[PATCH v8 1/8] powerpc: detect the secure boot mode of the system
From: Nayna Jain <nayna@linux.ibm.com>
Date: 2019-10-19 18:11:42
Also in:
linux-integrity, linuxppc-dev, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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
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; +}
--
2.20.1