2 files changed, 26 insertions, 8 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6afa72e080cb..6674fc1e51bf 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1558,6 +1558,14 @@ static inline void freeze(struct task_struct *p)
 }
 
 /*
+ * Sometimes we may need to cancel the previous 'freeze' request
+ */
+static inline void do_not_freeze(struct task_struct *p)
+{
+        p->flags &= ~PF_FREEZE;
+}
+
+/*
  * Wake up a frozen process
  */
 static inline int thaw_process(struct task_struct *p)
diff --git a/kernel/power/process.c b/kernel/power/process.c
index b2a5f671d6cd..72e72d2c61e6 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -66,13 +66,25 @@ static inline void freeze_process(struct task_struct *p)
         }
 }
 
+static void cancel_freezing(struct task_struct *p)
+{
+        unsigned long flags;
+
+        if (freezing(p)) {
+                pr_debug("  clean up: %s\n", p->comm);
+                do_not_freeze(p);
+                spin_lock_irqsave(&p->sighand->siglock, flags);
+                recalc_sigpending_tsk(p);
+                spin_unlock_irqrestore(&p->sighand->siglock, flags);
+        }
+}
+
 /* 0 = success, else # of processes that we failed to stop */
 int freeze_processes(void)
 {
         int todo, nr_user, user_frozen;
         unsigned long start_time;
         struct task_struct *g, *p;
-        unsigned long flags;
 
         printk( "Stopping tasks: " );
         start_time = jiffies;
@@ -85,6 +97,10 @@ int freeze_processes(void)
                                 continue;
                         if (frozen(p))
                                 continue;
+                        if (p->state == TASK_TRACED && frozen(p->parent)) {
+                                cancel_freezing(p);
+                                continue;
+                        }
                         if (p->mm && !(p->flags & PF_BORROWED_MM)) {
                                 /* The task is a user-space one.
                                  * Freeze it unless there's a vfork completion
@@ -126,13 +142,7 @@ int freeze_processes(void)
                 do_each_thread(g, p) {
                         if (freezeable(p) && !frozen(p))
                                 printk(KERN_ERR "  %s\n", p->comm);
-                        if (freezing(p)) {
-                                pr_debug("  clean up: %s\n", p->comm);
-                                p->flags &= ~PF_FREEZE;
-                                spin_lock_irqsave(&p->sighand->siglock, flags);
-                                recalc_sigpending_tsk(p);
-                                spin_unlock_irqrestore(&p->sighand->siglock, flags);
-                        }
+                        cancel_freezing(p);
                 } while_each_thread(g, p);
                 read_unlock(&tasklist_lock);
                 return todo;