linux-kernel - Re: [PATCH 1/1] ACPI: property: Return present device nodes only on fwnode interface

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CAJZ5v0hdgbLG3fjtsiWcKS0JO0r=O3zywvZhOqn26xEG3VnMbw@mail.gmail.com>
Date: Wed, 1 Oct 2025 20:49:59 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Sakari Ailus <sakari.ailus@...ux.intel.com>
Cc: linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org, 
	"Rafael J. Wysocki" <rafael@...nel.org>, Len Brown <lenb@...nel.org>, 
	Dmitry Torokhov <dmitry.torokhov@...il.com>, 
	Laurent Pinchart <laurent.pinchart@...asonboard.com>, 
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>, 
	Jonathan Cameron <Jonathan.Cameron@...wei.com>
Subject: Re: [PATCH 1/1] ACPI: property: Return present device nodes only on
 fwnode interface

On Wed, Oct 1, 2025 at 12:26 PM Sakari Ailus
<sakari.ailus@...ux.intel.com> wrote:
>
> fwnode_graph_get_next_subnode() may return fwnode backed by ACPI device
> nodes and there has been no check these devices are present in the system,
> unlike there has been on fwnode OF backend. In order to provide consistent
> behaviour towards callers, add a check for device presence by introducing
> a new function acpi_get_next_present_subnode(), used as the
> get_next_child_node() fwnode operation that also checks device node
> presence.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@...ux.intel.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@...asonboard.com>
> Reviewed-by: Jonathan Cameron <jonathan.cameron@...wei.com>
> ---
>  drivers/acpi/property.c | 24 +++++++++++++++++++++++-
>  1 file changed, 23 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
> index 436019d96027..10bab30300f3 100644
> --- a/drivers/acpi/property.c
> +++ b/drivers/acpi/property.c
> @@ -1318,6 +1318,28 @@ struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode,
>         return NULL;
>  }
>
> +/*
> + * acpi_get_next_present_subnode - Return the next present child node handle for a fwnode
> + * @fwnode: Firmware node to find the next child node for.
> + * @child: Handle to one of the device's child nodes or a null handle.
> + *
> + * Like acpi_get_next_subnode(), but the device nodes returned by
> + * acpi_get_next_present_subnode() are guaranteed to be present.
> + *
> + * Returns: The next sub-node fwnode handle.
> + */
> +static struct fwnode_handle *
> +acpi_get_next_present_subnode(const struct fwnode_handle *fwnode,
> +                             struct fwnode_handle *child)
> +{
> +       do {
> +               child = acpi_get_next_subnode(fwnode, child);
> +       } while (is_acpi_device_node(child) &&
> +                !acpi_device_is_present(to_acpi_device_node(child)));
> +
> +       return child;
> +}
> +
>  /**
>   * acpi_node_get_parent - Return parent fwnode of this fwnode
>   * @fwnode: Firmware node whose parent to get
> @@ -1662,7 +1684,7 @@ static int acpi_fwnode_irq_get(const struct fwnode_handle *fwnode,
>                 .property_read_string_array =                           \
>                         acpi_fwnode_property_read_string_array,         \
>                 .get_parent = acpi_node_get_parent,                     \
> -               .get_next_child_node = acpi_get_next_subnode,           \
> +               .get_next_child_node = acpi_get_next_present_subnode,   \
>                 .get_named_child_node = acpi_fwnode_get_named_child_node, \
>                 .get_name = acpi_fwnode_get_name,                       \
>                 .get_name_prefix = acpi_fwnode_get_name_prefix,         \
> --

Applied with some minor tweaks as 6.18 material, thanks!