[PATCH v3 11/12] of: overlay: remove a dependency on device node full_name

From: frowand . list
Date: Tue Oct 17 2017 - 19:37:05 EST


From: Frank Rowand <frank.rowand@xxxxxxxx>

The "%pOF" printf format was recently added to print the
full name of a device tree node, with the intent of changing
the node full_name field to contain only the node name instead
of the full path of the node.

dup_and_fixup_symbol_prop() duplicates a property from the
"/__symbols__" node of an overlay device tree. The value
of each duplicated property must be fixed up to include
the full path of a node in the live device tree. The
current code uses the node's full_name for that purpose.
Update the code to use the "%pOF" printf format to
determine the node's full path.

Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxx>
---
drivers/of/base.c | 2 +-
drivers/of/of_private.h | 2 ++
drivers/of/overlay.c | 90 ++++++++++++++++++++++++++++++-------------------
3 files changed, 59 insertions(+), 35 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index b98f3adffbb0..3de07e6e82a0 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -658,7 +658,7 @@ struct device_node *of_get_child_by_name(const struct device_node *node,
}
EXPORT_SYMBOL(of_get_child_by_name);

-static struct device_node *__of_find_node_by_path(struct device_node *parent,
+struct device_node *__of_find_node_by_path(struct device_node *parent,
const char *path)
{
struct device_node *child;
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 248730567dbe..92a9a3687446 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -110,6 +110,8 @@ extern void *__unflatten_device_tree(const void *blob,
struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags);
__printf(2, 3) struct device_node *__of_node_dup(const struct device_node *np, const char *fmt, ...);

+struct device_node *__of_find_node_by_path(struct device_node *parent,
+ const char *path);
struct device_node *__of_find_node_by_full_path(struct device_node *node,
const char *path);

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 602218e07ec3..0e9aefc1ff15 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -37,6 +37,7 @@ struct fragment {
/**
* struct overlay_changeset
* @ovcs_list: list on which we are located
+ * @overlay_tree: expanded device tree that contains the fragment nodes
* @count: count of fragment structures
* @fragments: fragment nodes in the overlay expanded device tree
* @symbols_fragment: last element of @fragments[] is the __symbols__ node
@@ -45,6 +46,7 @@ struct fragment {
struct overlay_changeset {
int id;
struct list_head ovcs_list;
+ struct device_node *overlay_tree;
int count;
struct fragment *fragments;
bool symbols_fragment;
@@ -145,12 +147,13 @@ static int overlay_notify(struct overlay_changeset *ovcs,
}

/*
- * The properties in the "/__symbols__" node are "symbols".
+ * The values of properties in the "/__symbols__" node are paths in
+ * the ovcs->overlay_tree. When duplicating the properties, the paths
+ * need to be adjusted to be the correct path for the live device tree.
*
- * The value of properties in the "/__symbols__" node is the path of a
- * node in the subtree of a fragment node's "__overlay__" node, for
- * example "/fragment@0/__overlay__/symbol_path_tail". Symbol_path_tail
- * can be a single node or it may be a multi-node path.
+ * The paths refer to a node in the subtree of a fragment node's "__overlay__"
+ * node, for example "/fragment@0/__overlay__/symbol_path_tail",
+ * where symbol_path_tail can be a single node or it may be a multi-node path.
*
* The duplicated property value will be modified by replacing the
* "/fragment_name/__overlay/" portion of the value with the target
@@ -160,59 +163,76 @@ static struct property *dup_and_fixup_symbol_prop(
struct overlay_changeset *ovcs, const struct property *prop)
{
struct fragment *fragment;
- struct property *new;
- const char *overlay_name;
- char *symbol_path_tail;
- char *symbol_path;
+ struct property *new_prop;
+ struct device_node *fragment_node;
+ struct device_node *overlay_node;
+ const char *path;
+ const char *path_tail;
const char *target_path;
int k;
- int symbol_path_tail_len;
int overlay_name_len;
+ int path_len;
+ int path_tail_len;
int target_path_len;

if (!prop->value)
return NULL;
- symbol_path = prop->value;
+ if (strnlen(prop->value, prop->length) >= prop->length)
+ return NULL;
+ path = prop->value;
+ path_len = strlen(path);

- new = kzalloc(sizeof(*new), GFP_KERNEL);
- if (!new)
+ if (path_len < 1)
return NULL;
+ fragment_node = __of_find_node_by_path(ovcs->overlay_tree, path + 1);
+ overlay_node = __of_find_node_by_path(fragment_node, "__overlay__/");
+ of_node_put(fragment_node);
+ of_node_put(overlay_node);

for (k = 0; k < ovcs->count; k++) {
fragment = &ovcs->fragments[k];
- overlay_name = fragment->overlay->full_name;
- overlay_name_len = strlen(overlay_name);
- if (!strncasecmp(symbol_path, overlay_name, overlay_name_len))
+ if (fragment->overlay == overlay_node)
break;
}
-
if (k >= ovcs->count)
- goto err_free;
+ return NULL;
+
+ overlay_name_len = snprintf(NULL, 0, "%pOF", fragment->overlay);

- target_path = fragment->target->full_name;
+ if (overlay_name_len > path_len)
+ return NULL;
+ path_tail = path + overlay_name_len;
+ path_tail_len = strlen(path_tail);
+
+ target_path = kasprintf(GFP_KERNEL, "%pOF", fragment->target);
+ if (!target_path)
+ return NULL;
target_path_len = strlen(target_path);

- symbol_path_tail = symbol_path + overlay_name_len;
- symbol_path_tail_len = strlen(symbol_path_tail);
+ new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
+ if (!new_prop)
+ goto err_free_target_path;

- new->name = kstrdup(prop->name, GFP_KERNEL);
- new->length = target_path_len + symbol_path_tail_len + 1;
- new->value = kzalloc(new->length, GFP_KERNEL);
+ new_prop->name = kstrdup(prop->name, GFP_KERNEL);
+ new_prop->length = target_path_len + path_tail_len + 1;
+ new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);
+ if (!new_prop->name || !new_prop->value)
+ goto err_free_new_prop;

- if (!new->name || !new->value)
- goto err_free;
+ strcpy(new_prop->value, target_path);
+ strcpy(new_prop->value + target_path_len, path_tail);

- strcpy(new->value, target_path);
- strcpy(new->value + target_path_len, symbol_path_tail);
+ of_property_set_flag(new_prop, OF_DYNAMIC);

- of_property_set_flag(new, OF_DYNAMIC);
+ return new_prop;

- return new;
+err_free_new_prop:
+ kfree(new_prop->name);
+ kfree(new_prop->value);
+ kfree(new_prop);
+err_free_target_path:
+ kfree(target_path);

- err_free:
- kfree(new->name);
- kfree(new->value);
- kfree(new);
return NULL;
}

@@ -519,6 +539,8 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs,
if (!of_node_is_root(tree))
pr_debug("%s() tree is not root\n", __func__);

+ ovcs->overlay_tree = tree;
+
INIT_LIST_HEAD(&ovcs->ovcs_list);

of_changeset_init(&ovcs->cset);
--
Frank Rowand <frank.rowand@xxxxxxxx>