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

#ifndef _LINUX_KPROBES_H
#define _LINUX_KPROBES_H
/*
 *  Kernel Probes (KProbes)
 *  include/linux/kprobes.h
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright (C) IBM Corporation, 2002, 2004
 *
 * 2002-Oct	Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
 *		Probes initial implementation ( includes suggestions from
 *		Rusty Russell).
 * 2004-July	Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
 *		interface to access function arguments.
 * 2005-May	Hien Nguyen <hien@us.ibm.com> and Jim Keniston
 *		<jkenisto@us.ibm.com>  and Prasanna S Panchamukhi
 *		<prasanna@in.ibm.com> added function-return probes.
 */
#include <linux/config.h>
#include <linux/list.h>
#include <linux/notifier.h>
#include <linux/smp.h>

#include <asm/kprobes.h>

/* kprobe_status settings */
#define KPROBE_HIT_ACTIVE	0x00000001
#define KPROBE_HIT_SS		0x00000002
#define KPROBE_REENTER		0x00000004
#define KPROBE_HIT_SSDONE	0x00000008

struct kprobe;
struct pt_regs;
struct kretprobe;
struct kretprobe_instance;
typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
				       unsigned long flags);
typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
				       int trapnr);
typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
				    struct pt_regs *);

struct kprobe {
	struct hlist_node hlist;

	/* list of kprobes for multi-handler support */
	struct list_head list;

	/*count the number of times this probe was temporarily disarmed */
	unsigned long nmissed;

	/* location of the probe point */
	kprobe_opcode_t *addr;

	/* Called before addr is executed. */
	kprobe_pre_handler_t pre_handler;

	/* Called after addr is executed, unless... */
	kprobe_post_handler_t post_handler;

	/* ... called if executing addr causes a fault (eg. page fault).
	 * Return 1 if it handled fault, otherwise kernel will see it. */
	kprobe_fault_handler_t fault_handler;

	/* ... called if breakpoint trap occurs in probe handler.
	 * Return 1 if it handled break, otherwise kernel will see it. */
	kprobe_break_handler_t break_handler;

	/* Saved opcode (which has been replaced with breakpoint) */
	kprobe_opcode_t opcode;

	/* copy of the original instruction */
	struct arch_specific_insn ainsn;
};

/*
 * Special probe type that uses setjmp-longjmp type tricks to resume
 * execution at a specified entry with a matching prototype corresponding
 * to the probed function - a trick to enable arguments to become
 * accessible seamlessly by probe handling logic.
 * Note:
 * Because of the way compilers allocate stack space for local variables
 * etc upfront, regardless of sub-scopes within a function, this mirroring
 * principle currently works only for probes placed on function entry points.
 */
struct jprobe {
	struct kprobe kp;
	kprobe_opcode_t *entry;	/* probe handling code to jump to */
};

#ifdef ARCH_SUPPORTS_KRETPROBES
extern void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs);
#else /* ARCH_SUPPORTS_KRETPROBES */
static inline void arch_prepare_kretprobe(struct kretprobe *rp,
					struct pt_regs *regs)
{
}
#endif /* ARCH_SUPPORTS_KRETPROBES */
/*
 * Function-return probe -
 * Note:
 * User needs to provide a handler function, and initialize maxactive.
 * maxactive - The maximum number of instances of the probed function that
 * can be active concurrently.
 * nmissed - tracks the number of times the probed function's return was
 * ignored, due to maxactive being too low.
 *
 */
struct kretprobe {
	struct kprobe kp;
	kretprobe_handler_t handler;
	int maxactive;
	int nmissed;
	struct hlist_head free_instances;
	struct hlist_head used_instances;
};

struct kretprobe_instance {
	struct hlist_node uflist; /* either on free list or used list */
	struct hlist_node hlist;
	struct kretprobe *rp;
	kprobe_opcode_t *ret_addr;
	struct task_struct *task;
};

#ifdef CONFIG_KPROBES
/* Locks kprobe: irq must be disabled */
void lock_kprobes(void);
void unlock_kprobes(void);

/* kprobe running now on this CPU? */
static inline int kprobe_running(void)
{
	extern unsigned int kprobe_cpu;
	return kprobe_cpu == smp_processor_id();
}

extern int arch_prepare_kprobe(struct kprobe *p);
extern void arch_copy_kprobe(struct kprobe *p);
extern void arch_arm_kprobe(struct kprobe *p);
extern void arch_disarm_kprobe(struct kprobe *p);
extern void arch_remove_kprobe(struct kprobe *p);
extern int arch_init_kprobes(void);
extern void show_registers(struct pt_regs *regs);
extern kprobe_opcode_t *get_insn_slot(void);
extern void free_insn_slot(kprobe_opcode_t *slot);

