Merge branch 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  generic-ipi: fix stack and rcu interaction bug in smp_call_function_mask(), fix

1 files changed, 6 insertions, 4 deletions

diff --git a/kernel/smp.c b/kernel/smp.c
index e6084f6efb4d..782e2b93e465 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -135,7 +135,8 @@ void generic_smp_call_function_interrupt(void)
                          */
                         smp_wmb();
                         data->csd.flags &= ~CSD_FLAG_WAIT;
-                } else
+                }
+                if (data->csd.flags & CSD_FLAG_ALLOC)
                         call_rcu(&data->rcu_head, rcu_free_call_data);
         }
         rcu_read_unlock();
@@ -289,10 +290,11 @@ static void smp_call_function_mask_quiesce_stack(cpumask_t mask)
 
         data.func = quiesce_dummy;
         data.info = NULL;
-        data.flags = CSD_FLAG_WAIT;
 
-        for_each_cpu_mask(cpu, mask)
+        for_each_cpu_mask(cpu, mask) {
+                data.flags = CSD_FLAG_WAIT;
                 generic_exec_single(cpu, &data);
+        }
 }
 
 /**
@@ -371,7 +373,7 @@ int smp_call_function_mask(cpumask_t mask, void (*func)(void *), void *info,
         if (wait) {
                 csd_flag_wait(&data->csd);
                 if (unlikely(slowpath))
-                        smp_call_function_mask_quiesce_stack(allbutself);
+                        smp_call_function_mask_quiesce_stack(mask);
         }
 
         return 0;