Merge branch 'for-rmk/broadcast' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into devel-stable

1 files changed, 12 insertions, 1 deletions

diff --git a/kernel/smp.c b/kernel/smp.c
index 29dd40a9f2f4..69f38bd98b42 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -33,6 +33,7 @@ struct call_function_data {
         struct call_single_data csd;
         atomic_t                refs;
         cpumask_var_t           cpumask;
+        cpumask_var_t           cpumask_ipi;
 };
 
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_function_data, cfd_data);
@@ -56,6 +57,9 @@ hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
                 if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
                                 cpu_to_node(cpu)))
                         return notifier_from_errno(-ENOMEM);
+                if (!zalloc_cpumask_var_node(&cfd->cpumask_ipi, GFP_KERNEL,
+                                cpu_to_node(cpu)))
+                        return notifier_from_errno(-ENOMEM);
                 break;
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -65,6 +69,7 @@ hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
         case CPU_DEAD:
         case CPU_DEAD_FROZEN:
                 free_cpumask_var(cfd->cpumask);
+                free_cpumask_var(cfd->cpumask_ipi);
                 break;
 #endif
         };
@@ -526,6 +531,12 @@ void smp_call_function_many(const struct cpumask *mask,
                 return;
         }
 
+        /*
+         * After we put an entry into the list, data->cpumask
+         * may be cleared again when another CPU sends another IPI for
+         * a SMP function call, so data->cpumask will be zero.
+         */
+        cpumask_copy(data->cpumask_ipi, data->cpumask);
         raw_spin_lock_irqsave(&call_function.lock, flags);
         /*
          * Place entry at the _HEAD_ of the list, so that any cpu still
@@ -549,7 +560,7 @@ void smp_call_function_many(const struct cpumask *mask,
         smp_mb();
 
         /* Send a message to all CPUs in the map */
-        arch_send_call_function_ipi_mask(data->cpumask);
+        arch_send_call_function_ipi_mask(data->cpumask_ipi);
 
         /* Optionally wait for the CPUs to complete */
         if (wait)