Merge commit 'gcl/next' into next
[deliverable/linux.git] / include / linux / kprobes.h
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1da177e4
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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.
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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
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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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76 /* list of kprobes for multi-handler support */
77 struct list_head list;
78
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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;
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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 */
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136};
137
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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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168};
169
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170struct kretprobe_blackpoint {
171 const char *name;
172 void *addr;
173};
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174
175struct kprobe_blackpoint {
176 const char *name;
177 unsigned long start_addr;
178 unsigned long range;
179};
180
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181#ifdef CONFIG_KPROBES
182DECLARE_PER_CPU(struct kprobe *, current_kprobe);
183DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
184
185#ifdef CONFIG_KRETPROBES
186extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
187 struct pt_regs *regs);
188extern int arch_trampoline_kprobe(struct kprobe *p);
189#else /* CONFIG_KRETPROBES */
190static inline void arch_prepare_kretprobe(struct kretprobe *rp,
191 struct pt_regs *regs)
192{
193}
194static inline int arch_trampoline_kprobe(struct kprobe *p)
195{
196 return 0;
197}
198#endif /* CONFIG_KRETPROBES */
199
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200extern struct kretprobe_blackpoint kretprobe_blacklist[];
201
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AM
202static inline void kretprobe_assert(struct kretprobe_instance *ri,
203 unsigned long orig_ret_address, unsigned long trampoline_address)
204{
205 if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
206 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
207 ri->rp, ri->rp->kp.addr);
208 BUG();
209 }
210}
211
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AM
212#ifdef CONFIG_KPROBES_SANITY_TEST
213extern int init_test_probes(void);
214#else
215static inline int init_test_probes(void)
216{
217 return 0;
218}
219#endif /* CONFIG_KPROBES_SANITY_TEST */
220
1da177e4 221extern int arch_prepare_kprobe(struct kprobe *p);
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222extern void arch_arm_kprobe(struct kprobe *p);
223extern void arch_disarm_kprobe(struct kprobe *p);
6772926b 224extern int arch_init_kprobes(void);
1da177e4 225extern void show_registers(struct pt_regs *regs);
9ec4b1f3 226extern kprobe_opcode_t *get_insn_slot(void);
b4c6c34a 227extern void free_insn_slot(kprobe_opcode_t *slot, int dirty);
bf8d5c52 228extern void kprobes_inc_nmissed_count(struct kprobe *p);
1da177e4 229
d217d545 230/* Get the kprobe at this addr (if any) - called with preemption disabled */
1da177e4 231struct kprobe *get_kprobe(void *addr);
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232void kretprobe_hash_lock(struct task_struct *tsk,
233 struct hlist_head **head, unsigned long *flags);
234void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
b94cce92 235struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
1da177e4 236
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237/* kprobe_running() will just return the current_kprobe on this CPU */
238static inline struct kprobe *kprobe_running(void)
239{
240 return (__get_cpu_var(current_kprobe));
241}
242
243static inline void reset_current_kprobe(void)
244{
245 __get_cpu_var(current_kprobe) = NULL;
246}
247
248static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
249{
250 return (&__get_cpu_var(kprobe_ctlblk));
251}
252
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253int register_kprobe(struct kprobe *p);
254void unregister_kprobe(struct kprobe *p);
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255int register_kprobes(struct kprobe **kps, int num);
256void unregister_kprobes(struct kprobe **kps, int num);
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257int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
258int longjmp_break_handler(struct kprobe *, struct pt_regs *);
259int register_jprobe(struct jprobe *p);
260void unregister_jprobe(struct jprobe *p);
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261int register_jprobes(struct jprobe **jps, int num);
262void unregister_jprobes(struct jprobe **jps, int num);
1da177e4 263void jprobe_return(void);
3d7e3382 264unsigned long arch_deref_entry_point(void *);
1da177e4 265
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266int register_kretprobe(struct kretprobe *rp);
267void unregister_kretprobe(struct kretprobe *rp);
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268int register_kretprobes(struct kretprobe **rps, int num);
269void unregister_kretprobes(struct kretprobe **rps, int num);
b94cce92 270
b94cce92 271void kprobe_flush_task(struct task_struct *tk);
99219a3f 272void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
8c1c9356 273
b94cce92 274#else /* CONFIG_KPROBES */
00d7c05a 275
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276static inline struct kprobe *get_kprobe(void *addr)
277{
278 return NULL;
279}
e6584523 280static inline struct kprobe *kprobe_running(void)
1da177e4 281{
e6584523 282 return NULL;
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283}
284static inline int register_kprobe(struct kprobe *p)
285{
286 return -ENOSYS;
287}
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288static inline int register_kprobes(struct kprobe **kps, int num)
289{
290 return -ENOSYS;
291}
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292static inline void unregister_kprobe(struct kprobe *p)
293{
294}
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295static inline void unregister_kprobes(struct kprobe **kps, int num)
296{
297}
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298static inline int register_jprobe(struct jprobe *p)
299{
300 return -ENOSYS;
301}
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302static inline int register_jprobes(struct jprobe **jps, int num)
303{
304 return -ENOSYS;
305}
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306static inline void unregister_jprobe(struct jprobe *p)
307{
308}
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309static inline void unregister_jprobes(struct jprobe **jps, int num)
310{
311}
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312static inline void jprobe_return(void)
313{
314}
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315static inline int register_kretprobe(struct kretprobe *rp)
316{
317 return -ENOSYS;
318}
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319static inline int register_kretprobes(struct kretprobe **rps, int num)
320{
321 return -ENOSYS;
322}
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323static inline void unregister_kretprobe(struct kretprobe *rp)
324{
325}
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326static inline void unregister_kretprobes(struct kretprobe **rps, int num)
327{
328}
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329static inline void kprobe_flush_task(struct task_struct *tk)
330{
331}
332#endif /* CONFIG_KPROBES */
1da177e4 333#endif /* _LINUX_KPROBES_H */
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