Linux kernel mirror (for testing)
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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.
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.
31 */
32#include <linux/config.h>
33#include <linux/list.h>
34#include <linux/notifier.h>
35#include <linux/smp.h>
36
37#include <asm/kprobes.h>
38
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
45struct kprobe;
46struct pt_regs;
47struct kretprobe;
48struct kretprobe_instance;
49typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
50typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
51typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
52 unsigned long flags);
53typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
54 int trapnr);
55typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
56 struct pt_regs *);
57
58struct kprobe {
59 struct hlist_node hlist;
60
61 /* list of kprobes for multi-handler support */
62 struct list_head list;
63
64 /*count the number of times this probe was temporarily disarmed */
65 unsigned long nmissed;
66
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 */
101struct jprobe {
102 struct kprobe kp;
103 kprobe_opcode_t *entry; /* probe handling code to jump to */
104};
105
106#ifdef ARCH_SUPPORTS_KRETPROBES
107extern void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs);
108#else /* ARCH_SUPPORTS_KRETPROBES */
109static inline void arch_prepare_kretprobe(struct kretprobe *rp,
110 struct pt_regs *regs)
111{
112}
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 */
124struct 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
133struct kretprobe_instance {
134 struct hlist_node uflist; /* either on free list or used list */
135 struct hlist_node hlist;
136 struct kretprobe *rp;
137 kprobe_opcode_t *ret_addr;
138 struct task_struct *task;
139};
140
141#ifdef CONFIG_KPROBES
142/* Locks kprobe: irq must be disabled */
143void lock_kprobes(void);
144void unlock_kprobes(void);
145
146/* kprobe running now on this CPU? */
147static inline int kprobe_running(void)
148{
149 extern unsigned int kprobe_cpu;
150 return kprobe_cpu == smp_processor_id();
151}
152
153extern int arch_prepare_kprobe(struct kprobe *p);
154extern void arch_copy_kprobe(struct kprobe *p);
155extern void arch_arm_kprobe(struct kprobe *p);
156extern void arch_disarm_kprobe(struct kprobe *p);
157extern void arch_remove_kprobe(struct kprobe *p);
158extern int arch_init_kprobes(void);
159extern void show_registers(struct pt_regs *regs);
160extern kprobe_opcode_t *get_insn_slot(void);
161extern void free_insn_slot(kprobe_opcode_t *slot);
162
163/* Get the kprobe at this addr (if any). Must have called lock_kprobes */
164struct kprobe *get_kprobe(void *addr);
165struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
166
167int register_kprobe(struct kprobe *p);
168void unregister_kprobe(struct kprobe *p);
169int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
170int longjmp_break_handler(struct kprobe *, struct pt_regs *);
171int register_jprobe(struct jprobe *p);
172void unregister_jprobe(struct jprobe *p);
173void jprobe_return(void);
174
175int register_kretprobe(struct kretprobe *rp);
176void unregister_kretprobe(struct kretprobe *rp);
177
178struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp);
179void add_rp_inst(struct kretprobe_instance *ri);
180void kprobe_flush_task(struct task_struct *tk);
181void recycle_rp_inst(struct kretprobe_instance *ri);
182#else /* CONFIG_KPROBES */
183static inline int kprobe_running(void)
184{
185 return 0;
186}
187static inline int register_kprobe(struct kprobe *p)
188{
189 return -ENOSYS;
190}
191static inline void unregister_kprobe(struct kprobe *p)
192{
193}
194static inline int register_jprobe(struct jprobe *p)
195{
196 return -ENOSYS;
197}
198static inline void unregister_jprobe(struct jprobe *p)
199{
200}
201static inline void jprobe_return(void)
202{
203}
204static inline int register_kretprobe(struct kretprobe *rp)
205{
206 return -ENOSYS;
207}
208static inline void unregister_kretprobe(struct kretprobe *rp)
209{
210}
211static inline void kprobe_flush_task(struct task_struct *tk)
212{
213}
214#endif /* CONFIG_KPROBES */
215#endif /* _LINUX_KPROBES_H */