[mirror_ubuntu-jammy-kernel.git] / include / linux / kprobes.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _LINUX_KPROBES_H
#define _LINUX_KPROBES_H
/*
 *  Kernel Probes (KProbes)
 *  include/linux/kprobes.h
 *
 * 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/compiler.h>
#include <linux/linkage.h>
#include <linux/list.h>
#include <linux/notifier.h>
#include <linux/smp.h>
#include <linux/bug.h>
#include <linux/percpu.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <linux/mutex.h>
#include <linux/ftrace.h>
#include <linux/refcount.h>
#include <linux/freelist.h>
#include <asm/kprobes.h>

#ifdef CONFIG_KPROBES

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

#else /* CONFIG_KPROBES */
#include <asm-generic/kprobes.h>
typedef int kprobe_opcode_t;
struct arch_specific_insn {
	int dummy;
};
#endif /* CONFIG_KPROBES */

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

	/* Allow user to indicate symbol name of the probe point */
	const char *symbol_name;

	/* Offset into the symbol */
	unsigned int offset;

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

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

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

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

	/*
	 * Indicates various status flags.
	 * Protected by kprobe_mutex after this kprobe is registered.
	 */
	u32 flags;
};

/* Kprobe status flags */
#define KPROBE_FLAG_GONE	1 /* breakpoint has already gone */
#define KPROBE_FLAG_DISABLED	2 /* probe is temporarily disabled */
#define KPROBE_FLAG_OPTIMIZED	4 /*
				   * probe is really optimized.
				   * NOTE:
				   * this flag is only for optimized_kprobe.
				   */
#define KPROBE_FLAG_FTRACE	8 /* probe is using ftrace */

/* Has this kprobe gone ? */
static inline int kprobe_gone(struct kprobe *p)
{
	return p->flags & KPROBE_FLAG_GONE;
}

/* Is this kprobe disabled ? */
static inline int kprobe_disabled(struct kprobe *p)
{
	return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
}

/* Is this kprobe really running optimized path ? */
static inline int kprobe_optimized(struct kprobe *p)
{
	return p->flags & KPROBE_FLAG_OPTIMIZED;
}

/* Is this kprobe uses ftrace ? */
static inline int kprobe_ftrace(struct kprobe *p)
{
	return p->flags & KPROBE_FLAG_FTRACE;
}

/*
 * 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_holder {
	struct kretprobe	*rp;
	refcount_t		ref;
};

struct kretprobe {
	struct kprobe kp;
	kretprobe_handler_t handler;
	kretprobe_handler_t entry_handler;
	int maxactive;
	int nmissed;
	size_t data_size;
	struct freelist_head freelist;
	struct kretprobe_holder *rph;
};

struct kretprobe_instance {
	union {
		struct freelist_node freelist;
		struct rcu_head rcu;
	};
	struct llist_node llist;
	struct kretprobe_holder *rph;
	kprobe_opcode_t *ret_addr;
	void *fp;
	char data[];
};

struct kretprobe_blackpoint {
	const char *name;
	void *addr;
};

struct kprobe_blacklist_entry {
	struct list_head list;
	unsigned long start_addr;
	unsigned long end_addr;
};

#ifdef CONFIG_KPROBES
DECLARE_PER_CPU(struct kprobe *, current_kprobe);
DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);

/*
 * For #ifdef avoidance:
 */
static inline int kprobes_built_in(void)
{
	return 1;
}

extern void kprobe_busy_begin(void);
extern void kprobe_busy_end(void);

#ifdef CONFIG_KRETPROBES
extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
				   struct pt_regs *regs);
extern int arch_trampoline_kprobe(struct kprobe *p);

/* If the trampoline handler called from a kprobe, use this version */
unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs,
				void *trampoline_address,
				void *frame_pointer);

static nokprobe_inline
unsigned long kretprobe_trampoline_handler(struct pt_regs *regs,
				void *trampoline_address,
				void *frame_pointer)
{
	unsigned long ret;
	/*
	 * Set a dummy kprobe for avoiding kretprobe recursion.
	 * Since kretprobe never runs in kprobe handler, no kprobe must
	 * be running at this point.
	 */
	kprobe_busy_begin();
	ret = __kretprobe_trampoline_handler(regs, trampoline_address, frame_pointer);
	kprobe_busy_end();

	return ret;
}

static nokprobe_inline struct kretprobe *get_kretprobe(struct kretprobe_instance *ri)
{
	RCU_LOCKDEP_WARN(!rcu_read_lock_any_held(),
		"Kretprobe is accessed from instance under preemptive context");

	return READ_ONCE(ri->rph->rp);
}

#else /* CONFIG_KRETPROBES */
static inline void arch_prepare_kretprobe(struct kretprobe *rp,
					struct pt_regs *regs)
{
}
static inline int arch_trampoline_kprobe(struct kprobe *p)
{
	return 0;
}
#endif /* CONFIG_KRETPROBES */

extern struct kretprobe_blackpoint kretprobe_blacklist[];

