Commit 420f0de9 authored by Rob Herring's avatar Rob Herring
Browse files

of: dynamic: Fix race in getting old property when updating property 



__of_update_property() returns the existing property if there is one, but
that value is never added to the changeset. Updates work because the
existing property was also retrieved before in of_changeset_action(),
but that is racy as of_changeset_action() doesn't hold any locks. The
property could be changed before the changeset is applied.

Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Tested-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230801-dt-changeset-fixes-v3-4-5f0410e007dd@kernel.org


Signed-off-by: default avatarRob Herring <robh@kernel.org>
parent 27a02f26

drivers/of/dynamic.c

+2 −5
Original line number Diff line number Diff line
@@ -564,7 +564,7 @@ static int __of_changeset_entry_notify(struct of_changeset_entry *ce, 


static int __of_changeset_entry_apply(struct of_changeset_entry *ce)

{

	struct property *old_prop, **propp;

	struct property **propp;

	unsigned long flags;

	int ret = 0;
@@ -604,7 +604,7 @@ static int __of_changeset_entry_apply(struct of_changeset_entry *ce) 
			}

		}



		ret = __of_update_property(ce->np, ce->prop, &old_prop);

		ret = __of_update_property(ce->np, ce->prop, &ce->old_prop);

		break;

	default:

		ret = -EINVAL;
@@ -908,9 +908,6 @@ int of_changeset_action(struct of_changeset *ocs, unsigned long action, 
	ce->np = of_node_get(np);

	ce->prop = prop;



	if (action == OF_RECONFIG_UPDATE_PROPERTY && prop)

		ce->old_prop = of_find_property(np, prop->name, NULL);



	/* add it to the list */

	list_add_tail(&ce->node, &ocs->entries);

	return 0;