1 files changed, 231 insertions, 61 deletions

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 42b1f73ac5f6..2b5ac43a5690 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -24,13 +24,33 @@
 #include "of_private.h"
 
 /**
+ * struct target - info about current target node as recursing through overlay
+ * @np:			node where current level of overlay will be applied
+ * @in_livetree:	@np is a node in the live devicetree
+ *
+ * Used in the algorithm to create the portion of a changeset that describes
+ * an overlay fragment, which is a devicetree subtree.  Initially @np is a node
+ * in the live devicetree where the overlay subtree is targeted to be grafted
+ * into.  When recursing to the next level of the overlay subtree, the target
+ * also recurses to the next level of the live devicetree, as long as overlay
+ * subtree node also exists in the live devicetree.  When a node in the overlay
+ * subtree does not exist at the same level in the live devicetree, target->np
+ * points to a newly allocated node, and all subsequent targets in the subtree
+ * will be newly allocated nodes.
+ */
+struct target {
+	struct device_node *np;
+	bool in_livetree;
+};
+
+/**
  * struct fragment - info about fragment nodes in overlay expanded device tree
  * @target:	target of the overlay operation
  * @overlay:	pointer to the __overlay__ node
  */
 struct fragment {
-	struct device_node *target;
 	struct device_node *overlay;
+	struct device_node *target;
 };
 
 /**
@@ -72,8 +92,7 @@ static int devicetree_corrupt(void)
 }
 
 static int build_changeset_next_level(struct overlay_changeset *ovcs,
-		struct device_node *target_node,
-		const struct device_node *overlay_node);
+		struct target *target, const struct device_node *overlay_node);
 
 /*
  * of_resolve_phandles() finds the largest phandle in the live tree.
@@ -257,15 +276,23 @@ err_free_target_path:
 /**
  * add_changeset_property() - add @overlay_prop to overlay changeset
  * @ovcs:		overlay changeset
- * @target_node:	where to place @overlay_prop in live tree
+ * @target:		where @overlay_prop will be placed
  * @overlay_prop:	property to add or update, from overlay tree
  * @is_symbols_prop:	1 if @overlay_prop is from node "/__symbols__"
  *
- * If @overlay_prop does not already exist in @target_node, add changeset entry
- * to add @overlay_prop in @target_node, else add changeset entry to update
+ * If @overlay_prop does not already exist in live devicetree, add changeset
+ * entry to add @overlay_prop in @target, else add changeset entry to update
  * value of @overlay_prop.
  *
- * Some special properties are not updated (no error returned).
+ * @target may be either in the live devicetree or in a new subtree that
+ * is contained in the changeset.
+ *
+ * Some special properties are not added or updated (no error returned):
+ * "name", "phandle", "linux,phandle".
+ *
+ * Properties "#address-cells" and "#size-cells" are not updated if they
+ * are already in the live tree, but if present in the live tree, the values
+ * in the overlay must match the values in the live tree.
  *
  * Update of property in symbols node is not allowed.
  *
@@ -273,19 +300,23 @@ err_free_target_path:
  * invalid @overlay.
  */
 static int add_changeset_property(struct overlay_changeset *ovcs,
-		struct device_node *target_node,
-		struct property *overlay_prop,
+		struct target *target, struct property *overlay_prop,
 		bool is_symbols_prop)
 {
 	struct property *new_prop = NULL, *prop;
 	int ret = 0;
+	bool check_for_non_overlay_node = false;
 
-	prop = of_find_property(target_node, overlay_prop->name, NULL);
+	if (target->in_livetree)
+		if (!of_prop_cmp(overlay_prop->name, "name") ||
+		    !of_prop_cmp(overlay_prop->name, "phandle") ||
+		    !of_prop_cmp(overlay_prop->name, "linux,phandle"))
+			return 0;
 
-	if (!of_prop_cmp(overlay_prop->name, "name") ||
-	    !of_prop_cmp(overlay_prop->name, "phandle") ||
-	    !of_prop_cmp(overlay_prop->name, "linux,phandle"))
-		return 0;
+	if (target->in_livetree)
+		prop = of_find_property(target->np, overlay_prop->name, NULL);
+	else
+		prop = NULL;
 
 	if (is_symbols_prop) {
 		if (prop)
@@ -298,12 +329,36 @@ static int add_changeset_property(struct overlay_changeset *ovcs,
 	if (!new_prop)
 		return -ENOMEM;
 
