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Date:   Mon, 8 Aug 2022 08:10:22 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Oded Gabbay <oded.gabbay@gmail.com>
Cc:     Jason Gunthorpe <jgg@nvidia.com>, Dave Airlie <airlied@gmail.com>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        Yuji Ishikawa <yuji2.ishikawa@toshiba.co.jp>,
        Jiho Chu <jiho.chu@samsung.com>, Arnd Bergmann <arnd@arndb.de>,
        "Linux-Kernel@Vger. Kernel. Org" <linux-kernel@vger.kernel.org>
Subject: Re: New subsystem for acceleration devices
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On Sun, Aug 07, 2022 at 02:25:33PM +0300, Oded Gabbay wrote:
> 2. Common code to handle drivers that want to allow a single user at a
> time to run open the device char file.

Note, that's an impossible request, and one that the kernel should never
worry about, so don't even try it.  Think about userspace doing an call
to dup() on an open char file descriptor and then passing that off
somewhere else.

thanks,

greg k-h