Re: [RFC v2 02/26] mm/asi: Abort isolation on interrupt, exception and context switch

[Alexandre Chartre]

On 7/11/19 10:17 PM, Mike Rapoport wrote:
> On Thu, Jul 11, 2019 at 01:11:43PM -0700, Andi Kleen wrote:
> > Alexandre Chartre <alexandre.chartre@xxxxxxxxxx> writes:
> > >   	jmp	paranoid_exit
> > > @@ -1182,6 +1196,16 @@ ENTRY(paranoid_entry)
> > >   	xorl	%ebx, %ebx
> > >   
> > >   1:
> > > +#ifdef CONFIG_ADDRESS_SPACE_ISOLATION
> > > +	/*
> > > +	 * If address space isolation is active then abort it and return
> > > +	 * the original kernel CR3 in %r14.
> > > +	 */
> > > +	ASI_START_ABORT_ELSE_JUMP 2f
> > > +	movq	%rdi, %r14
> > > +	ret
> > > +2:
> > > +#endif
> >
> > Unless I missed it you don't map the exception stacks into ASI, so it
> > has likely already triple faulted at this point.
>
> The exception stacks are in the CPU entry area, aren't they?
>   

That's my understanding, stacks come from tss in the CPU entry area and
the CPU entry area is part for the core ASI mappings (see patch 15/26).

alex.