[linux-2.6-block.git] / include / linux / fprobe.h

/* SPDX-License-Identifier: GPL-2.0 */
/* Simple ftrace probe wrapper */
#ifndef _LINUX_FPROBE_H
#define _LINUX_FPROBE_H

#include <linux/compiler.h>
#include <linux/ftrace.h>
#include <linux/rcupdate.h>
#include <linux/refcount.h>
#include <linux/slab.h>

struct fprobe;
typedef int (*fprobe_entry_cb)(struct fprobe *fp, unsigned long entry_ip,
			       unsigned long ret_ip, struct ftrace_regs *regs,
			       void *entry_data);

typedef void (*fprobe_exit_cb)(struct fprobe *fp, unsigned long entry_ip,
			       unsigned long ret_ip, struct ftrace_regs *regs,
			       void *entry_data);

/**
 * struct fprobe_hlist_node - address based hash list node for fprobe.
 *
 * @hlist: The hlist node for address search hash table.
 * @addr: One of the probing address of @fp.
 * @fp: The fprobe which owns this.
 */
struct fprobe_hlist_node {
	struct hlist_node	hlist;
	unsigned long		addr;
	struct fprobe		*fp;
};

/**
 * struct fprobe_hlist - hash list nodes for fprobe.
 *
 * @hlist: The hlist node for existence checking hash table.
 * @rcu: rcu_head for RCU deferred release.
 * @fp: The fprobe which owns this fprobe_hlist.
 * @size: The size of @array.
 * @array: The fprobe_hlist_node for each address to probe.
 */
struct fprobe_hlist {
	struct hlist_node		hlist;
	struct rcu_head			rcu;
	struct fprobe			*fp;
	int				size;
	struct fprobe_hlist_node	array[] __counted_by(size);
};

/**
 * struct fprobe - ftrace based probe.
 *
 * @nmissed: The counter for missing events.
 * @flags: The status flag.
 * @entry_data_size: The private data storage size.
 * @entry_handler: The callback function for function entry.
 * @exit_handler: The callback function for function exit.
 * @hlist_array: The fprobe_hlist for fprobe search from IP hash table.
 */
struct fprobe {
	unsigned long		nmissed;
	unsigned int		flags;
	size_t			entry_data_size;

	fprobe_entry_cb entry_handler;
	fprobe_exit_cb  exit_handler;

	struct fprobe_hlist	*hlist_array;
};

/* This fprobe is soft-disabled. */
#define FPROBE_FL_DISABLED	1

/*
 * This fprobe handler will be shared with kprobes.
 * This flag must be set before registering.
 */
#define FPROBE_FL_KPROBE_SHARED	2

static inline bool fprobe_disabled(struct fprobe *fp)
{
	return (fp) ? fp->flags & FPROBE_FL_DISABLED : false;
}

static inline bool fprobe_shared_with_kprobes(struct fprobe *fp)
{
	return (fp) ? fp->flags & FPROBE_FL_KPROBE_SHARED : false;
}

#ifdef CONFIG_FPROBE
int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter);
int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num);
int register_fprobe_syms(struct fprobe *fp, const char **syms, int num);
int unregister_fprobe(struct fprobe *fp);
bool fprobe_is_registered(struct fprobe *fp);
#else
static inline int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter)
{
	return -EOPNOTSUPP;
}
static inline int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num)
{
	return -EOPNOTSUPP;
}
static inline int register_fprobe_syms(struct fprobe *fp, const char **syms, int num)
{
	return -EOPNOTSUPP;
}
static inline int unregister_fprobe(struct fprobe *fp)
{
	return -EOPNOTSUPP;
}
static inline bool fprobe_is_registered(struct fprobe *fp)
{
	return false;
}
#endif

/**
 * disable_fprobe() - Disable fprobe
 * @fp: The fprobe to be disabled.
 *
 * This will soft-disable @fp. Note that this doesn't remove the ftrace
 * hooks from the function entry.
 */
static inline void disable_fprobe(struct fprobe *fp)
{
	if (fp)
		fp->flags |= FPROBE_FL_DISABLED;
}

/**
 * enable_fprobe() - Enable fprobe
 * @fp: The fprobe to be enabled.
 *
 * This will soft-enable @fp.
 */
static inline void enable_fprobe(struct fprobe *fp)
{
	if (fp)
		fp->flags &= ~FPROBE_FL_DISABLED;
}

/* The entry data size is 4 bits (=16) * sizeof(long) in maximum */
#define FPROBE_DATA_SIZE_BITS		4
#define MAX_FPROBE_DATA_SIZE_WORD	((1L << FPROBE_DATA_SIZE_BITS) - 1)
#define MAX_FPROBE_DATA_SIZE		(MAX_FPROBE_DATA_SIZE_WORD * sizeof(long))

