Re: [PATCH 8/8] efi: pstore: Add module parameter for setting the record size

From: Kees Cook
Date: Fri Oct 07 2022 - 22:37:02 EST




On October 7, 2022 4:29:55 PM PDT, "Guilherme G. Piccoli" <gpiccoli@xxxxxxxxxx> wrote:
>On 07/10/2022 16:32, Kees Cook wrote:
>> [...]
>> Given OVMF showing this as a max, it doesn't seem right to also make
>> this a minimum? Perhaps choose a different minimum to be enforced.
>
>Hi Kees! Through my tests, I've noticed low values tend to cause issues
>(didn't go further in the investigation), IIRC even 512 caused problems
>on "deflate" (worked in the others).
>
>I'll try again 512 to see how it goes, but I'm not so sure what would be
>the use of such low values, it does truncate a lot and "pollute" the
>pstore fs with many small files. But I can go with any value you/Ard
>think is appropriate (given it works with all compression algorithms
>heh) - currently the minimum of 1024 is enforced in the patch.

Right, but not everyone uses compression. On the other hand, this was never configurable before, so, sure, let's do 1k as a minimum. (And a comment in the source.)


--
Kees Cook