On Tue, Jun 16, 2015 at 4:27 AM, hitmoon <zhaoxiaoqiang007@xxxxxxxxx> wrote: > Hi: > I recently read the book "understanding the linux kernel 3rd", in the > task switch process, there are two esp in thread_struct. In macro > 'switch_to' , The esp is loaded to switch to the next's kernel stack, but > in '__switch_to', esp0 is copied to tss's esp0 field, what the esp0 mean? > What the difference between them? esp0 is the stack pointer that is loaded into esp when the privileged level changes to 0. For example, when a process running in user mode (level 3) jumps into the kernel via a system call. You can read more about it in the Intel SDM, Volume 3 Chapter 7. http://www.intel.com/content/www/us/en/processors/architectures-software-developer-manuals.html _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
