Re: Linux 2.6.38-rc8

[Henrik Rydberg]

On Mon, Mar 07, 2011 at 09:40:04PM -0800, Linus Torvalds wrote:
> I would have been ok with releasing this as the final 38, but I'm
> going to be partially unreachable for several days next week, so I
> felt there was no point in opening the merge window yet.
> 
> Also, we do have regressions. Some of them hopefully fixed here, but
> it won't hurt to give it another week.
> 
> Not everything here is strictly a regression: the i_nlink fixes are
> long-standing races (very unlikely ones, admittedly), and the alpha
> updates just convert the irq chip descriptions so that we can enable
> GENERIC_HARDIRQS_NO_DEPRECATED on alpha too. But most everything is
> pretty simple, and the diffstat is fairly flat with nothing huge that
> stands out.
> 
> 40% drivers, 35% arch updates (alpha and arm), with the rest being fs,
> net and some block layer updates.
> 
> So please keep testing,

Hi Linus,

I stumbled upon this problem when a dkms package install claimed to
already have the latest version of a module, only it clearly did not.

It turns out the module srcversion is not unique. Doing a

cat /sys/module/*/srcversion | sort | uniq -c

shows something like this:

mainline>cat /sys/module/*/srcversion | sort | uniq -c
      1 3EF20C25CC62BD750F4C3F3
      1 41024DA8E830C7DAE171017
      1 47AD35AE180473EB06EED32
     19 533BB7E5866E52F63B9ACCB
      1 598C709DDDAB55EB331379A
      1 5AC5CB9DA8C242CBC76EEC0
      1 AAD974CC23F320629986F38
      2 AEBBDFD273E0316FD4E5D04
      [...]

Bisecting leads to this commit

commit b7bd182176960fdd139486cadb9962b39f8a2b50
Author: Michal Marek <mmarek@xxxxxxx>

    fixdep: Do not record dependency on the source file itself

which seems to be a change to the build system. Reverting followed by
"make clean" cures the symptoms, and all module srcversions are again
unique. Just doing make after the revert does not work, which seems
reasonable. However, I can't even begin to imagine what the real
reason is.

The patch below is what fixes it for me.

Thanks,
Henrik

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