[PATCH 0/2] of: overlay: of_overlay_fix_path: allow symbols without __overlay__

[PATCH 0/2] of: overlay: of_overlay_fix_path: allow symbols without __overlay__

[Stefan Kerkmann]

Signed-off-by: Stefan Kerkmann <s.kerkmann@pengutronix.de>
---
Stefan Kerkmann (2):
      of: overlay: of_overlay_fix_path: allow symbols without __overlay__
      of: overlay: fix_path/apply_symbols: add more debugging calls

 drivers/of/overlay.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)
---
base-commit: e82842ffe3c7993dac4f8493fb4a44c4d35810ca
change-id: 20261014-fix-overlay-b53fbdff8ddc

Best regards,
--  
Stefan Kerkmann <s.kerkmann@pengutronix.de>

[PATCH 1/2] of: overlay: of_overlay_fix_path: allow symbols without __overlay__

[Stefan Kerkmann]

An overlay with a label entry in the `__symbols__` table without a
matching fragment that contains an `__overlay__` is not an error. This
matches the behavior of the dtc libfdt implementation[1].

This edge case was triggered by:

1. Enabling CONFIG_OF_OVERLAY_LIVE this adds a `__symbols__` table to
   device trees compiled by barebox.

2. Passing the barebox devicetree via TF-A to OP-TEE that adds overlay
   fragments to the barebox device tree.

3. Enabling CONFIG_OPTEE_APPLY_OVERLAY and applying the same DT again as
   a DT overlay. The DT in this case was expanded by OP-TEE with overlay
   fragments (and still contains the __symbol__ table with entries that
   do not reference the OP-TEE fragments).

[1]: 5c715a4 ("fdtoverlay: Ignore symbols in overlays which don't apply to the target tree")

Fixes: 6553d2c2a5e3 ("of: overlay: avoid potential null pointer exception")
Signed-off-by: Stefan Kerkmann <s.kerkmann@pengutronix.de>
---
 drivers/of/overlay.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 4ce45513ea..410c6d3565 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -110,13 +110,13 @@ static char *of_overlay_fix_path(struct device_node *root,
 			break;
 	}
 	if (!fragment) {
-		pr_info("could not find __overlay__ node\n");
+		pr_debug("could not find __overlay__ node for %s\n", path);
 		return NULL;
 	}
 
 	target = find_target(root, fragment, false);
 	if (!target)
-		return NULL;
+		return ERR_PTR(-EINVAL);
 
 	prefix = of_get_child_by_name(fragment, "__overlay__")->full_name;
 	path_tail = path + strlen(prefix);
@@ -152,8 +152,10 @@ static int of_overlay_apply_symbols(struct device_node *root,
 
 		old_path = of_property_get_value(prop);
 		new_path = of_overlay_fix_path(root, overlay, old_path);
+		if (IS_ERR(new_path))
+			return PTR_ERR(new_path);
 		if (!new_path)
-			return -EINVAL;
+			continue;
 
 		pr_debug("add symbol %s with new path %s\n",
 			 prop->name, new_path);

-- 
2.47.3

[PATCH 2/2] of: overlay: fix_path/apply_symbols: add more debugging calls

[Stefan Kerkmann]

Signed-off-by: Stefan Kerkmann <s.kerkmann@pengutronix.de>
---
 drivers/of/overlay.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 410c6d3565..83c947d044 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -114,6 +114,8 @@ static char *of_overlay_fix_path(struct device_node *root,
 		return NULL;
 	}
 
+	pr_debug("using fragment %pOF\n", fragment);
+
 	target = find_target(root, fragment, false);
 	if (!target)
 		return ERR_PTR(-EINVAL);
@@ -157,8 +159,8 @@ static int of_overlay_apply_symbols(struct device_node *root,
 		if (!new_path)
 			continue;
 
-		pr_debug("add symbol %s with new path %s\n",
-			 prop->name, new_path);
+		pr_debug("add symbol %s with new path %s (was %s)\n",
+			 prop->name, new_path, old_path);
 		of_property_write_string(root_symbols, prop->name, new_path);
 		free(new_path);
 	}

-- 
2.47.3

Re: [PATCH 0/2] of: overlay: of_overlay_fix_path: allow symbols without __overlay__

[Stefan Kerkmann]

Hi Sascha,

I'll sent a V2 shortly which adds self tests and one more fix. Please don't apply.


On 10/14/26 17:09, Stefan Kerkmann wrote:
> Signed-off-by: Stefan Kerkmann <s.kerkmann@pengutronix.de>
> ---
> Stefan Kerkmann (2):
>        of: overlay: of_overlay_fix_path: allow symbols without __overlay__
>        of: overlay: fix_path/apply_symbols: add more debugging calls
> 
>   drivers/of/overlay.c | 14 +++++++++-----
>   1 file changed, 9 insertions(+), 5 deletions(-)
> ---
> base-commit: e82842ffe3c7993dac4f8493fb4a44c4d35810ca
> change-id: 20261014-fix-overlay-b53fbdff8ddc
> 
> Best regards,
> --
> Stefan Kerkmann <s.kerkmann@pengutronix.de>

Best regards,
Stefan

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