[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 (*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;

	/* 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;

	/*
	 * ... 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;

	/* 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 free_insn_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 *,
	56	unsigned long flags);
	57	typedef int (kprobe_fault_handler_t) (struct kprobe , struct pt_regs *,
	58	int trapnr);
b94cce92 HN	59	typedef int (kretprobe_handler_t) (struct kretprobe_instance ,
	60	struct pt_regs *);
	61
1da177e4 LT	62	struct kprobe {
	63	struct hlist_node hlist;
	64
64f562c6 AM	65	/* list of kprobes for multi-handler support */
	66	struct list_head list;
	67
ea32c65c PP	68	/count the number of times this probe was temporarily disarmed /
	69	unsigned long nmissed;
	70
1da177e4 LT	71	/* location of the probe point */
	72	kprobe_opcode_t *addr;
	73
3a872d89	74	/* Allow user to indicate symbol name of the probe point */
9b3af29b	75	const char *symbol_name;
3a872d89 AM	76
	77	/* Offset into the symbol */
	78	unsigned int offset;
	79
1da177e4 LT	80	/* Called before addr is executed. */
	81	kprobe_pre_handler_t pre_handler;
	82
	83	/* Called after addr is executed, unless... */
	84	kprobe_post_handler_t post_handler;
	85
cc00e9cf MH	86	/*
	87	* ... called if executing addr causes a fault (eg. page fault).
	88	* Return 1 if it handled fault, otherwise kernel will see it.
	89	*/
1da177e4 LT	90	kprobe_fault_handler_t fault_handler;
1da177e4 LT	91
1da177e4 LT	92	/* Saved opcode (which has been replaced with breakpoint) */
	93	kprobe_opcode_t opcode;
	94
	95	/* copy of the original instruction */
	96	struct arch_specific_insn ainsn;
e8386a0c	97
de5bd88d MH	98	/*
	99	* Indicates various status flags.
	100	* Protected by kprobe_mutex after this kprobe is registered.
	101	*/
e8386a0c	102	u32 flags;
1da177e4 LT	103	};
1da177e4 LT	104
e8386a0c MH	105	/* Kprobe status flags */
e8386a0c MH	106	#define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
de5bd88d	107	#define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
afd66255 MH	108	#define KPROBE_FLAG_OPTIMIZED 4 /*
	109	* probe is really optimized.
	110	* NOTE:
	111	* this flag is only for optimized_kprobe.
	112	*/
ae6aa16f	113	#define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */
e8386a0c	114
de5bd88d	115	/* Has this kprobe gone ? */
e8386a0c MH	116	static inline int kprobe_gone(struct kprobe *p)
	117	{
	118	return p->flags & KPROBE_FLAG_GONE;
	119	}
	120
de5bd88d MH	121	/* Is this kprobe disabled ? */
	122	static inline int kprobe_disabled(struct kprobe *p)
	123	{
	124	return p->flags & (KPROBE_FLAG_DISABLED \| KPROBE_FLAG_GONE);
	125	}
afd66255 MH	126
	127	/* Is this kprobe really running optimized path ? */
	128	static inline int kprobe_optimized(struct kprobe *p)
	129	{
	130	return p->flags & KPROBE_FLAG_OPTIMIZED;
	131	}
ae6aa16f MH	132
	133	/* Is this kprobe uses ftrace ? */
	134	static inline int kprobe_ftrace(struct kprobe *p)
	135	{
	136	return p->flags & KPROBE_FLAG_FTRACE;
	137	}
	138
b94cce92 HN	139	/*
	140	* Function-return probe -
	141	* Note:
	142	* User needs to provide a handler function, and initialize maxactive.
	143	* maxactive - The maximum number of instances of the probed function that
	144	* can be active concurrently.
	145	* nmissed - tracks the number of times the probed function's return was
	146	* ignored, due to maxactive being too low.
