Merge tag 'libnvdimm-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull nvdimm and DAX updates from Vishal Verma:
 "This is mostly small cleanups and fixes, with the biggest change being
  the change to the DAX fault handler allowing it to return
  VM_FAULT_HWPOISON.

  Summary:

   - DAX fixes and cleanups including a use after free, extra
     references, and device unregistration, and a redundant variable.

   - Allow the DAX fault handler to return VM_FAULT_HWPOISON

   - A few libnvdimm cleanups such as making some functions and
     variables static where sufficient.

   - Add a few missing prototypes for wrapped functions in
     tools/testing/nvdimm"

* tag 'libnvdimm-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: enable dax fault handler to report VM_FAULT_HWPOISON
  nvdimm: make security_show static
  nvdimm: make nd_class variable static
  dax/kmem: Pass valid argument to memory_group_register_static
  fsdax: remove redundant variable 'error'
  dax: Cleanup extra dax_region references
  dax: Introduce alloc_dev_dax_id()
  dax: Use device_unregister() in unregister_dax_mapping()
  dax: Fix dax_mapping_release() use after free
  tools/testing/nvdimm: Drop empty platform remove function
  libnvdimm: mark 'security_show' static again
  testing: nvdimm: add missing prototypes for wrapped functions
  dax: fix missing-prototype warnings

Author: torvalds

drivers/dax/bus.c

@@ -446,18 +446,33 @@ static void unregister_dev_dax(void *dev)
 	put_device(dev);
 }
 
+static void dax_region_free(struct kref *kref)
+{
+	struct dax_region *dax_region;
+
+	dax_region = container_of(kref, struct dax_region, kref);
+	kfree(dax_region);
+}
+
+static void dax_region_put(struct dax_region *dax_region)
+{
+	kref_put(&dax_region->kref, dax_region_free);
+}
+
 /* a return value >= 0 indicates this invocation invalidated the id */
 static int __free_dev_dax_id(struct dev_dax *dev_dax)
 {
-	struct dax_region *dax_region = dev_dax->region;
 	struct device *dev = &dev_dax->dev;
+	struct dax_region *dax_region;
 	int rc = dev_dax->id;
 
 	device_lock_assert(dev);
 
-	if (is_static(dax_region) || dev_dax->id < 0)
+	if (!dev_dax->dyn_id || dev_dax->id < 0)
 		return -1;
+	dax_region = dev_dax->region;
 	ida_free(&dax_region->ida, dev_dax->id);
+	dax_region_put(dax_region);
 	dev_dax->id = -1;
 	return rc;
 }
@@ -473,6 +488,20 @@ static int free_dev_dax_id(struct dev_dax *dev_dax)
 	return rc;
 }
 
+static int alloc_dev_dax_id(struct dev_dax *dev_dax)
+{
+	struct dax_region *dax_region = dev_dax->region;
+	int id;
+
+	id = ida_alloc(&dax_region->ida, GFP_KERNEL);
+	if (id < 0)
+		return id;
+	kref_get(&dax_region->kref);
+	dev_dax->dyn_id = true;
+	dev_dax->id = id;
+	return id;
+}
+
 static ssize_t delete_store(struct device *dev, struct device_attribute *attr,
 		const char *buf, size_t len)
 {
@@ -560,20 +589,6 @@ static const struct attribute_group *dax_region_attribute_groups[] = {
 	NULL,
 };
 
-static void dax_region_free(struct kref *kref)
-{
-	struct dax_region *dax_region;
-
-	dax_region = container_of(kref, struct dax_region, kref);
-	kfree(dax_region);
-}
-
-void dax_region_put(struct dax_region *dax_region)
-{
-	kref_put(&dax_region->kref, dax_region_free);
-}
-EXPORT_SYMBOL_GPL(dax_region_put);
-
 static void dax_region_unregister(void *region)
 {
 	struct dax_region *dax_region = region;
@@ -625,7 +640,6 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
 		return NULL;
 	}
 
-	kref_get(&dax_region->kref);
 	if (devm_add_action_or_reset(parent, dax_region_unregister, dax_region))
 		return NULL;
 	return dax_region;
@@ -635,10 +649,12 @@ EXPORT_SYMBOL_GPL(alloc_dax_region);
 static void dax_mapping_release(struct device *dev)
 {
 	struct dax_mapping *mapping = to_dax_mapping(dev);
-	struct dev_dax *dev_dax = to_dev_dax(dev->parent);
+	struct device *parent = dev->parent;
+	struct dev_dax *dev_dax = to_dev_dax(parent);
 
 	ida_free(&dev_dax->ida, mapping->id);
 	kfree(mapping);
+	put_device(parent);
 }
 
 static void unregister_dax_mapping(void *data)
@@ -655,8 +671,7 @@ static void unregister_dax_mapping(void *data)
 	dev_dax->ranges[mapping->range_id].mapping = NULL;
 	mapping->range_id = -1;
 