#ifdef CONFIG_KPROBES_SANITY_TEST
extern int init_test_probes(void);
#else
static inline int init_test_probes(void)
{
	return 0;
}
#endif /* CONFIG_KPROBES_SANITY_TEST */

extern int arch_prepare_kprobe(struct kprobe *p);
extern void arch_arm_kprobe(struct kprobe *p);
extern void arch_disarm_kprobe(struct kprobe *p);
extern int arch_init_kprobes(void);
extern void kprobes_inc_nmissed_count(struct kprobe *p);
extern bool arch_within_kprobe_blacklist(unsigned long addr);
extern int arch_populate_kprobe_blacklist(void);
extern bool arch_kprobe_on_func_entry(unsigned long offset);
extern int kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset);

extern bool within_kprobe_blacklist(unsigned long addr);
extern int kprobe_add_ksym_blacklist(unsigned long entry);
extern int kprobe_add_area_blacklist(unsigned long start, unsigned long end);

struct kprobe_insn_cache {
	struct mutex mutex;
	void *(*alloc)(void);	/* allocate insn page */
	void (*free)(void *);	/* free insn page */
	const char *sym;	/* symbol for insn pages */
	struct list_head pages; /* list of kprobe_insn_page */
	size_t insn_size;	/* size of instruction slot */
	int nr_garbage;
};

#ifdef __ARCH_WANT_KPROBES_INSN_SLOT
extern kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c);
extern void __free_insn_slot(struct kprobe_insn_cache *c,
			     kprobe_opcode_t *slot, int dirty);
/* sleep-less address checking routine  */
extern bool __is_insn_slot_addr(struct kprobe_insn_cache *c,
				unsigned long addr);

#define DEFINE_INSN_CACHE_OPS(__name)					\
extern struct kprobe_insn_cache kprobe_##__name##_slots;		\
									\
static inline kprobe_opcode_t *get_##__name##_slot(void)		\
{									\
	return __get_insn_slot(&kprobe_##__name##_slots);		\
}									\
									\
static inline void free_##__name##_slot(kprobe_opcode_t *slot, int dirty)\
{									\
	__free_insn_slot(&kprobe_##__name##_slots, slot, dirty);	\
}									\
									\
static inline bool is_kprobe_##__name##_slot(unsigned long addr)	\
{									\
	return __is_insn_slot_addr(&kprobe_##__name##_slots, addr);	\
}
#define KPROBE_INSN_PAGE_SYM		"kprobe_insn_page"
#define KPROBE_OPTINSN_PAGE_SYM		"kprobe_optinsn_page"
int kprobe_cache_get_kallsym(struct kprobe_insn_cache *c, unsigned int *symnum,
			     unsigned long *value, char *type, char *sym);
#else /* __ARCH_WANT_KPROBES_INSN_SLOT */
#define DEFINE_INSN_CACHE_OPS(__name)					\
static inline bool is_kprobe_##__name##_slot(unsigned long addr)	\
{									\
	return 0;							\
}
#endif

DEFINE_INSN_CACHE_OPS(insn);

#ifdef CONFIG_OPTPROBES
/*
 * Internal structure for direct jump optimized probe
 */
struct optimized_kprobe {
	struct kprobe kp;
	struct list_head list;	/* list for optimizing queue */
	struct arch_optimized_insn optinsn;
};

/* Architecture dependent functions for direct jump optimization */
extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op,
					 struct kprobe *orig);
extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
extern void arch_optimize_kprobes(struct list_head *oplist);
extern void arch_unoptimize_kprobes(struct list_head *oplist,
				    struct list_head *done_list);
extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
					unsigned long addr);

extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);

DEFINE_INSN_CACHE_OPS(optinsn);

