From patchwork Sun Aug 27 21:14:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maximilian Luz X-Patchwork-Id: 717800 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37420C83F16 for ; Sun, 27 Aug 2023 21:15:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230289AbjH0VOl (ORCPT ); Sun, 27 Aug 2023 17:14:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230260AbjH0VOa (ORCPT ); Sun, 27 Aug 2023 17:14:30 -0400 Received: from mail-wm1-x32e.google.com (mail-wm1-x32e.google.com [IPv6:2a00:1450:4864:20::32e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CEC94C1; Sun, 27 Aug 2023 14:14:25 -0700 (PDT) Received: by mail-wm1-x32e.google.com with SMTP id 5b1f17b1804b1-401b393df02so25104015e9.1; Sun, 27 Aug 2023 14:14:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1693170864; x=1693775664; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=QjxWGZxEr43tmM5213OUEm8iz+l1Kob15ocpmTgaGcM=; b=UZ5V4Ml9KimE+oTCtuOH7uyw3kqXBe9wMmzwIKfMKV1YO2tg6Tc5vLhdCq5wz69qZq 15Q99DO9nEAKRjnwYalANDrpyFc8hYGUQKMTfIC+ICWQrasbo0UCzCWpxnRfHkC9bbdQ 73SQNvrTjh6VXE6oliRnIPH7ElfTtubGBz5cH6Wmku6YCqrVIF5M7X9iijA3ghYN5/zN qDWsAO2ge1Fzdu5JpLTXHK+ER3FgA0WVhKdjMz5j17V36GqBZqbn4rJt4eu8lEVKB76F 0tv2/8by259sDxZKKY18PLpC0sKfIE7G+w+CDbPLy9wDFHdF+ITxEZAnvmuDjI6INkRs +zFw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1693170864; x=1693775664; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=QjxWGZxEr43tmM5213OUEm8iz+l1Kob15ocpmTgaGcM=; b=B2X5Tq/NhE5lpwgWdFm/YifzaCPSTmYX23esQj9Lc9aWkUV3/DFNqftwmDHUBfc765 AuUNyyBLHVld3cQXxRYh0SrHnoI4mBCLZ3kGUS/856Npp6dVNPTRKCGqqG0AyXtnxWMJ gA746ACY/eF7Ds48vFe8pYRVMNO6RtYwQBVbKSwcBSsPCTJ/jphb+//CHJrpTlHGguLg tjGIkfvd7G1w/w4JZJMzv99XPuzXGTj2ik7U5WbOaBkivB29tGup4zy+adGb4yUlsX1a L5gaLDW1d33JLXuMY0k0wKboo9awFdr0Te3ZZ1X5oge+W1zYacLJAho74LvKPEmplSws /3AA== X-Gm-Message-State: AOJu0YzN+uuXRiix2CaQBv6DYyRzWHyluzkFEXhaKOKRPXyz7goaiLvd quGRQ03R/QIP2pzGKBmk/NI= X-Google-Smtp-Source: AGHT+IErC+X4Uz+DCwoKeTedvrGFBNbJgzpYpedh508kPf7H6AJpi+gijQvPbZROr6SSWG4wrA/4+A== X-Received: by 2002:a5d:634e:0:b0:31a:ed75:75d6 with SMTP id b14-20020a5d634e000000b0031aed7575d6mr16034365wrw.15.1693170864110; Sun, 27 Aug 2023 14:14:24 -0700 (PDT) Received: from xws.fritz.box ([2a02:8071:b783:140:927c:82ba:d32d:99c1]) by smtp.gmail.com with ESMTPSA id p14-20020a5d638e000000b0031971ab70c9sm8541997wru.73.2023.08.27.14.14.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 27 Aug 2023 14:14:23 -0700 (PDT) From: Maximilian Luz To: Bjorn Andersson Cc: Maximilian Luz , Andy Gross , Konrad Dybcio , Ard Biesheuvel , Ilias Apalodimas , Srinivas Kandagatla , Sudeep Holla , Johan Hovold , Steev Klimaszewski , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold Subject: [PATCH v6 3/3] firmware: Add support for Qualcomm UEFI Secure Application Date: Sun, 27 Aug 2023 23:14:06 +0200 Message-ID: <20230827211408.689076-4-luzmaximilian@gmail.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230827211408.689076-1-luzmaximilian@gmail.com> References: <20230827211408.689076-1-luzmaximilian@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On platforms using the Qualcomm UEFI Secure Application (uefisecapp), EFI variables cannot be accessed via the standard interface in EFI runtime mode. The respective functions return EFI_UNSUPPORTED. On these platforms, we instead need to talk to uefisecapp. This commit provides support for this and registers the respective efivars operations to access EFI variables from the kernel. Communication with uefisecapp follows the Qualcomm QSEECOM / Secure OS conventions via the respective SCM call interface. This is also the reason why variable access works normally while boot services are active. During this time, said SCM interface is managed by the boot services. When calling ExitBootServices(), the ownership is transferred to the kernel. Therefore, UEFI must not use that interface itself (as multiple parties accessing this interface at the same time may lead to complications) and cannot access variables for us. Signed-off-by: Maximilian Luz Acked-by: Ard Biesheuvel Reviewed-by: Johan Hovold --- Changes in v6: - Remove unnecessary 'depends on QCOM_SCM' in KConfig - Add missing documentation for guid_offset parameter in struct qsee_rsp_uefi_get_next_variable. Changes in v5: - Clean up some comments inside functions and remove simple ones. Changes in v4: - Adapt to changes in DMA allocation in patch 3. - Rework alignment: Use native alignment of types instead of a general 8 byte alignment. While the windows driver uses 8 byte alignment for GUIDs, the native (4 byte) alignment seems to work fine here. - Add a helper macro for determining size and layout of request and response buffers, taking care of proper alignment. - Implement support for EFI's query_variable_info() call, which is now supported by the kernel (and expected by efivarfs). - Move UCS-2 string helpers to lib/ucs2_string.c Changes in v3: - No functional changes. Changes in v2: - Rename (qctree -> qseecom) to allow differentiation between old (qseecom) and new (smcinvoke) interfaces to the trusted execution environment. --- MAINTAINERS | 6 + drivers/firmware/Kconfig | 16 + drivers/firmware/Makefile | 1 + drivers/firmware/qcom_qseecom.c | 4 +- drivers/firmware/qcom_qseecom_uefisecapp.c | 871 +++++++++++++++++++++ 5 files changed, 897 insertions(+), 1 deletion(-) create mode 100644 drivers/firmware/qcom_qseecom_uefisecapp.c diff --git a/MAINTAINERS b/MAINTAINERS index e239e2f0748f..e82c9db981d3 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17651,6 +17651,12 @@ L: linux-arm-msm@vger.kernel.org S: Maintained F: drivers/firmware/qcom_qseecom.c +QUALCOMM QSEECOM UEFISECAPP DRIVER +M: Maximilian Luz +L: linux-arm-msm@vger.kernel.org +S: Maintained +F: drivers/firmware/qcom_qseecom_uefisecapp.c + QUALCOMM RMNET DRIVER M: Subash Abhinov Kasiviswanathan M: Sean Tranchetti diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index 3e41efe494d4..a94202229a71 100644 --- a/drivers/firmware/Kconfig +++ b/drivers/firmware/Kconfig @@ -242,6 +242,22 @@ config QCOM_QSEECOM Select Y here to enable the QSEECOM interface driver. +config QCOM_QSEECOM_UEFISECAPP + bool "Qualcomm SEE UEFI Secure App client driver" + depends on QCOM_QSEECOM + depends on EFI + help + Various Qualcomm SoCs do not allow direct access to EFI variables. + Instead, these need to be accessed via the UEFI Secure Application + (uefisecapp), residing in the Secure Execution Environment (SEE). + + This module provides a client driver for uefisecapp, installing efivar + operations to allow the kernel accessing EFI variables, and via that also + provide user-space with access to EFI variables via efivarfs. + + Select Y here to provide access to EFI variables on the aforementioned + platforms. + config SYSFB bool select BOOT_VESA_SUPPORT diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile index aa48e0821b7d..d41b094a5e58 100644 --- a/drivers/firmware/Makefile +++ b/drivers/firmware/Makefile @@ -21,6 +21,7 @@ obj-$(CONFIG_FW_CFG_SYSFS) += qemu_fw_cfg.o obj-$(CONFIG_QCOM_SCM) += qcom-scm.o qcom-scm-objs += qcom_scm.o qcom_scm-smc.o qcom_scm-legacy.o obj-$(CONFIG_QCOM_QSEECOM) += qcom_qseecom.o +obj-$(CONFIG_QCOM_QSEECOM_UEFISECAPP) += qcom_qseecom_uefisecapp.o obj-$(CONFIG_SYSFB) += sysfb.o obj-$(CONFIG_SYSFB_SIMPLEFB) += sysfb_simplefb.o obj-$(CONFIG_TI_SCI_PROTOCOL) += ti_sci.o diff --git a/drivers/firmware/qcom_qseecom.c b/drivers/firmware/qcom_qseecom.c index bba32096c956..731e6d5719f9 100644 --- a/drivers/firmware/qcom_qseecom.c +++ b/drivers/firmware/qcom_qseecom.c @@ -83,7 +83,9 @@ static int qseecom_client_register(struct platform_device *qseecom_dev, * assuming the app has already been loaded (usually by firmware bootloaders) * and its ID can be queried successfully. */ -static const struct qseecom_app_desc qcom_qseecom_apps[] = {}; +static const struct qseecom_app_desc qcom_qseecom_apps[] = { + { "qcom.tz.uefisecapp", "uefisecapp" }, +}; static int qcom_qseecom_probe(struct platform_device *qseecom_dev) { diff --git a/drivers/firmware/qcom_qseecom_uefisecapp.c b/drivers/firmware/qcom_qseecom_uefisecapp.c new file mode 100644 