[PATCH 6/6] efi: Add EFI_SECURE_BOOT bit [ver #2]

David Howells
2016-11-23T00:23:12Z

From: Josh Boyer <jwboyer@fedoraproject.org>

UEFI machines can be booted in Secure Boot mode. Add a EFI_SECURE_BOOT bit
that can be passed to efi_enabled() to find out whether secure boot is
enabled.

This will be used by the SysRq+x handler, registered by the x86 arch, to find
out whether secure boot mode is enabled so that it can be disabled.

Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: David Howells <dhowells@redhat.com>
---

arch/x86/kernel/setup.c | 7 +++++++
include/linux/efi.h | 1 +
2 files changed, 8 insertions(+)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 9c337b0e8ba7..522915d6de1f 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1160,6 +1160,13 @@ void __init setup_arch(char **cmdline_p)

io_delay_init();

+#ifdef CONFIG_EFI
+ if (boot_params.secure_boot) {
+ set_bit(EFI_SECURE_BOOT, &efi.flags);
+ pr_info("Secure boot enabled\n");
+ }
+#endif
+
/*
* Parse the ACPI tables for possible boot-time SMP configuration.
*/
diff --git a/include/linux/efi.h b/include/linux/efi.h
index ff01ad6f2823..d95bb9e69974 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1066,6 +1066,7 @@ extern int __init efi_setup_pcdp_console(char *);
#define EFI_ARCH_1 7 /* First arch-specific bit */
#define EFI_DBG 8 /* Print additional debug info at runtime */
#define EFI_NX_PE_DATA 9 /* Can runtime data regions be mapped non-executable? */
+#define EFI_SECURE_BOOT 10 /* Are we in Secure Boot mode? */

#ifdef CONFIG_EFI
/*