1 files changed, 142 insertions, 0 deletions
diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h
new file mode 100644
index 000000000000..d10563afd91c
--- /dev/null
+++ b/include/linux/ref_tracker.h
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef _LINUX_REF_TRACKER_H
+#define _LINUX_REF_TRACKER_H
+#include <linux/refcount.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/stackdepot.h>
+
+#define __ostream_printf __printf(2, 3)
+
+struct ref_tracker;
+
+struct ref_tracker_dir {
+#ifdef CONFIG_REF_TRACKER
+	spinlock_t		lock;
+	unsigned int		quarantine_avail;
+	refcount_t		untracked;
+	refcount_t		no_tracker;
+	bool			dead;
+	struct list_head	list; /* List of active trackers */
+	struct list_head	quarantine; /* List of dead trackers */
+	const char		*class; /* object classname */
+#endif
+};
+
+#ifdef CONFIG_REF_TRACKER
+
+#ifdef CONFIG_DEBUG_FS
+
+void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir);
+void ref_tracker_dir_symlink(struct ref_tracker_dir *dir, const char *fmt, ...);
+
+#else /* CONFIG_DEBUG_FS */
+
+static inline void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir)
+{
+}
+
+static inline __ostream_printf
+void ref_tracker_dir_symlink(struct ref_tracker_dir *dir, const char *fmt, ...)
+{
+}
+
+#endif /* CONFIG_DEBUG_FS */
+
+/**
+ * ref_tracker_dir_init - initialize a ref_tracker dir
+ * @dir: ref_tracker_dir to be initialized
+ * @quarantine_count: max number of entries to be tracked
+ * @class: pointer to static string that describes object type
+ *
+ * Initialize a ref_tracker_dir. If debugfs is configured, then a file
+ * will also be created for it under the top-level ref_tracker debugfs
+ * directory.
+ *
+ * Note that @class must point to a static string.
+ */
+static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir,
+					unsigned int quarantine_count,
+					const char *class)
+{
+	INIT_LIST_HEAD(&dir->list);
+	INIT_LIST_HEAD(&dir->quarantine);
+	spin_lock_init(&dir->lock);
+	dir->quarantine_avail = quarantine_count;
+	dir->dead = false;
+	refcount_set(&dir->untracked, 1);
+	refcount_set(&dir->no_tracker, 1);
+	dir->class = class;
+	ref_tracker_dir_debugfs(dir);
+	stack_depot_init();
+}
+
+void ref_tracker_dir_exit(struct ref_tracker_dir *dir);
+
+void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir,
+				  unsigned int display_limit);
+
+void ref_tracker_dir_print(struct ref_tracker_dir *dir,
+			   unsigned int display_limit);
+
+int ref_tracker_dir_snprint(struct ref_tracker_dir *dir, char *buf, size_t size);
+
+int ref_tracker_alloc(struct ref_tracker_dir *dir,
+		      struct ref_tracker **trackerp, gfp_t gfp);
+
+int ref_tracker_free(struct ref_tracker_dir *dir,
+		     struct ref_tracker **trackerp);
+
+#else /* CONFIG_REF_TRACKER */
+
+static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir,
+					unsigned int quarantine_count,
+					const char *class)
+{
+}
+
+static inline void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir)
+{
+}
+
+static inline __ostream_printf
+void ref_tracker_dir_symlink(struct ref_tracker_dir *dir, const char *fmt, ...)
+{
+}
+
+static inline void ref_tracker_dir_exit(struct ref_tracker_dir *dir)
+{
+}
+
+static inline void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir,
+						unsigned int display_limit)
+{
+}
+
+static inline void ref_tracker_dir_print(struct ref_tracker_dir *dir,
+					 unsigned int display_limit)
+{
+}
+
+static inline int ref_tracker_dir_snprint(struct ref_tracker_dir *dir,
+					  char *buf, size_t size)
+{
+	return 0;
+}
+
+static inline int ref_tracker_alloc(struct ref_tracker_dir *dir,
+				    struct ref_tracker **trackerp,
+				    gfp_t gfp)
+{
+	return 0;
+}
+
+static inline int ref_tracker_free(struct ref_tracker_dir *dir,
+				   struct ref_tracker **trackerp)
+{
+	return 0;
+}
+
+#endif
+
+#endif /* _LINUX_REF_TRACKER_H */