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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#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.
Hien Nguyenb94cce92005-06-23 00:09:19 -070028 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <linux/list.h>
33#include <linux/notifier.h>
34#include <linux/smp.h>
Ananth N Mavinakayanahallie6584522005-11-07 01:00:07 -080035#include <linux/percpu.h>
Ananth N Mavinakayanahalli3516a462005-11-07 01:00:13 -080036#include <linux/spinlock.h>
37#include <linux/rcupdate.h>
Ingo Molnar7a7d1cf2006-03-23 03:00:35 -080038#include <linux/mutex.h>
Hien Nguyenb94cce92005-06-23 00:09:19 -070039
Keshavamurthy Anil S00d7c052005-12-12 00:37:33 -080040#ifdef CONFIG_KPROBES
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include <asm/kprobes.h>
42
Prasanna S Panchamukhiea32c652005-06-23 00:09:36 -070043/* kprobe_status settings */
44#define KPROBE_HIT_ACTIVE 0x00000001
45#define KPROBE_HIT_SS 0x00000002
46#define KPROBE_REENTER 0x00000004
47#define KPROBE_HIT_SSDONE 0x00000008
48
Prasanna S Panchamukhid0aaff92005-09-06 15:19:26 -070049/* Attach to insert probes on any functions which should be ignored*/
50#define __kprobes __attribute__((__section__(".kprobes.text")))
51
Linus Torvalds1da177e2005-04-16 15:20:36 -070052struct kprobe;
53struct pt_regs;
Hien Nguyenb94cce92005-06-23 00:09:19 -070054struct kretprobe;
55struct kretprobe_instance;
Linus Torvalds1da177e2005-04-16 15:20:36 -070056typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
57typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
58typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
59 unsigned long flags);
60typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
61 int trapnr);
Hien Nguyenb94cce92005-06-23 00:09:19 -070062typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
63 struct pt_regs *);
64
Linus Torvalds1da177e2005-04-16 15:20:36 -070065struct kprobe {
66 struct hlist_node hlist;
67
Ananth N Mavinakayanahalli64f562c2005-05-05 16:15:42 -070068 /* list of kprobes for multi-handler support */
69 struct list_head list;
70
Keshavamurthy Anil Sdf019b12006-01-11 12:17:41 -080071 /* Indicates that the corresponding module has been ref counted */
72 unsigned int mod_refcounted;
73
Prasanna S Panchamukhiea32c652005-06-23 00:09:36 -070074 /*count the number of times this probe was temporarily disarmed */
75 unsigned long nmissed;
76
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 /* location of the probe point */
78 kprobe_opcode_t *addr;
79
Ananth N Mavinakayanahalli3a872d82006-10-02 02:17:30 -070080 /* Allow user to indicate symbol name of the probe point */
81 char *symbol_name;
82
83 /* Offset into the symbol */
84 unsigned int offset;
85
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 /* Called before addr is executed. */
87 kprobe_pre_handler_t pre_handler;
88
89 /* Called after addr is executed, unless... */
90 kprobe_post_handler_t post_handler;
91
92 /* ... called if executing addr causes a fault (eg. page fault).
93 * Return 1 if it handled fault, otherwise kernel will see it. */
94 kprobe_fault_handler_t fault_handler;
95
96 /* ... called if breakpoint trap occurs in probe handler.
97 * Return 1 if it handled break, otherwise kernel will see it. */
98 kprobe_break_handler_t break_handler;
99
100 /* Saved opcode (which has been replaced with breakpoint) */
101 kprobe_opcode_t opcode;
102
103 /* copy of the original instruction */
104 struct arch_specific_insn ainsn;
105};
106
107/*
108 * Special probe type that uses setjmp-longjmp type tricks to resume
109 * execution at a specified entry with a matching prototype corresponding
110 * to the probed function - a trick to enable arguments to become
111 * accessible seamlessly by probe handling logic.
112 * Note:
113 * Because of the way compilers allocate stack space for local variables
114 * etc upfront, regardless of sub-scopes within a function, this mirroring
115 * principle currently works only for probes placed on function entry points.
116 */
117struct jprobe {
118 struct kprobe kp;
119 kprobe_opcode_t *entry; /* probe handling code to jump to */
120};
121
Ananth N Mavinakayanahallie6584522005-11-07 01:00:07 -0800122DECLARE_PER_CPU(struct kprobe *, current_kprobe);
123DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
124
Hien Nguyenb94cce92005-06-23 00:09:19 -0700125#ifdef ARCH_SUPPORTS_KRETPROBES
Hien Nguyenb94cce92005-06-23 00:09:19 -0700126extern void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs);
Hien Nguyenb94cce92005-06-23 00:09:19 -0700127#else /* ARCH_SUPPORTS_KRETPROBES */
Hien Nguyenb94cce92005-06-23 00:09:19 -0700128static inline void arch_prepare_kretprobe(struct kretprobe *rp,
129 struct pt_regs *regs)
130{
131}
Hien Nguyenb94cce92005-06-23 00:09:19 -0700132#endif /* ARCH_SUPPORTS_KRETPROBES */
133/*
134 * Function-return probe -
135 * Note:
136 * User needs to provide a handler function, and initialize maxactive.
