[SLOF] [PATCH v2 20/20] make last entry in log appear

Thomas Huth thuth at redhat.com
Fri Nov 20 04:05:38 AEDT 2015

On 19/11/15 17:21, Stefan Berger wrote:
> On 11/19/2015 06:34 AM, Thomas Huth wrote:
>> On 17/11/15 18:02, Stefan Berger wrote:
>>> From: Stefan Berger <stefanb at linux.vnet.ibm.com>
>>> Due to the off-by-one error in Linux, we need to add a 1 to the
>>> actual size of the log.
>> If there's a bug in Linux, why don't you fix it there instead?
>> Introducing wrong behavior here sounds wrong to me.
> The problem is that this a bug that's been in Linux basically forever.
> So it's unfortunately 'cheaper' now to fix it here.

Well, I don't think so. It's maybe cheaper at a first glance, but
including hacks like this will most likely result in much more severe
problems in the future:

- If Linux gets fixed, you suddenly would see an invalid data there at
  the end?

- Linux is not the only OS that could be running under QEMU-sPAPR
  machine in the future ... maybe we've got FreeBSD or something else
  one day ... and then you don't want to mess with firmware interfaces
  there that have been broken on purpose just for Linux.

- What if PowerVM one day supports the vTPM interface (or does it
  already?) ... should it also include this hack, or not ... and
  then would this also be required for AIX etc. ...?

So better get this properly fixed where it should be fixed, i.e. in the
Linux kernel (and you can always send your patch to the "stable" kernel
mailing lists, too, so that also older kernel trees will pick up the fix).


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