	147	*
	148	*/
d741bf41 PZ	149	struct kretprobe_holder {
	150	struct kretprobe *rp;
	151	refcount_t ref;
	152	};
	153
b94cce92 HN	154	struct kretprobe {
	155	struct kprobe kp;
	156	kretprobe_handler_t handler;
f47cd9b5	157	kretprobe_handler_t entry_handler;
b94cce92 HN	158	int maxactive;
b94cce92 HN	159	int nmissed;
f47cd9b5	160	size_t data_size;
6e426e0f	161	struct freelist_head freelist;
d741bf41	162	struct kretprobe_holder *rph;
b94cce92 HN	163	};
	164
	165	struct kretprobe_instance {
b3388178	166	union {
6e426e0f	167	struct freelist_node freelist;
b3388178 MH	168	struct rcu_head rcu;
b3388178 MH	169	};
6e426e0f	170	struct llist_node llist;
d741bf41	171	struct kretprobe_holder *rph;
802eae7c	172	kprobe_opcode_t *ret_addr;
3ff9c075	173	void *fp;
67a862a9	174	char data[];
b94cce92 HN	175	};
b94cce92 HN	176
f438d914 MH	177	struct kretprobe_blackpoint {
	178	const char *name;
	179	void *addr;
	180	};
3d8d996e	181
376e2424 MH	182	struct kprobe_blacklist_entry {
376e2424 MH	183	struct list_head list;
3d8d996e	184	unsigned long start_addr;
376e2424	185	unsigned long end_addr;
3d8d996e SD	186	};
3d8d996e SD	187
dc19835d MH	188	#ifdef CONFIG_KPROBES
	189	DECLARE_PER_CPU(struct kprobe *, current_kprobe);
	190	DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
	191
b1801812 IM	192	/*
	193	* For #ifdef avoidance:
	194	*/
	195	static inline int kprobes_built_in(void)
	196	{
	197	return 1;
	198	}
	199
66ada2cc MH	200	extern void kprobe_busy_begin(void);
	201	extern void kprobe_busy_end(void);
	202
dc19835d MH	203	#ifdef CONFIG_KRETPROBES
	204	extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
	205	struct pt_regs *regs);
	206	extern int arch_trampoline_kprobe(struct kprobe *p);
66ada2cc MH	207
	208	/* If the trampoline handler called from a kprobe, use this version */
	209	unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs,
	210	void *trampoline_address,
	211	void *frame_pointer);
	212
	213	static nokprobe_inline
	214	unsigned long kretprobe_trampoline_handler(struct pt_regs *regs,
	215	void *trampoline_address,
	216	void *frame_pointer)
	217	{
	218	unsigned long ret;
	219	/*
	220	* Set a dummy kprobe for avoiding kretprobe recursion.
	221	* Since kretprobe never runs in kprobe handler, no kprobe must
	222	* be running at this point.
	223	*/
	224	kprobe_busy_begin();
	225	ret = __kretprobe_trampoline_handler(regs, trampoline_address, frame_pointer);
	226	kprobe_busy_end();
	227
	228	return ret;
	229	}
	230
d741bf41 PZ	231	static nokprobe_inline struct kretprobe get_kretprobe(struct kretprobe_instance ri)
	232	{
	233	RCU_LOCKDEP_WARN(!rcu_read_lock_any_held(),
	234	"Kretprobe is accessed from instance under preemptive context");
	235
	236	return READ_ONCE(ri->rph->rp);
	237	}
	238
dc19835d MH	239	#else /* CONFIG_KRETPROBES */
	240	static inline void arch_prepare_kretprobe(struct kretprobe *rp,
	241	struct pt_regs *regs)
	242	{
	243	}
	244	static inline int arch_trampoline_kprobe(struct kprobe *p)
	245	{
	246	return 0;
	247	}
	248	#endif /* CONFIG_KRETPROBES */
	249
f438d914 MH	250	extern struct kretprobe_blackpoint kretprobe_blacklist[];
f438d914 MH	251
8c1c9356 AM	252	#ifdef CONFIG_KPROBES_SANITY_TEST
	253	extern int init_test_probes(void);
	254	#else
	255	static inline int init_test_probes(void)
	256	{
	257	return 0;
	258	}
