4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Dan Williams <[email protected]> commit bfb34527a32a1a576d9bfb7026d3ab0369a6cd60 upstream. When vmemmap_populate() allocates space for the memmap it does so in 2MB sized chunks. The libnvdimm-pfn driver incorrectly accounts for this when the alignment of the device is set to 4K. When this happens we trigger memory allocation failures in altmap_alloc_block_buf() and trigger warnings of the form: WARNING: CPU: 0 PID: 3376 at arch/x86/mm/init_64.c:656 arch_add_memory+0xe4/0xf0 [..] Call Trace: dump_stack+0x86/0xc3 __warn+0xcb/0xf0 warn_slowpath_null+0x1d/0x20 arch_add_memory+0xe4/0xf0 devm_memremap_pages+0x29b/0x4e0 Fixes: 315c562536c4 ("libnvdimm, pfn: add 'align' attribute, default to HPAGE_SIZE") Signed-off-by: Dan Williams <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/nvdimm/pfn_devs.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) --- a/drivers/nvdimm/pfn_devs.c +++ b/drivers/nvdimm/pfn_devs.c @@ -627,15 +627,12 @@ static int nd_pfn_init(struct nd_pfn *nd size = resource_size(&nsio->res); npfns = (size - start_pad - end_trunc - SZ_8K) / SZ_4K; if (nd_pfn->mode == PFN_MODE_PMEM) { - unsigned long memmap_size; - /* * vmemmap_populate_hugepages() allocates the memmap array in * HPAGE_SIZE chunks. */ - memmap_size = ALIGN(64 * npfns, HPAGE_SIZE); - offset = ALIGN(start + SZ_8K + memmap_size + dax_label_reserve, - nd_pfn->align) - start; + offset = ALIGN(start + SZ_8K + 64 * npfns + dax_label_reserve, + max(nd_pfn->align, HPAGE_SIZE)) - start; } else if (nd_pfn->mode == PFN_MODE_RAM) offset = ALIGN(start + SZ_8K + dax_label_reserve, nd_pfn->align) - start;