#ifdef CONFIG_SYSCTL
extern int sysctl_kprobes_optimization;
extern int proc_kprobes_optimization_handler(struct ctl_table *table,
					     int write, void *buffer,
					     size_t *length, loff_t *ppos);
#endif
extern void wait_for_kprobe_optimizer(void);
#else
static inline void wait_for_kprobe_optimizer(void) { }
#endif /* CONFIG_OPTPROBES */
#ifdef CONFIG_KPROBES_ON_FTRACE
extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
				  struct ftrace_ops *ops, struct ftrace_regs *fregs);
extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
#endif

int arch_check_ftrace_location(struct kprobe *p);

/* Get the kprobe at this addr (if any) - called with preemption disabled */
struct kprobe *get_kprobe(void *addr);

/* kprobe_running() will just return the current_kprobe on this CPU */
static inline struct kprobe *kprobe_running(void)
{
	return (__this_cpu_read(current_kprobe));
}

static inline void reset_current_kprobe(void)
{
	__this_cpu_write(current_kprobe, NULL);
}

static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
{
	return this_cpu_ptr(&kprobe_ctlblk);
}

kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset);
int register_kprobe(struct kprobe *p);
void unregister_kprobe(struct kprobe *p);
int register_kprobes(struct kprobe **kps, int num);
void unregister_kprobes(struct kprobe **kps, int num);
unsigned long arch_deref_entry_point(void *);

int register_kretprobe(struct kretprobe *rp);
void unregister_kretprobe(struct kretprobe *rp);
int register_kretprobes(struct kretprobe **rps, int num);
void unregister_kretprobes(struct kretprobe **rps, int num);

void kprobe_flush_task(struct task_struct *tk);

void kprobe_free_init_mem(void);

int disable_kprobe(struct kprobe *kp);
int enable_kprobe(struct kprobe *kp);

void dump_kprobe(struct kprobe *kp);

void *alloc_insn_page(void);

void *alloc_optinsn_page(void);
void free_optinsn_page(void *page);

int kprobe_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
		       char *sym);

int arch_kprobe_get_kallsym(unsigned int *symnum, unsigned long *value,
			    char *type, char *sym);
#else /* !CONFIG_KPROBES: */

static inline int kprobes_built_in(void)
{
	return 0;
}
static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
	return 0;
}
static inline struct kprobe *get_kprobe(void *addr)
{
	return NULL;
}
static inline struct kprobe *kprobe_running(void)
{
	return NULL;
}
static inline int register_kprobe(struct kprobe *p)
{
	return -ENOSYS;
}
static inline int register_kprobes(struct kprobe **kps, int num)
{
	return -ENOSYS;
}
static inline void unregister_kprobe(struct kprobe *p)
{
}
static inline void unregister_kprobes(struct kprobe **kps, int num)
{
}
static inline int register_kretprobe(struct kretprobe *rp)
{
	return -ENOSYS;
}
static inline int register_kretprobes(struct kretprobe **rps, int num)
{
	return -ENOSYS;
}
static inline void unregister_kretprobe(struct kretprobe *rp)
{
}
static inline void unregister_kretprobes(struct kretprobe **rps, int num)
{
}
static inline void kprobe_flush_task(struct task_struct *tk)
{
}
static inline void kprobe_free_init_mem(void)
{
}
static inline int disable_kprobe(struct kprobe *kp)
{
	return -ENOSYS;
}
static inline int enable_kprobe(struct kprobe *kp)
{
	return -ENOSYS;
}

static inline bool within_kprobe_blacklist(unsigned long addr)
{
	return true;
}
static inline int kprobe_get_kallsym(unsigned int symnum, unsigned long *value,
				     char *type, char *sym)
{
	return -ERANGE;
}
#endif /* CONFIG_KPROBES */
static inline int disable_kretprobe(struct kretprobe *rp)
{
	return disable_kprobe(&rp->kp);
}
static inline int enable_kretprobe(struct kretprobe *rp)
{
	return enable_kprobe(&rp->kp);
}

#ifndef CONFIG_KPROBES
static inline bool is_kprobe_insn_slot(unsigned long addr)
{
	return false;
}
#endif
#ifndef CONFIG_OPTPROBES
static inline bool is_kprobe_optinsn_slot(unsigned long addr)
{
	return false;
}
#endif

/* Returns true if kprobes handled the fault */
static nokprobe_inline bool kprobe_page_fault(struct pt_regs *regs,
					      unsigned int trap)
{
	if (!kprobes_built_in())
		return false;
	if (user_mode(regs))
		return false;
	/*
	 * To be potentially processing a kprobe fault and to be allowed
	 * to call kprobe_running(), we have to be non-preemptible.
	 */
	if (preemptible())
		return false;
	if (!kprobe_running())
		return false;
	return kprobe_fault_handler(regs, trap);
}