	259	#endif /* CONFIG_KPROBES_SANITY_TEST */
	260
1da177e4	261	extern int arch_prepare_kprobe(struct kprobe *p);
7e1048b1 RL	262	extern void arch_arm_kprobe(struct kprobe *p);
7e1048b1 RL	263	extern void arch_disarm_kprobe(struct kprobe *p);
6772926b	264	extern int arch_init_kprobes(void);
bf8d5c52	265	extern void kprobes_inc_nmissed_count(struct kprobe *p);
be8f2743	266	extern bool arch_within_kprobe_blacklist(unsigned long addr);
fb1a59fa	267	extern int arch_populate_kprobe_blacklist(void);
659b957f	268	extern bool arch_kprobe_on_func_entry(unsigned long offset);
97c753e6	269	extern int kprobe_on_func_entry(kprobe_opcode_t addr, const char sym, unsigned long offset);
1da177e4	270
e5779e8e	271	extern bool within_kprobe_blacklist(unsigned long addr);
fb1a59fa MH	272	extern int kprobe_add_ksym_blacklist(unsigned long entry);
fb1a59fa MH	273	extern int kprobe_add_area_blacklist(unsigned long start, unsigned long end);
e5779e8e	274
c802d64a HC	275	struct kprobe_insn_cache {
c802d64a HC	276	struct mutex mutex;
af96397d HC	277	void (alloc)(void); /* allocate insn page */
af96397d HC	278	void (free)(void ); /* free insn page */
d002b8bc	279	const char sym; / symbol for insn pages */
c802d64a HC	280	struct list_head pages; /* list of kprobe_insn_page */
	281	size_t insn_size; /* size of instruction slot */
	282	int nr_garbage;
	283	};
	284
5b485629	285	#ifdef __ARCH_WANT_KPROBES_INSN_SLOT
c802d64a HC	286	extern kprobe_opcode_t __get_insn_slot(struct kprobe_insn_cache c);
	287	extern void __free_insn_slot(struct kprobe_insn_cache *c,
	288	kprobe_opcode_t *slot, int dirty);
5b485629 MH	289	/* sleep-less address checking routine */
	290	extern bool __is_insn_slot_addr(struct kprobe_insn_cache *c,
	291	unsigned long addr);
c802d64a HC	292
	293	#define DEFINE_INSN_CACHE_OPS(__name) \
	294	extern struct kprobe_insn_cache kprobe_##__name##_slots; \
	295	\
	296	static inline kprobe_opcode_t *get_##__name##_slot(void) \
	297	{ \
	298	return __get_insn_slot(&kprobe_##__name##_slots); \
	299	} \
	300	\
	301	static inline void free_##__name##_slot(kprobe_opcode_t *slot, int dirty)\
	302	{ \
	303	__free_insn_slot(&kprobe_##__name##_slots, slot, dirty); \
	304	} \
5b485629 MH	305	\
	306	static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
	307	{ \
	308	return __is_insn_slot_addr(&kprobe_##__name##_slots, addr); \
	309	}
d002b8bc AH	310	#define KPROBE_INSN_PAGE_SYM "kprobe_insn_page"
	311	#define KPROBE_OPTINSN_PAGE_SYM "kprobe_optinsn_page"
	312	int kprobe_cache_get_kallsym(struct kprobe_insn_cache c, unsigned int symnum,
	313	unsigned long value, char type, char *sym);
5b485629 MH	314	#else /* __ARCH_WANT_KPROBES_INSN_SLOT */
	315	#define DEFINE_INSN_CACHE_OPS(__name) \
	316	static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
	317	{ \
	318	return 0; \
	319	}
	320	#endif
c802d64a HC	321
	322	DEFINE_INSN_CACHE_OPS(insn);
	323
afd66255 MH	324	#ifdef CONFIG_OPTPROBES
	325	/*
	326	* Internal structure for direct jump optimized probe
	327	*/
	328	struct optimized_kprobe {
	329	struct kprobe kp;
	330	struct list_head list; /* list for optimizing queue */
	331	struct arch_optimized_insn optinsn;
	332	};
	333
	334	/* Architecture dependent functions for direct jump optimization */
	335	extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
