[PATCH 5/6] arm64/ima: add ima arch support

[Chester Lin]

Add arm64 IMA arch support. The arch policy is inherited from x86.

Signed-off-by: Chester Lin <clin@xxxxxxxx>
---
 arch/arm64/Kconfig           |  1 +
 arch/arm64/kernel/Makefile   |  2 ++
 arch/arm64/kernel/ima_arch.c | 37 ++++++++++++++++++++++++++++++++++++
 3 files changed, 40 insertions(+)
 create mode 100644 arch/arm64/kernel/ima_arch.c

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 6d232837cbee..b5518e7b604d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -196,6 +196,7 @@ config ARM64
 	select SWIOTLB
 	select SYSCTL_EXCEPTION_TRACE
 	select THREAD_INFO_IN_TASK
+	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
 	help
 	  ARM 64-bit (AArch64) Linux support.
 
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index a561cbb91d4d..0300ab60785d 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -71,3 +71,5 @@ extra-y					+= $(head-y) vmlinux.lds
 ifeq ($(CONFIG_DEBUG_EFI),y)
 AFLAGS_head.o += -DVMLINUX_PATH="\"$(realpath $(objtree)/vmlinux)\""
 endif
+
+obj-$(CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT)	+= ima_arch.o
diff --git a/arch/arm64/kernel/ima_arch.c b/arch/arm64/kernel/ima_arch.c
new file mode 100644
index 000000000000..46f5641c3da5
--- /dev/null
+++ b/arch/arm64/kernel/ima_arch.c
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2018 IBM Corporation
+ */
+#include <linux/efi.h>
+#include <linux/module.h>
+
+bool arch_ima_get_secureboot(void)
+{
+	if (efi_enabled(EFI_SECURE_BOOT))
+		return true;
+
+	return false;
+}
+
+/* secureboot arch rules */
+static const char * const sb_arch_rules[] = {
+#if !IS_ENABLED(CONFIG_KEXEC_SIG)
+	"appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig",
+#endif /* CONFIG_KEXEC_SIG */
+	"measure func=KEXEC_KERNEL_CHECK",
+#if !IS_ENABLED(CONFIG_MODULE_SIG)
+	"appraise func=MODULE_CHECK appraise_type=imasig",
+#endif
+	"measure func=MODULE_CHECK",
+	NULL
+};
+
+const char * const *arch_get_ima_policy(void)
+{
+	if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) {
+		if (IS_ENABLED(CONFIG_MODULE_SIG))
+			set_module_sig_enforced();
+		return sb_arch_rules;
+	}
+	return NULL;
+}
-- 
2.26.1