From ab489d6002fc27dc5db6d66f121da6fc0bda13ad Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sun, 1 May 2022 17:40:14 +0900
Subject: [PATCH] modpost: traverse the namespace_list in order

Use the doubly linked list to traverse the list in the added order.
This makes the code more consistent.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---
 scripts/mod/modpost.c | 33 +++++++++++++++------------------
 scripts/mod/modpost.h |  4 ++--
 2 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index a6a55f359396..8bdde738803f 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -186,6 +186,8 @@ static struct module *new_module(const char *modname)
 	memset(mod, 0, sizeof(*mod));
 
 	INIT_LIST_HEAD(&mod->unresolved_symbols);
+	INIT_LIST_HEAD(&mod->missing_namespaces);
+	INIT_LIST_HEAD(&mod->imported_namespaces);
 
 	strcpy(mod->name, modname);
 	mod->is_vmlinux = (strcmp(modname, "vmlinux") == 0);
@@ -288,39 +290,34 @@ static struct symbol *find_symbol(const char *name)
 }
 
 struct namespace_list {
-	struct namespace_list *next;
+	struct list_head list;
 	char namespace[];
 };
 
-static bool contains_namespace(struct namespace_list *list,
-			       const char *namespace)
+static bool contains_namespace(struct list_head *head, const char *namespace)
 {
-	for (; list; list = list->next)
+	struct namespace_list *list;
+
+	list_for_each_entry(list, head, list) {
 		if (!strcmp(list->namespace, namespace))
 			return true;
+	}
 
 	return false;
 }
 
-static void add_namespace(struct namespace_list **list, const char *namespace)
+static void add_namespace(struct list_head *head, const char *namespace)
 {
 	struct namespace_list *ns_entry;
 
-	if (!contains_namespace(*list, namespace)) {
-		ns_entry = NOFAIL(malloc(sizeof(struct namespace_list) +
+	if (!contains_namespace(head, namespace)) {
+		ns_entry = NOFAIL(malloc(sizeof(*ns_entry) +
 					 strlen(namespace) + 1));
 		strcpy(ns_entry->namespace, namespace);
-		ns_entry->next = *list;
-		*list = ns_entry;
+		list_add_tail(&ns_entry->list, head);
 	}
 }
 
-static bool module_imports_namespace(struct module *module,
-				     const char *namespace)
-{
-	return contains_namespace(module->imported_namespaces, namespace);
-}
-
 static const struct {
 	const char *str;
 	enum export export;
@@ -2190,7 +2187,7 @@ static void check_exports(struct module *mod)
 			basename = mod->name;
 
 		if (exp->namespace &&
-		    !module_imports_namespace(mod, exp->namespace)) {
+		    !contains_namespace(&mod->imported_namespaces, exp->namespace)) {
 			modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR,
 				    "module %s uses symbol %s from namespace %s, but does not import it.\n",
 				    basename, exp->name, exp->namespace);
@@ -2489,12 +2486,12 @@ static void write_namespace_deps_files(const char *fname)
 
 	list_for_each_entry(mod, &modules, list) {
 
-		if (mod->from_dump || !mod->missing_namespaces)
+		if (mod->from_dump || list_empty(&mod->missing_namespaces))
 			continue;
 
 		buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
 
-		for (ns = mod->missing_namespaces; ns; ns = ns->next)
+		list_for_each_entry(ns, &mod->missing_namespaces, list)
 			buf_printf(&ns_deps_buf, " %s", ns->namespace);
 
 		buf_printf(&ns_deps_buf, "\n");
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index f06bbd0ba93c..2e13a736ab38 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -123,9 +123,9 @@ struct module {
 	struct buffer dev_table_buf;
 	char	     srcversion[25];
 	// Missing namespace dependencies
-	struct namespace_list *missing_namespaces;
+	struct list_head missing_namespaces;
 	// Actual imported namespaces
-	struct namespace_list *imported_namespaces;
+	struct list_head imported_namespaces;
 	char name[];
 };