#endif /* _LINUX_KPROBES_H */
Commit	Line	Data
1a59d1b8	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
1da177e4 LT	2	#ifndef _LINUX_KPROBES_H
	3	#define _LINUX_KPROBES_H
	4	/*
	5	* Kernel Probes (KProbes)
	6	* include/linux/kprobes.h
	7	*
1da177e4 LT	8	* Copyright (C) IBM Corporation, 2002, 2004
	9	*
	10	* 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
	11	* Probes initial implementation ( includes suggestions from
	12	* Rusty Russell).
	13	* 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
	14	* interface to access function arguments.
b94cce92 HN	15	* 2005-May Hien Nguyen <hien@us.ibm.com> and Jim Keniston
	16	* <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
	17	* <prasanna@in.ibm.com> added function-return probes.
1da177e4	18	*/
7d134b2c	19	#include <linux/compiler.h>
36dcd67a	20	#include <linux/linkage.h>
1da177e4 LT	21	#include <linux/list.h>
	22	#include <linux/notifier.h>
	23	#include <linux/smp.h>
187f1882	24	#include <linux/bug.h>
e6584523	25	#include <linux/percpu.h>
3516a460 AM	26	#include <linux/spinlock.h>
3516a460 AM	27	#include <linux/rcupdate.h>
7a7d1cf9	28	#include <linux/mutex.h>
ae6aa16f	29	#include <linux/ftrace.h>
d741bf41	30	#include <linux/refcount.h>
6e426e0f	31	#include <linux/freelist.h>
7d134b2c	32	#include <asm/kprobes.h>
b94cce92	33
00d7c05a	34	#ifdef CONFIG_KPROBES
1da177e4	35
ea32c65c PP	36	/* kprobe_status settings */
	37	#define KPROBE_HIT_ACTIVE 0x00000001
	38	#define KPROBE_HIT_SS 0x00000002
	39	#define KPROBE_REENTER 0x00000004
	40	#define KPROBE_HIT_SSDONE 0x00000008
	41
dc19835d	42	#else /* CONFIG_KPROBES */
7d134b2c	43	#include <asm-generic/kprobes.h>
dc19835d MH	44	typedef int kprobe_opcode_t;
	45	struct arch_specific_insn {
	46	int dummy;
	47	};
dc19835d	48	#endif /* CONFIG_KPROBES */
d0aaff97	49
1da177e4 LT	50	struct kprobe;
1da177e4 LT	51	struct pt_regs;
b94cce92 HN	52	struct kretprobe;
b94cce92 HN	53	struct kretprobe_instance;
1da177e4	54	typedef int (kprobe_pre_handler_t) (struct kprobe , struct pt_regs *);
1da177e4 LT	55	typedef void (kprobe_post_handler_t) (struct kprobe , struct pt_regs *,
1da177e4 LT	56	unsigned long flags);
b94cce92 HN	57	typedef int (kretprobe_handler_t) (struct kretprobe_instance ,
	58	struct pt_regs *);
	59
1da177e4 LT	60	struct kprobe {
	61	struct hlist_node hlist;
	62
64f562c6 AM	63	/* list of kprobes for multi-handler support */
	64	struct list_head list;
	65
ea32c65c PP	66	/count the number of times this probe was temporarily disarmed /
	67	unsigned long nmissed;
	68
1da177e4 LT	69	/* location of the probe point */
	70	kprobe_opcode_t *addr;
	71
3a872d89	72	/* Allow user to indicate symbol name of the probe point */
9b3af29b	73	const char *symbol_name;
3a872d89 AM	74
	75	/* Offset into the symbol */
	76	unsigned int offset;
	77
1da177e4 LT	78	/* Called before addr is executed. */
	79	kprobe_pre_handler_t pre_handler;
	80
	81	/* Called after addr is executed, unless... */
	82	kprobe_post_handler_t post_handler;
	83
1da177e4 LT	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;
e8386a0c	89
de5bd88d MH	90	/*
	91	* Indicates various status flags.
	92	* Protected by kprobe_mutex after this kprobe is registered.
	93	*/
e8386a0c	94	u32 flags;
1da177e4 LT	95	};
1da177e4 LT	96
e8386a0c MH	97	/* Kprobe status flags */
e8386a0c MH	98	#define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
de5bd88d	99	#define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
afd66255 MH	100	#define KPROBE_FLAG_OPTIMIZED 4 /*
	101	* probe is really optimized.
	102	* NOTE:
	103	* this flag is only for optimized_kprobe.
	104	*/
