forked from Minki/linux
399574c64e
The secure boot mode may not be detected on boot for some reason (eg. buggy firmware). This patch attempts one more time to detect the secure boot mode. Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
76 lines
1.7 KiB
C
76 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ */
|
|
/*
|
|
* Copyright (C) 2018 IBM Corporation
|
|
*/
|
|
#include <linux/efi.h>
|
|
#include <linux/ima.h>
|
|
|
|
extern struct boot_params boot_params;
|
|
|
|
static enum efi_secureboot_mode get_sb_mode(void)
|
|
{
|
|
efi_char16_t efi_SecureBoot_name[] = L"SecureBoot";
|
|
efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
|
|
efi_status_t status;
|
|
unsigned long size;
|
|
u8 secboot;
|
|
|
|
size = sizeof(secboot);
|
|
|
|
/* Get variable contents into buffer */
|
|
status = efi.get_variable(efi_SecureBoot_name, &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;
|
|
}
|
|
|
|
if (secboot == 0) {
|
|
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_VERIFY_SIG)
|
|
"appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig",
|
|
#endif /* CONFIG_KEXEC_VERIFY_SIG */
|
|
"measure func=KEXEC_KERNEL_CHECK",
|
|
NULL
|
|
};
|
|
|
|
const char * const *arch_get_ima_policy(void)
|
|
{
|
|
if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot())
|
|
return sb_arch_rules;
|
|
return NULL;
|
|
}
|