linux-kernel - Re: [v8 PATCH 0/2] PCI/ACPI: Support Microsoft's "DmaProperty"

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <2025022053-circulate-pamphlet-a718@gregkh>
Date: Thu, 20 Feb 2025 09:27:13 +0100
From: Greg KH <gregkh@...uxfoundation.org>
To: Joshua Peraza <jperaza@...gle.com>
Cc: baolu.lu@...ux.intel.com, bhelgaas@...gle.com, dtor@...gle.com,
	dwmw2@...radead.org, helgaas@...nel.org,
	iommu@...ts.linux-foundation.org, jean-philippe@...aro.org,
	joro@...tes.org, jsbarnes@...gle.com, lenb@...nel.org,
	linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-pci@...r.kernel.org, mika.westerberg@...ux.intel.com,
	oohall@...il.com, pavel@...x.de, rafael.j.wysocki@...el.com,
	rafael@...nel.org, rajatja@...gle.com, rajatxjain@...il.com,
	will@...nel.org
Subject: Re: [v8 PATCH 0/2] PCI/ACPI: Support Microsoft's "DmaProperty"

On Wed, Feb 19, 2025 at 01:53:48PM -0800, Joshua Peraza wrote:
> On Mon, Nov 18, 2024 at 11:43 AM Greg KH <gregkh@...uxfoundation.org> wrote:

Wow this is a slow discussion :)

> > On Mon, Nov 18, 2024 at 07:30:22PM +0000, Joshua Peraza wrote:
> > > This patchset rebases two previously posted patches supporting
> > > recognition of Microsoft's DmaProperty.
> > >
> > > v8: Joshua renames untrusted_dma to requires_dma_protection and updates
> > > some comments, reducing use of the word "trust" to refer to PCI devices
> > > and matching the word choice in Microsoft's documentation.
> >
> > So this is the "clarity"?  I'm not sold, sorry.  Again, did you look at
> > the previous discussions we had about this name?  We don't have to use
> > Microsoft's term here as it is used differently by Linux today, right?
> > If you really want to support the DmaProperty, why not just support that
> > with a new bit as that's something different here, right?
> >
> > Again, look at what this is supposed to be conveying.  They ability to
> > DMA to anywhere isn't really the root issue here, or is it?  What is the
> > threat model you are trying to mitigate?
> >
> > > v7: Rajat updates a comment with Robin's suggestion. Joshua re-sends and
> > > Greg requests clarity and documentation on why untrusted_dma is the
> > > right name.
> > >
> > > v6: Rajat renames pci_dev_has_dma_property and links to Microsoft's
> > > documentation in the commit message. Robin suggests clarifying a
> > > comment.
> > >
> > > v5: Rajat changes the name to untrusted_dma. Bjorn suggesting changing
> > > another function's name pci_acpi_check_for_dma_protection to
> > > pci_dev_has_dma_property and seeks clarified documentation.
> > >
> > > v4: Rajat changes the name to poses_dma_risk. Christoph suggests this
> > > name doesn't capture the intent as well as untrusted_dma and Rafael
> > > agrees.
> > >
> > > v1,v2,v3: Greg suggests that (un)trusted is the wrong word for referring
> > > to PCI devices, recommending a name something like "platform wants to
> > > protect dma access for this device."
> >
> > Or is it?  I said this when?  Just how old is this patch series?
> >
> > confused,
> >
> > greg k-h
> 
> (sorry if you're getting this again; re-sending as plain text)
> 
> Sorry for the confusion! What do you think about the following for a
> new cover letter?

I really don't remember anymore, sorry.  Try submitting the whole series
again as I don't know what you wrote the first time here.

thanks,

greg "I get 1000 emails a day" k-h