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#include <linux/percpu.h>
37#include <linux/spinlock.h>
38#include <linux/rcupdate.h>
39
40#include <asm/kprobes.h>
41
42/* kprobe_status settings */
43#define KPROBE_HIT_ACTIVE 0x00000001
44#define KPROBE_HIT_SS 0x00000002
45#define KPROBE_REENTER 0x00000004
46#define KPROBE_HIT_SSDONE 0x00000008
47
48/* Attach to insert probes on any functions which should be ignored*/
49#define __kprobes __attribute__((__section__(".kprobes.text")))
50
51struct kprobe;
52struct pt_regs;
53struct kretprobe;
54struct kretprobe_instance;
55typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
56typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
57typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
58 unsigned long flags);
59typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
60 int trapnr);
61typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
62 struct pt_regs *);
63
64struct kprobe {
65 struct hlist_node hlist;
66
67 /* list of kprobes for multi-handler support */
68 struct list_head list;
69
70 /*count the number of times this probe was temporarily disarmed */
71 unsigned long nmissed;
72
73 /* location of the probe point */
74 kprobe_opcode_t *addr;
75
76 /* Called before addr is executed. */
77 kprobe_pre_handler_t pre_handler;
78
79 /* Called after addr is executed, unless... */
80 kprobe_post_handler_t post_handler;
81
82 /* ... called if executing addr causes a fault (eg. page fault).
83 * Return 1 if it handled fault, otherwise kernel will see it. */
84 kprobe_fault_handler_t fault_handler;
85
86 /* ... called if breakpoint trap occurs in probe handler.
87 * Return 1 if it handled break, otherwise kernel will see it. */
88 kprobe_break_handler_t break_handler;
89
90 /* Saved opcode (which has been replaced with breakpoint) */
91 kprobe_opcode_t opcode;
92
93 /* copy of the original instruction */
94 struct arch_specific_insn ainsn;
95};
96
97/*
98 * Special probe type that uses setjmp-longjmp type tricks to resume
99 * execution at a specified entry with a matching prototype corresponding
100 * to the probed function - a trick to enable arguments to become
101 * accessible seamlessly by probe handling logic.
102 * Note:
103 * Because of the way compilers allocate stack space for local variables
104 * etc upfront, regardless of sub-scopes within a function, this mirroring
105 * principle currently works only for probes placed on function entry points.
106 */
107struct jprobe {
108 struct kprobe kp;
109 kprobe_opcode_t *entry; /* probe handling code to jump to */
110};
111
112DECLARE_PER_CPU(struct kprobe *, current_kprobe);
113DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
114
115#ifdef ARCH_SUPPORTS_KRETPROBES
116extern void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs);
117#else /* ARCH_SUPPORTS_KRETPROBES */
118static inline void arch_prepare_kretprobe(struct kretprobe *rp,
119 struct pt_regs *regs)
120{
121}
122#endif /* ARCH_SUPPORTS_KRETPROBES */
123/*
124 * Function-return probe -
125 * Note:
126 * User needs to provide a handler function, and initialize maxactive.
127 * maxactive - The maximum number of instances of the probed function that
128 * can be active concurrently.
129 * nmissed - tracks the number of times the probed function's return was
130 * ignored, due to maxactive being too low.
131 *
132 */
133struct kretprobe {
134 struct kprobe kp;
135 kretprobe_handler_t handler;
136 int maxactive;
137 int nmissed;
138 struct hlist_head free_instances;
139 struct hlist_head used_instances;
140};
141
142struct kretprobe_instance {
143 struct hlist_node uflist; /* either on free list or used list */
144 struct hlist_node hlist;
145 struct kretprobe *rp;
146 kprobe_opcode_t *ret_addr;
147 struct task_struct *task;
148};
149
150#ifdef CONFIG_KPROBES
151extern spinlock_t kretprobe_lock;
152extern int arch_prepare_kprobe(struct kprobe *p);
153extern void arch_copy_kprobe(struct kprobe *p);
154extern void arch_arm_kprobe(struct kprobe *p);
155extern void arch_disarm_kprobe(struct kprobe *p);
156extern void arch_remove_kprobe(struct kprobe *p);
157extern int arch_init_kprobes(void);
158extern void show_registers(struct pt_regs *regs);
159extern kprobe_opcode_t *get_insn_slot(void);
160extern void free_insn_slot(kprobe_opcode_t *slot);
161
162/* Get the kprobe at this addr (if any) - called with preemption disabled */
163struct kprobe *get_kprobe(void *addr);
164struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
165
166/* kprobe_running() will just return the current_kprobe on this CPU */
167static inline struct kprobe *kprobe_running(void)
168{
169 return (__get_cpu_var(current_kprobe));
170}
171
172static inline void reset_current_kprobe(void)
173{
174 __get_cpu_var(current_kprobe) = NULL;
175}
176
177static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
178{
179 return (&__get_cpu_var(kprobe_ctlblk));
180}
181
182int register_kprobe(struct kprobe *p);
183void unregister_kprobe(struct kprobe *p);
184int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
185int longjmp_break_handler(struct kprobe *, struct pt_regs *);
186int register_jprobe(struct jprobe *p);
187void unregister_jprobe(struct jprobe *p);
188void jprobe_return(void);
189
190int register_kretprobe(struct kretprobe *rp);
191void unregister_kretprobe(struct kretprobe *rp);
192
193struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp);
194void add_rp_inst(struct kretprobe_instance *ri);
195void kprobe_flush_task(struct task_struct *tk);
196void recycle_rp_inst(struct kretprobe_instance *ri);
197#else /* CONFIG_KPROBES */
198static inline struct kprobe *kprobe_running(void)
199{
200 return NULL;
201}
202static inline int register_kprobe(struct kprobe *p)
203{
204 return -ENOSYS;
205}
206static inline void unregister_kprobe(struct kprobe *p)
207{
208}
209static inline int register_jprobe(struct jprobe *p)
210{
211 return -ENOSYS;
212}
213static inline void unregister_jprobe(struct jprobe *p)
214{
215}
216static inline void jprobe_return(void)
217{
218}
219static inline int register_kretprobe(struct kretprobe *rp)
220{
221 return -ENOSYS;
222}
223static inline void unregister_kretprobe(struct kretprobe *rp)
224{
225}
226static inline void kprobe_flush_task(struct task_struct *tk)
227{
228}
229#endif /* CONFIG_KPROBES */
230#endif /* _LINUX_KPROBES_H */