From: Darren Hart <dvhart@infradead.org>
To: Mario Limonciello <mario.limonciello@dell.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
platform-driver-x86@vger.kernel.org,
Andy Lutomirski <luto@kernel.org>,
quasisec@google.com, pali.rohar@gmail.com, rjw@rjwysocki.net,
mjg59@google.com, hch@lst.de, Greg KH <greg@kroah.com>,
Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH v12 00/16] Introduce support for Dell SMBIOS over WMI
Date: Thu, 2 Nov 2017 17:50:25 -0700 [thread overview]
Message-ID: <20171103005025.GA7971@fury> (raw)
In-Reply-To: <cover.1509561822.git.mario.limonciello@dell.com>
On Wed, Nov 01, 2017 at 02:25:21PM -0500, Mario Limonciello wrote:
> The existing way that the dell-smbios helper module and associated
> other drivers (dell-laptop, dell-wmi) communicate with the platform
> really isn't secure. It requires creating a buffer in physical
> DMA32 memory space and passing that to the platform via SMM.
>
> Since the platform got a physical memory pointer, you've just got
> to trust that the platform has only modified (and accessed) memory
> within that buffer.
>
> Dell Platform designers recognize this security risk and offer a
> safer way to communicate with the platform over ACPI. This is
> in turn exposed via a WMI interface to the OS.
>
> When communicating over WMI-ACPI the communication doesn't occur
> with physical memory pointers. When the ASL is invoked, the fixed
> length ACPI buffer is copied to a small operating region. The ASL
> will invoke the SMI, and SMM will only have access to this operating
> region. When the ASL returns the buffer is copied back for the OS
> to process.
>
> This method of communication should also deprecate the usage of the
> dcdbas kernel module and software dependent upon it's interface.
> Instead offer a character device interface for communicating with this
> ASL method to allow userspace to use instead.
>
> To faciliate that this patch series introduces a generic way for WMI
> drivers to be able to create discoverable character devices with
> a predictable IOCTL interface through the WMI bus when desired.
> Requiring WMI drivers to explicitly ask for this functionality will
> act as an effective vendor whitelist to character device creation.
>
> Some of this work is the basis for what will be a proper interpreter
> of MOF in the kernel and controls for what drivers will be able to
> do with that MOF.
>
> NOTE: This patch series is intended to go on top of platform-drivers-x86
> linux-next.
>
> For convenience the entire series including those is also available here:
> https://github.com/dell/linux/tree/wmi-smbios
Queued for testing, thanks Mario.
--
Darren Hart
VMware Open Source Technology Center
next prev parent reply other threads:[~2017-11-03 0:50 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-01 19:25 [PATCH v12 00/16] Introduce support for Dell SMBIOS over WMI Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 01/16] platform/x86: dell-smbios: Prefix class/select with cmd_ Mario Limonciello
2017-11-02 0:30 ` Edward O'Callaghan
2017-11-01 19:25 ` [PATCH v12 02/16] platform/x86: wmi: Add new method wmidev_evaluate_method Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 03/16] platform/x86: dell-wmi: increase severity of some failures Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 04/16] platform/x86: dell-wmi: clean up wmi descriptor check Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 05/16] platform/x86: dell-wmi: don't check length returned Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 06/16] platform/x86: dell-wmi-descriptor: split WMI descriptor into it's own driver Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 07/16] platform/x86: wmi: Don't allow drivers to get each other's GUIDs Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 08/16] platform/x86: dell-smbios: only run if proper oem string is detected Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 09/16] platform/x86: dell-smbios: Add a sysfs interface for SMBIOS tokens Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 10/16] platform/x86: dell-smbios: Introduce dispatcher for SMM calls Mario Limonciello
2018-01-27 14:48 ` Pali Rohár
2017-11-01 19:25 ` [PATCH v12 11/16] platform/x86: dell-smbios-wmi: Add new WMI dispatcher driver Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 12/16] platform/x86: dell-smbios-smm: test for WSMT Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 13/16] platform/x86: dell-smbios: Add filtering support Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 14/16] platform/x86: wmi: create userspace interface for drivers Mario Limonciello
2017-11-02 0:31 ` Edward O'Callaghan
2017-11-01 19:25 ` [PATCH v12 15/16] platform/x86: dell-smbios-wmi: introduce userspace interface Mario Limonciello
2017-11-01 19:25 ` [PATCH v12 16/16] tools/wmi: add a sample for dell smbios communication over WMI Mario Limonciello
2017-11-03 0:50 ` Darren Hart [this message]
2017-11-03 16:30 ` [PATCH v12 00/16] Introduce support for Dell SMBIOS " Mario.Limonciello
2017-11-03 21:00 ` Darren Hart
2017-11-03 21:02 ` Mario.Limonciello
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