sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK

[cascardo/linux.git] / include / linux / sched.h

diff --git a/include/linux/sched.h b/include/linux/sched.h
index a958672..abb795a 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1936,6 +1936,10 @@ struct task_struct {
 #ifdef CONFIG_VMAP_STACK
        struct vm_struct *stack_vm_area;
 #endif
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+       /* A live task holds one reference. */
+       atomic_t stack_refcount;
+#endif
 /* CPU-specific state of this task */
        struct thread_struct thread;
 /*
@@ -3143,12 +3147,22 @@ static inline unsigned long *end_of_stack(struct task_struct *p)
 
 #endif
 
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+static inline void *try_get_task_stack(struct task_struct *tsk)
+{
+       return atomic_inc_not_zero(&tsk->stack_refcount) ?
+               task_stack_page(tsk) : NULL;
+}
+
+extern void put_task_stack(struct task_struct *tsk);
+#else
 static inline void *try_get_task_stack(struct task_struct *tsk)
 {
        return task_stack_page(tsk);
 }
 
 static inline void put_task_stack(struct task_struct *tsk) {}
+#endif
 
 #define task_stack_end_corrupted(task) \
                (*(end_of_stack(task)) != STACK_END_MAGIC)