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

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.