+static inline int is_kernel_stack(struct task_struct *task,
+ struct reg_window *rw)
+{
+ unsigned long rw_addr = (unsigned long) rw;
+ unsigned long thread_base, thread_end;
+
+ if (rw_addr < PAGE_OFFSET) {
+ if (task != &init_task)
+ return 0;
+ }
+
+ thread_base = (unsigned long) task->thread_info;
+ thread_end = thread_base + sizeof(union thread_union);
+ if (rw_addr >= thread_base &&
+ rw_addr < thread_end &&
+ !(rw_addr & 0x7UL))
+ return 1;
+
+ return 0;
+}
+
+static inline struct reg_window *kernel_stack_up(struct reg_window *rw)
+{
+ unsigned long fp = rw->ins[6];
+
+ if (!fp)
+ return NULL;
+
+ return (struct reg_window *) (fp + STACK_BIAS);
+}
+