-	device_del(dev);
-	put_device(dev);
+	device_unregister(dev);
 }
 
 static struct dev_dax_range *get_dax_range(struct device *dev)
@@ -778,6 +793,7 @@ static int devm_register_dax_mapping(struct dev_dax *dev_dax, int range_id)
 	dev = &mapping->dev;
 	device_initialize(dev);
 	dev->parent = &dev_dax->dev;
+	get_device(dev->parent);
 	dev->type = &dax_mapping_type;
 	dev_set_name(dev, "mapping%d", mapping->id);
 	rc = device_add(dev);
@@ -1295,12 +1311,10 @@ static const struct attribute_group *dax_attribute_groups[] = {
 static void dev_dax_release(struct device *dev)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
-	struct dax_region *dax_region = dev_dax->region;
 	struct dax_device *dax_dev = dev_dax->dax_dev;
 
 	put_dax(dax_dev);
 	free_dev_dax_id(dev_dax);
-	dax_region_put(dax_region);
 	kfree(dev_dax->pgmap);
 	kfree(dev_dax);
 }
@@ -1324,6 +1338,7 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 	if (!dev_dax)
 		return ERR_PTR(-ENOMEM);
 
+	dev_dax->region = dax_region;
 	if (is_static(dax_region)) {
 		if (dev_WARN_ONCE(parent, data->id < 0,
 				"dynamic id specified to static region\n")) {
@@ -1339,13 +1354,11 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 			goto err_id;
 		}
 
-		rc = ida_alloc(&dax_region->ida, GFP_KERNEL);
+		rc = alloc_dev_dax_id(dev_dax);
 		if (rc < 0)
 			goto err_id;
-		dev_dax->id = rc;
 	}
 
-	dev_dax->region = dax_region;
 	dev = &dev_dax->dev;
 	device_initialize(dev);
 	dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id);
@@ -1386,7 +1399,6 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 	dev_dax->target_node = dax_region->target_node;
 	dev_dax->align = dax_region->align;
 	ida_init(&dev_dax->ida);
-	kref_get(&dax_region->kref);
 
 	inode = dax_inode(dax_dev);
 	dev->devt = inode->i_rdev;

drivers/dax/bus.h

@@ -9,7 +9,6 @@ struct dev_dax;
 struct resource;
 struct dax_device;
 struct dax_region;
-void dax_region_put(struct dax_region *dax_region);
 
 /* dax bus specific ioresource flags */
 #define IORESOURCE_DAX_STATIC BIT(0)
@@ -49,13 +48,6 @@ void dax_driver_unregister(struct dax_device_driver *dax_drv);
 void kill_dev_dax(struct dev_dax *dev_dax);
 bool static_dev_dax(struct dev_dax *dev_dax);
 
-/*
- * While run_dax() is potentially a generic operation that could be
- * defined in include/linux/dax.h we don't want to grow any users
- * outside of drivers/dax/
- */
-void run_dax(struct dax_device *dax_dev);
-
 #define MODULE_ALIAS_DAX_DEVICE(type) \
 	MODULE_ALIAS("dax:t" __stringify(type) "*")
 #define DAX_DEVICE_MODALIAS_FMT "dax:t%d"

drivers/dax/cxl.c

@@ -13,7 +13,6 @@ static int cxl_dax_region_probe(struct device *dev)
 	struct cxl_region *cxlr = cxlr_dax->cxlr;
 	struct dax_region *dax_region;
 	struct dev_dax_data data;
-	struct dev_dax *dev_dax;
 
 	if (nid == NUMA_NO_NODE)
 		nid = memory_add_physaddr_to_nid(cxlr_dax->hpa_range.start);
@@ -28,13 +27,8 @@ static int cxl_dax_region_probe(struct device *dev)
 		.id = -1,
 		.size = range_len(&cxlr_dax->hpa_range),
 	};
-	dev_dax = devm_create_dev_dax(&data);
-	if (IS_ERR(dev_dax))
-		return PTR_ERR(dev_dax);
 
-	/* child dev_dax instances now own the lifetime of the dax_region */
-	dax_region_put(dax_region);
-	return 0;
+	return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data));
 }
 
 static struct cxl_driver cxl_dax_region_driver = {

drivers/dax/dax-private.h

@@ -52,7 +52,8 @@ struct dax_mapping {
  * @region - parent region
  * @dax_dev - core dax functionality
  * @target_node: effective numa node if dev_dax memory range is onlined
- * @id: ida allocated id
+ * @dyn_id: is this a dynamic or statically created instance
+ * @id: ida allocated id when the dax_region is not static
  * @ida: mapping id allocator
  * @dev - device core
  * @pgmap - pgmap for memmap setup / lifetime (driver owned)
@@ -64,6 +65,7 @@ struct dev_dax {
 	struct dax_device *dax_dev;
 	unsigned int align;
 	int target_node;
+	bool dyn_id;
 	int id;
 	struct ida ida;
 	struct device dev;
@@ -76,6 +78,13 @@ struct dev_dax {
 	} *ranges;
 };
 
