Modules updates for v4.14

Summary of modules changes for the 4.14 merge window:
 
 - Minor code cleanups and fixes
 
 - modpost: avoid building modules that have names that exceed the size
   of the name field in struct module
 
 Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull modules updates from Jessica Yu:
 "Summary of modules changes for the 4.14 merge window:

   - minor code cleanups and fixes

   - modpost: avoid building modules that have names that exceed the
     size of the name field in struct module"

* tag 'modules-for-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module: Remove const attribute from alias for MODULE_DEVICE_TABLE
  module: fix ddebug_remove_module()
  modpost: abort if module name is too long

include/linux/module.h

@@ -209,7 +209,7 @@ extern void cleanup_module(void);
 #ifdef MODULE
 /* Creates an alias so file2alias.c can find device table. */
 #define MODULE_DEVICE_TABLE(type, name)					\
-extern const typeof(name) __mod_##type##__##name##_device_table		\
+extern typeof(name) __mod_##type##__##name##_device_table		\
   __attribute__ ((unused, alias(__stringify(name))))
 #else  /* !MODULE */
 #define MODULE_DEVICE_TABLE(type, name)

kernel/module.c

@@ -2707,21 +2707,21 @@ static void add_kallsyms(struct module *mod, const struct load_info *info)
 }
 #endif /* CONFIG_KALLSYMS */
 
-static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
+static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
 {
 	if (!debug)
 		return;
 #ifdef CONFIG_DYNAMIC_DEBUG
-	if (ddebug_add_module(debug, num, debug->modname))
+	if (ddebug_add_module(debug, num, mod->name))
 		pr_err("dynamic debug error adding module: %s\n",
 			debug->modname);
 #endif
 }
 
-static void dynamic_debug_remove(struct _ddebug *debug)
+static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
 {
 	if (debug)
-		ddebug_remove_module(debug->modname);
+		ddebug_remove_module(mod->name);
 }
 
 void * __weak module_alloc(unsigned long size)
@@ -3715,7 +3715,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
 		goto free_arch_cleanup;
 	}
 
-	dynamic_debug_setup(info->debug, info->num_debug);
+	dynamic_debug_setup(mod, info->debug, info->num_debug);
 
 	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
 	ftrace_module_init(mod);
@@ -3779,7 +3779,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
 	module_disable_nx(mod);
 
  ddebug_cleanup:
-	dynamic_debug_remove(info->debug);
+	dynamic_debug_remove(mod, info->debug);
 	synchronize_sched();
 	kfree(mod->args);
  free_arch_cleanup:

scripts/mod/modpost.c

@@ -47,6 +47,12 @@ enum export {
 	export_unused_gpl, export_gpl_future, export_unknown
 };
 
+/* In kernel, this size is defined in linux/module.h;
+ * here we use Elf_Addr instead of long for covering cross-compile
+ */
+
+#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
+
 #define PRINTF __attribute__ ((format (printf, 1, 2)))
 
 PRINTF void fatal(const char *fmt, ...)
@@ -2111,6 +2117,23 @@ static void check_exports(struct module *mod)
 	}
 }
 
+static int check_modname_len(struct module *mod)
+{
+	const char *mod_name;
+
+	mod_name = strrchr(mod->name, '/');
+	if (mod_name == NULL)
+		mod_name = mod->name;
+	else
+		mod_name++;
+	if (strlen(mod_name) >= MODULE_NAME_LEN) {
+		merror("module name is too long [%s.ko]\n", mod->name);
+		return 1;
+	}
+
+	return 0;
+}
+
 /**
  * Header for the generated file
  **/
@@ -2150,11 +2173,6 @@ static void add_staging_flag(struct buffer *b, const char *name)
 		buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
 }
 
-/* In kernel, this size is defined in linux/module.h;
- * here we use Elf_Addr instead of long for covering cross-compile
- */
-#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
-
 /**
  * Record CRCs for unresolved symbols
  **/
@@ -2485,6 +2503,7 @@ int main(int argc, char **argv)
 
 		buf.pos = 0;
 
+		err |= check_modname_len(mod);
 		add_header(&buf, mod);
 		add_intree_flag(&buf, !external_module);
 		add_staging_flag(&buf, mod->name);