From patchwork Tue Sep 26 18:50:08 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Limonciello, Mario" X-Patchwork-Id: 9972539 X-Patchwork-Delegate: dvhart@infradead.org Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B23BC6037E for ; Tue, 26 Sep 2017 18:51:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A43E528F82 for ; Tue, 26 Sep 2017 18:51:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 974F328F8A; Tue, 26 Sep 2017 18:51:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1834D28F82 for ; Tue, 26 Sep 2017 18:51:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031757AbdIZSv3 (ORCPT ); Tue, 26 Sep 2017 14:51:29 -0400 Received: from esa7.dell-outbound.iphmx.com ([68.232.153.96]:6321 "EHLO esa7.dell-outbound.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031670AbdIZSuZ (ORCPT ); Tue, 26 Sep 2017 14:50:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=dell.com; i=@dell.com; q=dns/txt; s=smtpout; t=1506451417; x=1537987417; h=from:to:cc:subject:date:message-id; bh=lHGMca6zO1PtWyxkXJ9hWU0+tICODk/BWDxEfTOERLE=; b=pd7Vh2/sR6uCNVfncZqzPFPczDIoxjuPevPyrgP5wns4orOkKkwybWEW V5rEA+QkvxfvnFtsp7Z1AiwtGblLIjZt7YlOYizmJKCX3KXNoE1Kb6I5X KGWouScNOgOd2qXWygNAtBbahE85/upV4F1pig1TEZo0ZW5IklwqIjWcJ g=; Received: from esa5.dell-outbound2.iphmx.com ([68.232.153.203]) by esa7.dell-outbound.iphmx.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Sep 2017 13:43:35 -0500 Received: from ausc60pc101.us.dell.com ([143.166.85.206]) by esa5.dell-outbound2.iphmx.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Sep 2017 00:43:20 +0600 X-LoopCount0: from 10.208.86.39 X-IronPort-AV: E=Sophos;i="5.42,441,1500958800"; d="scan'208";a="1157572868" X-DLP: DLP_GlobalPCIDSS From: Mario Limonciello To: dvhart@infradead.org, Andy Shevchenko Cc: LKML , platform-driver-x86@vger.kernel.org, quasisec@google.com, pali.rohar@gmail.com, Mario Limonciello Subject: [PATCH v2 10/14] platform/x86: dell-wmi-smbios: Use Dell WMI descriptor check Date: Tue, 26 Sep 2017 13:50:08 -0500 Message-Id: X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: Sender: platform-driver-x86-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The Dell WMI descriptor check is used as an indication that WMI calls are safe to run both when used with the notification ASL/GUID pair as well as the SMBIOS calling ASL/GUID pair. As some code in dell-wmi-smbios is already a prerequisite for dell-wmi, move the code for performing the descriptor check into dell-wmi-smbios and let both drivers use it from there. Signed-off-by: Mario Limonciello --- drivers/platform/x86/dell-wmi-smbios.c | 84 ++++++++++++++++++++++++++++++++++ drivers/platform/x86/dell-wmi-smbios.h | 3 ++ drivers/platform/x86/dell-wmi.c | 75 +----------------------------- 3 files changed, 88 insertions(+), 74 deletions(-) diff --git a/drivers/platform/x86/dell-wmi-smbios.c b/drivers/platform/x86/dell-wmi-smbios.c index b0812a8fa860..699757f3e154 100644 --- a/drivers/platform/x86/dell-wmi-smbios.c +++ b/drivers/platform/x86/dell-wmi-smbios.c @@ -28,6 +28,7 @@ #endif #define DELL_WMI_SMBIOS_GUID "A80593CE-A997-11DA-B012-B622A1EF5492" +#define DELL_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492" struct calling_interface_structure { struct dmi_header header; @@ -223,13 +224,92 @@ static void __init find_tokens(const struct dmi_header *dm, void *dummy) } } +/* + * Descriptor buffer is 128 byte long and contains: + * + * Name Offset Length Value + * Vendor Signature 0 4 "DELL" + * Object Signature 4 4 " WMI" + * WMI Interface Version 8 4 + * WMI buffer length 12 4 4096 + */ +int dell_wmi_check_descriptor_buffer(struct wmi_device *wdev, u32 *version) +{ + union acpi_object *obj = NULL; + struct wmi_device *desc_dev; + u32 *desc_buffer; + int ret; + + desc_dev = wmidev_get_other_guid(wdev, DELL_DESCRIPTOR_GUID); + if (!desc_dev) { + dev_err(&wdev->dev, "Dell WMI descriptor does not exist\n"); + return -ENODEV; + } + + obj = wmidev_block_query(desc_dev, 0); + if (!obj) { + dev_err(&wdev->dev, "failed to read Dell WMI descriptor\n"); + ret = -EIO; + goto out; + } + + if (obj->type != ACPI_TYPE_BUFFER) { + dev_err(&wdev->dev, "Dell descriptor has wrong type\n"); + ret = -EINVAL; + goto out; + } + + if (obj->buffer.length != 128) { + dev_err(&wdev->dev, + "Dell descriptor buffer has invalid length (%d)\n", + obj->buffer.length); + if (obj->buffer.length < 16) { + ret = -EINVAL; + goto out; + } + } + desc_buffer = (u32 *)obj->buffer.pointer; + + if (desc_buffer[0] != 0x4C4C4544 && desc_buffer[1] != 0x494D5720) + dev_warn(&wdev->dev, "Dell descriptor buffer has invalid signature (%*ph)\n", + 