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Commit 15151d00 authored by Frank Rowand's avatar Frank Rowand Committed by Greg Kroah-Hartman
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of: overlay: validate overlay properties #address-cells and #size-cells 



commit 6f75118800acf77f8ad6afec61ca1b2349ade371 upstream.

If overlay properties #address-cells or #size-cells are already in
the live devicetree for any given node, then the values in the
overlay must match the values in the live tree.

If the properties are already in the live tree then there is no
need to create a changeset entry to add them since they must
have the same value.  This reduces the memory used by the
changeset and eliminates a possible memory leak.

Tested-by: default avatarAlan Tull <atull@kernel.org>
Signed-off-by: default avatarFrank Rowand <frank.rowand@sony.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 26dace36

drivers/of/overlay.c

+29 −3
Original line number Diff line number Diff line
@@ -287,7 +287,12 @@ static struct property *dup_and_fixup_symbol_prop( 
 * @target may be either in the live devicetree or in a new subtree that

 * is contained in the changeset.

 *

 * Some special properties are not updated (no error returned).

 * 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.

 *
@@ -300,6 +305,7 @@ static int add_changeset_property(struct overlay_changeset *ovcs, 
{

	struct property *new_prop = NULL, *prop;

	int ret = 0;

	bool check_for_non_overlay_node = false;



	if (!of_prop_cmp(overlay_prop->name, "name") ||

	    !of_prop_cmp(overlay_prop->name, "phandle") ||
@@ -322,12 +328,32 @@ static int add_changeset_property(struct overlay_changeset *ovcs, 
	if (!new_prop)

		return -ENOMEM;



	if (!prop)

	if (!prop) {

		check_for_non_overlay_node = true;

		ret = of_changeset_add_property(&ovcs->cset, target->np,

						new_prop);

	else

	} 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);

include/linux/of.h

+6 −0
Original line number Diff line number Diff line
@@ -968,6 +968,12 @@ static inline int of_cpu_node_to_id(struct device_node *np) 
#define of_node_cmp(s1, s2)		strcasecmp((s1), (s2))

#endif



static inline int of_prop_val_eq(struct property *p1, struct property *p2)

{

	return p1->length == p2->length &&

	       !memcmp(p1->value, p2->value, (size_t)p1->length);

}



#if defined(CONFIG_OF) && defined(CONFIG_NUMA)

extern int of_node_to_nid(struct device_node *np);

#else