/* Get the kprobe at this addr (if any).  Must have called lock_kprobes */
struct kprobe *get_kprobe(void *addr);
struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);

int register_kprobe(struct kprobe *p);
void unregister_kprobe(struct kprobe *p);
int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
int longjmp_break_handler(struct kprobe *, struct pt_regs *);
int register_jprobe(struct jprobe *p);
void unregister_jprobe(struct jprobe *p);
void jprobe_return(void);

int register_kretprobe(struct kretprobe *rp);
void unregister_kretprobe(struct kretprobe *rp);

struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp);
void add_rp_inst(struct kretprobe_instance *ri);
void kprobe_flush_task(struct task_struct *tk);
void recycle_rp_inst(struct kretprobe_instance *ri);
#else /* CONFIG_KPROBES */
static inline int kprobe_running(void)
{
	return 0;
}
static inline int register_kprobe(struct kprobe *p)
{
	return -ENOSYS;
}
static inline void unregister_kprobe(struct kprobe *p)
{
}
static inline int register_jprobe(struct jprobe *p)
{
	return -ENOSYS;
}
static inline void unregister_jprobe(struct jprobe *p)
{
}
static inline void jprobe_return(void)
{
}
static inline int register_kretprobe(struct kretprobe *rp)
{
	return -ENOSYS;
}
static inline void unregister_kretprobe(struct kretprobe *rp)
{
}
static inline void kprobe_flush_task(struct task_struct *tk)
{
}
#endif				/* CONFIG_KPROBES */
#endif				/* _LINUX_KPROBES_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_KPROBES_H
	2	#define _LINUX_KPROBES_H
	3	/*
	4	* Kernel Probes (KProbes)
	5	* include/linux/kprobes.h
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	20	*
	21	* Copyright (C) IBM Corporation, 2002, 2004
	22	*
	23	* 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
	24	* Probes initial implementation ( includes suggestions from
	25	* Rusty Russell).
	26	* 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
	27	* interface to access function arguments.
b94cce92 HN	28	* 2005-May Hien Nguyen <hien@us.ibm.com> and Jim Keniston
	29	* <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
	30	* <prasanna@in.ibm.com> added function-return probes.
1da177e4 LT	31	*/
	32	#include <linux/config.h>
	33	#include <linux/list.h>
	34	#include <linux/notifier.h>
	35	#include <linux/smp.h>
b94cce92	36
1da177e4 LT	37	#include <asm/kprobes.h>
1da177e4 LT	38
ea32c65c PP	39	/* kprobe_status settings */
	40	#define KPROBE_HIT_ACTIVE 0x00000001
	41	#define KPROBE_HIT_SS 0x00000002
	42	#define KPROBE_REENTER 0x00000004
	43	#define KPROBE_HIT_SSDONE 0x00000008
	44
1da177e4 LT	45	struct kprobe;
1da177e4 LT	46	struct pt_regs;
b94cce92 HN	47	struct kretprobe;
b94cce92 HN	48	struct kretprobe_instance;
1da177e4 LT	49	typedef int (kprobe_pre_handler_t) (struct kprobe , struct pt_regs *);
	50	typedef int (kprobe_break_handler_t) (struct kprobe , struct pt_regs *);
	51	typedef void (kprobe_post_handler_t) (struct kprobe , struct pt_regs *,
	52	unsigned long flags);
	53	typedef int (kprobe_fault_handler_t) (struct kprobe , struct pt_regs *,
	54	int trapnr);
b94cce92 HN	55	typedef int (kretprobe_handler_t) (struct kretprobe_instance ,
	56	struct pt_regs *);
	57
1da177e4 LT	58	struct kprobe {
	59	struct hlist_node hlist;
	60
64f562c6 AM	61	/* list of kprobes for multi-handler support */
	62	struct list_head list;
	63
ea32c65c PP	64	/count the number of times this probe was temporarily disarmed /
	65	unsigned long nmissed;
	66
1da177e4 LT	67	/* location of the probe point */
	68	kprobe_opcode_t *addr;
	69
	70	/* Called before addr is executed. */
	71	kprobe_pre_handler_t pre_handler;
	72
	73	/* Called after addr is executed, unless... */
	74	kprobe_post_handler_t post_handler;
	75
	76	/* ... called if executing addr causes a fault (eg. page fault).
	77	* Return 1 if it handled fault, otherwise kernel will see it. */
	78	kprobe_fault_handler_t fault_handler;
	79
	80	/* ... called if breakpoint trap occurs in probe handler.
	81	* Return 1 if it handled break, otherwise kernel will see it. */
	82	kprobe_break_handler_t break_handler;
	83
	84	/* Saved opcode (which has been replaced with breakpoint) */
	85	kprobe_opcode_t opcode;
	86
	87	/* copy of the original instruction */
	88	struct arch_specific_insn ainsn;
	89	};
	90
	91	/*
	92	* Special probe type that uses setjmp-longjmp type tricks to resume
	93	* execution at a specified entry with a matching prototype corresponding