index 000000000000..a33acdaf7b78 --- /dev/null +++ b/drivers/firmware/qcom_qseecom_uefisecapp.c @@ -0,0 +1,871 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Client driver for Qualcomm UEFI Secure Application (qcom.tz.uefisecapp). + * Provides access to UEFI variables on platforms where they are secured by the + * aforementioned Secure Execution Environment (SEE) application. + * + * Copyright (C) 2023 Maximilian Luz + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +/* -- Qualcomm "uefisecapp" interface definitions. -------------------------- */ + +/* Maximum length of name string with null-terminator */ +#define QSEE_MAX_NAME_LEN 1024 + +#define QSEE_CMD_UEFI(x) (0x8000 | (x)) +#define QSEE_CMD_UEFI_GET_VARIABLE QSEE_CMD_UEFI(0) +#define QSEE_CMD_UEFI_SET_VARIABLE QSEE_CMD_UEFI(1) +#define QSEE_CMD_UEFI_GET_NEXT_VARIABLE QSEE_CMD_UEFI(2) +#define QSEE_CMD_UEFI_QUERY_VARIABLE_INFO QSEE_CMD_UEFI(3) + +/** + * struct qsee_req_uefi_get_variable - Request for GetVariable command. + * @command_id: The ID of the command. Must be %QSEE_CMD_UEFI_GET_VARIABLE. + * @length: Length of the request in bytes, including this struct and any + * parameters (name, GUID) stored after it as well as any padding + * thereof for alignment. + * @name_offset: Offset from the start of this struct to where the variable + * name is stored (as utf-16 string), in bytes. + * @name_size: Size of the name parameter in bytes, including null-terminator. + * @guid_offset: Offset from the start of this struct to where the GUID + * parameter is stored, in bytes. + * @guid_size: Size of the GUID parameter in bytes, i.e. sizeof(efi_guid_t). + * @data_size: Size of the output buffer, in bytes. + */ +struct qsee_req_uefi_get_variable { + u32 command_id; + u32 length; + u32 name_offset; + u32 name_size; + u32 guid_offset; + u32 guid_size; + u32 data_size; +} __packed; + +/** + * struct qsee_rsp_uefi_get_variable - Response for GetVariable command. + * @command_id: The ID of the command. Should be %QSEE_CMD_UEFI_GET_VARIABLE. + * @length: Length of the response in bytes, including this struct and the + * returned data. + * @status: Status of this command. + * @attributes: EFI variable attributes. + * @data_offset: Offset from the start of this struct to where the data is + * stored, in bytes. + * @data_size: Size of the returned data, in bytes. In case status indicates + * that the buffer is too small, this will be the size required + * to store the EFI variable data. + */ +struct qsee_rsp_uefi_get_variable { + u32 command_id; + u32 length; + u32 status; + u32 attributes; + u32 data_offset; + u32 data_size; +} __packed; + +/** + * struct qsee_req_uefi_set_variable - Request for the SetVariable command. + * @command_id: The ID of the command. Must be %QSEE_CMD_UEFI_SET_VARIABLE. + * @length: Length of the request in bytes, including this struct and any + * parameters (name, GUID, data) stored after it as well as any + * padding thereof required for alignment. + * @name_offset: Offset from the start of this struct to where the variable + * name is stored (as utf-16 string), in bytes. + * @name_size: Size of the name parameter in bytes, including null-terminator. + * @guid_offset: Offset from the start of this struct to where the GUID + * parameter is stored, in bytes. + * @guid_size: Size of the GUID parameter in bytes, i.e. sizeof(efi_guid_t). + * @attributes: The EFI variable attributes to set for this variable. + * @data_offset: Offset from the start of this struct to where the EFI variable + * data is stored, in bytes. + * @data_size: Size of EFI variable data, in bytes. + * + */ +struct qsee_req_uefi_set_variable { + u32 command_id; + u32 length; + u32 name_offset; + u32 name_size; + u32 guid_offset; + u32 guid_size; + u32 attributes; + u32 data_offset; + u32 data_size; +} __packed; + +/** + * struct qsee_rsp_uefi_set_variable - Response for the SetVariable command. + * @command_id: The ID of the command. Should be %QSEE_CMD_UEFI_SET_VARIABLE. + * @length: The length of this response, i.e. the size of this