打印栈深度

#define read_esp() ({ \

         unsigned int __dummy; \

         __asm__( \

                 "movl %%esp,%0\n\t" \

                 :"=r" (__dummy)); \

         __dummy; \

 })

 

 

current stack size:

(__u32)current_thread_info() + 0x2000 - read_esp()