	94	* to the probed function - a trick to enable arguments to become
	95	* accessible seamlessly by probe handling logic.
	96	* Note:
	97	* Because of the way compilers allocate stack space for local variables
	98	* etc upfront, regardless of sub-scopes within a function, this mirroring
	99	* principle currently works only for probes placed on function entry points.
	100	*/
	101	struct jprobe {
	102	struct kprobe kp;
	103	kprobe_opcode_t entry; / probe handling code to jump to */
	104	};
	105
b94cce92	106	#ifdef ARCH_SUPPORTS_KRETPROBES
b94cce92	107	extern void arch_prepare_kretprobe(struct kretprobe rp, struct pt_regs regs);
b94cce92	108	#else /* ARCH_SUPPORTS_KRETPROBES */
b94cce92 HN	109	static inline void arch_prepare_kretprobe(struct kretprobe *rp,
	110	struct pt_regs *regs)
	111	{
	112	}
b94cce92 HN	113	#endif /* ARCH_SUPPORTS_KRETPROBES */
	114	/*
	115	* Function-return probe -
	116	* Note:
	117	* User needs to provide a handler function, and initialize maxactive.
	118	* maxactive - The maximum number of instances of the probed function that
	119	* can be active concurrently.
	120	* nmissed - tracks the number of times the probed function's return was
	121	* ignored, due to maxactive being too low.
	122	*
	123	*/
	124	struct kretprobe {
	125	struct kprobe kp;
	126	kretprobe_handler_t handler;
	127	int maxactive;
	128	int nmissed;
	129	struct hlist_head free_instances;
	130	struct hlist_head used_instances;
	131	};
	132
	133	struct kretprobe_instance {
	134	struct hlist_node uflist; /* either on free list or used list */
	135	struct hlist_node hlist;
	136	struct kretprobe *rp;
802eae7c RL	137	kprobe_opcode_t *ret_addr;
802eae7c RL	138	struct task_struct *task;
b94cce92 HN	139	};
b94cce92 HN	140
1da177e4 LT	141	#ifdef CONFIG_KPROBES
	142	/* Locks kprobe: irq must be disabled */
	143	void lock_kprobes(void);
	144	void unlock_kprobes(void);
	145
	146	/* kprobe running now on this CPU? */
	147	static inline int kprobe_running(void)
	148	{
	149	extern unsigned int kprobe_cpu;
	150	return kprobe_cpu == smp_processor_id();
	151	}
	152
	153	extern int arch_prepare_kprobe(struct kprobe *p);
	154	extern void arch_copy_kprobe(struct kprobe *p);
7e1048b1 RL	155	extern void arch_arm_kprobe(struct kprobe *p);
7e1048b1 RL	156	extern void arch_disarm_kprobe(struct kprobe *p);
1da177e4	157	extern void arch_remove_kprobe(struct kprobe *p);
6772926b	158	extern int arch_init_kprobes(void);
1da177e4	159	extern void show_registers(struct pt_regs *regs);
9ec4b1f3 AM	160	extern kprobe_opcode_t *get_insn_slot(void);
9ec4b1f3 AM	161	extern void free_insn_slot(kprobe_opcode_t *slot);
1da177e4 LT	162
	163	/* Get the kprobe at this addr (if any). Must have called lock_kprobes */
	164	struct kprobe get_kprobe(void addr);
b94cce92	165	struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
1da177e4 LT	166
	167	int register_kprobe(struct kprobe *p);
	168	void unregister_kprobe(struct kprobe *p);
	169	int setjmp_pre_handler(struct kprobe , struct pt_regs );
	170	int longjmp_break_handler(struct kprobe , struct pt_regs );
	171	int register_jprobe(struct jprobe *p);
	172	void unregister_jprobe(struct jprobe *p);
	173	void jprobe_return(void);
	174
b94cce92 HN	175	int register_kretprobe(struct kretprobe *rp);
	176	void unregister_kretprobe(struct kretprobe *rp);
	177
	178	struct kretprobe_instance get_free_rp_inst(struct kretprobe rp);
b94cce92 HN	179	void add_rp_inst(struct kretprobe_instance *ri);
	180	void kprobe_flush_task(struct task_struct *tk);
	181	void recycle_rp_inst(struct kretprobe_instance *ri);
	182	#else /* CONFIG_KPROBES */
1da177e4 LT	183	static inline int kprobe_running(void)
	184	{
	185	return 0;
	186	}
	187	static inline int register_kprobe(struct kprobe *p)
	188	{
	189	return -ENOSYS;
	190	}
	191	static inline void unregister_kprobe(struct kprobe *p)
	192	{
	193	}
	194	static inline int register_jprobe(struct jprobe *p)
	195	{
	196	return -ENOSYS;
	197	}
	198	static inline void unregister_jprobe(struct jprobe *p)
	199	{
	200	}
	201	static inline void jprobe_return(void)
	202	{
	203	}
b94cce92 HN	204	static inline int register_kretprobe(struct kretprobe *rp)
	205	{
	206	return -ENOSYS;
	207	}
	208	static inline void unregister_kretprobe(struct kretprobe *rp)
	209	{
	210	}
	211	static inline void kprobe_flush_task(struct task_struct *tk)
	212	{
	213	}
	214	#endif /* CONFIG_KPROBES */
1da177e4	215	#endif /* _LINUX_KPROBES_H */