struct in + * bytes. + * @status: Status of this command. + * @_unknown1: Unknown response field. + * @_unknown2: Unknown response field. + */ +struct qsee_rsp_uefi_set_variable { + u32 command_id; + u32 length; + u32 status; + u32 _unknown1; + u32 _unknown2; +} __packed; + +/** + * struct qsee_req_uefi_get_next_variable - Request for the + * GetNextVariableName command. + * @command_id: The ID of the command. Must be + * %QSEE_CMD_UEFI_GET_NEXT_VARIABLE. + * @length: Length of the request in bytes, including this struct and any + * parameters (name, GUID) stored after it as well as any padding + * thereof for alignment. + * @guid_offset: Offset from the start of this struct to where the GUID + * parameter is stored, in bytes. + * @guid_size: Size of the GUID parameter in bytes, i.e. sizeof(efi_guid_t). + * @name_offset: Offset from the start of this struct to where the variable + * name is stored (as utf-16 string), in bytes. + * @name_size: Size of the name parameter in bytes, including null-terminator. + */ +struct qsee_req_uefi_get_next_variable { + u32 command_id; + u32 length; + u32 guid_offset; + u32 guid_size; + u32 name_offset; + u32 name_size; +} __packed; + +/** + * struct qsee_rsp_uefi_get_next_variable - Response for the + * GetNextVariableName command. + * @command_id: The ID of the command. Should be + * %QSEE_CMD_UEFI_GET_NEXT_VARIABLE. + * @length: Length of the response in bytes, including this struct and any + * parameters (name, GUID) stored after it as well as any padding + * thereof for alignment. + * @status: Status of this command. + * @guid_offset: Offset from the start of this struct to where the GUID + * parameter is stored, in bytes. + * @guid_size: Size of the GUID parameter in bytes, i.e. sizeof(efi_guid_t). + * @name_offset: Offset from the start of this struct to where the variable + * name is stored (as utf-16 string), in bytes. + * @name_size: Size of the name parameter in bytes, including null-terminator. + */ +struct qsee_rsp_uefi_get_next_variable { + u32 command_id; + u32 length; + u32 status; + u32 guid_offset; + u32 guid_size; + u32 name_offset; + u32 name_size; +} __packed; + +/** + * struct qsee_req_uefi_query_variable_info - Response for the + * GetNextVariableName command. + * @command_id: The ID of the command. Must be + * %QSEE_CMD_UEFI_QUERY_VARIABLE_INFO. + * @length: The length of this request, i.e. the size of this struct in + * bytes. + * @attributes: The storage attributes to query the info for. + */ +struct qsee_req_uefi_query_variable_info { + u32 command_id; + u32 length; + u32 attributes; +} __packed; + +/** + * struct qsee_rsp_uefi_query_variable_info - Response for the + * GetNextVariableName command. + * @command_id: The ID of the command. Must be + * %QSEE_CMD_UEFI_QUERY_VARIABLE_INFO. + * @length: The length of this response, i.e. the size of this + * struct in bytes. + * @status: Status of this command. + * @_pad: Padding. + * @storage_space: Full storage space size, in bytes. + * @remaining_space: Free storage space available, in bytes. + * @max_variable_size: Maximum variable data size, in bytes. + */ +struct qsee_rsp_uefi_query_variable_info { + u32 command_id; + u32 length; + u32 status; + u32 _pad; + u64 storage_space; + u64 remaining_space; + u64 max_variable_size; +} __packed; + +/* -- Alignment helpers ----------------------------------------------------- */ + +/* + * Helper macro to ensure proper alignment of types (fields and arrays) when + * stored in some (contiguous) buffer. + * + * Note: The driver from which this one has been reverse-engineered expects an + * alignment of 8 bytes (64 bits) for GUIDs. Our definition of efi_guid_t, + * however, has an alignment of 4 byte (32 bits). So far, this seems to work + * fine here. See also the comment on the typedef of efi_guid_t. + */ +#define qcuefi_buf_align_fields(fields...) \ + ({ \ + size_t __len = 0; \ + fields \ + __len; \ + }) + +#define __field_impl(size, align, offset) \ + ({ \ + size_t *__offset = (offset); \ + size_t __aligned; \ + \ + __aligned = ALIGN(__len, align); \ + __len = __aligned + (size); \ + \ + if (__offset) \ + *__offset = __aligned; \ + }); + +#define __array_offs(type, count, offset) \ + __field_impl(sizeof(type) * (count), __alignof__(type), offset) + +#define __array(type, count) __array_offs(type, count, NULL) +#define __field_offs(type, offset) __array_offs(type, 1, offset) +#define __field(type) __array_offs(type, 1, NULL) + +/* -- UEFI app interface. --------------------------------------------------- */ + +struct qcuefi_client { + struct qseecom_client *client; + struct efivars efivars; +}; + +static struct device *qcuefi_dev(struct qcuefi_client *qcuefi) +{ + return &qcuefi->client->aux_dev.dev; +} + +static efi_status_t qsee_uefi_status_to_efi(u32 status) +{ + u64 category = status & 0xf0000000; + u64 code = status & 0x0fffffff; + + return category << (BITS_PER_LONG - 32) | code; +} + +static efi_status_t qsee_uefi_get_variable(struct qcuefi_client *qcuefi, const efi_char16_t *name, + const efi_guid_t *guid, u32 *attributes, + unsigned long *data_size, void *data) +{ + struct qsee_req_uefi_get_variable *req_data; + struct qsee_rsp_uefi_get_variable *rsp_data; + unsigned long buffer_size = *data_size; + efi_status_t efi_status = EFI_SUCCESS; + unsigned long name_length; + size_t guid_offs; + size_t name_offs; + size_t req_size; + size_t rsp_size; + ssize_t status; + + if (!name || !guid) + return EFI_INVALID_PARAMETER; + + name_length = ucs2_strnlen(name, QSEE_MAX_NAME_LEN) + 1; + if (name_length > QSEE_MAX_NAME_LEN) + return EFI_INVALID_PARAMETER; + + if (buffer_size && !data) + return EFI_INVALID_PARAMETER; + + req_size = qcuefi_buf_align_fields( + __field(*req_data) + __array_offs(*name, name_length, &name_offs) + __field_offs(*guid, &guid_offs) + ); + + rsp_size = qcuefi_buf_align_fields( + __field(*rsp_data) + __array(u8, buffer_size) + ); + + req_data = kzalloc(req_size, GFP_KERNEL); + if (!req_data) { + efi_status = EFI_OUT_OF_RESOURCES; + goto out; + } + + rsp_data = kzalloc(rsp_size, GFP_KERNEL); + if (!rsp_data) { + efi_status = EFI_OUT_OF_RESOURCES; + goto out_free_req; + } + + req_data->command_id = QSEE_CMD_UEFI_GET_VARIABLE; + req_data->data_size = buffer_size; + req_data->name_offset = name_offs; + req_data->name_size = name_length * sizeof(*name); + req_data->guid_offset = guid_offs; + req_data->guid_size = sizeof(*guid); + req_data->length = req_size; + + status = ucs2_strscpy(((void *)req_data) + req_data->name_offset, name, name_length); + if (status < 0) + return EFI_INVALID_PARAMETER; + + memcpy(((void *)req_data) + req_data->guid_offset, guid, req_data->guid_size); + + status = qcom_qseecom_app_send(qcuefi->client, req_data, req_size, rsp_data, rsp_size); + if (status) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->command_id != QSEE_CMD_UEFI_GET_VARIABLE) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->length < sizeof(*rsp_data)) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->status) { + dev_dbg(qcuefi_dev(qcuefi), "%s: uefisecapp error: 0x%x\n", + __func__, rsp_data->status); + efi_status = qsee_uefi_status_to_efi(rsp_data->status); + + /* Update size and attributes in case buffer is too small. */ + if (efi_status == EFI_BUFFER_TOO_SMALL) { + *data_size = rsp_data->data_size; + if (attributes) + *attributes = rsp_data->attributes; + } + + goto out_free; + } + + if (rsp_data->length > rsp_size) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->data_offset + rsp_data->data_size > rsp_data->length) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + /* + * Note: We need to set attributes and data size even if the buffer is + * too small and we won't copy any data. This is described in spec, so + * that callers can either allocate a buffer properly (with two calls + * to this function) or just read back attributes withouth having to + * deal with that. + * + * Specifically: + * - If we have a buffer size of zero and no buffer, just return the + * attributes, required size, and indicate success. + * - If the buffer size is nonzero but too small, indicate that