Re: [PATCH v6 3/6] x86/e820: Refactor range_update and range_remove

[Martin Fernandez]

On 2/8/22, Mike Rapoport <rppt@xxxxxxxxxx> wrote:
> On Mon, Feb 07, 2022 at 01:45:40PM -0800, Kees Cook wrote:
>> On Thu, Feb 03, 2022 at 01:43:25PM -0300, Martin Fernandez wrote:
>> > __e820__range_update and e820__range_remove had a very similar
>> > implementation with a few lines different from each other, the lines
>> > that actually perform the modification over the e820_table. The
>> > similiraties were found in the checks for the different cases on how
>> > each entry intersects with the given range (if it does at all). These
>> > checks were very presice and error prone so it was not a good idea to
>> > have them in both places.
>>
>> Yay removing copy/paste code! :)
>
> Removing copy/paste is nice but diffstat of
>
>  arch/x86/kernel/e820.c | 383 ++++++++++++++++++++++++++++++-----------
>  1 file changed, 283 insertions(+), 100 deletions(-)
>
> does not look nice even accounting for lots of comments :(
>
> I didn't look closely, but diffstat clues that the refactoring making
> things much more complex.
>

Yes, that diffstat surprised me as well.

I have to mention that 110 of those lines are kerneldocs and blank
lines, which is quite a lot. Also you have to take into account that I
expanded most of the function definitions for better formatting, which
also took some space.

And as I was able to focus the "hard" part of the problem into a
single function, testing can be done easily as Kees suggested and I'm
planning to do so in the next patch.