Re: [PATCH v6 1/2] of: kobj: export of_node_ktype for use by modules

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The patch misdiagnoses the root cause of the linkage error and introduces a new modpost namespace error, while leaving non-KUnit modules vulnerable.
--

--- Patch [1]: [PATCH v6 1/2] of: kobj: export of_node_ktype for use by modules ---
commit b369d1afd3eb881423af86a559a0aec84ce01a01
Author: Xu Yang <xu.yang_2@nxp.com>

of: kobj: export of_node_ktype for use by modules

This commit attempts to fix a modpost build error where of_node_ktype is
undefined in the KUnit property-entry test by exporting the symbol via
EXPORT_SYMBOL_IF_KUNIT.

Link: https://lore.kernel.org/oe-kbuild-all/202607181651.RnUuV8n6-lkp@intel.com/

> diff --git a/drivers/of/kobj.c b/drivers/of/kobj.c
> index 1bb61a2c33994..081b8fa38603f 100644
> --- a/drivers/of/kobj.c
> +++ b/drivers/of/kobj.c

[ ... ]

> @@ -27,6 +28,7 @@ static void of_node_release(struct kobject *kobj)
>  const struct kobj_type of_node_ktype = {
>  	.release = of_node_release,
>  };
> +EXPORT_SYMBOL_IF_KUNIT(of_node_ktype);

[Severity: Medium]
Does this export actually resolve the build failure, or does it replace the
undefined symbol error with a modpost namespace error?

Since the property-entry test module likely lacks a corresponding
MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING"), the build might still fail
with an error indicating that the module uses a symbol from the
EXPORTED_FOR_KUNIT_TESTING namespace but does not import it.

Additionally, is the root cause actually the static inline of_node_init()
function in include/linux/of.h?

include/linux/of.h:of_node_init() {
#if defined(CONFIG_OF_KOBJ)
    kobject_init(&node->kobj, &of_node_ktype);
#endif
    fwnode_init(&node->fwnode, &of_fwnode_ops);
}

If non-KUnit modules include include/linux/of.h and are built with compiler
flags that emit out-of-line copies of unused static inline functions (such
as under KASAN or with keep-inline-functions), won't they still encounter
the undefined symbol error since of_node_ktype is only exported for KUnit?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260721105448.2109894-1-xu.yang_2@oss.nxp.com?part=1