On Tue, Jan 10, 2023 at 5:45 AM William McVicker
<willmcvicker@xxxxxxxxxx> wrote:
>
> Hi Masahiro,
>
> I recently noticed that in commit 4475dff55c54 ("kbuild: fix false-positive
> modpost warning when all symbols are trimmed") [1] you modified the modpost
> behavior to always warn (by passing `-w`) when there are missing Module.symver
> files in order to allow module builds to continue building with warnings
> instead of errors. I'm curious why you decided to not continue to rely on
> KBUILD_MODPOST_WARN to enable/disable that functionality?
>
> I personally find it useful to keep these types of warnings as errors in order
> to catch missing dependencies at build time (ideally by the CI build) instead
> of at runtime when a module fails to load due to a missing symbol dependency.
>
> Let me know your thoughts on this and I'll try to come up with a solution to
> factor in any concerns you have.
>
> Thanks,
> Will
>
> [1] https://lore.kernel.org/all/20210325185412.2352951-3-masahiroy@xxxxxxxxxx/
Good point.
I think we can always require KBUILD_MODPOST_WARN=1 explicitly.
Skipping unresolved symbols is not a good idea.
Users can proceed if they want,
but they should be aware of what they are doing, at least.
How about something like this?
diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index 43343e13c542..34baef239816 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -121,16 +121,14 @@ modpost-args += -e $(addprefix -i ,
$(KBUILD_EXTRA_SYMBOLS))
endif # ($(KBUILD_EXTMOD),)
-ifneq ($(missing-input),)
-modpost-args += -w
-endif
-
quiet_cmd_modpost = MODPOST $@
cmd_modpost = \
$(if $(missing-input), \
echo >&2 "WARNING: $(missing-input) is missing."; \
echo >&2 " Modules may not have dependencies
or modversions."; \
- echo >&2 " You may get many unresolved symbol
warnings.";) \
+ echo >&2 " You may get many unresolved symbol
errors.";) \
+ echo >&2 " You can set KBUILD_MODPOST_WARN=1
to turn errors into warning"; \
+ echo >&2 " if you know what you are doing."; \
$(MODPOST) $(modpost-args)
targets += $(output-symdump)
--
Best Regards
Masahiro Yamada
