Re: [PATCH] x86/kbuild: enable modversions for symbols exported from asm

From: Ingo Molnar
Date: Tue Nov 29 2016 - 08:30:09 EST



* Adam Borowski <kilobyte@xxxxxxxxxx> wrote:

> Here's some history:
> The day of -rc1, multiple people immediately reported the breakage; it was
> quickly found out that reverting 784d5699eddc fixes it. A "going forward"
> patch has been posted but was insufficient; when the real devs went to bed
> the last message was
> https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1250370.html
> which ends with instructions and "Care to do a patch for x86?".
>
> Then a random person (me) did the legwork, gathered affected symbols, wrote
> and tested the x86 patch. It was then tested by multiple people; Arnd
> Bergmann wrote the ARM equivalent. Whenever a new lkml thread reporting the
> breakage popped up, we pointed people to the patches and everyone was happy.
> As for upstreaming, there was a delay because Michal Marek was on vacation.
>
> Michal returned and sent you the pull request, you merged it as 04e36857 on
> Nov 18. For some reason the per-arch pieces were excluded; I was instructed
> to send my part to x86 maintainers.
>
> I did so; the patch later got a better description by Nick and a bunch of
> Tested-by -- but alas, nary a comment or action from x86 guys, despite
> pings/resends (last one: https://lkml.org/lkml/2016/11/23/706). I guess I'm
> lacking the secret handshake or something -- thus, it looks like it's my
> fault, the rest of you can be blamed mostly for letting a
> not-a-real-kernel-dev unsupervised.

My part of the story is easy to explain: the reason I skipped the 11/23 patch was
because it was tagged 'kbuild' and because the commit that broke it was never
acked by (or was upstreamed via) the x86 maintainers - we never upstreamed any
modversions changes in the past AFAIR - so I assumed it would be handled via
whatever path got the breakage upstream (turns out it was via the VFS tree?),
or via the kbuild tree.

> On Nov 24 finally Ingo responded, the discussion ended with you marking
> modversions as BROKEN.

Yeah, that was when my internal timer ran out: modversions breakage was reported
against -rc1 already and it still wasn't working (a seemingly working kernel build
resulted in an unbootable system) - due to the timeline and confusion you
explained.

I totally agree with marking it BROKEN: it was the simplest, most robust way to
fix it and nobody seemed to be owning the modversions feature.

Thanks,

Ingo