[PATCH v3 3/5] module: Extend the MODULE_ namespace parsing

[Peter Zijlstra <peterz@infradead.org>]

Instead of only accepting "module:${name}", extend it with a comma
separated list of module names and add tail glob support.

That is, something like: "module:foo-*,bar" is now possible.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 kernel/module/main.c  |   36 ++++++++++++++++++++++++++++++++++--
 scripts/mod/modpost.c |   36 ++++++++++++++++++++++++++++++++++--
 2 files changed, 68 insertions(+), 4 deletions(-)

--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1083,12 +1083,44 @@ static char *get_modinfo(const struct lo
 	return get_next_modinfo(info, tag, NULL);
 }
 
+/**
+ * verify_module_namespace() - does @modname have access to this symbol's @namespace
+ * @namespace: export symbol namespace
+ * @modname: module name
+ *
+ * If @namespace is prefixed with "module:" to indicate it is a module namespace
+ * then test if @modname matches any of the comma separated patterns.
+ *
+ * The patterns only support tail-glob.
+ */
 static bool verify_module_namespace(const char *namespace, const char *modname)
 {
+	size_t len, modlen = strlen(modname);
 	const char *prefix = "module:";
+	const char *sep;
+	bool glob;
 
-	return strstarts(namespace, prefix) &&
-	       !strsmp(namespace + strlen(prefix), modname);
+	if (!strstarts(namespace, prefix))
+		return false;
+
+	for (namespace += strlen(prefix); *namespace; namespace = sep) {
+		sep = strchrnul(namespace, ',');
+		len = sep - namespace;
+
+		glob = false;
+		if (sep[-1] == '*') {
+			len--;
+			glob = true;
+		}
+
+		if (*sep)
+			sep++;
+
+		if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen))
+			return true;
+	}
+
+	return false;
 }
 
 static int verify_namespace_is_imported(const struct load_info *info,
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1682,12 +1682,44 @@ void buf_write(struct buffer *buf, const
 	buf->pos += len;
 }
 
+/**
+ * verify_module_namespace() - does @modname have access to this symbol's @namespace
+ * @namespace: export symbol namespace
+ * @modname: module name
+ *
+ * If @namespace is prefixed with "module:" to indicate it is a module namespace
+ * then test if @modname matches any of the comma separated patterns.
+ *
+ * The patterns only support tail-glob.
+ */
 static bool verify_module_namespace(const char *namespace, const char *modname)
 {
+	size_t len, modlen = strlen(modname);
 	const char *prefix = "module:";
+	const char *sep;
+	bool glob;
 
-	return strstarts(namespace, prefix) &&
-	       !strcmp(namespace + strlen(prefix), modname);
+	if (!strstarts(namespace, prefix))
+		return false;
+
+	for (namespace += strlen(prefix); *namespace; namespace = sep) {
+		sep = strchrnul(namespace, ',');
+		len = sep - namespace;
+
+		glob = false;
+		if (sep[-1] == '*') {
+			len--;
+			glob = true;
+		}
+
+		if (*sep)
+			sep++;
+
+		if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen))
+			return true;
+	}
+
+	return false;
 }
 
 static void check_exports(struct module *mod)