CPU: Avoid using unititialized error variable in disable_nonboot_cpus()

[pandora-kernel.git] / kernel / cpu.c

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 124ad9d..8b92539 100644 (file)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -20,6 +20,20 @@
 /* Serializes the updates to cpu_online_mask, cpu_present_mask */
 static DEFINE_MUTEX(cpu_add_remove_lock);
 
+/*
+ * The following two API's must be used when attempting
+ * to serialize the updates to cpu_online_mask, cpu_present_mask.
+ */
+void cpu_maps_update_begin(void)
+{
+       mutex_lock(&cpu_add_remove_lock);
+}
+
+void cpu_maps_update_done(void)
+{
+       mutex_unlock(&cpu_add_remove_lock);
+}
+
 static __cpuinitdata RAW_NOTIFIER_HEAD(cpu_chain);
 
 /* If set, cpu_up and cpu_down will return -EBUSY and do nothing.
@@ -27,6 +41,8 @@ static __cpuinitdata RAW_NOTIFIER_HEAD(cpu_chain);
  */
 static int cpu_hotplug_disabled;
 
+#ifdef CONFIG_HOTPLUG_CPU
+
 static struct {
        struct task_struct *active_writer;
        struct mutex lock; /* Synchronizes accesses to refcount, */
@@ -41,8 +57,6 @@ static struct {
        .refcount = 0,
 };
 
-#ifdef CONFIG_HOTPLUG_CPU
-
 void get_online_cpus(void)
 {
        might_sleep();
@@ -67,22 +81,6 @@ void put_online_cpus(void)
 }
 EXPORT_SYMBOL_GPL(put_online_cpus);
 
-#endif /* CONFIG_HOTPLUG_CPU */
-
-/*
- * The following two API's must be used when attempting
- * to serialize the updates to cpu_online_mask, cpu_present_mask.
- */
-void cpu_maps_update_begin(void)
-{
-       mutex_lock(&cpu_add_remove_lock);
-}
-
-void cpu_maps_update_done(void)
-{
-       mutex_unlock(&cpu_add_remove_lock);
-}
-
 /*
  * This ensures that the hotplug operation can begin only when the
  * refcount goes to zero.
@@ -124,6 +122,12 @@ static void cpu_hotplug_done(void)
        cpu_hotplug.active_writer = NULL;
        mutex_unlock(&cpu_hotplug.lock);
 }
+
+#else /* #if CONFIG_HOTPLUG_CPU */
+static void cpu_hotplug_begin(void) {}
+static void cpu_hotplug_done(void) {}
+#endif /* #esle #if CONFIG_HOTPLUG_CPU */
+
 /* Need to know about CPUs going up/down? */
 int __ref register_cpu_notifier(struct notifier_block *nb)
 {
@@ -134,8 +138,29 @@ int __ref register_cpu_notifier(struct notifier_block *nb)
        return ret;
 }
 
+static int __cpu_notify(unsigned long val, void *v, int nr_to_call,
+                       int *nr_calls)
+{
+       int ret;
+
+       ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call,
+                                       nr_calls);
+
+       return notifier_to_errno(ret);
+}
+
+static int cpu_notify(unsigned long val, void *v)
+{
+       return __cpu_notify(val, v, -1, NULL);
+}
+
 #ifdef CONFIG_HOTPLUG_CPU
 
+static void cpu_notify_nofail(unsigned long val, void *v)
+{
+       BUG_ON(cpu_notify(val, v));
+}
+
 EXPORT_SYMBOL(register_cpu_notifier);
 
 void __ref unregister_cpu_notifier(struct notifier_block *nb)
@@ -181,8 +206,7 @@ static int __ref take_cpu_down(void *_param)
        if (err < 0)
                return err;
 
-       raw_notifier_call_chain(&cpu_chain, CPU_DYING | param->mod,
-                               param->hcpu);
+       cpu_notify(CPU_DYING | param->mod, param->hcpu);
 
        if (task_cpu(param->caller) == cpu)
                move_task_off_dead_cpu(cpu, param->caller);
@@ -212,17 +236,14 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
 
        cpu_hotplug_begin();
        set_cpu_active(cpu, false);
-       err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
-                                       hcpu, -1, &nr_calls);
-       if (err == NOTIFY_BAD) {
+       err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
+       if (err) {
                set_cpu_active(cpu, true);
 
                nr_calls--;
-               __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
-                                         hcpu, nr_calls, NULL);
+               __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL);
                printk("%s: attempt to take down CPU %u failed\n",
                                __func__, cpu);
-               err = -EINVAL;
                goto out_release;
        }
 
@@ -230,9 +251,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
        if (err) {
                set_cpu_active(cpu, true);
                /* CPU didn't die: tell everyone.  Can't complain. */
-               if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
-                                           hcpu) == NOTIFY_BAD)
-                       BUG();
+               cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
 
                goto out_release;
        }
@@ -246,19 +265,14 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
        __cpu_die(cpu);
 
        /* CPU is completely dead: tell everyone.  Too late to complain. */
-       if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD | mod,
-                                   hcpu) == NOTIFY_BAD)
-               BUG();
+       cpu_notify_nofail(CPU_DEAD | mod, hcpu);
 
        check_for_tasks(cpu);
 
 out_release:
        cpu_hotplug_done();
-       if (!err) {
-               if (raw_notifier_call_chain(&cpu_chain, CPU_POST_DEAD | mod,
-                                           hcpu) == NOTIFY_BAD)
-                       BUG();
-       }
+       if (!err)
+               cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
        return err;
 }
 
@@ -293,13 +307,11 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
                return -EINVAL;
 
        cpu_hotplug_begin();
-       ret = __raw_notifier_call_chain(&cpu_chain, CPU_UP_PREPARE | mod, hcpu,
-                                                       -1, &nr_calls);
-       if (ret == NOTIFY_BAD) {
+       ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
+       if (ret) {
                nr_calls--;
                printk("%s: attempt to bring up CPU %u failed\n",
                                __func__, cpu);
-               ret = -EINVAL;
                goto out_notify;
        }
 
@@ -312,12 +324,11 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
        set_cpu_active(cpu, true);
 
        /* Now call notifier in preparation. */
-       raw_notifier_call_chain(&cpu_chain, CPU_ONLINE | mod, hcpu);
+       cpu_notify(CPU_ONLINE | mod, hcpu);
 
 out_notify:
        if (ret != 0)
-               __raw_notifier_call_chain(&cpu_chain,
-                               CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
+               __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
        cpu_hotplug_done();
 
        return ret;
@@ -383,7 +394,7 @@ static cpumask_var_t frozen_cpus;
 
 int disable_nonboot_cpus(void)
 {
-       int cpu, first_cpu, error;
+       int cpu, first_cpu, error = 0;
 
        cpu_maps_update_begin();
        first_cpu = cpumask_first(cpu_online_mask);
@@ -481,7 +492,7 @@ void __cpuinit notify_cpu_starting(unsigned int cpu)
        if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus))
                val = CPU_STARTING_FROZEN;
 #endif /* CONFIG_PM_SLEEP_SMP */
-       raw_notifier_call_chain(&cpu_chain, val, (void *)(long)cpu);
+       cpu_notify(val, (void *)(long)cpu);
 }
 
 #endif /* CONFIG_SMP */