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Message-Id: <20230801-dt-changeset-fixes-v3-2-5f0410e007dd@kernel.org>
Date: Fri, 18 Aug 2023 15:40:57 -0500
From: Rob Herring <robh@...nel.org>
To: Frank Rowand <frowand.list@...il.com>,
"Enrico Weigelt, metux IT consult" <info@...ux.net>,
"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
Sakari Ailus <sakari.ailus@...ux.intel.com>,
Petr Mladek <pmladek@...e.com>,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
Geert Uytterhoeven <geert+renesas@...der.be>
Cc: devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v3 2/6] 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 the multiple prints is the
action name, use the existing "action_names" to refactor the prints into
a single print.
Fixes: a92eb7621b9fb2c2 ("lib/vsprintf: Make use of fwnode API to obtain node names and separators")
Reported-by: Geert Uytterhoeven <geert+renesas@...der.be>
Signed-off-by: Rob Herring <robh@...nel.org>
---
v6 (v3 in this series):
- Add check on 'action' bounds. As action is only set in
of_changeset_action(), add the check there.
- Drop printing the changeset entry pointer
v5 (v2 in this series):
- Move majority of refactoring to separate patch and minimize the fix
to just moving the print out of the locked section.
v4:
- Add missing 'static' reported by 0-day
v3:
- Re-implement Geert's fix to move the prints rather than move the
spinlock
v1 and v2 from Geert simply moved the devtree_lock into each case
statement:
https://lore.kernel.org/all/c593d8389352c574b5be69d4ca4810da13326a50.1690533838.git.geert+renesas@glider.be/
---
drivers/of/dynamic.c | 31 +++++++++----------------------
1 file changed, 9 insertions(+), 22 deletions(-)
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index e311d406b170..4999636eaa92 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -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);
--
2.40.1
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