[PATCH 1/4] dax: check resource alignment at dax region/device create

[Dan Williams]

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 
---
 drivers/dax/dax.c |   22 +++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c
index 0a7899d5c65c..03bb54f7f58f 100644
--- a/drivers/dax/dax.c
+++ b/drivers/dax/dax.c
@@ -206,8 +206,11 @@ struct dax_region *alloc_dax_region(struct device *parent, 
int region_id,
 {
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 @@ int devm_create_dax_dev(struct dax_region *dax_region, 
struct resource *res,
 {
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([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(_region->ida, 0, 0, GFP_KERNEL);
if (dax_dev->id < 0) {
rc = dax_dev->id;
@@ -601,7 +618,6 @@ int devm_create_dax_dev(struct dax_region *dax_region, 
struct resource *res,
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;

[PATCH 1/4] dax: check resource alignment at dax region/device create

[Dan Williams]

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 
---
 drivers/dax/dax.c |   22 +++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c
index 0a7899d5c65c..03bb54f7f58f 100644
--- a/drivers/dax/dax.c
+++ b/drivers/dax/dax.c
@@ -206,8 +206,11 @@ struct dax_region *alloc_dax_region(struct device *parent, 
int region_id,
 {
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 @@ int devm_create_dax_dev(struct dax_region *dax_region, 
struct resource *res,
 {
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([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(_region->ida, 0, 0, GFP_KERNEL);
if (dax_dev->id < 0) {
rc = dax_dev->id;
@@ -601,7 +618,6 @@ int devm_create_dax_dev(struct dax_region *dax_region, 
struct resource *res,
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;