path: root/lib/debugobjects.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Generic infrastructure for lifetime debugging of objects.
 *
 * Copyright (C) 2008, Thomas Gleixner <tglx@linutronix.de>
 */

#define pr_fmt(fmt) "ODEBUG: " fmt

#include <linux/cpu.h>
#include <linux/debugobjects.h>
#include <linux/debugfs.h>
#include <linux/hash.h>
#include <linux/kmemleak.h>
#include <linux/sched.h>
#include <linux/sched/loadavg.h>
#include <linux/sched/task_stack.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/static_key.h>

#define ODEBUG_HASH_BITS	14
#define ODEBUG_HASH_SIZE	(1 << ODEBUG_HASH_BITS)

/* Must be power of two */
#define ODEBUG_BATCH_SIZE	16

/* Initial values. Must all be a multiple of batch size */
#define ODEBUG_POOL_SIZE	(64 * ODEBUG_BATCH_SIZE)
#define ODEBUG_POOL_MIN_LEVEL	(ODEBUG_POOL_SIZE / 4)

#define ODEBUG_POOL_PERCPU_SIZE	(8 * ODEBUG_BATCH_SIZE)

#define ODEBUG_CHUNK_SHIFT	PAGE_SHIFT
#define ODEBUG_CHUNK_SIZE	(1 << ODEBUG_CHUNK_SHIFT)
#define ODEBUG_CHUNK_MASK	(~(ODEBUG_CHUNK_SIZE - 1))

/*
 * We limit the freeing of debug objects via workqueue at a maximum
 * frequency of 10Hz and about 1024 objects for each freeing operation.
 * So it is freeing at most 10k debug objects per second.
 */
#define ODEBUG_FREE_WORK_MAX	(1024 / ODEBUG_BATCH_SIZE)
#define ODEBUG_FREE_WORK_DELAY	DIV_ROUND_UP(HZ, 10)

struct debug_bucket {
	struct hlist_head	list;
	raw_spinlock_t		lock;
};

struct pool_stats {
	unsigned int		cur_used;
	unsigned int		max_used;
	unsigned int		min_fill;
};

struct obj_pool {
	struct hlist_head