ae6aa16f	105	#define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */
e8386a0c	106
de5bd88d	107	/* Has this kprobe gone ? */
e8386a0c MH	108	static inline int kprobe_gone(struct kprobe *p)
	109	{
	110	return p->flags & KPROBE_FLAG_GONE;
	111	}
	112
de5bd88d MH	113	/* Is this kprobe disabled ? */
	114	static inline int kprobe_disabled(struct kprobe *p)
	115	{
	116	return p->flags & (KPROBE_FLAG_DISABLED \| KPROBE_FLAG_GONE);
	117	}
afd66255 MH	118
	119	/* Is this kprobe really running optimized path ? */
	120	static inline int kprobe_optimized(struct kprobe *p)
	121	{
	122	return p->flags & KPROBE_FLAG_OPTIMIZED;
	123	}
ae6aa16f MH	124
	125	/* Is this kprobe uses ftrace ? */
	126	static inline int kprobe_ftrace(struct kprobe *p)
	127	{
	128	return p->flags & KPROBE_FLAG_FTRACE;
	129	}
	130
b94cce92 HN	131	/*
	132	* Function-return probe -
	133	* Note:
	134	* User needs to provide a handler function, and initialize maxactive.
	135	* maxactive - The maximum number of instances of the probed function that
	136	* can be active concurrently.
	137	* nmissed - tracks the number of times the probed function's return was
	138	* ignored, due to maxactive being too low.
	139	*
	140	*/
d741bf41 PZ	141	struct kretprobe_holder {
	142	struct kretprobe *rp;
	143	refcount_t ref;
	144	};
	145
b94cce92 HN	146	struct kretprobe {
	147	struct kprobe kp;
	148	kretprobe_handler_t handler;
f47cd9b5	149	kretprobe_handler_t entry_handler;
b94cce92 HN	150	int maxactive;
b94cce92 HN	151	int nmissed;
f47cd9b5	152	size_t data_size;
6e426e0f	153	struct freelist_head freelist;
d741bf41	154	struct kretprobe_holder *rph;
b94cce92 HN	155	};
	156
	157	struct kretprobe_instance {
b3388178	158	union {
6e426e0f	159	struct freelist_node freelist;
b3388178 MH	160	struct rcu_head rcu;
b3388178 MH	161	};
6e426e0f	162	struct llist_node llist;
d741bf41	163	struct kretprobe_holder *rph;
802eae7c	164	kprobe_opcode_t *ret_addr;
3ff9c075	165	void *fp;
67a862a9	166	char data[];
b94cce92 HN	167	};
b94cce92 HN	168
f438d914 MH	169	struct kretprobe_blackpoint {
	170	const char *name;
	171	void *addr;
	172	};
3d8d996e	173
376e2424 MH	174	struct kprobe_blacklist_entry {
376e2424 MH	175	struct list_head list;
3d8d996e	176	unsigned long start_addr;
376e2424	177	unsigned long end_addr;
3d8d996e SD	178	};
3d8d996e SD	179
dc19835d MH	180	#ifdef CONFIG_KPROBES
	181	DECLARE_PER_CPU(struct kprobe *, current_kprobe);
	182	DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
	183
b1801812 IM	184	/*
	185	* For #ifdef avoidance:
	186	*/
	187	static inline int kprobes_built_in(void)
	188	{
	189	return 1;
	190	}
	191
66ada2cc MH	192	extern void kprobe_busy_begin(void);
	193	extern void kprobe_busy_end(void);
	194
dc19835d MH	195	#ifdef CONFIG_KRETPROBES
	196	extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
	197	struct pt_regs *regs);
	198	extern int arch_trampoline_kprobe(struct kprobe *p);
66ada2cc MH	199
	200	/* If the trampoline handler called from a kprobe, use this version */
	201	unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs,
	202	void *trampoline_address,
	203	void *frame_pointer);
	204
	205	static nokprobe_inline
	206	unsigned long kretprobe_trampoline_handler(struct pt_regs *regs,
	207	void *trampoline_address,
	208	void *frame_pointer)
	209	{
	210	unsigned long ret;
	211	/*
	212	* Set a dummy kprobe for avoiding kretprobe recursion.
	213	* Since kretprobe never runs in kprobe handler, no kprobe must
	214	* be running at this point.
	215	*/
	216	kprobe_busy_begin();
	217	ret = __kretprobe_trampoline_handler(regs, trampoline_address, frame_pointer);
	218	kprobe_busy_end();
	219
	220	return ret;
	221	}
	222