	336	extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
cbf6ab52 MH	337	extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op,
cbf6ab52 MH	338	struct kprobe *orig);
afd66255	339	extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
cd7ebe22	340	extern void arch_optimize_kprobes(struct list_head *oplist);
f984ba4e MH	341	extern void arch_unoptimize_kprobes(struct list_head *oplist,
f984ba4e MH	342	struct list_head *done_list);
afd66255	343	extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
afd66255 MH	344	extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
	345	unsigned long addr);
	346
	347	extern void opt_pre_handler(struct kprobe p, struct pt_regs regs);
b2be84df	348
c802d64a HC	349	DEFINE_INSN_CACHE_OPS(optinsn);
c802d64a HC	350
b2be84df MH	351	#ifdef CONFIG_SYSCTL
	352	extern int sysctl_kprobes_optimization;
	353	extern int proc_kprobes_optimization_handler(struct ctl_table *table,
32927393	354	int write, void *buffer,
b2be84df MH	355	size_t length, loff_t ppos);
b2be84df MH	356	#endif
30e7d894 TG	357	extern void wait_for_kprobe_optimizer(void);
	358	#else
	359	static inline void wait_for_kprobe_optimizer(void) { }
afd66255	360	#endif /* CONFIG_OPTPROBES */
e7dbfe34	361	#ifdef CONFIG_KPROBES_ON_FTRACE
ae6aa16f	362	extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
d19ad077	363	struct ftrace_ops ops, struct ftrace_regs fregs);
ae6aa16f MH	364	extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
	365	#endif
	366
f7f242ff	367	int arch_check_ftrace_location(struct kprobe *p);
afd66255	368
d217d545	369	/* Get the kprobe at this addr (if any) - called with preemption disabled */
1da177e4 LT	370	struct kprobe get_kprobe(void addr);
1da177e4 LT	371
e6584523 AM	372	/* kprobe_running() will just return the current_kprobe on this CPU */
	373	static inline struct kprobe *kprobe_running(void)
	374	{
b76834bc	375	return (__this_cpu_read(current_kprobe));
e6584523 AM	376	}
	377
	378	static inline void reset_current_kprobe(void)
	379	{
b76834bc	380	__this_cpu_write(current_kprobe, NULL);
e6584523 AM	381	}
	382
	383	static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
	384	{
bdffd893	385	return this_cpu_ptr(&kprobe_ctlblk);
e6584523 AM	386	}
e6584523 AM	387
290e3070	388	kprobe_opcode_t kprobe_lookup_name(const char name, unsigned int offset);
1da177e4 LT	389	int register_kprobe(struct kprobe *p);
1da177e4 LT	390	void unregister_kprobe(struct kprobe *p);
9861668f MH	391	int register_kprobes(struct kprobe **kps, int num);
9861668f MH	392	void unregister_kprobes(struct kprobe **kps, int num);
3d7e3382	393	unsigned long arch_deref_entry_point(void *);
1da177e4	394
b94cce92 HN	395	int register_kretprobe(struct kretprobe *rp);
b94cce92 HN	396	void unregister_kretprobe(struct kretprobe *rp);
4a296e07 MH	397	int register_kretprobes(struct kretprobe **rps, int num);
4a296e07 MH	398	void unregister_kretprobes(struct kretprobe **rps, int num);
b94cce92	399
b94cce92	400	void kprobe_flush_task(struct task_struct *tk);
8c1c9356	401
82d083ab MH	402	void kprobe_free_init_mem(void);
82d083ab MH	403
de5bd88d MH	404	int disable_kprobe(struct kprobe *kp);
	405	int enable_kprobe(struct kprobe *kp);
	406
24851d24 FW	407	void dump_kprobe(struct kprobe *kp);
24851d24 FW	408
ad3bc25a BP	409	void *alloc_insn_page(void);
	410	void free_insn_page(void *page);
	411
