Commit 914d9d83 authored by Rob Herring's avatar Rob Herring
Browse files

of: dynamic: Refactor action prints to not use "%pOF" inside devtree_lock 



While originally it was fine to format strings using "%pOF" while
holding devtree_lock, this now causes a deadlock.  Lockdep reports:

    of_get_parent from of_fwnode_get_parent+0x18/0x24
    ^^^^^^^^^^^^^
    of_fwnode_get_parent from fwnode_count_parents+0xc/0x28
    fwnode_count_parents from fwnode_full_name_string+0x18/0xac
    fwnode_full_name_string from device_node_string+0x1a0/0x404
    device_node_string from pointer+0x3c0/0x534
    pointer from vsnprintf+0x248/0x36c
    vsnprintf from vprintk_store+0x130/0x3b4

Fix this by moving the printing in __of_changeset_entry_apply() outside
the lock. As the only difference in the multiple prints is the action
name, use the existing "action_names" to refactor the prints into a
single print.

Fixes: a92eb762 ("lib/vsprintf: Make use of fwnode API to obtain node names and separators")
Cc: stable@vger.kernel.org
Reported-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230801-dt-changeset-fixes-v3-2-5f0410e007dd@kernel.org


Signed-off-by: default avatarRob Herring <robh@kernel.org>
parent 0aeae378

drivers/of/dynamic.c

+9 −22
Original line number Diff line number Diff line
@@ -63,15 +63,14 @@ int of_reconfig_notifier_unregister(struct notifier_block *nb) 
}

EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);



#ifdef DEBUG

const char *action_names[] = {

static const char *action_names[] = {

	[0] = "INVALID",

	[OF_RECONFIG_ATTACH_NODE] = "ATTACH_NODE",

	[OF_RECONFIG_DETACH_NODE] = "DETACH_NODE",

	[OF_RECONFIG_ADD_PROPERTY] = "ADD_PROPERTY",

	[OF_RECONFIG_REMOVE_PROPERTY] = "REMOVE_PROPERTY",

	[OF_RECONFIG_UPDATE_PROPERTY] = "UPDATE_PROPERTY",

};

#endif



int of_reconfig_notify(unsigned long action, struct of_reconfig_data *p)

{
@@ -620,21 +619,9 @@ static int __of_changeset_entry_apply(struct of_changeset_entry *ce) 
		}



		ret = __of_add_property(ce->np, ce->prop);

		if (ret) {

			pr_err("changeset: add_property failed @%pOF/%s\n",

				ce->np,

				ce->prop->name);

			break;

		}

		break;

	case OF_RECONFIG_REMOVE_PROPERTY:

		ret = __of_remove_property(ce->np, ce->prop);

		if (ret) {

			pr_err("changeset: remove_property failed @%pOF/%s\n",

				ce->np,

				ce->prop->name);

			break;

		}

		break;



	case OF_RECONFIG_UPDATE_PROPERTY:
@@ -648,20 +635,17 @@ static int __of_changeset_entry_apply(struct of_changeset_entry *ce) 
		}



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

		if (ret) {

			pr_err("changeset: update_property failed @%pOF/%s\n",

				ce->np,

				ce->prop->name);

			break;

		}

		break;

	default:

		ret = -EINVAL;

	}

	raw_spin_unlock_irqrestore(&devtree_lock, flags);



	if (ret)

	if (ret) {

		pr_err("changeset: apply failed: %-15s %pOF:%s\n",

		       action_names[ce->action], ce->np, ce->prop->name);

		return ret;

	}



	switch (ce->action) {

	case OF_RECONFIG_ATTACH_NODE:
@@ -947,6 +931,9 @@ int of_changeset_action(struct of_changeset *ocs, unsigned long action, 
	if (!ce)

		return -ENOMEM;



	if (WARN_ON(action >= ARRAY_SIZE(action_names)))

		return -EINVAL;



	/* get a reference to the node */

	ce->action = action;

	ce->np = of_node_get(np);