[PATCH 1/4] efi/stub: Extract efi_get_secureboot() to separate file

From: Daniel Kiper
Date: Tue Jan 09 2018 - 09:23:26 EST


We have to call efi_get_secureboot() from early Xen dom0 boot code to properly
initialize boot_params.secure_boot. Sadly it lives in the EFI stub. Hence, it is
not readily reachable from the kernel proper. So, move efi_get_secureboot() to
separate file which can be included from the core kernel code. Subsequent patch
will add efi_get_secureboot() call from Xen dom0 boot code.

There is no functional change.

Signed-off-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
---
drivers/firmware/efi/libstub/secureboot-core.c | 77 ++++++++++++++++++++++++
drivers/firmware/efi/libstub/secureboot.c | 66 +-------------------
2 files changed, 78 insertions(+), 65 deletions(-)
create mode 100644 drivers/firmware/efi/libstub/secureboot-core.c

diff --git a/drivers/firmware/efi/libstub/secureboot-core.c b/drivers/firmware/efi/libstub/secureboot-core.c
new file mode 100644
index 0000000..11a4feb
--- /dev/null
+++ b/drivers/firmware/efi/libstub/secureboot-core.c
@@ -0,0 +1,77 @@
+/*
+ * Secure boot handling.
+ *
+ * Copyright (C) 2013,2014 Linaro Limited
+ * Roy Franz <roy.franz@xxxxxxxxxx>
+ * Copyright (C) 2013 Red Hat, Inc.
+ * Mark Salter <msalter@xxxxxxxxxx>
+ *
+ * This file is part of the Linux kernel, and is made available under the
+ * terms of the GNU General Public License version 2.
+ */
+
+/* BIOS variables */
+static const efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
+static const efi_char16_t efi_SecureBoot_name[] = {
+ 'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0
+};
+static const efi_char16_t efi_SetupMode_name[] = {
+ 'S', 'e', 't', 'u', 'p', 'M', 'o', 'd', 'e', 0
+};
+
+/* SHIM variables */
+static const efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID;
+static const efi_char16_t shim_MokSBState_name[] = {
+ 'M', 'o', 'k', 'S', 'B', 'S', 't', 'a', 't', 'e', 0
+};
+
+/*
+ * Determine whether we're in secure boot mode.
+ */
+enum efi_secureboot_mode efi_get_secureboot(efi_system_table_t *sys_table_arg)
+{
+ u32 attr;
+ u8 secboot, setupmode, moksbstate;
+ unsigned long size;
+ efi_status_t status;
+
+ size = sizeof(secboot);
+ status = get_efi_var(efi_SecureBoot_name, &efi_variable_guid,
+ NULL, &size, &secboot);
+ if (status == EFI_NOT_FOUND)
+ return efi_secureboot_mode_disabled;
+ if (status != EFI_SUCCESS)
+ goto out_efi_err;
+
+ size = sizeof(setupmode);
+ status = get_efi_var(efi_SetupMode_name, &efi_variable_guid,
+ NULL, &size, &setupmode);
+ if (status != EFI_SUCCESS)
+ goto out_efi_err;
+
+ if (secboot == 0 || setupmode == 1)
+ return efi_secureboot_mode_disabled;
+
+ /*
+ * See if a user has put the shim into insecure mode. If so, and if the
+ * variable doesn't have the runtime attribute set, we might as well
+ * honor that.
+ */
+ size = sizeof(moksbstate);
+ status = get_efi_var(shim_MokSBState_name, &shim_guid,
+ &attr, &size, &moksbstate);
+
+ /* If it fails, we don't care why. Default to secure */
+ if (status != EFI_SUCCESS)
+ goto secure_boot_enabled;
+ if (!(attr & EFI_VARIABLE_RUNTIME_ACCESS) && moksbstate == 1)
+ return efi_secureboot_mode_disabled;
+
+secure_boot_enabled:
+ pr_efi(sys_table_arg, "UEFI Secure Boot is enabled.\n");
+ return efi_secureboot_mode_enabled;
+
+out_efi_err:
+ pr_efi_err(sys_table_arg, "Could not determine UEFI Secure Boot status.\n");
+ return efi_secureboot_mode_unknown;
+}
diff --git a/drivers/firmware/efi/libstub/secureboot.c b/drivers/firmware/efi/libstub/secureboot.c
index 959777e..4a6159f 100644
--- a/drivers/firmware/efi/libstub/secureboot.c
+++ b/drivers/firmware/efi/libstub/secureboot.c
@@ -14,73 +14,9 @@

#include "efistub.h"

-/* BIOS variables */
-static const efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
-static const efi_char16_t efi_SecureBoot_name[] = {
- 'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0
-};
-static const efi_char16_t efi_SetupMode_name[] = {
- 'S', 'e', 't', 'u', 'p', 'M', 'o', 'd', 'e', 0
-};
-
-/* SHIM variables */
-static const efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID;
-static efi_char16_t const shim_MokSBState_name[] = {
- 'M', 'o', 'k', 'S', 'B', 'S', 't', 'a', 't', 'e', 0
-};
-
#define get_efi_var(name, vendor, ...) \
efi_call_runtime(get_variable, \
(efi_char16_t *)(name), (efi_guid_t *)(vendor), \
__VA_ARGS__);

-/*
- * Determine whether we're in secure boot mode.
- */
-enum efi_secureboot_mode efi_get_secureboot(efi_system_table_t *sys_table_arg)
-{
- u32 attr;
- u8 secboot, setupmode, moksbstate;
- unsigned long size;
- efi_status_t status;
-
- size = sizeof(secboot);
- status = get_efi_var(efi_SecureBoot_name, &efi_variable_guid,
- NULL, &size, &secboot);
- if (status == EFI_NOT_FOUND)
- return efi_secureboot_mode_disabled;
- if (status != EFI_SUCCESS)
- goto out_efi_err;
-
- size = sizeof(setupmode);
- status = get_efi_var(efi_SetupMode_name, &efi_variable_guid,
- NULL, &size, &setupmode);
- if (status != EFI_SUCCESS)
- goto out_efi_err;
-
- if (secboot == 0 || setupmode == 1)
- return efi_secureboot_mode_disabled;
-
- /*
- * See if a user has put the shim into insecure mode. If so, and if the
- * variable doesn't have the runtime attribute set, we might as well
- * honor that.
- */
- size = sizeof(moksbstate);
- status = get_efi_var(shim_MokSBState_name, &shim_guid,
- &attr, &size, &moksbstate);
-
- /* If it fails, we don't care why. Default to secure */
- if (status != EFI_SUCCESS)
- goto secure_boot_enabled;
- if (!(attr & EFI_VARIABLE_RUNTIME_ACCESS) && moksbstate == 1)
- return efi_secureboot_mode_disabled;
-
-secure_boot_enabled:
- pr_efi(sys_table_arg, "UEFI Secure Boot is enabled.\n");
- return efi_secureboot_mode_enabled;
-
-out_efi_err:
- pr_efi_err(sys_table_arg, "Could not determine UEFI Secure Boot status.\n");
- return efi_secureboot_mode_unknown;
-}
+#include "secureboot-core.c"
--
1.7.10.4