-	if (!prop)
-		ret = of_changeset_add_property(&ovcs->cset, target_node,
+	if (!prop) {
+		check_for_non_overlay_node = true;
+		if (!target->in_livetree) {
+			new_prop->next = target->np->deadprops;
+			target->np->deadprops = new_prop;
+		}
+		ret = of_changeset_add_property(&ovcs->cset, target->np,
 						new_prop);
-	else
-		ret = of_changeset_update_property(&ovcs->cset, target_node,
+	} else if (!of_prop_cmp(prop->name, "#address-cells")) {
+		if (!of_prop_val_eq(prop, new_prop)) {
+			pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n",
+			       target->np);
+			ret = -EINVAL;
+		}
+	} else if (!of_prop_cmp(prop->name, "#size-cells")) {
+		if (!of_prop_val_eq(prop, new_prop)) {
+			pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n",
+			       target->np);
+			ret = -EINVAL;
+		}
+	} else {
+		check_for_non_overlay_node = true;
+		ret = of_changeset_update_property(&ovcs->cset, target->np,
 						   new_prop);
+	}
+
+	if (check_for_non_overlay_node &&
+	    !of_node_check_flag(target->np, OF_OVERLAY))
+		pr_err("WARNING: memory leak will occur if overlay removed, property: %pOF/%s\n",
+		       target->np, new_prop->name);
 
 	if (ret) {
 		kfree(new_prop->name);
@@ -315,14 +370,14 @@ static int add_changeset_property(struct overlay_changeset *ovcs,
 
 /**
  * add_changeset_node() - add @node (and children) to overlay changeset
- * @ovcs:		overlay changeset
- * @target_node:	where to place @node in live tree
- * @node:		node from within overlay device tree fragment
+ * @ovcs:	overlay changeset
+ * @target:	where @node will be placed in live tree or changeset
+ * @node:	node from within overlay device tree fragment
  *
- * If @node does not already exist in @target_node, add changeset entry
- * to add @node in @target_node.
+ * If @node does not already exist in @target, add changeset entry
+ * to add @node in @target.
  *
- * If @node already exists in @target_node, and the existing node has
+ * If @node already exists in @target, and the existing node has
  * a phandle, the overlay node is not allowed to have a phandle.
  *
  * If @node has child nodes, add the children recursively via
@@ -342,49 +397,65 @@ static int add_changeset_property(struct overlay_changeset *ovcs,
  *       a live devicetree created from Open Firmware.
  *
  * NOTE_2: Multiple mods of created nodes not supported.
- *       If more than one fragment contains a node that does not already exist
- *       in the live tree, then for each fragment of_changeset_attach_node()
- *       will add a changeset entry to add the node.  When the changeset is
- *       applied, __of_attach_node() will attach the node twice (once for
- *       each fragment).  At this point the device tree will be corrupted.
- *
- *       TODO: add integrity check to ensure that multiple fragments do not
- *             create the same node.
  *
  * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
  * invalid @overlay.
  */
 static int add_changeset_node(struct overlay_changeset *ovcs,
-		struct device_node *target_node, struct device_node *node)
+		struct target *target, struct device_node *node)
 {
 	const char *node_kbasename;
+	const __be32 *phandle;
 	struct device_node *tchild;
-	int ret = 0;
+	struct target target_child;
+	int ret = 0, size;
 
 	node_kbasename = kbasename(node->full_name);
 
-	for_each_child_of_node(target_node, tchild)
+	for_each_child_of_node(target->np, tchild)
 		if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name)))
 			break;
 
 	if (!tchild) {
-		tchild = __of_node_dup(node, node_kbasename);
+		tchild = __of_node_dup(NULL, node_kbasename);
 		if (!tchild)
 			return -ENOMEM;
 
-		tchild->parent = target_node;
+		tchild->parent = target->np;
+		tchild->name = __of_get_property(node, "name", NULL);
+		tchild->type = __of_get_property(node, "device_type", NULL);
+
+		if (!tchild->name)
+			tchild->name = "<NULL>";
+		if (!tchild->type)
+			tchild->type = "<NULL>";
+
+		/* ignore obsolete "linux,phandle" */
+		phandle = __of_get_property(node, "phandle", &size);
+		if (phandle && (size == 4))
+			tchild->phandle = be32_to_cpup(phandle);
+
+		of_node_set_flag(tchild, OF_OVERLAY);
 
 		ret = of_changeset_attach_node(&ovcs->cset, tchild);
 		if (ret)
 			return ret;
 
-		return build_changeset_next_level(ovcs, tchild, node);
+		target_child.np = tchild;
+		target_child.in_livetree = false;
+
+		ret = build_changeset_next_level(ovcs, &target_child, node);
+		of_node_put(tchild);
+		return ret;
 	}
 