8, desc_buffer); + + if (desc_buffer[2] != 0 && desc_buffer[2] != 1) + dev_warn(&wdev->dev, "Dell descriptor buffer has unknown version (%d)\n", + desc_buffer[2]); + + if (desc_buffer[3] != 4096) + dev_warn(&wdev->dev, "Dell descriptor buffer has invalid buffer length (%d)\n", + desc_buffer[3]); + + *version = desc_buffer[2]; + ret = 0; + + dev_info(&wdev->dev, "Detected Dell WMI interface version %u\n", + *version); + +out: + kfree(obj); + put_device(&desc_dev->dev); + return ret; +} +EXPORT_SYMBOL_GPL(dell_wmi_check_descriptor_buffer); + + static int dell_smbios_wmi_probe(struct wmi_device *wdev) { + int ret; + u32 interface_version; + /* WMI buffer should be 32k */ wmi_buffer = (void *)__get_free_pages(GFP_KERNEL, 3); if (!wmi_buffer) return -ENOMEM; + ret = dell_wmi_check_descriptor_buffer(wdev, &interface_version); + if (ret) + goto fail_wmi_probe; + #ifdef CONFIG_DCDBAS /* no longer need the SMI page */ free_page((unsigned long)smi_buffer); @@ -238,6 +318,10 @@ static int dell_smbios_wmi_probe(struct wmi_device *wdev) has_wmi = 1; return 0; + +fail_wmi_probe: + free_pages((unsigned long)wmi_buffer, 3); + return ret; } static int dell_smbios_wmi_remove(struct wmi_device *wdev) diff --git a/drivers/platform/x86/dell-wmi-smbios.h b/drivers/platform/x86/dell-wmi-smbios.h index 14b7e2ece310..0e8b57f7d0f0 100644 --- a/drivers/platform/x86/dell-wmi-smbios.h +++ b/drivers/platform/x86/dell-wmi-smbios.h @@ -17,6 +17,8 @@ #ifndef _DELL_WMI_SMBIOS_H_ #define _DELL_WMI_SMBIOS_H_ +#include + struct notifier_block; /* If called through fallback SMI rather than WMI this structure will be @@ -62,5 +64,6 @@ enum dell_laptop_notifier_actions { int dell_laptop_register_notifier(struct notifier_block *nb); int dell_laptop_unregister_notifier(struct notifier_block *nb); void dell_laptop_call_notifier(unsigned long action, void *data); +int dell_wmi_check_descriptor_buffer(struct wmi_device *wdev, u32 *version); #endif diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c index e8b4d412eabc..e7011792127f 100644 --- a/drivers/platform/x86/dell-wmi.c +++ b/drivers/platform/x86/dell-wmi.c @@ -46,7 +46,6 @@ MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver"); MODULE_LICENSE("GPL"); #define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492" -#define DELL_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492" static bool wmi_requires_smbios_request; @@ -617,78 +616,6 @@ static void dell_wmi_input_destroy(struct wmi_device *wdev) input_unregister_device(priv->input_dev); } -/* - * Descriptor buffer is 128 byte long and contains: - * - * Name Offset Length Value - * Vendor Signature 0 4 "DELL" - * Object Signature 4 4 " WMI" - * WMI Interface Version 8 4 - * WMI buffer length 12 4 4096 - */ -static int dell_wmi_check_descriptor_buffer(struct wmi_device *wdev) -{ - struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev); - union acpi_object *obj = NULL; - struct wmi_device *desc_dev; - u32 *buffer; - int ret; - - desc_dev = wmidev_get_other_guid(wdev, DELL_DESCRIPTOR_GUID); - if (!desc_dev) { - dev_err(&wdev->dev, "Dell WMI descriptor does not exist\n"); - return -ENODEV; - } - - obj = wmidev_block_query(desc_dev, 0); - if (!obj) { - dev_err(&wdev->dev, "failed to read Dell WMI descriptor\n"); - ret = -EIO; - goto out; - } - - if (obj->type != ACPI_TYPE_BUFFER) { - dev_err(&wdev->dev, "Dell descriptor has wrong type\n"); - ret = -EINVAL; - goto out; - } - - if (obj->buffer.length != 128) { - dev_err(&wdev->dev, - "Dell descriptor buffer has invalid length (%d)\n", - obj->buffer.length); - if (obj->buffer.length < 16) { - ret = -EINVAL; - goto out; - } - } - - buffer = (u32 *)obj->buffer.pointer; - - if (buffer[0] != 0x4C4C4544 && buffer[1] != 0x494D5720) - dev_warn(&wdev->dev, "Dell descriptor buffer has invalid signature (%*ph)\n", - 8, buffer); - - if (buffer[2] != 0 && buffer[2] != 1) - dev_warn(&wdev->dev, "Dell descriptor buffer has unknown version (%d)\n", - buffer[2]); - - if (buffer[3] != 4096) - dev_warn(&wdev->dev, "Dell descriptor buffer has invalid buffer length (%d)\n", - buffer[3]); - - priv->interface_version = buffer[2]; - ret = 0; - - dev_info(&wdev->dev, "Detected Dell WMI interface version %u\n", - priv->interface_version); - -out: - kfree(obj); - put_device(&desc_dev->dev); - return ret; -} - /* * According to Dell SMBIOS documentation: * @@ -732,7 +659,7 @@ static int dell_wmi_probe(struct wmi_device *wdev) return -ENOMEM; dev_set_drvdata(&wdev->dev, priv); - err = dell_wmi_check_descriptor_buffer(wdev); + err = dell_wmi_check_descriptor_buffer(wdev, &priv->interface_version); if (err) return err;