Fwd: p4-projects Digest, Vol 209, Issue 11

[Oleksandr Tymoshenko]

Neelkanth Natu wrote:
> Hi Oleksandr,
> 
> When do you see this Address Error exception?
> 
> I would not expect this to happen as a result of a fork() called from userland because the status
> register you restore will have the EXL bit set (since you inherited it from the parent's trap 
> frame). And as long as the EXL bit is set you are still in the kernel mode irrespective of the
> KSU field.
> 
> One place where you might see this is when init is going into usermode for the very first time.
> If that is where you get the exception then the right way to fix is to set the EXL bit in 
> exec_setregs() in machdep.c. That way you don't need duplicate code in fork_trampoline() and
> exception_restore_registers().
	Thanks for pointing out. You're right it was when init was about
to go to user mode for the first time.

-- 
gonzo