cgroup: avoid accessing modular cgroup subsys structure without locking

[deliverable/linux.git] / include / linux / cgroup.h

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 75c6ec1ba1ba5b61e51eb9c4e44a8089ab7e78f0..5f76829dd75e19f49b0c716d353dd8f3f8df34a7 100644 (file)
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -44,14 +44,25 @@ extern void cgroup_unload_subsys(struct cgroup_subsys *ss);
 
 extern const struct file_operations proc_cgroup_operations;
 
-/* Define the enumeration of all builtin cgroup subsystems */
+/*
+ * Define the enumeration of all cgroup subsystems.
+ *
+ * We define ids for builtin subsystems and then modular ones.
+ */
 #define SUBSYS(_x) _x ## _subsys_id,
-#define IS_SUBSYS_ENABLED(option) IS_ENABLED(option)
 enum cgroup_subsys_id {
+#define IS_SUBSYS_ENABLED(option) IS_BUILTIN(option)
+#include <linux/cgroup_subsys.h>
+#undef IS_SUBSYS_ENABLED
+       CGROUP_BUILTIN_SUBSYS_COUNT,
+
+       __CGROUP_SUBSYS_TEMP_PLACEHOLDER = CGROUP_BUILTIN_SUBSYS_COUNT - 1,
+
+#define IS_SUBSYS_ENABLED(option) IS_MODULE(option)
 #include <linux/cgroup_subsys.h>
+#undef IS_SUBSYS_ENABLED
        CGROUP_SUBSYS_COUNT,
 };
-#undef IS_SUBSYS_ENABLED
 #undef SUBSYS
 
 /* Per-subsystem/per-cgroup state maintained by the system. */