[Crash-utility] [PATCH v1] arm64: fix kernel memory map handling for kaslr-enabled

[Dave Anderson]

----- Original Message -----
> On Tue, May 24, 2016 at 09:35:54AM -0400, Dave Anderson wrote:
> > 
> > 
> > ----- Original Message -----
> > > > > 
> > > > > Now that PHYS_OFFSET is defined as "memstart_addr",  we can get the value
> > > > > if we can access this symbol (on a live system).
> > > > 
> > > > When PHYS_OFFSET/memstart_addr is bumped up from the actual base of physical
> > > > memory, is the physical memory below it no longer used/accessible?
> > > 
> > > Yes, it is! That is what Ard has managed to do in his series of
> > > KASLR-related patches.
> > 
> > How is it accessed via a kernel virtual address?  Or is only accessible when
> > mapped into a vmalloc() or user-space address?
> 
> Through a linear(unity) mapping above PAGE_OFFSET.

I'm still confused...

Does PAGE_OFFSET+0 still refer to PHYS_OFFSET?  I'm trying to wrap my head around 
how __virt_to_phys() would work for the memory below the bumped-up PHYS_OFFSET.

Dave