-	if (node->phandle && tchild->phandle)
+	if (node->phandle && tchild->phandle) {
 		ret = -EINVAL;
-	else
-		ret = build_changeset_next_level(ovcs, tchild, node);
+	} else {
+		target_child.np = tchild;
+		target_child.in_livetree = target->in_livetree;
+		ret = build_changeset_next_level(ovcs, &target_child, node);
+	}
 	of_node_put(tchild);
 
 	return ret;
@@ -393,7 +464,7 @@ static int add_changeset_node(struct overlay_changeset *ovcs,
 /**
  * build_changeset_next_level() - add level of overlay changeset
  * @ovcs:		overlay changeset
- * @target_node:	where to place @overlay_node in live tree
+ * @target:		where to place @overlay_node in live tree
  * @overlay_node:	node from within an overlay device tree fragment
  *
  * Add the properties (if any) and nodes (if any) from @overlay_node to the
@@ -406,27 +477,26 @@ static int add_changeset_node(struct overlay_changeset *ovcs,
  * invalid @overlay_node.
  */
 static int build_changeset_next_level(struct overlay_changeset *ovcs,
-		struct device_node *target_node,
-		const struct device_node *overlay_node)
+		struct target *target, const struct device_node *overlay_node)
 {
 	struct device_node *child;
 	struct property *prop;
 	int ret;
 
 	for_each_property_of_node(overlay_node, prop) {
-		ret = add_changeset_property(ovcs, target_node, prop, 0);
+		ret = add_changeset_property(ovcs, target, prop, 0);
 		if (ret) {
 			pr_debug("Failed to apply prop @%pOF/%s, err=%d\n",
-				 target_node, prop->name, ret);
+				 target->np, prop->name, ret);
 			return ret;
 		}
 	}
 
 	for_each_child_of_node(overlay_node, child) {
-		ret = add_changeset_node(ovcs, target_node, child);
+		ret = add_changeset_node(ovcs, target, child);
 		if (ret) {
 			pr_debug("Failed to apply node @%pOF/%pOFn, err=%d\n",
-				 target_node, child, ret);
+				 target->np, child, ret);
 			of_node_put(child);
 			return ret;
 		}
@@ -439,17 +509,17 @@ static int build_changeset_next_level(struct overlay_changeset *ovcs,
  * Add the properties from __overlay__ node to the @ovcs->cset changeset.
  */
 static int build_changeset_symbols_node(struct overlay_changeset *ovcs,
-		struct device_node *target_node,
+		struct target *target,
 		const struct device_node *overlay_symbols_node)
 {
 	struct property *prop;
 	int ret;
 
 	for_each_property_of_node(overlay_symbols_node, prop) {
-		ret = add_changeset_property(ovcs, target_node, prop, 1);
+		ret = add_changeset_property(ovcs, target, prop, 1);
 		if (ret) {
-			pr_debug("Failed to apply prop @%pOF/%s, err=%d\n",
-				 target_node, prop->name, ret);
+			pr_debug("Failed to apply symbols prop @%pOF/%s, err=%d\n",
+				 target->np, prop->name, ret);
 			return ret;
 		}
 	}
@@ -457,6 +527,98 @@ static int build_changeset_symbols_node(struct overlay_changeset *ovcs,
 	return 0;
 }
 
