[PATCH v2 5/5] security: kernel_pinctrl: fixup pinctrl in kernel dts

[Sascha Hauer]

On Mon, Mar 16, 2026 at 12:36:32PM +0100, Fabian Pflug wrote:
> Going through the kernel dts and replacing
> barebox,policy-<active_policy> with default in order to change pinctrl
> not only for barebox, but also for kernel when booting with security
> profiles.
> 
> Signed-off-by: Fabian Pflug <f.pflug at pengutronix.de>
> ---
>  security/Makefile         |  1 +
>  security/kernel_pinctrl.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 59 insertions(+)
> 
> diff --git a/security/Makefile b/security/Makefile
> index 1096cbfb9b..2e8cdfe7c2 100644
> --- a/security/Makefile
> +++ b/security/Makefile
> @@ -2,6 +2,7 @@
>  
>  obj-$(CONFIG_SECURITY_POLICY)		+= policy.o
>  obj-$(CONFIG_SECURITY_POLICY_NAMES)	+= sconfig_names.o
> +obj-$(CONFIG_SECURITY_POLICY_PINCTRL)	+= kernel_pinctrl.o
>  obj-$(CONFIG_CRYPTO_KEYSTORE)	+= keystore.o
>  obj-$(CONFIG_JWT)		+= jwt.o
>  obj-pbl-$(CONFIG_HAVE_OPTEE)	+= optee.o
> diff --git a/security/kernel_pinctrl.c b/security/kernel_pinctrl.c
> new file mode 100644
> index 0000000000..af65961bbc
> --- /dev/null
> +++ b/security/kernel_pinctrl.c
> @@ -0,0 +1,58 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <common.h>
> +#include <linux/printk.h>
> +#include <pinctrl.h>
> +#include <security/policy.h>
> +#include <security/config.h>
> +
> +#define NUM_NAMES	10
> +
> +
> +/**
> + * Replace 'default' with 'old_default' and 'barebox,policy-<active_policy>'
> + * with 'default', if both are found in pinctrl.
> + */
> +static void kernel_of_fixup_pinctrl(struct device_node *node, char *policy_name)
> +{
> +	const char *names[NUM_NAMES];
> +	int num_read, pos_default, pos_policy;

You could reduce the scope of these variables.

> +	struct device_node *next;
> +
> +	while (node) {

list_for_each_entry(np, &node->list, list)

Or move the of_tree_for_each_node_from macro to include/of.h

> +		num_read = of_property_read_string_array(node, "pinctrl-names", names, NUM_NAMES);
> +
> +		pos_default = -1;
> +		pos_policy = -1;
> +		for (int i = 0; i < num_read; i++) {
> +			if (strcmp(policy_name, names[i]) == 0)
> +				pos_policy = i;
> +			if (strcmp("default", names[i]) == 0)
> +				pos_default = i;
> +		}
> +		if (pos_default >= 0 && pos_policy >= 0) {
> +			names[pos_default] = "old_default";
> +			names[pos_policy] = "default";
> +			of_property_write_string_array(node, "pinctrl-names", names, num_read);
> +		}
> +
> +		next = list_first_entry(&node->list, struct device_node, list);
> +		node = next->parent ? next : NULL;
> +	}
> +}

Sascha

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