+/*
+ * While run_dax() is potentially a generic operation that could be
+ * defined in include/linux/dax.h we don't want to grow any users
+ * outside of drivers/dax/
+ */
+void run_dax(struct dax_device *dax_dev);
+
 static inline struct dev_dax *to_dev_dax(struct device *dev)
 {
 	return container_of(dev, struct dev_dax, dev);

drivers/dax/device.c

@@ -396,7 +396,7 @@ static void dev_dax_kill(void *dev_dax)
 	kill_dev_dax(dev_dax);
 }
 
-int dev_dax_probe(struct dev_dax *dev_dax)
+static int dev_dax_probe(struct dev_dax *dev_dax)
 {
 	struct dax_device *dax_dev = dev_dax->dax_dev;
 	struct device *dev = &dev_dax->dev;
@@ -471,7 +471,6 @@ int dev_dax_probe(struct dev_dax *dev_dax)
 	run_dax(dax_dev);
 	return devm_add_action_or_reset(dev, dev_dax_kill, dev_dax);
 }
-EXPORT_SYMBOL_GPL(dev_dax_probe);
 
 static struct dax_device_driver device_dax_driver = {
 	.probe = dev_dax_probe,

drivers/dax/hmem/hmem.c

@@ -16,7 +16,6 @@ static int dax_hmem_probe(struct platform_device *pdev)
 	struct dax_region *dax_region;
 	struct memregion_info *mri;
 	struct dev_dax_data data;
-	struct dev_dax *dev_dax;
 
 	/*
 	 * @region_idle == true indicates that an administrative agent
@@ -38,13 +37,8 @@ static int dax_hmem_probe(struct platform_device *pdev)
 		.id = -1,
 		.size = region_idle ? 0 : range_len(&mri->range),
 	};
-	dev_dax = devm_create_dev_dax(&data);
-	if (IS_ERR(dev_dax))
-		return PTR_ERR(dev_dax);
 
-	/* child dev_dax instances now own the lifetime of the dax_region */
-	dax_region_put(dax_region);
-	return 0;
+	return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data));
 }
 
 static struct platform_driver dax_hmem_driver = {

drivers/dax/kmem.c

@@ -99,7 +99,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax)
 	if (!data->res_name)
 		goto err_res_name;
 
-	rc = memory_group_register_static(numa_node, total_len);
+	rc = memory_group_register_static(numa_node, PFN_UP(total_len));
 	if (rc < 0)
 		goto err_reg_mgid;
 	data->mgid = rc;

drivers/dax/pmem.c

@@ -13,7 +13,6 @@ static struct dev_dax *__dax_pmem_probe(struct device *dev)
 	int rc, id, region_id;
 	resource_size_t offset;
 	struct nd_pfn_sb *pfn_sb;
-	struct dev_dax *dev_dax;
 	struct dev_dax_data data;
 	struct nd_namespace_io *nsio;
 	struct dax_region *dax_region;
@@ -65,12 +64,8 @@ static struct dev_dax *__dax_pmem_probe(struct device *dev)
 		.pgmap = &pgmap,
 		.size = range_len(&range),
 	};
-	dev_dax = devm_create_dev_dax(&data);
 
-	/* child dev_dax instances now own the lifetime of the dax_region */
-	dax_region_put(dax_region);
-
-	return dev_dax;
+	return devm_create_dev_dax(&data);
 }
 
 static int dax_pmem_probe(struct device *dev)

drivers/dax/super.c

@@ -203,6 +203,8 @@ size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
 int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
 			size_t nr_pages)
 {
+	int ret;
+
 	if (!dax_alive(dax_dev))
 		return -ENXIO;
 	/*
@@ -213,7 +215,8 @@ int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
 	if (nr_pages != 1)
 		return -EIO;
 
-	return dax_dev->ops->zero_page_range(dax_dev, pgoff, nr_pages);
+	ret = dax_dev->ops->zero_page_range(dax_dev, pgoff, nr_pages);
+	return dax_mem2blk_err(ret);
 }
 EXPORT_SYMBOL_GPL(dax_zero_page_range);
 

drivers/nvdimm/bus.c

@@ -25,7 +25,7 @@
 
 int nvdimm_major;
 static int nvdimm_bus_major;
-struct class *nd_class;
+static struct class *nd_class;
 static DEFINE_IDA(nd_ida);
 
 static int to_nd_device_type(const struct device *dev)