On Mon, Jan 15, 2018 at 8:09 AM, John Nemeth <jnem...@cue.bc.ca> wrote:
> On Jan 15, 2:04pm, Michael van Elst wrote: > } m...@netbsd.org (Emmanuel Dreyfus) writes: > } > } >Sorry if that has been covered ad nauseum, but I canot find relevant > } >information about that: on NetBSD, how can I get the physical memory > } >address given a virtual memory address? This is to port the Linux > } >Meltdown PoC so that we have something to test our systems against. > } > } pmap_extract() returns the physical address of a virtual address. > } pmap_kernel() gives you the kernel map. > > I suspect that he wants to do this from userland. > You have to walk the page tables, or trick some driver into leaking this information somehow. There's no standard interface to get it. In FreeSBD there's no standard interface, but that hasn't stopped people from getting metldown and spectre working, though I don't think they have shared that PoC code. Warner