d741bf41 PZ	223	static nokprobe_inline struct kretprobe get_kretprobe(struct kretprobe_instance ri)
	224	{
	225	RCU_LOCKDEP_WARN(!rcu_read_lock_any_held(),
	226	"Kretprobe is accessed from instance under preemptive context");
	227
	228	return READ_ONCE(ri->rph->rp);
	229	}
	230
dc19835d MH	231	#else /* CONFIG_KRETPROBES */
	232	static inline void arch_prepare_kretprobe(struct kretprobe *rp,
	233	struct pt_regs *regs)
	234	{
	235	}
	236	static inline int arch_trampoline_kprobe(struct kprobe *p)
	237	{
	238	return 0;
	239	}
	240	#endif /* CONFIG_KRETPROBES */
	241
f438d914 MH	242	extern struct kretprobe_blackpoint kretprobe_blacklist[];
f438d914 MH	243
8c1c9356 AM	244	#ifdef CONFIG_KPROBES_SANITY_TEST
	245	extern int init_test_probes(void);
	246	#else
	247	static inline int init_test_probes(void)
	248	{
	249	return 0;
	250	}
	251	#endif /* CONFIG_KPROBES_SANITY_TEST */
	252
1da177e4	253	extern int arch_prepare_kprobe(struct kprobe *p);
7e1048b1 RL	254	extern void arch_arm_kprobe(struct kprobe *p);
7e1048b1 RL	255	extern void arch_disarm_kprobe(struct kprobe *p);
6772926b	256	extern int arch_init_kprobes(void);
bf8d5c52	257	extern void kprobes_inc_nmissed_count(struct kprobe *p);
be8f2743	258	extern bool arch_within_kprobe_blacklist(unsigned long addr);
fb1a59fa	259	extern int arch_populate_kprobe_blacklist(void);
659b957f	260	extern bool arch_kprobe_on_func_entry(unsigned long offset);
97c753e6	261	extern int kprobe_on_func_entry(kprobe_opcode_t addr, const char sym, unsigned long offset);
1da177e4	262
e5779e8e	263	extern bool within_kprobe_blacklist(unsigned long addr);
fb1a59fa MH	264	extern int kprobe_add_ksym_blacklist(unsigned long entry);
fb1a59fa MH	265	extern int kprobe_add_area_blacklist(unsigned long start, unsigned long end);
e5779e8e	266
c802d64a HC	267	struct kprobe_insn_cache {
c802d64a HC	268	struct mutex mutex;
af96397d HC	269	void (alloc)(void); /* allocate insn page */
af96397d HC	270	void (free)(void ); /* free insn page */
d002b8bc	271	const char sym; / symbol for insn pages */
c802d64a HC	272	struct list_head pages; /* list of kprobe_insn_page */
	273	size_t insn_size; /* size of instruction slot */
	274	int nr_garbage;
	275	};
	276
5b485629	277	#ifdef __ARCH_WANT_KPROBES_INSN_SLOT
c802d64a HC	278	extern kprobe_opcode_t __get_insn_slot(struct kprobe_insn_cache c);
	279	extern void __free_insn_slot(struct kprobe_insn_cache *c,
	280	kprobe_opcode_t *slot, int dirty);
5b485629 MH	281	/* sleep-less address checking routine */
	282	extern bool __is_insn_slot_addr(struct kprobe_insn_cache *c,
	283	unsigned long addr);
c802d64a HC	284
	285	#define DEFINE_INSN_CACHE_OPS(__name) \
	286	extern struct kprobe_insn_cache kprobe_##__name##_slots; \
	287	\
	288	static inline kprobe_opcode_t *get_##__name##_slot(void) \
	289	{ \
	290	return __get_insn_slot(&kprobe_##__name##_slots); \
	291	} \
	292	\
	293	static inline void free_##__name##_slot(kprobe_opcode_t *slot, int dirty)\
	294	{ \
	295	__free_insn_slot(&kprobe_##__name##_slots, slot, dirty); \
	296	} \
5b485629 MH	297	\
	298	static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
	299	{ \
	300	return __is_insn_slot_addr(&kprobe_##__name##_slots, addr); \
	301	}
d002b8bc AH	302	#define KPROBE_INSN_PAGE_SYM "kprobe_insn_page"
	303	#define KPROBE_OPTINSN_PAGE_SYM "kprobe_optinsn_page"
	304	int kprobe_cache_get_kallsym(struct kprobe_insn_cache c, unsigned int symnum,
	305	unsigned long value, char type, char *sym);
5b485629 MH	306	#else /* __ARCH_WANT_KPROBES_INSN_SLOT */
	307	#define DEFINE_INSN_CACHE_OPS(__name) \
	308	static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
