Messages in this thread | | | From | Dan Williams <> | Date | Mon, 2 Mar 2020 10:45:09 -0800 | Subject | Re: [PATCH v3 3/5] libnvdimm/namespace: Enforce memremap_compat_align() |
| |
On Mon, Mar 2, 2020 at 4:09 AM Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> wrote: > > Dan Williams <dan.j.williams@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, and nd_dax cases. This includes > > preventing the creation of namespaces where the base address is > > misaligned and cases there infoblock padding parameters are invalid. > > > > Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> > > > Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> > > Cc: Jeff Moyer <jmoyer@redhat.com> > > Fixes: a3619190d62e ("libnvdimm/pfn: stop padding pmem namespaces to section alignment") > > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > > --- > > drivers/nvdimm/namespace_devs.c | 12 ++++++++++++ > > drivers/nvdimm/pfn_devs.c | 26 +++++++++++++++++++++++--- > > 2 files changed, 35 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c > > index 032dc61725ff..68e89855f779 100644 > > --- a/drivers/nvdimm/namespace_devs.c > > +++ b/drivers/nvdimm/namespace_devs.c > > @@ -10,6 +10,7 @@ > > #include <linux/nd.h> > > #include "nd-core.h" > > #include "pmem.h" > > +#include "pfn.h" > > #include "nd.h" > > > > static void namespace_io_release(struct device *dev) > > @@ -1739,6 +1740,17 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev) > > return ERR_PTR(-ENODEV); > > } > > May be add a comment here that both dax/fsdax namespace details are > checked in nd_pfn_validate() so that we look at start_pad and end_trunc > while validating the namespace? > > > > > + if (pmem_should_map_pages(dev)) { > > + struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); > > + struct resource *res = &nsio->res; > > + > > + if (!IS_ALIGNED(res->start | (res->end + 1), > > + memremap_compat_align())) { > > + dev_err(&ndns->dev, "%pr misaligned, unable to map\n", res); > > + return ERR_PTR(-EOPNOTSUPP); > > + } > > + } > > + > > if (is_namespace_pmem(&ndns->dev)) { > > struct nd_namespace_pmem *nspm; > > > > diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c > > index 79fe02d6f657..3bdd4b883d05 100644 > > --- a/drivers/nvdimm/pfn_devs.c > > +++ b/drivers/nvdimm/pfn_devs.c > > @@ -446,6 +446,7 @@ static bool nd_supported_alignment(unsigned long align) > > int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig) > > { > > u64 checksum, offset; > > + struct resource *res; > > enum nd_pfn_mode mode; > > struct nd_namespace_io *nsio; > > unsigned long align, start_pad; > > @@ -578,13 +579,14 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig) > > * established. > > */ > > nsio = to_nd_namespace_io(&ndns->dev); > > - if (offset >= resource_size(&nsio->res)) { > > + res = &nsio->res; > > + if (offset >= resource_size(res)) { > > dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n", > > dev_name(&ndns->dev)); > > return -EOPNOTSUPP; > > } > > > > - if ((align && !IS_ALIGNED(nsio->res.start + offset + start_pad, align)) > > + if ((align && !IS_ALIGNED(res->start + offset + start_pad, align)) > > || !IS_ALIGNED(offset, PAGE_SIZE)) { > > dev_err(&nd_pfn->dev, > > "bad offset: %#llx dax disabled align: %#lx\n", > > @@ -592,6 +594,18 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig) > > return -EOPNOTSUPP; > > } > > > > + if (!IS_ALIGNED(res->start + le32_to_cpu(pfn_sb->start_pad), > > + memremap_compat_align())) { > > + dev_err(&nd_pfn->dev, "resource start misaligned\n"); > > + return -EOPNOTSUPP; > > + } > > + > > + if (!IS_ALIGNED(res->end + 1 - le32_to_cpu(pfn_sb->end_trunc), > > + memremap_compat_align())) { > > + dev_err(&nd_pfn->dev, "resource end misaligned\n"); > > + return -EOPNOTSUPP; > > + } > > + > > return 0; > > } > > EXPORT_SYMBOL(nd_pfn_validate); > > @@ -750,7 +764,13 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) > > start = nsio->res.start; > > size = resource_size(&nsio->res); > > npfns = PHYS_PFN(size - SZ_8K); > > - align = max(nd_pfn->align, SUBSECTION_SIZE); > > + align = max(nd_pfn->align, memremap_compat_align()); > > + if (!IS_ALIGNED(start, memremap_compat_align())) { > > + dev_err(&nd_pfn->dev, "%s: start %pa misaligned to %#lx\n", > > + dev_name(&ndns->dev), &start, > > + memremap_compat_align()); > > + return -EINVAL; > > + } > > This validates start in case of a new namespace creation where the user > updated nd_region->align value? A comment there would help when looking > at the code later?
Yeah, sounds good will respin with those updates.
| |