From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Ben Widawsky <ben.widawsky@intel.com>
Cc: linux-cxl@vger.kernel.org, linux-acpi@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org,
linux-pci@vger.kernel.org, Bjorn Helgaas <helgaas@kernel.org>,
Chris Browy <cbrowy@avery-design.com>,
Christoph Hellwig <hch@infradead.org>,
Dan Williams <dan.j.williams@intel.com>,
Ira Weiny <ira.weiny@intel.com>, Jon Masters <jcm@jonmasters.org>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Rafael Wysocki <rafael.j.wysocki@intel.com>,
Randy Dunlap <rdunlap@infradead.org>,
Vishal Verma <vishal.l.verma@intel.com>,
daniel.lll@alibaba-inc.com,
"John Groves (jgroves)" <jgroves@micron.com>,
"Kelley, Sean V" <sean.v.kelley@intel.com>
Subject: Re: [PATCH 08/14] taint: add taint for direct hardware access
Date: Mon, 1 Feb 2021 13:18:45 -0500 [thread overview]
Message-ID: <20210201181845.GJ197521@fedora> (raw)
In-Reply-To: <20210130002438.1872527-9-ben.widawsky@intel.com>
On Fri, Jan 29, 2021 at 04:24:32PM -0800, Ben Widawsky wrote:
> For drivers that moderate access to the underlying hardware it is
> sometimes desirable to allow userspace to bypass restrictions. Once
> userspace has done this, the driver can no longer guarantee the sanctity
> of either the OS or the hardware. When in this state, it is helpful for
> kernel developers to be made aware (via this taint flag) of this fact
> for subsequent bug reports.
>
> Example usage:
> - Hardware xyzzy accepts 2 commands, waldo and fred.
> - The xyzzy driver provides an interface for using waldo, but not fred.
> - quux is convinced they really need the fred command.
> - xyzzy driver allows quux to frob hardware to initiate fred.
Would it not be easier to _not_ frob the hardware for fred-operation?
Aka not implement it or just disallow in the first place?
> - kernel gets tainted.
> - turns out fred command is borked, and scribbles over memory.
> - developers laugh while closing quux's subsequent bug report.
Yeah good luck with that theory in-the-field. The customer won't
care about this and will demand a solution for doing fred-operation.
Just easier to not do fred-operation in the first place,no?
next prev parent reply other threads:[~2021-02-01 18:21 UTC|newest]
Thread overview: 96+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-30 0:24 [PATCH 00/14] CXL 2.0 Support Ben Widawsky
2021-01-30 0:24 ` [PATCH 01/14] cxl/mem: Introduce a driver for CXL-2.0-Type-3 endpoints Ben Widawsky
2021-01-30 23:51 ` David Rientjes
2021-02-01 17:21 ` Jonathan Cameron
2021-02-01 17:34 ` Konrad Rzeszutek Wilk
2021-02-02 17:58 ` Christoph Hellwig
2021-02-02 18:00 ` Christoph Hellwig
2021-01-30 0:24 ` [PATCH 02/14] cxl/mem: Map memory device registers Ben Widawsky
2021-01-30 23:51 ` David Rientjes
2021-02-01 16:46 ` Ben Widawsky
2021-02-01 18:19 ` Jonathan Cameron
2021-02-01 17:36 ` Konrad Rzeszutek Wilk
2021-02-02 18:04 ` Christoph Hellwig
2021-02-02 18:31 ` Ben Widawsky
2021-02-03 17:12 ` Christoph Hellwig
2021-01-30 0:24 ` [PATCH 03/14] cxl/mem: Find device capabilities Ben Widawsky
2021-01-30 23:51 ` David Rientjes
2021-02-01 16:53 ` Ben Widawsky
2021-02-01 21:51 ` David Rientjes
2021-02-01 21:58 ` Ben Widawsky
2021-02-01 22:23 ` David Rientjes
2021-02-01 22:28 ` Ben Widawsky