	309	{ \
	310	return 0; \
	311	}
	312	#endif
c802d64a HC	313
	314	DEFINE_INSN_CACHE_OPS(insn);
	315
afd66255 MH	316	#ifdef CONFIG_OPTPROBES
	317	/*
	318	* Internal structure for direct jump optimized probe
	319	*/
	320	struct optimized_kprobe {
	321	struct kprobe kp;
	322	struct list_head list; /* list for optimizing queue */
	323	struct arch_optimized_insn optinsn;
	324	};
	325
	326	/* Architecture dependent functions for direct jump optimization */
	327	extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
	328	extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
cbf6ab52 MH	329	extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op,
cbf6ab52 MH	330	struct kprobe *orig);
afd66255	331	extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
cd7ebe22	332	extern void arch_optimize_kprobes(struct list_head *oplist);
f984ba4e MH	333	extern void arch_unoptimize_kprobes(struct list_head *oplist,
f984ba4e MH	334	struct list_head *done_list);
afd66255	335	extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
afd66255 MH	336	extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
	337	unsigned long addr);
	338
	339	extern void opt_pre_handler(struct kprobe p, struct pt_regs regs);
b2be84df	340
c802d64a HC	341	DEFINE_INSN_CACHE_OPS(optinsn);
c802d64a HC	342
b2be84df MH	343	#ifdef CONFIG_SYSCTL
	344	extern int sysctl_kprobes_optimization;
	345	extern int proc_kprobes_optimization_handler(struct ctl_table *table,
32927393	346	int write, void *buffer,
b2be84df MH	347	size_t length, loff_t ppos);
b2be84df MH	348	#endif
30e7d894 TG	349	extern void wait_for_kprobe_optimizer(void);
	350	#else
	351	static inline void wait_for_kprobe_optimizer(void) { }
afd66255	352	#endif /* CONFIG_OPTPROBES */
e7dbfe34	353	#ifdef CONFIG_KPROBES_ON_FTRACE
ae6aa16f	354	extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
d19ad077	355	struct ftrace_ops ops, struct ftrace_regs fregs);
ae6aa16f MH	356	extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
	357	#endif
	358
f7f242ff	359	int arch_check_ftrace_location(struct kprobe *p);
afd66255	360
d217d545	361	/* Get the kprobe at this addr (if any) - called with preemption disabled */
1da177e4 LT	362	struct kprobe get_kprobe(void addr);
1da177e4 LT	363
e6584523 AM	364	/* kprobe_running() will just return the current_kprobe on this CPU */
	365	static inline struct kprobe *kprobe_running(void)
	366	{
b76834bc	367	return (__this_cpu_read(current_kprobe));
e6584523 AM	368	}
	369
	370	static inline void reset_current_kprobe(void)
	371	{
b76834bc	372	__this_cpu_write(current_kprobe, NULL);
e6584523 AM	373	}
	374
	375	static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
	376	{
bdffd893	377	return this_cpu_ptr(&kprobe_ctlblk);
e6584523 AM	378	}
e6584523 AM	379
290e3070	380	kprobe_opcode_t kprobe_lookup_name(const char name, unsigned int offset);
1da177e4 LT	381	int register_kprobe(struct kprobe *p);
1da177e4 LT	382	void unregister_kprobe(struct kprobe *p);
9861668f MH	383	int register_kprobes(struct kprobe **kps, int num);
9861668f MH	384	void unregister_kprobes(struct kprobe **kps, int num);
3d7e3382	385	unsigned long arch_deref_entry_point(void *);
1da177e4	386
b94cce92 HN	387	int register_kretprobe(struct kretprobe *rp);
b94cce92 HN	388	void unregister_kretprobe(struct kretprobe *rp);
4a296e07 MH	389	int register_kretprobes(struct kretprobe **rps, int num);
4a296e07 MH	390	void unregister_kretprobes(struct kretprobe **rps, int num);
b94cce92	391
b94cce92	392	void kprobe_flush_task(struct task_struct *tk);
8c1c9356	393
82d083ab MH	394	void kprobe_free_init_mem(void);
82d083ab MH	395
