kbuild: do not read $(KBUILD_EXTMOD)/Module.symvers

Since commit 040fcc819a2e ("kbuild: improved modversioning support for
external modules"), the external module build reads Module.symvers in
the directory of the module itself, then dumps symbols back into it.
It accumulates stale symbols in the file when you build an external
module incrementally.

The idea behind it was, as the commit log explained, you can copy
Modules.symvers from one module to another when you need to pass symbol
information between two modules. However, the manual copy of the file
sounds questionable to me, and containing stale symbols is a downside.

Some time later, commit 0d96fb20b7ed ("kbuild: Add new Kbuild variable
KBUILD_EXTRA_SYMBOLS") introduced a saner approach.

So, this commit removes the former one. Going forward, the external
module build dumps symbols into Module.symvers to be carried via
KBUILD_EXTRA_SYMBOLS, but never reads it automatically.

With the -I option removed, there is no one to set the external_module
flag unless KBUILD_EXTRA_SYMBOLS is passed. Now the -i option does it
instead.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

2 files changed, 2 insertions, 8 deletions

diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index 13842693c143..20359c7887b3 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -50,7 +50,6 @@ MODPOST = scripts/mod/modpost						\
 	$(if $(CONFIG_MODVERSIONS),-m)					\
 	$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a)			\
 	$(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile)			\
-	$(if $(KBUILD_EXTMOD),-I $(modulesymfile))			\
 	$(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS)))	\
 	$(if $(KBUILD_EXTMOD),-o $(modulesymfile))			\
 	$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E)			\
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index d2a30a7b3f07..37fa1c65ee4d 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2561,7 +2561,7 @@ int main(int argc, char **argv)
 {
 	struct module *mod;
 	struct buffer buf = { };
-	char *kernel_read = NULL, *module_read = NULL;
+	char *kernel_read = NULL;
 	char *dump_write = NULL, *files_source = NULL;
 	int opt;
 	int err;
@@ -2569,13 +2569,10 @@ int main(int argc, char **argv)
 	struct ext_sym_list *extsym_iter;
 	struct ext_sym_list *extsym_start = NULL;
 
-	while ((opt = getopt(argc, argv, "i:I:e:mnsT:o:awEd")) != -1) {
+	while ((opt = getopt(argc, argv, "i:e:mnsT:o:awEd")) != -1) {
 		switch (opt) {
 		case 'i':
 			kernel_read = optarg;
-			break;
-		case 'I':
-			module_read = optarg;
 			external_module = 1;
 			break;
 		case 'e':
@@ -2620,8 +2617,6 @@ int main(int argc, char **argv)
 
 	if (kernel_read)
 		read_dump(kernel_read, 1);
-	if (module_read)
-		read_dump(module_read, 0);
 	while (extsym_start) {
 		read_dump(extsym_start->file, 0);
 		extsym_iter = extsym_start->next;