On Tue Feb 3, 2026 at 2:35 PM CET, Kory Maincent wrote:
> On Tue, 3 Feb 2026 10:57:47 +0100
> Kory Maincent <[email protected]> wrote:
>
>> On Fri, 30 Jan 2026 00:21:19 +0800
>> Felix Gu <[email protected]> wrote:
>>
>> > The logicvc_drm_config_parse() function calls of_get_child_by_name() to
>> > find the "layers" node but fails to release the reference, leading to a
>> > device node reference leak.
>> >
>> > Fix this by using the __free(device_node) cleanup attribute to automatic
>> > release the reference when the variable goes out of scope.
>> >
>> > Fixes: efeeaefe9be5 ("drm: Add support for the LogiCVC display controller")
>> > Signed-off-by: Felix Gu <[email protected]>
>> > ---
>> >  drivers/gpu/drm/logicvc/logicvc_drm.c | 4 ++--
>> >  1 file changed, 2 insertions(+), 2 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/logicvc/logicvc_drm.c
>> > b/drivers/gpu/drm/logicvc/logicvc_drm.c index 204b0fee55d0..bbebf4fc7f51
>> > 100644 --- a/drivers/gpu/drm/logicvc/logicvc_drm.c
>> > +++ b/drivers/gpu/drm/logicvc/logicvc_drm.c
>> > @@ -92,7 +92,6 @@ static int logicvc_drm_config_parse(struct logicvc_drm
>> > *logicvc) struct device *dev = drm_dev->dev;
>> >    struct device_node *of_node = dev->of_node;
>> >    struct logicvc_drm_config *config = &logicvc->config;
>> > -  struct device_node *layers_node;
>> >    int ret;
>> >
>> >    logicvc_of_property_parse_bool(of_node,
>> > LOGICVC_OF_PROPERTY_DITHERING, @@ -128,7 +127,8 @@ static int
>> > logicvc_drm_config_parse(struct logicvc_drm *logicvc) if (ret)
>> >            return ret;
>> >
>> > -  layers_node = of_get_child_by_name(of_node, "layers");
>> > +  struct device_node *layers_node __free(device_node) =
>> > +          of_get_child_by_name(of_node, "layers");
>>
>> We usualy don't declare variable in the middle of a function.
>> You should rather simply change the declaration line at the top like this:
>> struct device_node *layers_node __free(device_node) = NULL;
>
> It seems Linus disagree on this topic and I understand his arguments:
> https://lore.kernel.org/all/CAHk-=whpzoi03zwphxiw6cuwptc3nykys8_bthgztcdgpwp...@mail.gmail.com/
> https://lore.kernel.org/all/CAHk-=wicotw5ufturanvjkr6769d29tf7of79gujdqhs_tk...@mail.gmail.com/

I agree it makes code much more readable, espacially in the case of cleanup
actions.

> Then, ok to me:
> Reviewed-by: Kory Maincent <[email protected]>

Thanks! I'm applying this patch to drm-misc-fixes perhaps next week.

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

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