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EVM and other LSMs need the ability to query the secure boot status of the system, without directly calling the IMA arch_ima_get_secureboot function. Refactor the secure boot status check into a general function named arch_get_secureboot. Reported-and-suggested-by: Mimi Zohar <zohar@linux.ibm.com> Suggested-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Coiby Xu <coxu@redhat.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
57 lines
1.3 KiB
C
57 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-1.0+
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/*
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* Copyright (C) 2018 IBM Corporation
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*/
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#include <linux/efi.h>
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#include <linux/secure_boot.h>
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#include <asm/efi.h>
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#ifndef arch_efi_boot_mode
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#define arch_efi_boot_mode efi_secureboot_mode_unset
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#endif
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static enum efi_secureboot_mode get_sb_mode(void)
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{
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enum efi_secureboot_mode mode;
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if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) {
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pr_info("integrity: secureboot mode unknown, no efi\n");
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return efi_secureboot_mode_unknown;
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}
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mode = efi_get_secureboot_mode(efi.get_variable);
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if (mode == efi_secureboot_mode_disabled)
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pr_info("integrity: secureboot mode disabled\n");
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else if (mode == efi_secureboot_mode_unknown)
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pr_info("integrity: secureboot mode unknown\n");
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else
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pr_info("integrity: secureboot mode enabled\n");
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return mode;
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}
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/*
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* Query secure boot status
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*
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* Note don't call this function too early e.g. in __setup hook otherwise the
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* kernel may hang when calling efi_get_secureboot_mode.
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*
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*/
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bool arch_get_secureboot(void)
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{
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static enum efi_secureboot_mode sb_mode;
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static bool initialized;
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if (!initialized && efi_enabled(EFI_BOOT)) {
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sb_mode = arch_efi_boot_mode;
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if (sb_mode == efi_secureboot_mode_unset)
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sb_mode = get_sb_mode();
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initialized = true;
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}
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if (sb_mode == efi_secureboot_mode_enabled)
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return true;
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else
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return false;
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}
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