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of: overlay: validate overlay properties #address-cells and #size-cells 

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: Alan Tull <atull@kernel.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
This commit is contained in:
Frank Rowand 2018-10-04 20:32:04 -07:00
parent 81225ea682
commit 6f75118800
2 changed files with 35 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
drivers/of/overlay.c
View File

@ -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);

6
include/linux/of.h
View File

@ -990,6 +990,12 @@ static inline int of_map_rid(struct device_node *np, u32 rid,
#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