1 files changed, 39 insertions, 1 deletions

diff --git a/kernel/power/process.c b/kernel/power/process.c
index 7b323221b9ee..5cc588c1abab 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -108,6 +108,28 @@ static int try_to_freeze_tasks(bool user_only)
         return todo ? -EBUSY : 0;
 }
 
+/*
+ * Returns true if all freezable tasks (except for current) are frozen already
+ */
+static bool check_frozen_processes(void)
+{
+        struct task_struct *g, *p;
+        bool ret = true;
+
+        read_lock(&tasklist_lock);
+        for_each_process_thread(g, p) {
+                if (p != current && !freezer_should_skip(p) &&
+                    !frozen(p)) {
+                        ret = false;
+                        goto done;
+                }
+        }
+done:
+        read_unlock(&tasklist_lock);
+
+        return ret;
+}
+
 /**
  * freeze_processes - Signal user space processes to enter the refrigerator.
  * The current thread will not be frozen.  The same process that calls
@@ -118,6 +140,7 @@ static int try_to_freeze_tasks(bool user_only)
 int freeze_processes(void)
 {
         int error;
+        int oom_kills_saved;
 
         error = __usermodehelper_disable(UMH_FREEZING);
         if (error)
@@ -132,12 +155,27 @@ int freeze_processes(void)
         pm_wakeup_clear();
         printk("Freezing user space processes ... ");
         pm_freezing = true;
+        oom_kills_saved = oom_kills_count();
         error = try_to_freeze_tasks(true);
         if (!error) {
-                printk("done.");
                 __usermodehelper_set_disable_depth(UMH_DISABLED);
                 oom_killer_disable();
+
+                /*
+                 * There might have been an OOM kill while we were
+                 * freezing tasks and the killed task might be still
+                 * on the way out so we have to double check for race.
+                 */
+                if (oom_kills_count() != oom_kills_saved &&
+                                !check_frozen_processes()) {
+                        __usermodehelper_set_disable_depth(UMH_ENABLED);
+                        printk("OOM in progress.");
+                        error = -EBUSY;
+                        goto done;
+                }
+                printk("done.");
         }
+done:
         printk("\n");
         BUG_ON(in_atomic());