dax: check resource alignment at dax region/device create
All the extents of a dax-device must match the alignment of the region.
Otherwise, we are unable to guarantee fault semantics of a given page
size. The region must be self-consistent itself as well.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c
index 0a7899d..03bb54f 100644
--- a/drivers/dax/dax.c
+++ b/drivers/dax/dax.c
@@ -206,8 +206,11 @@
{
struct dax_region *dax_region;
- dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL);
+ if (!IS_ALIGNED(res->start, align)
+ || !IS_ALIGNED(resource_size(res), align))
+ return NULL;
+ dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL);
if (!dax_region)
return NULL;
@@ -560,15 +563,29 @@
{
struct device *parent = dax_region->dev;
struct dax_dev *dax_dev;
+ int rc = 0, minor, i;
struct device *dev;
struct cdev *cdev;
- int rc, minor;
dev_t dev_t;
dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL);
if (!dax_dev)
return -ENOMEM;
+ for (i = 0; i < count; i++) {
+ if (!IS_ALIGNED(res[i].start, dax_region->align)
+ || !IS_ALIGNED(resource_size(&res[i]),
+ dax_region->align)) {
+ rc = -EINVAL;
+ break;
+ }
+ dax_dev->res[i].start = res[i].start;
+ dax_dev->res[i].end = res[i].end;
+ }
+
+ if (i < count)
+ goto err_id;
+
dax_dev->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);
if (dax_dev->id < 0) {
rc = dax_dev->id;
@@ -601,7 +618,6 @@
goto err_cdev;
/* from here on we're committed to teardown via dax_dev_release() */
- memcpy(dax_dev->res, res, sizeof(*res) * count);
dax_dev->num_resources = count;
dax_dev->alive = true;
dax_dev->region = dax_region;