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Date:   Wed, 23 Nov 2022 16:57:40 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Nayna <nayna@linux.vnet.ibm.com>
Cc:     Nayna Jain <nayna@linux.ibm.com>, linuxppc-dev@lists.ozlabs.org,
        linux-fsdevel@vger.kernel.org, linux-efi@vger.kernel.org,
        linux-security-module <linux-security-module@vger.kernel.org>,
        linux-kernel@vger.kernel.org,
        Michael Ellerman <mpe@ellerman.id.au>, npiggin@gmail.com,
        christophe.leroy@csgroup.eu, Dov Murik <dovmurik@linux.ibm.com>,
        George Wilson <gcwilson@linux.ibm.com>,
        Matthew Garrett <mjg59@srcf.ucam.org>,
        Dave Hansen <dave.hansen@intel.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Russell Currey <ruscur@russell.cc>,
        Andrew Donnellan <ajd@linux.ibm.com>,
        Stefan Berger <stefanb@linux.ibm.com>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Subject: Re: [PATCH 2/4] fs: define a firmware security filesystem named
 fwsecurityfs
Message-ID: <Y35C9O27J29bUDjA@kroah.com>
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On Wed, Nov 23, 2022 at 10:05:49AM -0500, Nayna wrote:
> 
> On 11/22/22 18:21, Nayna wrote:
> > 
> > From the perspective of our use case, we need to expose firmware
> > security objects to userspace for management. Not all of the objects
> > pre-exist and we would like to allow root to create them from userspace.
> > 
> > From a unification perspective, I have considered a common location at
> > /sys/firmware/security for managing any platform's security objects. And
> > I've proposed a generic filesystem, which could be used by any platform
> > to represent firmware security objects via /sys/firmware/security.
> > 
> > Here are some alternatives to generic filesystem in discussion:
> > 
> > 1. Start with a platform-specific filesystem. If more platforms would
> > like to use the approach, it can be made generic. We would still have a
> > common location of /sys/firmware/security and new code would live in
> > arch. This is my preference and would be the best fit for our use case.
> > 
> > 2. Use securityfs.? This would mean modifying it to satisfy other use
> > cases, including supporting userspace file creation. I don't know if the
> > securityfs maintainer would find that acceptable. I would also still
> > want some way to expose variables at /sys/firmware/security.
> > 
> > 3. Use a sysfs-based approach. This would be a platform-specific
> > implementation. However, sysfs has a similar issue to securityfs for
> > file creation. When I tried it in RFC v1[1], I had to implement a
> > workaround to achieve that.
> > 
> > [1] https://lore.kernel.org/linuxppc-dev/20220122005637.28199-3-nayna@linux.ibm.com/
> > 
> Hi Greg,
> 
> Based on the discussions so far, is Option 1, described above, an acceptable
> next step?

No, as I said almost a year ago, I do not want to see platform-only
filesystems going and implementing stuff that should be shared by all
platforms.

thanks,

greg k-h