1 files changed, 96 insertions, 0 deletions
diff --git a/arch/x86/kernel/ima_arch.c b/arch/x86/kernel/ima_arch.c
new file mode 100644
index 000000000..bd218470d
--- /dev/null
+++ b/arch/x86/kernel/ima_arch.c
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2018 IBM Corporation
+ */
+#include <linux/efi.h>
+#include <linux/module.h>
+#include <linux/ima.h>
+
+extern struct boot_params boot_params;
+
+static enum efi_secureboot_mode get_sb_mode(void)
+{
+	efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
+	efi_status_t status;
+	unsigned long size;
+	u8 secboot, setupmode;
+
+	size = sizeof(secboot);
+
+	if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) {
+		pr_info("ima: secureboot mode unknown, no efi\n");
+		return efi_secureboot_mode_unknown;
+	}
+
+	/* Get variable contents into buffer */
+	status = efi.get_variable(L"SecureBoot", &efi_variable_guid,
+				  NULL, &size, &secboot);
+	if (status == EFI_NOT_FOUND) {
+		pr_info("ima: secureboot mode disabled\n");
+		return efi_secureboot_mode_disabled;
+	}
+
+	if (status != EFI_SUCCESS) {
+		pr_info("ima: secureboot mode unknown\n");
+		return efi_secureboot_mode_unknown;
+	}
+
+	size = sizeof(setupmode);
+	status = efi.get_variable(L"SetupMode", &efi_variable_guid,
+				  NULL, &size, &setupmode);
+
+	if (status != EFI_SUCCESS)	/* ignore unknown SetupMode */
+		setupmode = 0;
+
+	if (secboot == 0 || setupmode == 1) {
+		pr_info("ima: secureboot mode disabled\n");
+		return efi_secureboot_mode_disabled;
+	}
+
+	pr_info("ima: secureboot mode enabled\n");
+	return efi_secureboot_mode_enabled;
+}
+
+bool arch_ima_get_secureboot(void)
+{
+	static enum efi_secureboot_mode sb_mode;
+	static bool initialized;
+
+	if (!initialized && efi_enabled(EFI_BOOT)) {
+		sb_mode = boot_params.secure_boot;
+
+		if (sb_mode == efi_secureboot_mode_unset)
+			sb_mode = get_sb_mode();
+		initialized = true;
+	}
+
+	if (sb_mode == efi_secureboot_mode_enabled)
+		return true;
+	else
+		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();
+		if (IS_ENABLED(CONFIG_KEXEC_SIG))
+			set_kexec_sig_enforced();
+		return sb_arch_rules;
+	}
+	return NULL;
+}