Re: [RFC] QR encoding for Oops messages

[Levente Kurusa <levex@linux.com>]

Hi,

2014-03-19 21:50 GMT+01:00 Teodora Băluţă <teobaluta@gmail.com>:
> On Wed, Mar 19, 2014 at 10:28 PM, Levente Kurusa <levex@linux.com> wrote:
>> Hi,
>>
>> 2014-03-19 21:18 GMT+01:00 Dave Jones <davej@redhat.com>:
>>> On Mon, Mar 17, 2014 at 02:59:47PM -0700, Teodora Baluta wrote:
>>>  > This feature encodes Oops messages into a QR barcode that is scannable by
>>>  > any device with a camera.
>>>
>>>  ...
>>>
>>>  >  include/linux/print_oops.h |   11 +
>>>  >  include/linux/qrencode.h   |  546 +++++++++++++
>>>  >  kernel/Makefile            |    1 +
>>>  >  kernel/panic.c             |    5 +
>>>  >  kernel/print_oops.c        |  173 +++++
>>>  >  kernel/printk/printk.c     |    9 +-
>>>  >  lib/Kconfig                |    5 +
>>>  >  lib/Kconfig.debug          |   11 +
>>>  >  lib/Makefile               |    3 +
>>>  >  lib/qr/Makefile            |    6 +
>>>  >  lib/qr/bitstream.c         |  233 ++++++
>>>  >  lib/qr/bitstream.h         |   37 +
>>>  >  lib/qr/mask.c              |  320 ++++++++
>>>  >  lib/qr/mask.h              |   39 +
>>>  >  lib/qr/mmask.c             |  175 +++++
>>>  >  lib/qr/mmask.h             |   36 +
>>>  >  lib/qr/mqrspec.c           |  259 +++++++
>>>  >  lib/qr/mqrspec.h           |  155 ++++
>>>  >  lib/qr/qrencode.c          |  871 +++++++++++++++++++++
>>>  >  lib/qr/qrencode.h          |  546 +++++++++++++
>>>  >  lib/qr/qrinput.c           | 1834 ++++++++++++++++++++++++++++++++++++++++++++
>>>  >  lib/qr/qrinput.h           |  129 ++++
>>>  >  lib/qr/qrspec.c            |  543 +++++++++++++
>>>  >  lib/qr/qrspec.h            |  178 +++++
>>>  >  lib/qr/rscode.c            |  325 ++++++++
>>>  >  lib/qr/rscode.h            |   38 +
>>>  >  lib/qr/split.c             |  331 ++++++++
>>>  >  lib/qr/split.h             |   44 ++
>>>  >  28 files changed, 6860 insertions(+), 3 deletions(-)
>>
>> This idea is certainly great.
>>
>> However, there are quite a few problems with the code in terms of code style and
>> other terms as well. I am not sure how could we help you make this code
>> appliable, but it would be great if you put up a branch somewhere. This way
>> I could send you a few commits that do some fixups.
>
> Wow, that'd be great! I have set up my clone of the kernel source up
> on gitlab [0] and github [1]. I will update the remote branch asap (I
> made some coding style fixups that aren't present on github/gitlab
> right now, only in a remote branch). Is this ok?

Yea, that's fine. Push your changes and send me a ping once you
are done. I will most likely send you a pull request on github though.

>
>>
>>>
>>> That's a ton of code we're adding into one of the most fragile parts of the kernel.
>>
>> Indeed, this should get split up.
>>
>>>
>>> A lot of what libqrencode does would seem to be superfluous to the requirements
>>> here, as we don't output kernel oopses in kanji for eg, and won't care about
>>> multiple versions of the qr spec.
>>>
>>> How much of this could we drop ?
>>
>> A lot, most likely.
>
> Indeed.
>
>>
>> Also, I wonder if we could do the same for panic()?
>> I hate it when I receive a panic and I have no idea what's the cause
>> since my display is filled up with the stack trace.
>
> Most likely panic is harder to do for reasons discussed in this thread here [2].
>

Yes I see.

>
> [0] https://gitlab.com/teobaluta/opw
> [1] https://github.com/teobaluta/qr-linux-kernel
> [2] https://lwn.net/Articles/503677/
>
> Thanks,
> Teodora
>>
>> --
>> Regards,
>> Levente Kurusa