serial: fix NULL pointer dereference

[safe/jmp/linux-2.6] / include / linux / freezer.h

diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index c8e02de..5a361f8 100644 (file)
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -4,8 +4,9 @@
 #define FREEZER_H_INCLUDED
 
 #include <linux/sched.h>
+#include <linux/wait.h>
 
-#ifdef CONFIG_PM
+#ifdef CONFIG_FREEZER
 /*
  * Check if a process has been frozen
  */
@@ -38,29 +39,14 @@ static inline void clear_freeze_flag(struct task_struct *p)
        clear_tsk_thread_flag(p, TIF_FREEZE);
 }
 
-/*
- * Wake up a frozen process
- *
- * task_lock() is taken to prevent the race with refrigerator() which may
- * occur if the freezing of tasks fails.  Namely, without the lock, if the
- * freezing of tasks failed, thaw_tasks() might have run before a task in
- * refrigerator() could call frozen_process(), in which case the task would be
- * frozen and no one would thaw it.
- */
-static inline int thaw_process(struct task_struct *p)
+static inline bool should_send_signal(struct task_struct *p)
 {
-       task_lock(p);
-       if (frozen(p)) {
-               p->flags &= ~PF_FROZEN;
-               task_unlock(p);
-               wake_up_process(p);
-               return 1;
-       }
-       clear_freeze_flag(p);
-       task_unlock(p);
-       return 0;
+       return !(p->flags & PF_FREEZER_NOSIG);
 }
 
+/* Takes and releases task alloc lock using task_lock() */
+extern int thaw_process(struct task_struct *p);
+
 extern void refrigerator(void);
 extern int freeze_processes(void);
 extern void thaw_processes(void);
@@ -74,6 +60,15 @@ static inline int try_to_freeze(void)
                return 0;
 }
 
+extern bool freeze_task(struct task_struct *p, bool sig_only);
+extern void cancel_freezing(struct task_struct *p);
+
+#ifdef CONFIG_CGROUP_FREEZER
+extern int cgroup_frozen(struct task_struct *task);
+#else /* !CONFIG_CGROUP_FREEZER */
+static inline int cgroup_frozen(struct task_struct *task) { return 0; }
+#endif /* !CONFIG_CGROUP_FREEZER */
+
 /*
  * The PF_FREEZER_SKIP flag should be set by a vfork parent right before it
  * calls wait_for_completion(&vfork) and reset right after it returns from this
@@ -126,7 +121,46 @@ static inline void set_freezable(void)
        current->flags &= ~PF_NOFREEZE;
 }
 
-#else
+/*
+ * Tell the freezer that the current task should be frozen by it and that it
+ * should send a fake signal to the task to freeze it.
+ */
+static inline void set_freezable_with_signal(void)
+{
+       current->flags &= ~(PF_NOFREEZE | PF_FREEZER_NOSIG);
+}
+
+/*
+ * Freezer-friendly wrappers around wait_event_interruptible() and
+ * wait_event_interruptible_timeout(), originally defined in <linux/wait.h>
+ */
+
+#define wait_event_freezable(wq, condition)                            \
+({                                                                     \
+       int __retval;                                                   \
+       do {                                                            \
+               __retval = wait_event_interruptible(wq,                 \
+                               (condition) || freezing(current));      \
+               if (__retval && !freezing(current))                     \
+                       break;                                          \
+               else if (!(condition))                                  \
+                       __retval = -ERESTARTSYS;                        \
+       } while (try_to_freeze());                                      \
+       __retval;                                                       \
+})
+
+
+#define wait_event_freezable_timeout(wq, condition, timeout)           \
+({                                                                     \
+       long __retval = timeout;                                        \
+       do {                                                            \
+               __retval = wait_event_interruptible_timeout(wq,         \
+                               (condition) || freezing(current),       \
+                               __retval);                              \
+       } while (try_to_freeze());                                      \
+       __retval;                                                       \
+})
+#else /* !CONFIG_FREEZER */
 static inline int frozen(struct task_struct *p) { return 0; }
 static inline int freezing(struct task_struct *p) { return 0; }
 static inline void set_freeze_flag(struct task_struct *p) {}
@@ -143,6 +177,14 @@ static inline void freezer_do_not_count(void) {}
 static inline void freezer_count(void) {}
 static inline int freezer_should_skip(struct task_struct *p) { return 0; }
 static inline void set_freezable(void) {}
-#endif
+static inline void set_freezable_with_signal(void) {}
+
+#define wait_event_freezable(wq, condition)                            \
+               wait_event_interruptible(wq, condition)
+
+#define wait_event_freezable_timeout(wq, condition, timeout)           \
+               wait_event_interruptible_timeout(wq, condition, timeout)
+
+#endif /* !CONFIG_FREEZER */
 
 #endif /* FREEZER_H_INCLUDED */