FreeBSD Memory Management questions ?

[John-Mark Gurney]

Aziz Kezzou wrote this message on Tue, Jun 14, 2005 at 04:21 -0400:
> I have two questions concerning FreeBSD Memory management :
> 
> 1 - Right now to access the memory address space of a user process
> from kernel mode, I only have to set, on x86 systems, the register CR3
> to the right value.  How can I do that on other architectures ? is
> there an architecture-independant way of doing that ?
> 
> 2- I have noticed that while in kernel mode the value of CR3 is equal
> to that of the user process beeing interrupted. Doesn't the kernel
> supposed to have its "own" page-directory, i.e it's own CR3  value ?
> or is kernel virtual address resolution does  not go through CR3 at
> all ?

You should be using copyin(9)/copyout(9) instead of playing around with
CR3 directly...  or fuword(9)/suword(9)...  This provides a platform
independant way of accessing user's memory (for the current running
process)...

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."