /*
+                 * If it has already passed perf_event_exit_task().
+                 * we must see PF_EXITING, it takes this mutex too.
+                 */
+                if (task->flags & PF_EXITING)
+                        err = -ESRCH;
+                else if (task->perf_event_ctxp[ctxn])
+                        err = -EAGAIN;
+                else
+                        rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx);
+                mutex_unlock(&task->perf_event_mutex);
+
+                if (unlikely(err)) {
                         put_task_struct(task);
                         kfree(ctx);
-                        goto retry;
+
+                        if (err == -EAGAIN)
+                                goto retry;
+                        goto errout;
                 }
         }
 
@@ -5374,6 +5380,8 @@ free_dev:
         goto out;
 }
 
+static struct lock_class_key cpuctx_mutex;
+
 int perf_pmu_register(struct pmu *pmu, char *name, int type)
 {
         int cpu, ret;
@@ -5422,6 +5430,7 @@ skip_type:
 
                 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
                 __perf_event_init_context(&cpuctx->ctx);
+                lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
                 cpuctx->ctx.type = cpu_context;
                 cpuctx->ctx.pmu = pmu;
                 cpuctx->jiffies_interval = 1;
@@ -6127,7 +6136,7 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
          * scheduled, so we are now safe from rescheduling changing
          * our context.
          */
-        child_ctx = child->perf_event_ctxp[ctxn];
+        child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]);
         task_ctx_sched_out(child_ctx, EVENT_ALL);
 
         /*
@@ -6440,11 +6449,6 @@ int perf_event_init_context(struct task_struct *child, int ctxn)
         unsigned long flags;
         int ret = 0;
 
-        child->perf_event_ctxp[ctxn] = NULL;
-
-        mutex_init(&child->perf_event_mutex);
-        INIT_LIST_HEAD(&child->perf_event_list);
-
         if (likely(!parent->perf_event_ctxp[ctxn]))
                 return 0;
 
@@ -6533,6 +6537,10 @@ int perf_event_init_task(struct task_struct *child)
 {
         int ctxn, ret;
 
+        memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp));
+        mutex_init(&child->perf_event_mutex);
+        INIT_LIST_HEAD(&child->perf_event_list);
+
         for_each_task_context_nr(ctxn) {
                 ret = perf_event_init_context(child, ctxn);
                 if (ret)
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 77e9166d7bbf..354769979c02 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -699,7 +699,8 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
         cfs_rq->nr_running--;
 }
 
-#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
+#ifdef CONFIG_FAIR_GROUP_SCHED
+# ifdef CONFIG_SMP
 static void update_cfs_rq_load_contribution(struct cfs_rq *cfs_rq,
                                             int global_update)
 {
@@ -762,6 +763,51 @@ static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
                 list_del_leaf_cfs_rq(cfs_rq);
 }
 
+static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg,
+                                long weight_delta)
+{
+        long load_weight, load, shares;
+
+        load = cfs_rq->load.weight + weight_delta;
+
+        load_weight = atomic_read(&tg->load_weight);
+        load_weight -= cfs_rq->load_contribution;
+        load_weight += load;
+
+        shares = (tg->shares * load);
+        if (load_weight)
+                shares /= load_weight;
+
+        if (shares < MIN_SHARES)
+                shares = MIN_SHARES;
+        if (shares > tg->shares)
+                shares = tg->shares;
+
+        return shares;
+}
+
+static void update_entity_shares_tick(struct cfs_rq *cfs_rq)
+{
+        if (cfs_rq->load_unacc_exec_time > sysctl_sched_shares_window) {
+                update_cfs_load(cfs_rq, 0);
+                update_cfs_shares(cfs_rq, 0);
+        }
+}
+# else /* CONFIG_SMP */
+static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
+{
+}
+
+static inline long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg,
+                                long weight_delta)
+{
+        return tg->shares;
+}
+
+static inline void update_entity_shares_tick(struct cfs_rq *cfs_rq)
+{
+}
+# endif /* CONFIG_SMP */
 static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
                             unsigned long weight)
 {
@@ -782,7 +828,7 @@ static void update_cfs_shares(struct cfs_rq *cfs_rq, long weight_delta)
 {
         struct task_group *tg;
         struct sched_entity *se;
-        long load_weight, load, shares;
+        long shares;
 
         if (!cfs_rq)
                 return;
@@ -791,32 +837,14 @@ static void update_cfs_shares(struct cfs_rq *cfs_rq, long weight_delta)
         se = tg->se[cpu_of(rq_of(cfs_rq))];
         if (!se)
                 return;
-
-        load = cfs_rq->load.weight + weight_delta;
-
-        load_weight = atomic_read(&tg->load_weight);
-        load_weight -= cfs_rq->load_contribution;
-        load_weight += load;
-
-        shares = (tg->shares * load);
-        if (load_weight)
-                shares /= load_weight;
-
-        if (shares < MIN_SHARES)
-                shares = MIN_SHARES;
-        if (shares > tg->shares)
-                shares = tg->shares;
+#ifndef CONFIG_SMP
+        if (likely(se->load.weight == tg->shares))
+                return;
+#endif
+        shares = calc_cfs_shares(cfs_rq, tg, weight_delta);
 
         reweight_entity(cfs_rq_of(se), se, shares);
 }
-
-static void update_entity_shares_tick(struct cfs_rq *cfs_rq)
-{
-        if (cfs_rq->load_unacc_exec_time > sysctl_sched_shares_window) {
-                update_cfs_load(cfs_rq, 0);
-                update_cfs_shares(cfs_rq, 0);
-        }
-}
 #else /* CONFIG_FAIR_GROUP_SCHED */
 static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
 {
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 3e216e01bbd1..c55ea2433471 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -642,8 +642,7 @@ static void tick_nohz_switch_to_nohz(void)
         }
         local_irq_enable();
 
-        printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n",
-               smp_processor_id());
+        printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n", smp_processor_id());
 }
 
 /*
@@ -795,8 +794,10 @@ void tick_setup_sched_timer(void)
         }
 
 #ifdef CONFIG_NO_HZ
-        if (tick_nohz_enabled)
+        if (tick_nohz_enabled) {
                 ts->nohz_mode = NOHZ_MODE_HIGHRES;
+                printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n", smp_processor_id());
+        }
 #endif
 }
 #endif /* HIGH_RES_TIMERS */