Re: [PATCH] TPM: Fixup pubek sysfs file

From: Greg KH
Date: Fri Sep 11 2009 - 12:31:47 EST


On Fri, Sep 04, 2009 at 03:23:16PM -0600, Jason Gunthorpe wrote:
> On Fri, Sep 04, 2009 at 02:03:25PM -0700, Andrew Morton wrote:
> > On Thu, 03 Sep 2009 22:02:24 -0700
> > Roland Dreier <rdreier@xxxxxxxxx> wrote:
> >
> > >
> > > > Algorithm: 00 00 00 01
> > > > Encscheme: 00 03
> > > > Sigscheme: 00 01
> > > > Parameters: 00 00 08 00 00 00 00 02 00 00 00 00
> > > > Modulus length: 256
> > >
> > > No argument that this fix is an improvement, but what happened to the
> > > "one value per file" rule for sysfs??
> >
> > We goofed. This one snuck through.
> >
> > It's one of the reasons why I recommend that people cite examples of
> > the sysfs/procfs output in changelogs. These things are part of the
> > kernel ABI and once they go in we cannot change them so we have to get
> > them right first time.
>
> Several of the sysfs files in the TPM driver are goofed:
>
> /sys/devices/platform/tpm_tis.0 # cat caps
> Manufacturer: 0x57454300
> TCG version: 1.2
> Firmware version: 2.16
>
> /sys/devices/platform/tpm_tis.0 # cat pcrs
> PCR-00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-01: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-02: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-03: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-04: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-05: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-06: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-07: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-08: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-09: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-11: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-12: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-13: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-14: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-15: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-16: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> PCR-17: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
> PCR-18: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
> PCR-19: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
> PCR-20: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
> PCR-21: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
> PCR-22: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
> PCR-23: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>
> /sys/devices/platform/tpm_tis.0 # cat pubek
> Algorithm: 00 00 00 01
> Encscheme: 00 03
> Sigscheme: 00 01
> Parameters: 00 00 08 00 00 00 00 02 00 00 00 00
> Modulus length: 256
> Modulus:
> AF 6B 30 9B 0D B3 B4 7D 74 35 68 45 8D CA A5 EF
> A8 8A DD 0F D7 84 8E 8D 1F 40 22 92 09 CF 12 C8
> 9F 6E 55 57 6A 2C A8 0B 5E 45 C7 5E 3D 56 DA 64
> E6 E1 F7 8C DD 41 92 28 2E 06 41 02 3E 11 7D B2
> C5 46 38 E5 8C 60 D2 96 EE 0C D6 3D F8 99 E3 02
> 3A 32 7A 02 C8 31 29 98 28 B9 1B EF 30 A1 A0 45
> A0 C0 05 0E C5 96 95 FD 91 47 0A 35 E0 69 B0 8B
> 49 BD B9 F6 5D 25 21 25 79 1B 20 0D C3 C7 1F 87
> 5E 5F 41 4B DE 32 DF 55 F3 BD 7F CA D8 7D 3A B4
> D5 0A EF CF 8E 72 20 52 15 FA FB C6 C0 2E C2 AB
> C6 07 D0 9D 96 6B 2E 30 F7 54 C4 A5 CD 9B 13 54
> A0 D1 71 66 91 97 06 12 B5 2D B2 33 62 FB 56 62
> 64 A8 AA E9 F2 F4 03 C3 F4 49 2A 09 0D 7D 75 99
> 6C F0 47 1E 7D D5 A5 CA CE EF 45 B2 DA 88 93 B4
> EE EB FB B0 A6 A4 19 C4 B8 0D 04 46 AE BD C5 2E
> 30 84 49 57 25 34 78 E6 ED C4 50 AF 3B F6 86 43
>
> At least this has been like this since before the git history, so it
> isn't recent..
>
> Can these be scheduled for removal or some such process? I haven't
> seen anything actually using the files, the only one that is really
> useful is caps...
>
> They probably should have been in debugfs, had it existed at the time.

Feel free to move them to debugfs, it looks like that is what they are
for.

thanks,

greg k-h
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