as an + * error. + * - Otherwise, we are good to copy the data. + * + * Note that we have already ensured above that the buffer pointer is + * non-NULL if its size is nonzero. + */ + *data_size = rsp_data->data_size; + if (attributes) + *attributes = rsp_data->attributes; + + if (buffer_size == 0 && !data) { + efi_status = EFI_SUCCESS; + goto out_free; + } + + if (buffer_size < rsp_data->data_size) { + efi_status = EFI_BUFFER_TOO_SMALL; + goto out_free; + } + + memcpy(data, ((void *)rsp_data) + rsp_data->data_offset, rsp_data->data_size); + +out_free: + kfree(rsp_data); +out_free_req: + kfree(req_data); +out: + return efi_status; +} + +static efi_status_t qsee_uefi_set_variable(struct qcuefi_client *qcuefi, const efi_char16_t *name, + const efi_guid_t *guid, u32 attributes, + unsigned long data_size, const void *data) +{ + struct qsee_req_uefi_set_variable *req_data; + struct qsee_rsp_uefi_set_variable *rsp_data; + efi_status_t efi_status = EFI_SUCCESS; + unsigned long name_length; + size_t name_offs; + size_t guid_offs; + size_t data_offs; + size_t req_size; + ssize_t status; + + if (!name || !guid) + return EFI_INVALID_PARAMETER; + + name_length = ucs2_strnlen(name, QSEE_MAX_NAME_LEN) + 1; + if (name_length > QSEE_MAX_NAME_LEN) + return EFI_INVALID_PARAMETER; + + /* + * Make sure we have some data if data_size is nonzero. Note that using + * a size of zero is a valid use-case described in spec and deletes the + * variable. + */ + if (data_size && !data) + return EFI_INVALID_PARAMETER; + + req_size = qcuefi_buf_align_fields( + __field(*req_data) + __array_offs(*name, name_length, &name_offs) + __field_offs(*guid, &guid_offs) + __array_offs(u8, data_size, &data_offs) + ); + + req_data = kzalloc(req_size, GFP_KERNEL); + if (!req_data) { + efi_status = EFI_OUT_OF_RESOURCES; + goto out; + } + + rsp_data = kzalloc(sizeof(*rsp_data), GFP_KERNEL); + if (!rsp_data) { + efi_status = EFI_OUT_OF_RESOURCES; + goto out_free_req; + } + + req_data->command_id = QSEE_CMD_UEFI_SET_VARIABLE; + req_data->attributes = attributes; + req_data->name_offset = name_offs; + req_data->name_size = name_length * sizeof(*name); + req_data->guid_offset = guid_offs; + req_data->guid_size = sizeof(*guid); + req_data->data_offset = data_offs; + req_data->data_size = data_size; + req_data->length = req_size; + + status = ucs2_strscpy(((void *)req_data) + req_data->name_offset, name, name_length); + if (status < 0) + return EFI_INVALID_PARAMETER; + + memcpy(((void *)req_data) + req_data->guid_offset, guid, req_data->guid_size); + + if (data_size) + memcpy(((void *)req_data) + req_data->data_offset, data, req_data->data_size); + + status = qcom_qseecom_app_send(qcuefi->client, req_data, req_size, rsp_data, + sizeof(*rsp_data)); + if (status) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->command_id != QSEE_CMD_UEFI_SET_VARIABLE) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->length != sizeof(*rsp_data)) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->status) { + dev_dbg(qcuefi_dev(qcuefi), "%s: uefisecapp error: 0x%x\n", + __func__, rsp_data->status); + efi_status = qsee_uefi_status_to_efi(rsp_data->status); + } + +out_free: + kfree(rsp_data); +out_free_req: + kfree(req_data); +out: + return efi_status; +} + +static efi_status_t qsee_uefi_get_next_variable(struct qcuefi_client *qcuefi, + unsigned long *name_size, efi_char16_t *name, + efi_guid_t *guid) +{ + struct qsee_req_uefi_get_next_variable *req_data; + struct qsee_rsp_uefi_get_next_variable *rsp_data; + efi_status_t efi_status = EFI_SUCCESS; + size_t guid_offs; + size_t name_offs; + size_t req_size; + size_t rsp_size; + ssize_t status; + + if (!name_size || !name || !guid) + return EFI_INVALID_PARAMETER; + + if (*name_size == 0) + return EFI_INVALID_PARAMETER; + + req_size = qcuefi_buf_align_fields( + __field(*req_data) + __field_offs(*guid, &guid_offs) + __array_offs(*name, *name_size / sizeof(*name), &name_offs) + ); + + rsp_size = qcuefi_buf_align_fields( + __field(*rsp_data) + __field(*guid) + __array(*name, *name_size / sizeof(*name)) + ); + + req_data = kzalloc(req_size, GFP_KERNEL); + if (!req_data) { + efi_status = EFI_OUT_OF_RESOURCES; + goto out; + } + + rsp_data = kzalloc(rsp_size, GFP_KERNEL); + if (!rsp_data) { + efi_status = EFI_OUT_OF_RESOURCES; + goto out_free_req; + } + + req_data->command_id = QSEE_CMD_UEFI_GET_NEXT_VARIABLE; + req_data->guid_offset = guid_offs; + req_data->guid_size = sizeof(*guid); + req_data->name_offset = name_offs; + req_data->name_size = *name_size; + req_data->length = req_size; + + memcpy(((void *)req_data) + req_data->guid_offset, guid, req_data->guid_size); + status = ucs2_strscpy(((void *)req_data) + req_data->name_offset, name, + *name_size / sizeof(*name)); + if (status < 0) + return EFI_INVALID_PARAMETER; + + status = qcom_qseecom_app_send(qcuefi->client, req_data, req_size, rsp_data, rsp_size); + if (status) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->command_id != QSEE_CMD_UEFI_GET_NEXT_VARIABLE) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->length < sizeof(*rsp_data)) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->status) { + dev_dbg(qcuefi_dev(qcuefi), "%s: uefisecapp error: 0x%x\n", + __func__, rsp_data->status); + efi_status = qsee_uefi_status_to_efi(rsp_data->status); + + /* + * If the buffer to hold the name is too small, update the + * name_size with the required size, so that callers can + * reallocate it accordingly. + */ + if (efi_status == EFI_BUFFER_TOO_SMALL) + *name_size = rsp_data->name_size; + + goto out_free; + } + + if (rsp_data->length > rsp_size) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->name_offset + rsp_data->name_size > rsp_data->length) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->guid_offset + rsp_data->guid_size > rsp_data->length) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->name_size > *name_size) { + *name_size = rsp_data->name_size; + efi_status = EFI_BUFFER_TOO_SMALL; + goto out_free; + } + + if (rsp_data->guid_size != sizeof(*guid)) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + memcpy(guid, ((void *)rsp_data) + rsp_data->guid_offset, rsp_data->guid_size); + status = ucs2_strscpy(name, ((void *)rsp_data) + rsp_data->name_offset, + rsp_data->name_size / sizeof(*name)); + *name_size = rsp_data->name_size; + + if (status < 0) { + /* + * Return EFI_DEVICE_ERROR here because the buffer size should + * have already been validated above, causing this function to + * bail with EFI_BUFFER_TOO_SMALL. + */ + return EFI_DEVICE_ERROR; + } + +out_free: + kfree(rsp_data); +out_free_req: + kfree(req_data); +out: + return efi_status; +} + +static efi_status_t qsee_uefi_query_variable_info(struct qcuefi_client *qcuefi, u32 attr, + u64 *storage_space, u64 *remaining_space, + u64 *max_variable_size) +{ + struct qsee_req_uefi_query_variable_info *req_data; + struct qsee_rsp_uefi_query_variable_info *rsp_data; + efi_status_t efi_status = EFI_SUCCESS; + int status; + + req_data = kzalloc(sizeof(*req_data), GFP_KERNEL); + if (!req_data) { + efi_status = EFI_OUT_OF_RESOURCES; + goto out; + } + + rsp_data = kzalloc(sizeof(*rsp_data), GFP_KERNEL); + if (!rsp_data) { + efi_status = EFI_OUT_OF_RESOURCES; + goto out_free_req; + } + + req_data->command_id = QSEE_CMD_UEFI_QUERY_VARIABLE_INFO; + req_data->attributes = attr; + req_data->length = sizeof(*req_data); + + status = qcom_qseecom_app_send(qcuefi->client, req_data, sizeof(*req_data), rsp_data, + sizeof(*rsp_data)); + if (status) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->command_id != QSEE_CMD_UEFI_QUERY_VARIABLE_INFO) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->length != sizeof(*rsp_data)) { + efi_status = EFI_DEVICE_ERROR; + goto out_free; + } + + if (rsp_data->status) { + dev_dbg(qcuefi_dev(qcuefi), "%s: uefisecapp error: 0x%x\n", + __func__, rsp_data->status); + efi_status = qsee_uefi_status_to_efi(rsp_data->status); + goto out_free; + } + + if (storage_space) + *storage_space = rsp_data->storage_space; + + if (remaining_space) + *remaining_space = rsp_data->remaining_space; + + if (max_variable_size) + *max_variable_size = rsp_data->max_variable_size; + +out_free: + kfree(rsp_data); +out_free_req: + kfree(req_data); +out: + return efi_status; +} + +/* -- Global efivar interface. ---------------------------------------------- */ + +static struct qcuefi_client *__qcuefi; +static DEFINE_MUTEX(__qcuefi_lock); + +static int qcuefi_set_reference(struct qcuefi_client *qcuefi) +{ + mutex_lock(&__qcuefi_lock); + + if (qcuefi && __qcuefi) { + mutex_unlock(&__qcuefi_lock); + return -EEXIST; + } + + __qcuefi = qcuefi; + + mutex_unlock(&__qcuefi_lock); + return 0; +} + +static struct qcuefi_client *qcuefi_acquire(void) +{ + mutex_lock(&__qcuefi_lock); + return __qcuefi; +} + +static void qcuefi_release(void) +{ + mutex_unlock(&__qcuefi_lock); +} + +static efi_status_t qcuefi_get_variable(efi_char16_t *name, efi_guid_t *vendor, u32 *attr, + unsigned long *data_size, void *data) +{ + struct qcuefi_client *qcuefi; + efi_status_t status; + + qcuefi = qcuefi_acquire(); + if (!qcuefi) + return EFI_NOT_READY; + + status = qsee_uefi_get_variable(qcuefi, name, vendor, attr, data_size, data); + + qcuefi_release(); + return status; +} + +static efi_status_t qcuefi_set_variable(efi_char16_t *name, efi_guid_t *vendor, + u32 attr, unsigned long data_size, void *data) +{ + struct qcuefi_client *qcuefi; + efi_status_t status; + + qcuefi = qcuefi_acquire(); + if (!qcuefi) + return EFI_NOT_READY; + + status = qsee_uefi_set_variable(qcuefi, name, vendor, attr, data_size, data); + + qcuefi_release(); + return status; +} + +static efi_status_t qcuefi_get_next_variable(unsigned long *name_size, efi_char16_t *name, + efi_guid_t *vendor) +{ + struct qcuefi_client *qcuefi; + efi_status_t status; + + qcuefi = qcuefi_acquire(); + if (!qcuefi) + return EFI_NOT_READY; + + status = qsee_uefi_get_next_variable(qcuefi, name_size, name, vendor); + + qcuefi_release(); + return status; +} + +static efi_status_t qcuefi_query_variable_info(u32 attr, u64 *storage_space, u64 *remaining_space, + u64 *max_variable_size) +{ + struct qcuefi_client *qcuefi; + efi_status_t status; + + qcuefi = qcuefi_acquire(); + if (!qcuefi) + return EFI_NOT_READY; + + status = qsee_uefi_query_variable_info(qcuefi, attr, storage_space, remaining_space, + max_variable_size); + + qcuefi_release(); + return status; +} + +static const struct efivar_operations qcom_efivar_ops = { + .get_variable = qcuefi_get_variable, + .set_variable = qcuefi_set_variable, + .get_next_variable = qcuefi_get_next_variable, + .query_variable_info = qcuefi_query_variable_info, +}; + +/* -- Driver setup. --------------------------------------------------------- */ + +static int qcom_uefisecapp_probe(struct auxiliary_device *aux_dev, + const struct auxiliary_device_id *aux_dev_id) +{ + struct qcuefi_client *qcuefi; + int status; + + qcuefi = devm_kzalloc(&aux_dev->dev, sizeof(*qcuefi), GFP_KERNEL); + if (!qcuefi) + return -ENOMEM; + + qcuefi->client = container_of(aux_dev, struct qseecom_client, aux_dev); + + auxiliary_set_drvdata(aux_dev, qcuefi); + status = qcuefi_set_reference(qcuefi); + if (status) + return status; + + status = efivars_register(&qcuefi->efivars, &qcom_efivar_ops); + if (status) + qcuefi_set_reference(NULL); + + return status; +} + +static void qcom_uefisecapp_remove(struct auxiliary_device *aux_dev) +{ + struct qcuefi_client *qcuefi = auxiliary_get_drvdata(aux_dev); + + efivars_unregister(&qcuefi->efivars); + qcuefi_set_reference(NULL); +} + +static const struct auxiliary_device_id qcom_uefisecapp_id_table[] = { + { .name = "qcom_qseecom.uefisecapp" }, + {} +}; +MODULE_DEVICE_TABLE(auxiliary, qcom_uefisecapp_id_table); + +static struct auxiliary_driver qcom_uefisecapp_driver = { + .probe = qcom_uefisecapp_probe, + .remove = qcom_uefisecapp_remove, + .id_table = qcom_uefisecapp_id_table, + .driver = { + .name = "qcom_qseecom_uefisecapp", + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, +}; +module_auxiliary_driver(qcom_uefisecapp_driver); + +MODULE_AUTHOR("Maximilian Luz "); +MODULE_DESCRIPTION("Client driver for Qualcomm SEE UEFI Secure App"); +MODULE_LICENSE("GPL");