+static int find_dup_cset_node_entry(struct overlay_changeset *ovcs,
+		struct of_changeset_entry *ce_1)
+{
+	struct of_changeset_entry *ce_2;
+	char *fn_1, *fn_2;
+	int node_path_match;
+
+	if (ce_1->action != OF_RECONFIG_ATTACH_NODE &&
+	    ce_1->action != OF_RECONFIG_DETACH_NODE)
+		return 0;
+
+	ce_2 = ce_1;
+	list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {
+		if ((ce_2->action != OF_RECONFIG_ATTACH_NODE &&
+		     ce_2->action != OF_RECONFIG_DETACH_NODE) ||
+		    of_node_cmp(ce_1->np->full_name, ce_2->np->full_name))
+			continue;
+
+		fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
+		fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
+		node_path_match = !strcmp(fn_1, fn_2);
+		kfree(fn_1);
+		kfree(fn_2);
+		if (node_path_match) {
+			pr_err("ERROR: multiple fragments add and/or delete node %pOF\n",
+			       ce_1->np);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int find_dup_cset_prop(struct overlay_changeset *ovcs,
+		struct of_changeset_entry *ce_1)
+{
+	struct of_changeset_entry *ce_2;
+	char *fn_1, *fn_2;
+	int node_path_match;
+
+	if (ce_1->action != OF_RECONFIG_ADD_PROPERTY &&
+	    ce_1->action != OF_RECONFIG_REMOVE_PROPERTY &&
+	    ce_1->action != OF_RECONFIG_UPDATE_PROPERTY)
+		return 0;
+
+	ce_2 = ce_1;
+	list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {
+		if ((ce_2->action != OF_RECONFIG_ADD_PROPERTY &&
+		     ce_2->action != OF_RECONFIG_REMOVE_PROPERTY &&
+		     ce_2->action != OF_RECONFIG_UPDATE_PROPERTY) ||
+		    of_node_cmp(ce_1->np->full_name, ce_2->np->full_name))
+			continue;
+
+		fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
+		fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
+		node_path_match = !strcmp(fn_1, fn_2);
+		kfree(fn_1);
+		kfree(fn_2);
+		if (node_path_match &&
+		    !of_prop_cmp(ce_1->prop->name, ce_2->prop->name)) {
+			pr_err("ERROR: multiple fragments add, update, and/or delete property %pOF/%s\n",
+			       ce_1->np, ce_1->prop->name);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * changeset_dup_entry_check() - check for duplicate entries
+ * @ovcs:	Overlay changeset
+ *
+ * Check changeset @ovcs->cset for multiple {add or delete} node entries for
+ * the same node or duplicate {add, delete, or update} properties entries
+ * for the same property.
+ *
+ * Returns 0 on success, or -EINVAL if duplicate changeset entry found.
+ */
+static int changeset_dup_entry_check(struct overlay_changeset *ovcs)
+{
+	struct of_changeset_entry *ce_1;
+	int dup_entry = 0;
+
+	list_for_each_entry(ce_1, &ovcs->cset.entries, node) {
+		dup_entry |= find_dup_cset_node_entry(ovcs, ce_1);
+		dup_entry |= find_dup_cset_prop(ovcs, ce_1);
+	}
+
+	return dup_entry ? -EINVAL : 0;
+}
+
 /**
  * build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments
  * @ovcs:	Overlay changeset
@@ -472,6 +634,7 @@ static int build_changeset_symbols_node(struct overlay_changeset *ovcs,
 static int build_changeset(struct overlay_changeset *ovcs)
 {
 	struct fragment *fragment;
+	struct target target;
 	int fragments_count, i, ret;
 
 	/*
@@ -486,25 +649,32 @@ static int build_changeset(struct overlay_changeset *ovcs)
 	for (i = 0; i < fragments_count; i++) {
 		fragment = &ovcs->fragments[i];
 
-		ret = build_changeset_next_level(ovcs, fragment->target,
+		target.np = fragment->target;
+		target.in_livetree = true;
+		ret = build_changeset_next_level(ovcs, &target,
 						 fragment->overlay);
 		if (ret) {
-			pr_debug("apply failed '%pOF'\n", fragment->target);
+			pr_debug("fragment apply failed '%pOF'\n",
+				 fragment->target);
 			return ret;
 		}
 	}
 
 	if (ovcs->symbols_fragment) {
 		fragment = &ovcs->fragments[ovcs->count - 1];
-		ret = build_changeset_symbols_node(ovcs, fragment->target,
+
+		target.np = fragment->target;
+		target.in_livetree = true;
+		ret = build_changeset_symbols_node(ovcs, &target,
 						   fragment->overlay);
 		if (ret) {
-			pr_debug("apply failed '%pOF'\n", fragment->target);
+			pr_debug("symbols fragment apply failed '%pOF'\n",
+				 fragment->target);
 			return ret;
 		}
 	}
 
-	return 0;
+	return changeset_dup_entry_check(ovcs);
 }
 
 /*
@@ -514,7 +684,7 @@ static int build_changeset(struct overlay_changeset *ovcs)
  * 1) "target" property containing the phandle of the target
  * 2) "target-path" property containing the path of the target
  */
-static struct device_node *find_target_node(struct device_node *info_node)
+static struct device_node *find_target(struct device_node *info_node)
 {
 	struct device_node *node;
 	const char *path;
@@ -620,7 +790,7 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs,
 
 		fragment = &fragments[cnt];
 		fragment->overlay = overlay_node;
-		fragment->target = find_target_node(node);
+		fragment->target = find_target(node);
 		if (!fragment->target) {
 			of_node_put(fragment->overlay);
 			ret = -EINVAL;
@@ -808,7 +978,7 @@ static int of_overlay_apply(const void *fdt, struct device_node *tree,
 
 	ret = __of_changeset_apply_notify(&ovcs->cset);
 	if (ret)
-		pr_err("overlay changeset entry notify error %d\n", ret);
+		pr_err("overlay apply changeset entry notify error %d\n", ret);
 	/* notify failure is not fatal, continue */
 
 	list_add_tail(&ovcs->ovcs_list, &ovcs_list);
@@ -1067,7 +1237,7 @@ int of_overlay_remove(int *ovcs_id)
 
 	ret = __of_changeset_revert_notify(&ovcs->cset);
 	if (ret)
-		pr_err("overlay changeset entry notify error %d\n", ret);
+		pr_err("overlay remove changeset entry notify error %d\n", ret);
 	/* notify failure is not fatal, continue */
 
 	*ovcs_id = 0;