Re: [PATCH] modpost: allow modpost to fail on warnings

[Pierre-Louis Bossart]

Thanks for the review,

> > Set KBUILD_MODPOST_FAIL_ON_WARNINGS to a non-empty value to make the
> > kbuild fail when modpost generates any warnings. This will avoid
> > misses such as [1] where the SOF CI did not catch a missing module
> > license.
> >
> > This was initially contributed in 2016 [2], rebase/clean-ups and tests
> > by Pierre Bossart.
> >
> > Test example:
> > $ KBUILD_MODPOST_FAIL_ON_WARNINGS=1 make
> >    GEN     Makefile
> >    DESCEND  objtool
> >    CALL    sof-dev/scripts/atomic/check-atomics.sh
> >    CALL    sof-dev/scripts/checksyscalls.sh
> >    CHK     include/generated/compile.h
> >    MODPOST Module.symvers
> > Kernel: arch/x86/boot/bzImage is ready  (#13)
> > WARNING: modpost: missing MODULE_LICENSE() in sound/soc/intel/boards/snd-soc-sof-sdw.o
> > make[2]: *** [sof-dev/scripts/Makefile.modpost:114: Module.symvers] Error 2
>
>
> I think [1] should be an error instead of a warning
> by default.

would the following patch be what you have in mind?

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 422f1cfca289..ae1eb67aa0f2 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2018,7 +2018,7 @@ static void read_symbols(const char *modname)
        if (!mod->is_vmlinux) {
                license = get_modinfo(&info, "license");
                if (!license)
-                       warn("missing MODULE_LICENSE() in %s\n", modname);
+                       error("missing MODULE_LICENSE() in %s\n", modname);
                while (license) {
                        if (license_is_gpl_compatible(license))
                                mod->gpl_compatible = 1;


If yes, also wondering if we can still add the option to treat warnings 
as errors as an opt-in behavior?

Thanks!
-Pierre