137 * maxactive - The maximum number of instances of the probed function that
138 * can be active concurrently.
139 * nmissed - tracks the number of times the probed function's return was
140 * ignored, due to maxactive being too low.
141 *
142 */
143struct kretprobe {
144 struct kprobe kp;
145 kretprobe_handler_t handler;
146 int maxactive;
147 int nmissed;
148 struct hlist_head free_instances;
149 struct hlist_head used_instances;
150};
151
152struct kretprobe_instance {
153 struct hlist_node uflist; /* either on free list or used list */
154 struct hlist_node hlist;
155 struct kretprobe *rp;
Rusty Lynch802eae72005-06-27 15:17:08 -0700156 kprobe_opcode_t *ret_addr;
157 struct task_struct *task;
Hien Nguyenb94cce92005-06-23 00:09:19 -0700158};
159
Ananth N Mavinakayanahalli3516a462005-11-07 01:00:13 -0800160extern spinlock_t kretprobe_lock;
Ingo Molnar7a7d1cf2006-03-23 03:00:35 -0800161extern struct mutex kprobe_mutex;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162extern int arch_prepare_kprobe(struct kprobe *p);
Rusty Lynch7e1048b2005-06-23 00:09:25 -0700163extern void arch_arm_kprobe(struct kprobe *p);
164extern void arch_disarm_kprobe(struct kprobe *p);
Rusty Lynch67729262005-07-05 18:54:50 -0700165extern int arch_init_kprobes(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166extern void show_registers(struct pt_regs *regs);
Ananth N Mavinakayanahalli9ec4b1f2005-06-27 15:17:01 -0700167extern kprobe_opcode_t *get_insn_slot(void);
Masami Hiramatsub4c6c342006-12-06 20:38:11 -0800168extern void free_insn_slot(kprobe_opcode_t *slot, int dirty);
Keshavamurthy Anil Sbf8d5c52005-12-12 00:37:34 -0800169extern void kprobes_inc_nmissed_count(struct kprobe *p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Ananth N Mavinakayanahallid217d542005-11-07 01:00:14 -0800171/* Get the kprobe at this addr (if any) - called with preemption disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172struct kprobe *get_kprobe(void *addr);
Hien Nguyenb94cce92005-06-23 00:09:19 -0700173struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174
Ananth N Mavinakayanahallie6584522005-11-07 01:00:07 -0800175/* kprobe_running() will just return the current_kprobe on this CPU */
176static inline struct kprobe *kprobe_running(void)
177{
178 return (__get_cpu_var(current_kprobe));
179}
180
181static inline void reset_current_kprobe(void)
182{
183 __get_cpu_var(current_kprobe) = NULL;
184}
185
186static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
187{
188 return (&__get_cpu_var(kprobe_ctlblk));
189}
190
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191int register_kprobe(struct kprobe *p);
192void unregister_kprobe(struct kprobe *p);
193int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
194int longjmp_break_handler(struct kprobe *, struct pt_regs *);
195int register_jprobe(struct jprobe *p);
196void unregister_jprobe(struct jprobe *p);
197void jprobe_return(void);
198
Hien Nguyenb94cce92005-06-23 00:09:19 -0700199int register_kretprobe(struct kretprobe *rp);
200void unregister_kretprobe(struct kretprobe *rp);
201
202struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp);
Hien Nguyenb94cce92005-06-23 00:09:19 -0700203void add_rp_inst(struct kretprobe_instance *ri);
204void kprobe_flush_task(struct task_struct *tk);
bibo,mao99219a32006-10-02 02:17:35 -0700205void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
Hien Nguyenb94cce92005-06-23 00:09:19 -0700206#else /* CONFIG_KPROBES */
Keshavamurthy Anil S00d7c052005-12-12 00:37:33 -0800207
208#define __kprobes /**/
209struct jprobe;
210struct kretprobe;
211
Ananth N Mavinakayanahallie6584522005-11-07 01:00:07 -0800212static inline struct kprobe *kprobe_running(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213{
Ananth N Mavinakayanahallie6584522005-11-07 01:00:07 -0800214 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215}
216static inline int register_kprobe(struct kprobe *p)
217{
218 return -ENOSYS;
219}
220static inline void unregister_kprobe(struct kprobe *p)
221{
222}
223static inline int register_jprobe(struct jprobe *p)
224{
225 return -ENOSYS;
226}
227static inline void unregister_jprobe(struct jprobe *p)
228{
229}
230static inline void jprobe_return(void)
231{
232}
Hien Nguyenb94cce92005-06-23 00:09:19 -0700233static inline int register_kretprobe(struct kretprobe *rp)
234{
235 return -ENOSYS;
236}
237static inline void unregister_kretprobe(struct kretprobe *rp)
238{
239}
240static inline void kprobe_flush_task(struct task_struct *tk)
241{
242}
243#endif /* CONFIG_KPROBES */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244#endif /* _LINUX_KPROBES_H */