2021-02-01 22:33 ` Ben Widawsky
2021-02-01 22:45 ` David Rientjes
2021-02-01 22:50 ` Ben Widawsky
2021-02-01 23:09 ` David Rientjes
2021-02-01 23:17 ` Ben Widawsky
2021-02-01 23:58 ` David Rientjes
2021-02-02 0:11 ` Ben Widawsky
2021-02-02 0:14 ` Dan Williams
2021-02-02 1:09 ` David Rientjes
2021-02-01 22:02 ` Dan Williams
2021-02-01 17:41 ` Konrad Rzeszutek Wilk
2021-02-01 17:50 ` Ben Widawsky
2021-02-01 18:08 ` Konrad Rzeszutek Wilk
2021-02-02 18:10 ` Christoph Hellwig
2021-02-02 18:24 ` Ben Widawsky
2021-02-03 17:15 ` Christoph Hellwig
2021-02-03 17:23 ` Ben Widawsky
2021-02-03 21:23 ` Dan Williams
2021-02-04 7:16 ` Christoph Hellwig
2021-02-04 15:29 ` Ben Widawsky
2021-01-30 0:24 ` [PATCH 04/14] cxl/mem: Implement polled mode mailbox Ben Widawsky
2021-01-30 23:51 ` David Rientjes
2021-02-01 20:00 ` Dan Williams
2021-02-02 22:57 ` Ben Widawsky
2021-02-02 23:54 ` Dan Williams
2021-02-03 0:54 ` Ben Widawsky
2021-02-02 22:50 ` Ben Widawsky
2021-02-01 17:54 ` Konrad Rzeszutek Wilk
2021-02-01 19:13 ` Ben Widawsky
2021-02-01 19:28 ` Dan Williams
[not found] ` <SN6PR08MB46052FE9BC20A747CACD8F50D1B39@SN6PR08MB4605.namprd08.prod.outlook.com>
2021-02-04 22:24 ` [EXT] " Ben Widawsky
2021-01-30 0:24 ` [PATCH 05/14] cxl/mem: Register CXL memX devices Ben Widawsky
2021-01-30 0:31 ` Dan Williams
2021-01-30 23:52 ` David Rientjes
2021-02-01 17:10 ` Ben Widawsky
2021-02-01 21:53 ` David Rientjes
2021-02-01 21:55 ` Dan Williams
2021-02-02 18:13 ` Christoph Hellwig
2021-01-30 0:24 ` [PATCH 06/14] cxl/mem: Add basic IOCTL interface Ben Widawsky
2021-02-02 18:15 ` Christoph Hellwig
2021-02-02 18:33 ` Ben Widawsky
2021-01-30 0:24 ` [PATCH 07/14] cxl/mem: Add send command Ben Widawsky
2021-02-01 18:15 ` Konrad Rzeszutek Wilk
2021-02-02 23:08 ` Ben Widawsky
2021-01-30 0:24 ` [PATCH 08/14] taint: add taint for direct hardware access Ben Widawsky
2021-02-01 18:18 ` Konrad Rzeszutek Wilk [this message]
2021-02-01 18:34 ` Ben Widawsky
2021-02-01 19:01 ` Dan Williams
2021-02-02 2:49 ` Konrad Rzeszutek Wilk
2021-02-02 17:46 ` Dan Williams
2021-02-08 22:00 ` Dan Williams
2021-02-08 22:09 ` Kees Cook
2021-02-08 23:05 ` Ben Widawsky
2021-02-08 23:36 ` Dan Williams
2021-02-09 1:03 ` Dan Williams
2021-02-09 3:36 ` Ben Widawsky
2021-01-30 0:24 ` [PATCH 09/14] cxl/mem: Add a "RAW" send command Ben Widawsky
2021-02-01 18:24 ` Konrad Rzeszutek Wilk
2021-02-01 19:27 ` Ben Widawsky
2021-02-01 19:34 ` Konrad Rzeszutek Wilk
2021-02-01 21:20 ` Dan Williams
2021-01-30 0:24 ` [PATCH 10/14] cxl/mem: Create concept of enabled commands Ben Widawsky
2021-01-30 0:24 ` [PATCH 11/14] cxl/mem: Use CEL for enabling commands Ben Widawsky
2021-01-30 0:24 ` [PATCH 12/14] cxl/mem: Add set of informational commands Ben Widawsky
2021-01-30 0:24 ` [PATCH 13/14] cxl/mem: Add limited Get Log command (0401h) Ben Widawsky
2021-02-01 18:28 ` Konrad Rzeszutek Wilk
2021-02-02 23:51 ` Ben Widawsky
2021-02-02 23:57 ` Dan Williams
2021-02-03 17:16 ` Ben Widawsky
2021-02-03 18:14 ` Konrad Rzeszutek Wilk
2021-02-03 20:31 ` Dan Williams
2021-02-04 18:55 ` Ben Widawsky
2021-02-04 21:01 ` Dan Williams
2021-01-30 0:24 ` [PATCH 14/14] MAINTAINERS: Add maintainers of the CXL driver Ben Widawsky
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