[PATCH 19/29] modpost: show warning if it fails to read symbol dump file

Masahiro Yamada
2020-05-17T09:50:37Z

If modpost fails to load a symbol dump file, it cannot check unresolved
symbols, hence module dependency will not be added. Nor CRCs can be added.

Currently, external module builds check only $(objtree)/Module.symvers,
but it should check files specified by KBUILD_EXTRA_SYMBOLS as well.

Print the warnings in modpost. The warning in Makefile is unneeded.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

Makefile | 10 +---------
scripts/mod/modpost.c | 11 +++++++++--
2 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/Makefile b/Makefile
index aeb690c692ee..27e8a0522a3c 100644
--- a/Makefile
+++ b/Makefile
@@ -1638,17 +1638,9 @@ else # KBUILD_EXTMOD
# We are always building modules
KBUILD_MODULES := 1

-PHONY += $(objtree)/Module.symvers
-$(objtree)/Module.symvers:
- @test -e $(objtree)/Module.symvers || ( \
- echo; \
- echo " WARNING: Symbol version dump $(objtree)/Module.symvers"; \
- echo " is missing; modules will have no dependencies and modversions."; \
- echo )
-
build-dirs := $(KBUILD_EXTMOD)
PHONY += modules
-modules: descend $(objtree)/Module.symvers
+modules: descend
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost

PHONY += modules_install
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 8150be00e3df..ff715623b37e 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -41,6 +41,8 @@ static int sec_mismatch_fatal = 0;
static int ignore_missing_files;
/* If set to 1, only warn (instead of error) about missing ns imports */
static int allow_missing_ns_imports;
+/* Set when at list one dump file is missing */
+static int missing_dump_file;

enum export {
export_plain, export_unused, export_gpl,
@@ -2428,9 +2430,11 @@ static void read_dump(const char *fname)
char *buf, *pos, *line;

buf = read_text_file(fname);
- if (!buf)
- /* No symbol versions, silently ignore */
+ if (!buf) {
+ warn("failed to read '%s'\n", fname);
+ missing_dump_file = 1;
return;
+ }

pos = buf;

@@ -2615,6 +2619,9 @@ int main(int argc, char **argv)
if (files_source)
read_symbols_from_files(files_source);

+ if (missing_dump_file)
+ warn("Symbol dump file is missing. Modules may not have dependencies or movversions.\n");
+
/*
* When there's no vmlinux, don't print warnings about
* unresolved symbols (since there'll be too many ;)
--
2.25.1