Dan Williams <dan.j.willi...@intel.com> writes: > The pmem driver on PowerPC crashes with the following signature when > instantiating misaligned namespaces that map their capacity via > memremap_pages(). > > BUG: Unable to handle kernel data access at 0xc001000406000000 > Faulting instruction address: 0xc000000000090790 > NIP [c000000000090790] arch_add_memory+0xc0/0x130 > LR [c000000000090744] arch_add_memory+0x74/0x130 > Call Trace: > arch_add_memory+0x74/0x130 (unreliable) > memremap_pages+0x74c/0xa30 > devm_memremap_pages+0x3c/0xa0 > pmem_attach_disk+0x188/0x770 > nvdimm_bus_probe+0xd8/0x470 > > With the assumption that only memremap_pages() has alignment > constraints, enforce memremap_compat_align() for > pmem_should_map_pages(), nd_pfn, or nd_dax cases. > > Reported-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com> > Cc: Jeff Moyer <jmo...@redhat.com> > Reviewed-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com> > Link: > https://lore.kernel.org/r/158041477336.3889308.4581652885008605170.st...@dwillia2-desk3.amr.corp.intel.com > Signed-off-by: Dan Williams <dan.j.willi...@intel.com> > --- > drivers/nvdimm/namespace_devs.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c > index 032dc61725ff..aff1f32fdb4f 100644 > --- a/drivers/nvdimm/namespace_devs.c > +++ b/drivers/nvdimm/namespace_devs.c > @@ -1739,6 +1739,16 @@ struct nd_namespace_common > *nvdimm_namespace_common_probe(struct device *dev) > return ERR_PTR(-ENODEV); > } > > + if (pmem_should_map_pages(dev) || nd_pfn || nd_dax) { > + struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); > + resource_size_t start = nsio->res.start; > + > + if (!IS_ALIGNED(start | size, memremap_compat_align())) { > + dev_dbg(&ndns->dev, "misaligned, unable to map\n"); > + return ERR_PTR(-EOPNOTSUPP); > + } > + } > + > if (is_namespace_pmem(&ndns->dev)) { > struct nd_namespace_pmem *nspm; >
Actually, I take back my ack. :) This prevents a previously working namespace from being successfully probed/setup. I thought we were only going to enforce the alignment for a newly created namespace? This should only check whether the alignment works for the current platform. -Jeff
