Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758504AbcCCVq1 (ORCPT ); Thu, 3 Mar 2016 16:46:27 -0500 Received: from g9t1613g.houston.hp.com ([15.240.0.71]:41742 "EHLO g9t1613g.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758478AbcCCVqY (ORCPT ); Thu, 3 Mar 2016 16:46:24 -0500 From: Linn Crosetto To: matt@codeblueprint.co.uk, ard.biesheuvel@linaro.org, roy.franz@linaro.org, mingo@kernel.org, mark.rutland@arm.com Cc: linux-kernel@vger.kernel.org, Linn Crosetto Subject: [PATCH v3 2/2] arm64/efi: check SetupMode when determining Secure Boot status Date: Thu, 3 Mar 2016 14:45:50 -0700 Message-Id: <1457041550-15736-3-git-send-email-linn@hpe.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1457041550-15736-1-git-send-email-linn@hpe.com> References: <1456445895-97647-1-git-send-email-linn@hpe.com> <1457041550-15736-1-git-send-email-linn@hpe.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2232 Lines: 72 According to the UEFI specification (version 2.5 Errata A, page 87): The platform firmware is operating in secure boot mode if the value of the SetupMode variable is 0 and the SecureBoot variable is set to 1. A platform cannot operate in secure boot mode if the SetupMode variable is set to 1. Check the value of the SetupMode variable when determining the state of Secure Boot. Minor cleanup, change sizeof to match kernel style guidelines. Signed-off-by: Linn Crosetto --- v2: - Reformat quote from UEFI specification and note cleanup (Mark Rutland) - Restructure code on top of changes in patch 1/2 drivers/firmware/efi/libstub/arm-stub.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index 1e98fb7..c049d41 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -20,21 +20,39 @@ static int efi_get_secureboot(efi_system_table_t *sys_table_arg) { - static efi_guid_t const var_guid = EFI_GLOBAL_VARIABLE_GUID; - static efi_char16_t const var_name[] = { + static efi_char16_t const sb_var_name[] = { 'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 }; + static efi_char16_t const sm_var_name[] = { + 'S', 'e', 't', 'u', 'p', 'M', 'o', 'd', 'e', 0 }; + efi_guid_t var_guid = EFI_GLOBAL_VARIABLE_GUID; efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable; - unsigned long size = sizeof(u8); - efi_status_t status; u8 val; + unsigned long size = sizeof(val); + efi_status_t status; - status = f_getvar((efi_char16_t *)var_name, (efi_guid_t *)&var_guid, + status = f_getvar((efi_char16_t *)sb_var_name, (efi_guid_t *)&var_guid, NULL, &size, &val); + if (status != EFI_SUCCESS) + goto out_efi_err; + + if (val == 0) + return 0; + + status = f_getvar((efi_char16_t *)sm_var_name, (efi_guid_t *)&var_guid, + NULL, &size, &val); + + if (status != EFI_SUCCESS) + goto out_efi_err; + + if (val == 1) + return 0; + + return 1; + +out_efi_err: switch (status) { - case EFI_SUCCESS: - return val; case EFI_NOT_FOUND: return 0; case EFI_DEVICE_ERROR: -- 2.1.4