[v8,1/8] powerpc: detect the secure boot mode of the system
diff mbox series

Message ID 1571508377-23603-2-git-send-email-nayna@linux.ibm.com
State Superseded
Headers show
Series
  • powerpc: Enabling IMA arch specific secure boot policies
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Commit Message

Nayna Jain Oct. 19, 2019, 6:06 p.m. UTC
This patch defines a function to detect the secure boot state of a
PowerNV system.

The PPC_SECURE_BOOT config represents the base enablement of secure boot
for powerpc.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
---
 arch/powerpc/Kconfig                   | 10 +++++++++
 arch/powerpc/include/asm/secure_boot.h | 23 ++++++++++++++++++++
 arch/powerpc/kernel/Makefile           |  2 ++
 arch/powerpc/kernel/secure_boot.c      | 30 ++++++++++++++++++++++++++
 4 files changed, 65 insertions(+)
 create mode 100644 arch/powerpc/include/asm/secure_boot.h
 create mode 100644 arch/powerpc/kernel/secure_boot.c

Comments

Michael Ellerman Oct. 22, 2019, 11:37 p.m. UTC | #1
Nayna Jain <nayna@linux.ibm.com> writes:
> diff --git a/arch/powerpc/kernel/secure_boot.c b/arch/powerpc/kernel/secure_boot.c
> new file mode 100644
> index 000000000000..99bba7915629
> --- /dev/null
> +++ b/arch/powerpc/kernel/secure_boot.c
> @@ -0,0 +1,30 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019 IBM Corporation
> + * Author: Nayna Jain
> + */
> +#include <linux/types.h>
> +#include <linux/of.h>
> +#include <asm/secure_boot.h>
> +
> +bool is_ppc_secureboot_enabled(void)
> +{
> +	struct device_node *node;
> +	bool enabled = false;
> +
> +	node = of_find_compatible_node(NULL, NULL, "ibm,secvar-v1");

If this found a node then you have a node with an elevated refcount
which you need to drop on the way out.

> +	if (!of_device_is_available(node)) {
> +		pr_err("Cannot find secure variable node in device tree; failing to secure state\n");
> +		goto out;
> +	}
> +
> +	/*
> +	 * secureboot is enabled if os-secure-enforcing property exists,
> +	 * else disabled.
> +	 */
> +	enabled = of_property_read_bool(node, "os-secure-enforcing");
> +
> +out:

So here you need:

	of_node_put(node);


> +	pr_info("Secure boot mode %s\n", enabled ? "enabled" : "disabled");
> +	return enabled;
> +}

cheers

Patch
diff mbox series

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 3e56c9c2f16e..56ea0019b616 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -934,6 +934,16 @@  config PPC_MEM_KEYS
 
 	  If unsure, say y.
 
+config PPC_SECURE_BOOT
+	prompt "Enable secure boot support"
+	bool
+	depends on PPC_POWERNV
+	help
+	  Systems with firmware secure boot enabled need to define security
+	  policies to extend secure boot to the OS. This config allows a user
+	  to enable OS secure boot on systems that have firmware support for
+	  it. If in doubt say N.
+
 endmenu
 
 config ISA_DMA_API
diff --git a/arch/powerpc/include/asm/secure_boot.h b/arch/powerpc/include/asm/secure_boot.h
new file mode 100644
index 000000000000..07d0fe0ca81f
--- /dev/null
+++ b/arch/powerpc/include/asm/secure_boot.h
@@ -0,0 +1,23 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Secure boot definitions
+ *
+ * Copyright (C) 2019 IBM Corporation
+ * Author: Nayna Jain
+ */
+#ifndef _ASM_POWER_SECURE_BOOT_H
+#define _ASM_POWER_SECURE_BOOT_H
+
+#ifdef CONFIG_PPC_SECURE_BOOT
+
+bool is_ppc_secureboot_enabled(void);
+
+#else
+
+static inline bool is_ppc_secureboot_enabled(void)
+{
+	return false;
+}
+
+#endif
+#endif
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index a7ca8fe62368..e2a54fa240ac 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -161,6 +161,8 @@  ifneq ($(CONFIG_PPC_POWERNV)$(CONFIG_PPC_SVM),)
 obj-y				+= ucall.o
 endif
 
+obj-$(CONFIG_PPC_SECURE_BOOT)	+= secure_boot.o
+
 # Disable GCOV, KCOV & sanitizers in odd or sensitive code
 GCOV_PROFILE_prom_init.o := n
 KCOV_INSTRUMENT_prom_init.o := n
diff --git a/arch/powerpc/kernel/secure_boot.c b/arch/powerpc/kernel/secure_boot.c
new file mode 100644
index 000000000000..99bba7915629
--- /dev/null
+++ b/arch/powerpc/kernel/secure_boot.c
@@ -0,0 +1,30 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 IBM Corporation
+ * Author: Nayna Jain
+ */
+#include <linux/types.h>
+#include <linux/of.h>
+#include <asm/secure_boot.h>
+
+bool is_ppc_secureboot_enabled(void)
+{
+	struct device_node *node;
+	bool enabled = false;
+
+	node = of_find_compatible_node(NULL, NULL, "ibm,secvar-v1");
+	if (!of_device_is_available(node)) {
+		pr_err("Cannot find secure variable node in device tree; failing to secure state\n");
+		goto out;
+	}
+
+	/*
+	 * secureboot is enabled if os-secure-enforcing property exists,
+	 * else disabled.
+	 */
+	enabled = of_property_read_bool(node, "os-secure-enforcing");
+
+out:
+	pr_info("Secure boot mode %s\n", enabled ? "enabled" : "disabled");
+	return enabled;
+}