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1da177e4
LT
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.
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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.
1da177e4 31 */
36dcd67a 32#include <linux/linkage.h>
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33#include <linux/list.h>
34#include <linux/notifier.h>
35#include <linux/smp.h>
e6584523 36#include <linux/percpu.h>
3516a460
AM
37#include <linux/spinlock.h>
38#include <linux/rcupdate.h>
7a7d1cf9 39#include <linux/mutex.h>
b94cce92 40
00d7c05a 41#ifdef CONFIG_KPROBES
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42#include <asm/kprobes.h>
43
ea32c65c
PP
44/* kprobe_status settings */
45#define KPROBE_HIT_ACTIVE 0x00000001
46#define KPROBE_HIT_SS 0x00000002
47#define KPROBE_REENTER 0x00000004
48#define KPROBE_HIT_SSDONE 0x00000008
49
d0aaff97 50/* Attach to insert probes on any functions which should be ignored*/
36dcd67a 51#define __kprobes __attribute__((__section__(".kprobes.text"))) notrace
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52#else /* CONFIG_KPROBES */
53typedef int kprobe_opcode_t;
54struct arch_specific_insn {
55 int dummy;
56};
57#define __kprobes notrace
58#endif /* CONFIG_KPROBES */
d0aaff97 59
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60struct kprobe;
61struct pt_regs;
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62struct kretprobe;
63struct kretprobe_instance;
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64typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
65typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
66typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
67 unsigned long flags);
68typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
69 int trapnr);
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70typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
71 struct pt_regs *);
72
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73struct kprobe {
74 struct hlist_node hlist;
75
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AM
76 /* list of kprobes for multi-handler support */
77 struct list_head list;
78
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PP
79 /*count the number of times this probe was temporarily disarmed */
80 unsigned long nmissed;
81
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82 /* location of the probe point */
83 kprobe_opcode_t *addr;
84
3a872d89 85 /* Allow user to indicate symbol name of the probe point */
9b3af29b 86 const char *symbol_name;
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87
88 /* Offset into the symbol */
89 unsigned int offset;
90
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91 /* Called before addr is executed. */
92 kprobe_pre_handler_t pre_handler;
93
94 /* Called after addr is executed, unless... */
95 kprobe_post_handler_t post_handler;
96
97 /* ... called if executing addr causes a fault (eg. page fault).
98 * Return 1 if it handled fault, otherwise kernel will see it. */
99 kprobe_fault_handler_t fault_handler;
100
101 /* ... called if breakpoint trap occurs in probe handler.
102 * Return 1 if it handled break, otherwise kernel will see it. */
103 kprobe_break_handler_t break_handler;
104
105 /* Saved opcode (which has been replaced with breakpoint) */
106 kprobe_opcode_t opcode;
107
108 /* copy of the original instruction */
109 struct arch_specific_insn ainsn;
e8386a0c
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110
111 /* Indicates various status flags. Protected by kprobe_mutex. */
112 u32 flags;
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113};
114
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115/* Kprobe status flags */
116#define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
117
118static inline int kprobe_gone(struct kprobe *p)
119{
120 return p->flags & KPROBE_FLAG_GONE;
121}
122
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123/*
124 * Special probe type that uses setjmp-longjmp type tricks to resume
125 * execution at a specified entry with a matching prototype corresponding
126 * to the probed function - a trick to enable arguments to become
127 * accessible seamlessly by probe handling logic.
128 * Note:
129 * Because of the way compilers allocate stack space for local variables
130 * etc upfront, regardless of sub-scopes within a function, this mirroring
131 * principle currently works only for probes placed on function entry points.
132 */
133struct jprobe {
134 struct kprobe kp;
81eae375 135 void *entry; /* probe handling code to jump to */
1da177e4
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136};
137
9e367d85
ME
138/* For backward compatibility with old code using JPROBE_ENTRY() */
139#define JPROBE_ENTRY(handler) (handler)
140
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141/*
142 * Function-return probe -
143 * Note:
144 * User needs to provide a handler function, and initialize maxactive.
145 * maxactive - The maximum number of instances of the probed function that
146 * can be active concurrently.
147 * nmissed - tracks the number of times the probed function's return was
148 * ignored, due to maxactive being too low.