#endif
Commit	Line	Data
cad9931f MH	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/* Simple ftrace probe wrapper */
	3	#ifndef _LINUX_FPROBE_H
	4	#define _LINUX_FPROBE_H
	5
	6	#include <linux/compiler.h>
	7	#include <linux/ftrace.h>
4346ba16 MHG	8	#include <linux/rcupdate.h>
	9	#include <linux/refcount.h>
	10	#include <linux/slab.h>
cad9931f	11
73142cab	12	struct fprobe;
73142cab	13	typedef int (fprobe_entry_cb)(struct fprobe fp, unsigned long entry_ip,
46bc0823	14	unsigned long ret_ip, struct ftrace_regs *regs,
73142cab JO	15	void *entry_data);
	16
	17	typedef void (fprobe_exit_cb)(struct fprobe fp, unsigned long entry_ip,
762abbc0	18	unsigned long ret_ip, struct ftrace_regs *regs,
73142cab JO	19	void *entry_data);
73142cab JO	20
4346ba16 MHG	21	/**
	22	* struct fprobe_hlist_node - address based hash list node for fprobe.
	23	*
	24	* @hlist: The hlist node for address search hash table.
	25	* @addr: One of the probing address of @fp.
	26	* @fp: The fprobe which owns this.
	27	*/
	28	struct fprobe_hlist_node {
	29	struct hlist_node hlist;
	30	unsigned long addr;
	31	struct fprobe *fp;
	32	};
	33
	34	/**
	35	* struct fprobe_hlist - hash list nodes for fprobe.
	36	*
	37	* @hlist: The hlist node for existence checking hash table.
	38	* @rcu: rcu_head for RCU deferred release.
	39	* @fp: The fprobe which owns this fprobe_hlist.
	40	* @size: The size of @array.
	41	* @array: The fprobe_hlist_node for each address to probe.
	42	*/
	43	struct fprobe_hlist {
	44	struct hlist_node hlist;
	45	struct rcu_head rcu;
	46	struct fprobe *fp;
	47	int size;
	48	struct fprobe_hlist_node array[] __counted_by(size);
	49	};
	50
cad9931f MH	51	/**
cad9931f MH	52	* struct fprobe - ftrace based probe.
4346ba16	53	*
cad9931f MH	54	* @nmissed: The counter for missing events.
cad9931f MH	55	* @flags: The status flag.
76d0de57	56	* @entry_data_size: The private data storage size.
cad9931f	57	* @entry_handler: The callback function for function entry.
5b0ab789	58	* @exit_handler: The callback function for function exit.
4346ba16	59	* @hlist_array: The fprobe_hlist for fprobe search from IP hash table.
cad9931f MH	60	*/
cad9931f MH	61	struct fprobe {
cad9931f MH	62	unsigned long nmissed;
cad9931f MH	63	unsigned int flags;
76d0de57	64	size_t entry_data_size;
5b0ab789	65
73142cab JO	66	fprobe_entry_cb entry_handler;
73142cab JO	67	fprobe_exit_cb exit_handler;
4346ba16 MHG	68
4346ba16 MHG	69	struct fprobe_hlist *hlist_array;
cad9931f MH	70	};
cad9931f MH	71
ab51e15d	72	/* This fprobe is soft-disabled. */
cad9931f MH	73	#define FPROBE_FL_DISABLED 1
cad9931f MH	74
ab51e15d MH	75	/*
	76	* This fprobe handler will be shared with kprobes.
	77	* This flag must be set before registering.
	78	*/
	79	#define FPROBE_FL_KPROBE_SHARED 2
	80
cad9931f MH	81	static inline bool fprobe_disabled(struct fprobe *fp)
	82	{
	83	return (fp) ? fp->flags & FPROBE_FL_DISABLED : false;
	84	}
	85
ab51e15d MH	86	static inline bool fprobe_shared_with_kprobes(struct fprobe *fp)
	87	{
	88	return (fp) ? fp->flags & FPROBE_FL_KPROBE_SHARED : false;
	89	}
	90
cad9931f MH	91	#ifdef CONFIG_FPROBE
	92	int register_fprobe(struct fprobe fp, const char filter, const char *notfilter);
	93	int register_fprobe_ips(struct fprobe fp, unsigned long addrs, int num);
	94	int register_fprobe_syms(struct fprobe fp, const char *syms, int num);
	95	int unregister_fprobe(struct fprobe *fp);
334e5519	96	bool fprobe_is_registered(struct fprobe *fp);
cad9931f MH	97	#else
	98	static inline int register_fprobe(struct fprobe fp, const char filter, const char *notfilter)
	99	{
	100	return -EOPNOTSUPP;
	101	}
	102	static inline int register_fprobe_ips(struct fprobe fp, unsigned long addrs, int num)
	103	{
	104	return -EOPNOTSUPP;
	105	}
	106	static inline int register_fprobe_syms(struct fprobe fp, const char *syms, int num)
	107	{
	108	return -EOPNOTSUPP;
	109	}
	110	static inline int unregister_fprobe(struct fprobe *fp)
	111	{
	112	return -EOPNOTSUPP;
	113	}
334e5519 MHG	114	static inline bool fprobe_is_registered(struct fprobe *fp)
	115	{
	116	return false;
	117	}
cad9931f MH	118	#endif
	119
	120	/**
	121	* disable_fprobe() - Disable fprobe
	122	* @fp: The fprobe to be disabled.
	123	*
	124	* This will soft-disable @fp. Note that this doesn't remove the ftrace
	125	* hooks from the function entry.
	126	*/
	127	static inline void disable_fprobe(struct fprobe *fp)
	128	{
	129	if (fp)
	130	fp->flags \|= FPROBE_FL_DISABLED;
	131	}
	132
	133	/**
	134	* enable_fprobe() - Enable fprobe
	135	* @fp: The fprobe to be enabled.
	136	*
	137	* This will soft-enable @fp.
	138	*/
	139	static inline void enable_fprobe(struct fprobe *fp)
	140	{
	141	if (fp)
	142	fp->flags &= ~FPROBE_FL_DISABLED;
	143	}
	144
4346ba16 MHG	145	/* The entry data size is 4 bits (=16) * sizeof(long) in maximum */
	146	#define FPROBE_DATA_SIZE_BITS 4
	147	#define MAX_FPROBE_DATA_SIZE_WORD ((1L << FPROBE_DATA_SIZE_BITS) - 1)
	148	#define MAX_FPROBE_DATA_SIZE (MAX_FPROBE_DATA_SIZE_WORD * sizeof(long))
	149
cad9931f	150	#endif