de5bd88d MH	396	int disable_kprobe(struct kprobe *kp);
	397	int enable_kprobe(struct kprobe *kp);
	398
24851d24 FW	399	void dump_kprobe(struct kprobe *kp);
24851d24 FW	400
ad3bc25a	401	void *alloc_insn_page(void);
ad3bc25a	402
7ee3e97e CL	403	void *alloc_optinsn_page(void);
	404	void free_optinsn_page(void *page);
	405
d002b8bc AH	406	int kprobe_get_kallsym(unsigned int symnum, unsigned long value, char type,
	407	char *sym);
	408
	409	int arch_kprobe_get_kallsym(unsigned int symnum, unsigned long value,
	410	char type, char sym);
b1801812	411	#else /* !CONFIG_KPROBES: */
00d7c05a	412
b1801812 IM	413	static inline int kprobes_built_in(void)
	414	{
	415	return 0;
	416	}
	417	static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
	418	{
	419	return 0;
	420	}
785656a4 AS	421	static inline struct kprobe get_kprobe(void addr)
	422	{
	423	return NULL;
	424	}
e6584523	425	static inline struct kprobe *kprobe_running(void)
1da177e4	426	{
e6584523	427	return NULL;
1da177e4 LT	428	}
	429	static inline int register_kprobe(struct kprobe *p)
	430	{
	431	return -ENOSYS;
	432	}
9861668f MH	433	static inline int register_kprobes(struct kprobe **kps, int num)
	434	{
	435	return -ENOSYS;
	436	}
1da177e4 LT	437	static inline void unregister_kprobe(struct kprobe *p)
	438	{
	439	}
9861668f MH	440	static inline void unregister_kprobes(struct kprobe **kps, int num)
	441	{
	442	}
b94cce92 HN	443	static inline int register_kretprobe(struct kretprobe *rp)
	444	{
	445	return -ENOSYS;
	446	}
4a296e07 MH	447	static inline int register_kretprobes(struct kretprobe **rps, int num)
	448	{
	449	return -ENOSYS;
	450	}
b94cce92 HN	451	static inline void unregister_kretprobe(struct kretprobe *rp)
	452	{
	453	}
4a296e07 MH	454	static inline void unregister_kretprobes(struct kretprobe **rps, int num)
	455	{
	456	}
b94cce92 HN	457	static inline void kprobe_flush_task(struct task_struct *tk)
	458	{
	459	}
82d083ab MH	460	static inline void kprobe_free_init_mem(void)
	461	{
	462	}
de5bd88d MH	463	static inline int disable_kprobe(struct kprobe *kp)
	464	{
	465	return -ENOSYS;
	466	}
	467	static inline int enable_kprobe(struct kprobe *kp)
	468	{
	469	return -ENOSYS;
	470	}
fab94075 BP	471
	472	static inline bool within_kprobe_blacklist(unsigned long addr)
	473	{
	474	return true;
	475	}
d002b8bc AH	476	static inline int kprobe_get_kallsym(unsigned int symnum, unsigned long *value,
	477	char type, char sym)
	478	{
	479	return -ERANGE;
	480	}
b1801812	481	#endif /* CONFIG_KPROBES */
8f9b1528 MH	482	static inline int disable_kretprobe(struct kretprobe *rp)
	483	{
	484	return disable_kprobe(&rp->kp);
	485	}
	486	static inline int enable_kretprobe(struct kretprobe *rp)
	487	{
	488	return enable_kprobe(&rp->kp);
	489	}
8f9b1528	490
5b485629 MH	491	#ifndef CONFIG_KPROBES
	492	static inline bool is_kprobe_insn_slot(unsigned long addr)
	493	{
	494	return false;
	495	}
	496	#endif
	497	#ifndef CONFIG_OPTPROBES
	498	static inline bool is_kprobe_optinsn_slot(unsigned long addr)
	499	{
	500	return false;
	501	}
	502	#endif
	503
b98cca44 AK	504	/* Returns true if kprobes handled the fault */
	505	static nokprobe_inline bool kprobe_page_fault(struct pt_regs *regs,
	506	unsigned int trap)
	507	{
	508	if (!kprobes_built_in())
	509	return false;
	510	if (user_mode(regs))
	511	return false;
	512	/*
	513	* To be potentially processing a kprobe fault and to be allowed
	514	* to call kprobe_running(), we have to be non-preemptible.
	515	*/
	516	if (preemptible())
	517	return false;
	518	if (!kprobe_running())
	519	return false;
	520	return kprobe_fault_handler(regs, trap);
	521	}
	522
b1801812	523	#endif /* _LINUX_KPROBES_H */