d002b8bc AH	412	int kprobe_get_kallsym(unsigned int symnum, unsigned long value, char type,
	413	char *sym);
	414
	415	int arch_kprobe_get_kallsym(unsigned int symnum, unsigned long value,
	416	char type, char sym);
b1801812	417	#else /* !CONFIG_KPROBES: */
00d7c05a	418
b1801812 IM	419	static inline int kprobes_built_in(void)
	420	{
	421	return 0;
	422	}
	423	static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
	424	{
	425	return 0;
	426	}
785656a4 AS	427	static inline struct kprobe get_kprobe(void addr)
	428	{
	429	return NULL;
	430	}
e6584523	431	static inline struct kprobe *kprobe_running(void)
1da177e4	432	{
e6584523	433	return NULL;
1da177e4 LT	434	}
	435	static inline int register_kprobe(struct kprobe *p)
	436	{
	437	return -ENOSYS;
	438	}
9861668f MH	439	static inline int register_kprobes(struct kprobe **kps, int num)
	440	{
	441	return -ENOSYS;
	442	}
1da177e4 LT	443	static inline void unregister_kprobe(struct kprobe *p)
	444	{
	445	}
9861668f MH	446	static inline void unregister_kprobes(struct kprobe **kps, int num)
	447	{
	448	}
b94cce92 HN	449	static inline int register_kretprobe(struct kretprobe *rp)
	450	{
	451	return -ENOSYS;
	452	}
4a296e07 MH	453	static inline int register_kretprobes(struct kretprobe **rps, int num)
	454	{
	455	return -ENOSYS;
	456	}
b94cce92 HN	457	static inline void unregister_kretprobe(struct kretprobe *rp)
	458	{
	459	}
4a296e07 MH	460	static inline void unregister_kretprobes(struct kretprobe **rps, int num)
	461	{
	462	}
b94cce92 HN	463	static inline void kprobe_flush_task(struct task_struct *tk)
	464	{
	465	}
82d083ab MH	466	static inline void kprobe_free_init_mem(void)
	467	{
	468	}
de5bd88d MH	469	static inline int disable_kprobe(struct kprobe *kp)
	470	{
	471	return -ENOSYS;
	472	}
	473	static inline int enable_kprobe(struct kprobe *kp)
	474	{
	475	return -ENOSYS;
	476	}
fab94075 BP	477
	478	static inline bool within_kprobe_blacklist(unsigned long addr)
	479	{
	480	return true;
	481	}
d002b8bc AH	482	static inline int kprobe_get_kallsym(unsigned int symnum, unsigned long *value,
	483	char type, char sym)
	484	{
	485	return -ERANGE;
	486	}
b1801812	487	#endif /* CONFIG_KPROBES */
8f9b1528 MH	488	static inline int disable_kretprobe(struct kretprobe *rp)
	489	{
	490	return disable_kprobe(&rp->kp);
	491	}
	492	static inline int enable_kretprobe(struct kretprobe *rp)
	493	{
	494	return enable_kprobe(&rp->kp);
	495	}
8f9b1528	496
5b485629 MH	497	#ifndef CONFIG_KPROBES
	498	static inline bool is_kprobe_insn_slot(unsigned long addr)
	499	{
	500	return false;
	501	}
	502	#endif
	503	#ifndef CONFIG_OPTPROBES
	504	static inline bool is_kprobe_optinsn_slot(unsigned long addr)
	505	{
	506	return false;
	507	}
	508	#endif
	509
b98cca44 AK	510	/* Returns true if kprobes handled the fault */
	511	static nokprobe_inline bool kprobe_page_fault(struct pt_regs *regs,
	512	unsigned int trap)
	513	{
	514	if (!kprobes_built_in())
	515	return false;
	516	if (user_mode(regs))
	517	return false;
	518	/*
	519	* To be potentially processing a kprobe fault and to be allowed
	520	* to call kprobe_running(), we have to be non-preemptible.
	521	*/
	522	if (preemptible())
	523	return false;
	524	if (!kprobe_running())
	525	return false;
	526	return kprobe_fault_handler(regs, trap);
	527	}
	528
b1801812	529	#endif /* _LINUX_KPROBES_H */