On Tue, 23 Aug 2016 12:43:20 -0600 Toshi Kani <toshi.k...@hpe.com> wrote:
> The following BUG was observed while starting up KVM with nvdimm > device as memory-backend-file to /dev/dax. > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 > > ... > > devm_memremap_pages() calls for_each_device_pfn() to walk through > all pfns in page_map. pfn_first(), however, returns a wrong pfn > that leaves page->pgmap uninitialized. > > Since arch_add_memory() has set up direct mappings to the NVDIMM > range with altmap, pfn_first() should not modify the start pfn. > Change pfn_first() to simply return pfn of res->start. Which kernel version(s) do you think need fixing?
