Re: [PATCH v2] modpost: move the namespace field in Module.symvers last

[Jessica Yu]

+++ John Stultz [31/03/20 15:09 -0700]:
> On Tue, Mar 31, 2020 at 2:58 AM Jessica Yu <jeyu@xxxxxxxxxx> wrote:
> > +++ John Stultz [30/03/20 23:25 -0700]:
> > >On Mon, Mar 30, 2020 at 10:49 PM John Stultz <john.stultz@xxxxxxxxxx> wrote:
> > >> The only difference I can find is that the Module.symvers in the
> > >> external module project doesn't seem to have a tab at the end of each
> > >> line (where as Module.symvers for the kernel - which doesn't seem to
> > >> have any namespace names - does).
> > >>
> > >> Is there something I need to tweak on the external Kbuild to get
> > >> Module.symvers to be generated properly (with the empty tab at the
> > >> end) for this new change?
> > >> Or does the parser need to be a bit more flexible?
> > >>
> > >
> > >One extra clue on this: I noticed the external module Makefile had
> > >KBUILD_EXTRA_SYMBOLS="$(EXTRA_SYMBOLS)"  in the $(MAKE) string, where
> > >EXTRA_SYMBOLS pointed to some files that no longer exist.  I removed
> > >the KBUILD_EXTRA_SYMBOLS= argument, and magically, the generated
> > >Module.symvers now had tabs at the end of each line.
> > >
> > >I wonder if there some path in the KBUILD_EXTRA_SYMBOLS= handling that
> > >isn't generating the output in the same way?
> >
> > I'm afraid we're going to need some specifics on reproducing this
> > issue. Could you provide a reproducer or steps on how to reproduce? I
> > have not been able to trigger this problem even with
> > KBUILD_EXTRA_SYMBOLS pointing to an invalid path (I also tested with
> > valid paths).
> >
> > I tested with a skeleton external module that exports two functions,
> > one with a namespace and one without. I built this module against the
> > latest v5.6 kernel. The generated Module.symvers was correct - the
> > namespaced function had the namespace at the end and the other
> > function without a namespace had a tab at the end.
> >
> > I also tested with two external modules, one with a symbol dependency
> > on the other, so KBUILD_EXTRA_SYMBOLS usage is required here. The
> > generated Module.symvers was also correct here.
> >
> > The only advice I can offer at this time is that all external modules
> > must be built against the new kernel to generate a correctly formated
> > Module.symvers file. If you have any KBUILD_EXTRA_SYMBOLS pointing to
> > an outdated Module.symvers file for example, you will see the "FATAL:
> > parse error in symbol dump file" error.
>
> Well, my apologies.  :(  In the light of day, this isn't reproducing
> anymore. I'm a bit at a loss as to why I was tripping over it so
> regularly before, but I suspect something in the build is leaving a
> stale Modules.symvers around from before this patch landed.
>
> Terribly sorry for the noise.

No problem, thank for reporting back!

Jessica