Utcb in syscall

Adam Lackorzynski adam at os.inf.tu-dresden.de
Sun May 17 22:44:12 CEST 2015


On Tue May 12, 2015 at 11:01:13 +0800, watermirror wrote:
> hi ,in sys_ipc_wrapper, the code first get the current thread's syscall entry frame:
> ....
> Thread *curr=current_thread();
> Syscall_frame *f = curr-regs();
> ...
> 
> 
> according to the Syscall_frame's implemention, it can get the Utcb by Syscall_frame::utcb().
> 
> 
> but the following code get the Utcb in another way:
> 
> 
> Utcb *utcb = curr->utcb().access(true);
> 
> 
> what's the difference between those two Utcb?

Specifying the utcb via the syscall is not used currently, there's just
one.



Adam
-- 
Adam                 adam at os.inf.tu-dresden.de
  Lackorzynski         http://os.inf.tu-dresden.de/~adam/



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