[PATCH] Remove in-kernel init_module/cleanup_module stubs

This patch removes the default stubs for init_module and cleanup_module,
and checks for NULL instead.  It changes modpost to only create references
to those functions if they actually exist.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 15 insertions, 16 deletions

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 65072d76a101e3..2a174e504c22bb 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -376,6 +376,10 @@ handle_modversions(struct module *mod, struct elf_info *info,
 			add_exported_symbol(symname + strlen(KSYMTAB_PFX),
 					    mod, NULL);
 		}
+		if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
+			mod->has_init = 1;
+		if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
+			mod->has_cleanup = 1;
 		break;
 	}
 }
@@ -410,9 +414,6 @@ read_symbols(char *modname)
 	if (is_vmlinux(modname)) {
 		unsigned int fake_crc = 0;
 		have_vmlinux = 1;
-		/* May not have this if !CONFIG_MODULE_UNLOAD: fake it.
-		   If it appears, we'll get the real CRC. */
-		add_exported_symbol("cleanup_module", mod, &fake_crc);
 		add_exported_symbol("struct_module", mod, &fake_crc);
 		mod->skip = 1;
 	}
@@ -431,14 +432,8 @@ read_symbols(char *modname)
 	 * never passed as an argument to an exported function, so
 	 * the automatic versioning doesn't pick it up, but it's really
 	 * important anyhow */
-	if (modversions) {
+	if (modversions)
 		mod->unres = alloc_symbol("struct_module", mod->unres);
-
-		/* Always version init_module and cleanup_module, in
-		 * case module doesn't have its own. */
-		mod->unres = alloc_symbol("init_module", mod->unres);
-		mod->unres = alloc_symbol("cleanup_module", mod->unres);
-	}
 }
 
 #define SZ 500
@@ -479,7 +474,7 @@ buf_write(struct buffer *buf, const char *s, int len)
 /* Header for the generated file */
 
 void
-add_header(struct buffer *b)
+add_header(struct buffer *b, struct module *mod)
 {
 	buf_printf(b, "#include <linux/module.h>\n");
 	buf_printf(b, "#include <linux/vermagic.h>\n");
@@ -491,10 +486,12 @@ add_header(struct buffer *b)
 	buf_printf(b, "struct module __this_module\n");
 	buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
 	buf_printf(b, " .name = __stringify(KBUILD_MODNAME),\n");
-	buf_printf(b, " .init = init_module,\n");
-	buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n");
-	buf_printf(b, " .exit = cleanup_module,\n");
-	buf_printf(b, "#endif\n");
+	if (mod->has_init)
+		buf_printf(b, " .init = init_module,\n");
+	if (mod->has_cleanup)
+		buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
+			      " .exit = cleanup_module,\n"
+			      "#endif\n");
 	buf_printf(b, "};\n");
 }
 
@@ -723,7 +720,7 @@ main(int argc, char **argv)
 
 		buf.pos = 0;
 
-		add_header(&buf);
+		add_header(&buf, mod);
 		add_versions(&buf, mod);
 		add_depends(&buf, mod, modules);
 		add_moddevtable(&buf, mod);
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index ddb013d9fd9872..4871343e192a51 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -74,6 +74,8 @@ struct module {
 	struct symbol *unres;
 	int seen;
 	int skip;
+	int has_init;
+	int has_cleanup;
 	struct buffer dev_table_buf;
 };