lkml.org 
[lkml]   [2017]   [Oct]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH v5 08/14] platform/x86: dell-smbios: Add a sysfs interface for SMBIOS tokens
On Sat, Oct 07, 2017 at 11:56:04AM +0000, Mario.Limonciello@dell.com wrote:
> > -----Original Message-----
> > From: Greg KH [mailto:greg@kroah.com]
> > Sent: Saturday, October 7, 2017 1:54 AM
> > To: Limonciello, Mario <Mario_Limonciello@Dell.com>
> > Cc: dvhart@infradead.org; Andy Shevchenko <andy.shevchenko@gmail.com>;
> > LKML <linux-kernel@vger.kernel.org>; platform-driver-x86@vger.kernel.org;
> > Andy Lutomirski <luto@kernel.org>; quasisec@google.com;
> > pali.rohar@gmail.com; rjw@rjwysocki.net; mjg59@google.com; hch@lst.de
> > Subject: Re: [PATCH v5 08/14] platform/x86: dell-smbios: Add a sysfs interface for
> > SMBIOS tokens
> >
> > On Fri, Oct 06, 2017 at 11:59:52PM -0500, Mario Limonciello wrote:
> > > Currently userspace tools can access system tokens via the dcdbas
> > > kernel module and a SMI call that will cause the platform to execute
> > > SMM code.
> > >
> > > With a goal in mind of deprecating the dcdbas kernel module a different
> > > method for accessing these tokens from userspace needs to be created.
> > >
> > > This is intentionally marked to only be readable as root as it can
> > > contain sensitive information about the platform's configuration.
> > >
> > > MAINTAINERS was missing for this driver. Add myself and Pali to
> > > maintainers list for it.
> > >
> > > Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
> > > ---
> > > .../ABI/testing/sysfs-platform-dell-smbios | 16 ++++++
> > > MAINTAINERS | 7 +++
> > > drivers/platform/x86/dell-smbios.c | 64 ++++++++++++++++++++++
> > > 3 files changed, 87 insertions(+)
> > > create mode 100644 Documentation/ABI/testing/sysfs-platform-dell-smbios
> > >
> > > diff --git a/Documentation/ABI/testing/sysfs-platform-dell-smbios
> > b/Documentation/ABI/testing/sysfs-platform-dell-smbios
> > > new file mode 100644
> > > index 000000000000..d97f4bd5bd91
> > > --- /dev/null
> > > +++ b/Documentation/ABI/testing/sysfs-platform-dell-smbios
> > > @@ -0,0 +1,16 @@
> > > +What: /sys/devices/platform/<platform>/tokens
> > > +Date: November 2017
> > > +KernelVersion: 4.15
> > > +Contact: "Mario Limonciello" <mario.limonciello@dell.com>
> > > +Description:
> > > + A read-only description of Dell platform tokens
> > > + available on the machine.
> > > +
> > > + The tokens will be displayed in the following
> > > + machine readable format with each token on a
> > > + new line:
> > > +
> > > + ID Location value
> > > +
> > > + For example token:
> > > + 5 5 3
> > That's more than "one value per file" which is what sysfs requires, so
> > this isn't acceptable, sorry.
>
> What's more acceptable to you to relay this information?
> Binary sysfs attribute and export the structure format in a uapi?

binary sysfs apis are for passing "raw" data to/from firmware/hardware
to userspace, without the kernel knowing anything about the structure
or format of the data. Putting the format in a structure in a uapi
header kind of defeats that purpose :)

> or a collection of sysfs files?
> Eg:
> tokens/$x/id
> tokens/$x/location
> tokens/$s/value
>
> I'm guessing the latter is the better way to go.

Good guess :)

thanks,

greg k-h

\
 
 \ /
  Last update: 2017-10-07 14:39    [W:0.052 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site