linux-kernel - Re: [PATCH 02/11] driver core: Set DMA ownership during driver bind/unbind

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 for Android: free password hash cracker in your pocket

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

Message-ID: <YZJekd9tdz8cLAz+@infradead.org>
Date:   Mon, 15 Nov 2021 05:20:17 -0800
From:   Christoph Hellwig <hch@...radead.org>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Lu Baolu <baolu.lu@...ux.intel.com>,
        Kevin Tian <kevin.tian@...el.com>,
        Chaitanya Kulkarni <kch@...dia.com>,
        Ashok Raj <ashok.raj@...el.com>, kvm@...r.kernel.org,
        rafael@...nel.org, linux-pci@...r.kernel.org,
        Cornelia Huck <cohuck@...hat.com>,
        iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
        Alex Williamson <alex.williamson@...hat.com>,
        Jacob jun Pan <jacob.jun.pan@...el.com>,
        Jason Gunthorpe <jgg@...dia.com>,
        Diana Craciun <diana.craciun@....nxp.com>,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        Will Deacon <will@...nel.org>
Subject: Re: [PATCH 02/11] driver core: Set DMA ownership during driver
 bind/unbind

On Mon, Nov 15, 2021 at 07:59:10AM +0100, Greg Kroah-Hartman wrote:
> This feels wrong to be doing it in the driver core, why doesn't the bus
> that cares about this handle it instead?
> 
> You just caused all drivers in the kernel today to set and release this
> ownership, as none set this flag.  Shouldn't it be the other way around?
> 
> And again, why not in the bus that cares?
> 
> You only have problems with 1 driver out of thousands, this feels wrong
> to abuse the driver core this way for just that one.

This isn't really a bus thingy, but related to the IOMMU subsystem.
That being said as pointed out in my previous reply I'd expect this
to go along with other IOMMU setup.