of: base: Handle optional argument in of_parse_phandle_with_args_map()

The kernel doc claims out_args is optional. In practice, the function
unconditionally dereferences it. It feels like calling this function
with a NULL out_args argument may be a valid use case (in order to know
if the lookup would work, even though we might not care about the
result), even though in practice there seem to be no actual user of that
possibility. All callers give an on-stack object to fill.

There are two ways out: either we drop the "optional" wording from the
kernel doc, or we handle the NULL case properly. Since handling this
case goes in favor of more harmonization of the semantics and since
of_parse_phandle_with_args() actually do handle that situation
correctly, let's handle it in the _map() case as well.

Use a local on-stack object in case no argument is passed. This way, we
actually go through the same logic as if there was an argument. We may
however return rather early, since the second part of the function is
dedicated at filling that argument.

Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260710183359.61D3A1F000E9@smtp.kernel.org/
Signed-off-by: Miquel Raynal (Schneider Electric) <miquel.raynal@bootlin.com>
Link: https://patch.msgid.link/20260716-schneider-v7-2-rc1-eip-of-fix-v1-1-9b9383f936c6@bootlin.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

0 files changed, 0 insertions, 0 deletions