[PATCH] kbuild: readd -w option when vmlinux.o or Module.symver is missing

From: Masahiro Yamada
Date: Wed Jan 04 2023 - 09:05:27 EST


Commit 63ffe00d8c93 ("kbuild: Fix running modpost with musl libc")
accidentally turned the unresolved symbol warnings into errors when
vmlinux.o (for in-tree builds) or Module.symver (for external module
builds) is missing.

In those cases, unresolved symbols are expected, but the -w option
is not set because 'missing-input' is referenced before set.

Move $(missing-input back to the original place. This should be fine
for musl libc because vmlinux.o and -w are not added at the same time.

With this change, -w may be passed twice, but it is not a big deal.

Link: https://lore.kernel.org/all/b56a03b8-2a2a-f833-a5d2-cdc50a7ca2bb@xxxxxxxxxxx/
Fixes: 63ffe00d8c93 ("kbuild: Fix running modpost with musl libc")
Reported-by: Christopher Schramm <debian@xxxxxxxxxxx>
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---

scripts/Makefile.modpost | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index 0ee296cf520c..43343e13c542 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -44,6 +44,7 @@ modpost-args = \
$(if $(CONFIG_MODVERSIONS),-m) \
$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
+ $(if $(KBUILD_MODPOST_WARN),-w) \
$(if $(KBUILD_NSDEPS),-d $(MODULES_NSDEPS)) \
$(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) \
-o $@
@@ -55,10 +56,6 @@ ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
modpost-args += -n
endif

-ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
-modpost-args += -w
-endif
-
# Read out modules.order to pass in modpost.
# Otherwise, allmodconfig would fail with "Argument list too long".
ifdef KBUILD_MODULES
@@ -124,6 +121,10 @@ 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), \
--
2.34.1