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linux/debian/patches/features/all/lockdown/efi-add-an-efi_secure_boot-flag-to-indicate-secure-b.patch
Konstantin Demin c3d09a3e94 initial commit
imported from https://salsa.debian.org/kernel-team/linux.git
commit 9d5cc9d9d6501d7f1dd7e194d4b245bd0b6c6a22
version 6.11.4-1
2024-10-23 12:12:30 +03:00

154 lines
5.0 KiB
Diff

From: David Howells <dhowells@redhat.com>
Date: Mon, 18 Feb 2019 12:45:03 +0000
Subject: [28/30] efi: Add an EFI_SECURE_BOOT flag to indicate secure boot mode
Origin: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/commit?id=a5d70c55c603233c192b375f72116a395909da28
UEFI machines can be booted in Secure Boot mode. Add an EFI_SECURE_BOOT
flag that can be passed to efi_enabled() to find out whether secure boot is
enabled.
Move the switch-statement in x86's setup_arch() that inteprets the
secure_boot boot parameter to generic code and set the bit there.
Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
cc: linux-efi@vger.kernel.org
[rperier: Forward-ported to 5.5:
- Use pr_warn()
- Adjust context]
[bwh: Forward-ported to 5.6: adjust context]
[bwh: Forward-ported to 5.7:
- Use the next available bit in efi.flags
- Adjust context]
---
arch/x86/kernel/setup.c | 14 +----------
drivers/firmware/efi/Makefile | 1 +
drivers/firmware/efi/secureboot.c | 39 +++++++++++++++++++++++++++++++
include/linux/efi.h | 16 ++++++++-----
4 files changed, 51 insertions(+), 19 deletions(-)
create mode 100644 drivers/firmware/efi/secureboot.c
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1193,19 +1193,7 @@ void __init setup_arch(char **cmdline_p)
/* Allocate bigger log buffer */
setup_log_buf(1);
- if (efi_enabled(EFI_BOOT)) {
- switch (boot_params.secure_boot) {
- case efi_secureboot_mode_disabled:
- pr_info("Secure boot disabled\n");
- break;
- case efi_secureboot_mode_enabled:
- pr_info("Secure boot enabled\n");
- break;
- default:
- pr_info("Secure boot could not be determined\n");
- break;
- }
- }
+ efi_set_secure_boot(boot_params.secure_boot);
reserve_initrd();
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_EFI_FAKE_MEMMAP) += fake_m
obj-$(CONFIG_EFI_BOOTLOADER_CONTROL) += efibc.o
obj-$(CONFIG_EFI_TEST) += test/
obj-$(CONFIG_EFI_DEV_PATH_PARSER) += dev-path-parser.o
+obj-$(CONFIG_EFI) += secureboot.o
obj-$(CONFIG_APPLE_PROPERTIES) += apple-properties.o
obj-$(CONFIG_EFI_RCI2_TABLE) += rci2-table.o
obj-$(CONFIG_EFI_EMBEDDED_FIRMWARE) += embedded-firmware.o
--- /dev/null
+++ b/drivers/firmware/efi/secureboot.c
@@ -0,0 +1,39 @@
+
+/* Core kernel secure boot support.
+ *
+ * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/efi.h>
+#include <linux/kernel.h>
+#include <linux/printk.h>
+
+/*
+ * Decide what to do when UEFI secure boot mode is enabled.
+ */
+void __init efi_set_secure_boot(enum efi_secureboot_mode mode)
+{
+ if (efi_enabled(EFI_BOOT)) {
+ switch (mode) {
+ case efi_secureboot_mode_disabled:
+ pr_info("Secure boot disabled\n");
+ break;
+ case efi_secureboot_mode_enabled:
+ set_bit(EFI_SECURE_BOOT, &efi.flags);
+ pr_info("Secure boot enabled\n");
+ break;
+ default:
+ pr_warn("Secure boot could not be determined (mode %u)\n",
+ mode);
+ break;
+ }
+ }
+}
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -871,6 +871,14 @@ extern int __init efi_setup_pcdp_console
#define EFI_MEM_ATTR 10 /* Did firmware publish an EFI_MEMORY_ATTRIBUTES table? */
#define EFI_MEM_NO_SOFT_RESERVE 11 /* Is the kernel configured to ignore soft reservations? */
#define EFI_PRESERVE_BS_REGIONS 12 /* Are EFI boot-services memory segments available? */
+#define EFI_SECURE_BOOT 13 /* Are we in Secure Boot mode? */
+
+enum efi_secureboot_mode {
+ efi_secureboot_mode_unset,
+ efi_secureboot_mode_unknown,
+ efi_secureboot_mode_disabled,
+ efi_secureboot_mode_enabled,
+};
#ifdef CONFIG_EFI
/*
@@ -895,6 +903,7 @@ static inline bool efi_rt_services_suppo
return (efi.runtime_supported_mask & mask) == mask;
}
extern void efi_find_mirror(void);
+extern void __init efi_set_secure_boot(enum efi_secureboot_mode mode);
#else
static inline bool efi_enabled(int feature)
{
@@ -914,6 +923,7 @@ static inline bool efi_rt_services_suppo
}
static inline void efi_find_mirror(void) {}
+static inline void efi_set_secure_boot(enum efi_secureboot_mode mode) {}
#endif
extern int efi_status_to_err(efi_status_t status);
@@ -1133,13 +1143,6 @@ static inline bool efi_runtime_disabled(
extern void efi_call_virt_check_flags(unsigned long flags, const void *caller);
extern unsigned long efi_call_virt_save_flags(void);
-enum efi_secureboot_mode {
- efi_secureboot_mode_unset,
- efi_secureboot_mode_unknown,
- efi_secureboot_mode_disabled,
- efi_secureboot_mode_enabled,
-};
-
static inline
enum efi_secureboot_mode efi_get_secureboot_mode(efi_get_variable_t *get_var)
{