149 *
150 */
151struct kretprobe {
152 struct kprobe kp;
153 kretprobe_handler_t handler;
f47cd9b5 154 kretprobe_handler_t entry_handler;
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155 int maxactive;
156 int nmissed;
f47cd9b5 157 size_t data_size;
b94cce92 158 struct hlist_head free_instances;
ef53d9c5 159 spinlock_t lock;
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160};
161
162struct kretprobe_instance {
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163 struct hlist_node hlist;
164 struct kretprobe *rp;
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165 kprobe_opcode_t *ret_addr;
166 struct task_struct *task;
f47cd9b5 167 char data[0];
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HN
168};
169
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MH
170struct kretprobe_blackpoint {
171 const char *name;
172 void *addr;
173};
3d8d996e
SD
174
175struct kprobe_blackpoint {
176 const char *name;
177 unsigned long start_addr;
178 unsigned long range;
179};
180
dc19835d
MH
181#ifdef CONFIG_KPROBES
182DECLARE_PER_CPU(struct kprobe *, current_kprobe);
183DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
184
b1801812
IM
185/*
186 * For #ifdef avoidance:
187 */
188static inline int kprobes_built_in(void)
189{
190 return 1;
191}
192
dc19835d
MH
193#ifdef CONFIG_KRETPROBES
194extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
195 struct pt_regs *regs);
196extern int arch_trampoline_kprobe(struct kprobe *p);
197#else /* CONFIG_KRETPROBES */
198static inline void arch_prepare_kretprobe(struct kretprobe *rp,
199 struct pt_regs *regs)
200{
201}
202static inline int arch_trampoline_kprobe(struct kprobe *p)
203{
204 return 0;
205}
206#endif /* CONFIG_KRETPROBES */
207
f438d914
MH
208extern struct kretprobe_blackpoint kretprobe_blacklist[];
209
0f95b7fc
AM
210static inline void kretprobe_assert(struct kretprobe_instance *ri,
211 unsigned long orig_ret_address, unsigned long trampoline_address)
212{
213 if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
214 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
215 ri->rp, ri->rp->kp.addr);
216 BUG();
217 }
218}
219
8c1c9356
AM
220#ifdef CONFIG_KPROBES_SANITY_TEST
221extern int init_test_probes(void);
222#else
223static inline int init_test_probes(void)
224{
225 return 0;
226}
227#endif /* CONFIG_KPROBES_SANITY_TEST */
228
1da177e4 229extern int arch_prepare_kprobe(struct kprobe *p);
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230extern void arch_arm_kprobe(struct kprobe *p);
231extern void arch_disarm_kprobe(struct kprobe *p);
6772926b 232extern int arch_init_kprobes(void);
1da177e4 233extern void show_registers(struct pt_regs *regs);
9ec4b1f3 234extern kprobe_opcode_t *get_insn_slot(void);
b4c6c34a 235extern void free_insn_slot(kprobe_opcode_t *slot, int dirty);
bf8d5c52 236extern void kprobes_inc_nmissed_count(struct kprobe *p);
1da177e4 237
d217d545 238/* Get the kprobe at this addr (if any) - called with preemption disabled */
1da177e4 239struct kprobe *get_kprobe(void *addr);
ef53d9c5
S
240void kretprobe_hash_lock(struct task_struct *tsk,
241 struct hlist_head **head, unsigned long *flags);
242void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
b94cce92 243struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
1da177e4 244
e6584523
AM
245/* kprobe_running() will just return the current_kprobe on this CPU */
246static inline struct kprobe *kprobe_running(void)
247{
248 return (__get_cpu_var(current_kprobe));
249}
250
251static inline void reset_current_kprobe(void)
252{
253 __get_cpu_var(current_kprobe) = NULL;
254}
255
256static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
257{
258 return (&__get_cpu_var(kprobe_ctlblk));
259}
260
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261int register_kprobe(struct kprobe *p);
262void unregister_kprobe(struct kprobe *p);
9861668f
MH
263int register_kprobes(struct kprobe **kps, int num);
264void unregister_kprobes(struct kprobe **kps, int num);
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LT
265int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
266int longjmp_break_handler(struct kprobe *, struct pt_regs *);
267int register_jprobe(struct jprobe *p);
268void unregister_jprobe(struct jprobe *p);
26b31c19
MH
269int register_jprobes(struct jprobe **jps, int num);
270void unregister_jprobes(struct jprobe **jps, int num);
1da177e4 271void jprobe_return(void);
3d7e3382 272unsigned long arch_deref_entry_point(void *);
1da177e4 273
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HN
274int register_kretprobe(struct kretprobe *rp);
275void unregister_kretprobe(struct kretprobe *rp);
4a296e07
MH
276int register_kretprobes(struct kretprobe **rps, int num);
277void unregister_kretprobes(struct kretprobe **rps, int num);
b94cce92 278
b94cce92 279void kprobe_flush_task(struct task_struct *tk);
99219a3f 280void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
8c1c9356 281
b1801812 282#else /* !CONFIG_KPROBES: */
00d7c05a 283
b1801812
IM
284static inline int kprobes_built_in(void)
285{
286 return 0;
287}
288static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
289{
290 return 0;
291}
785656a4
AS
292static inline struct kprobe *get_kprobe(void *addr)
293{
294 return NULL;
295}
e6584523 296static inline struct kprobe *kprobe_running(void)
1da177e4 297{
e6584523 298 return NULL;
1da177e4
LT
299}
300static inline int register_kprobe(struct kprobe *p)
301{
302 return -ENOSYS;
303}
9861668f
MH
304static inline int register_kprobes(struct kprobe **kps, int num)
305{
306 return -ENOSYS;
307}
1da177e4
LT
308static inline void unregister_kprobe(struct kprobe *p)
309{
310}
9861668f
MH
311static inline void unregister_kprobes(struct kprobe **kps, int num)
312{
313}
1da177e4
LT
314static inline int register_jprobe(struct jprobe *p)
315{
316 return -ENOSYS;
317}
26b31c19
MH
318static inline int register_jprobes(struct jprobe **jps, int num)
319{
320 return -ENOSYS;
321}
1da177e4
LT
322static inline void unregister_jprobe(struct jprobe *p)
323{
324}
26b31c19
MH
325static inline void unregister_jprobes(struct jprobe **jps, int num)
326{
327}
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LT
328static inline void jprobe_return(void)
329{
330}
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HN
331static inline int register_kretprobe(struct kretprobe *rp)
332{
333 return -ENOSYS;
334}
4a296e07
MH
335static inline int register_kretprobes(struct kretprobe **rps, int num)
336{
337 return -ENOSYS;
338}
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HN
339static inline void unregister_kretprobe(struct kretprobe *rp)
340{
341}
4a296e07
MH
342static inline void unregister_kretprobes(struct kretprobe **rps, int num)
343{
344}
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HN
345static inline void kprobe_flush_task(struct task_struct *tk)
346{
347}
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IM
348#endif /* CONFIG_KPROBES */
349#endif /* _LINUX_KPROBES_H */