[PATCH v4 2/6] libnvdimm/namespace: Validate namespace start addr and size

["Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>]

Make sure namespace start addr and size are properly aligned as per architecture
restrictions. If the namespace is not aligned kernel mark the namespace 'disabled'

Architectures like ppc64 use different page size than PAGE_SIZE to map
direct-map address range. The kernel needs to make sure the namespace size is aligned
correctly for the direct-map page size.

kernel log will contain information as below.

[    5.810939] nd_pmem namespace0.1: invalid size/SPA
[    5.810969] nd_pmem: probe of namespace0.1 failed with error -95

and the namespace will be marked 'disabled'

  {
    "dev":"namespace0.1",
    "mode":"fsdax",
    "map":"mem",
    "size":1071644672,
    "uuid":"25577a00-c012-421d-89ca-3ee189e08848",
    "sector_size":512,
    "state":"disabled"
  },

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 drivers/nvdimm/namespace_devs.c | 50 +++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 032dc61725ff..0e2c90730ce3 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -1113,6 +1113,51 @@ resource_size_t nvdimm_namespace_capacity(struct nd_namespace_common *ndns)
 }
 EXPORT_SYMBOL(nvdimm_namespace_capacity);
 
+static bool nvdimm_valid_namespace(struct device *dev,
+		struct nd_namespace_common *ndns, resource_size_t size)
+{
+	struct device *ndns_dev = &ndns->dev;
+	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
+	unsigned long map_size = arch_namespace_map_size();
+	struct resource *res;
+	u32 remainder;
+
+	/*
+	 * Don't validate the start and size for blk namespace type
+	 */
+	if (is_namespace_blk(ndns_dev))
+		return true;
+
+	/*
+	 * For btt and raw namespace kernel use ioremap. Assume both can work
+	 * with PAGE_SIZE alignment.
+	 */
+	if (is_nd_btt(dev) || is_namespace_io(ndns_dev))
+		map_size = PAGE_SIZE;
+
+	div_u64_rem(size, map_size * nd_region->ndr_mappings, &remainder);
+	if (remainder)
+		return false;
+
+	if (is_namespace_pmem(ndns_dev)) {
+		struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(ndns_dev);
+
+		res = &nspm->nsio.res;
+	} else if (is_namespace_io(ndns_dev)) {
+		struct nd_namespace_io *nsio = to_nd_namespace_io(ndns_dev);
+
+		res = &nsio->res;
+	} else
+		/* cannot reach */
+		return false;
+
+	div_u64_rem(res->start, map_size * nd_region->ndr_mappings, &remainder);
+	if (remainder)
+		return false;
+
+	return true;
+}
+
 bool nvdimm_namespace_locked(struct nd_namespace_common *ndns)
 {
 	int i;
@@ -1739,6 +1784,11 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev)
 		return ERR_PTR(-ENODEV);
 	}
 
+	if (!nvdimm_valid_namespace(dev, ndns, size)) {
+		dev_err(&ndns->dev, "invalid size/SPA");
+		return ERR_PTR(-EOPNOTSUPP);
+	}
+
 	if (is_namespace_pmem(&ndns->dev)) {
 		struct nd_namespace_pmem *nspm;
 
-- 
2.24.1
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org