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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 */
Ingo Molnar36dcd672008-07-29 12:00:59 +020032#include <linux/linkage.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/list.h>
34#include <linux/notifier.h>
35#include <linux/smp.h>
Ananth N Mavinakayanahallie6584522005-11-07 01:00:07 -080036#include <linux/percpu.h>
Ananth N Mavinakayanahalli3516a462005-11-07 01:00:13 -080037#include <linux/spinlock.h>
38#include <linux/rcupdate.h>
Ingo Molnar7a7d1cf2006-03-23 03:00:35 -080039#include <linux/mutex.h>
Hien Nguyenb94cce92005-06-23 00:09:19 -070040
Keshavamurthy Anil S00d7c052005-12-12 00:37:33 -080041#ifdef CONFIG_KPROBES
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#include <asm/kprobes.h>
43
Prasanna S Panchamukhiea32c652005-06-23 00:09:36 -070044/* 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
Prasanna S Panchamukhid0aaff92005-09-06 15:19:26 -070050/* Attach to insert probes on any functions which should be ignored*/
Steven Rostedtfe832a32009-09-15 23:51:31 -040051#define __kprobes __attribute__((__section__(".kprobes.text")))
Masami Hiramatsudc198352009-01-29 14:25:08 -080052#else /* CONFIG_KPROBES */
53typedef int kprobe_opcode_t;
54struct arch_specific_insn {
55 int dummy;
56};
Steven Rostedtfe832a32009-09-15 23:51:31 -040057#define __kprobes
Masami Hiramatsudc198352009-01-29 14:25:08 -080058#endif /* CONFIG_KPROBES */
Prasanna S Panchamukhid0aaff92005-09-06 15:19:26 -070059
Linus Torvalds1da177e2005-04-16 15:20:36 -070060struct kprobe;
61struct pt_regs;
Hien Nguyenb94cce92005-06-23 00:09:19 -070062struct kretprobe;
63struct kretprobe_instance;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064typedef 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);
Hien Nguyenb94cce92005-06-23 00:09:19 -070070typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
71 struct pt_regs *);
72
Linus Torvalds1da177e2005-04-16 15:20:36 -070073struct kprobe {
74 struct hlist_node hlist;
75
Ananth N Mavinakayanahalli64f562c2005-05-05 16:15:42 -070076 /* list of kprobes for multi-handler support */
77 struct list_head list;
78
Prasanna S Panchamukhiea32c652005-06-23 00:09:36 -070079 /*count the number of times this probe was temporarily disarmed */
80 unsigned long nmissed;
81
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 /* location of the probe point */
83 kprobe_opcode_t *addr;
84
Ananth N Mavinakayanahalli3a872d82006-10-02 02:17:30 -070085 /* Allow user to indicate symbol name of the probe point */
Ananth N Mavinakayanahalli9b3af292007-05-08 00:26:23 -070086 const char *symbol_name;
Ananth N Mavinakayanahalli3a872d82006-10-02 02:17:30 -070087
88 /* Offset into the symbol */
89 unsigned int offset;
90
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 /* 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
Masami Hiramatsucc00e9c2009-04-06 19:01:00 -070097 /*
98 * ... called if executing addr causes a fault (eg. page fault).
99 * Return 1 if it handled fault, otherwise kernel will see it.
100 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 kprobe_fault_handler_t fault_handler;
102
Masami Hiramatsucc00e9c2009-04-06 19:01:00 -0700103 /*
104 * ... called if breakpoint trap occurs in probe handler.
105 * Return 1 if it handled break, otherwise kernel will see it.
106 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 kprobe_break_handler_t break_handler;
108
109 /* Saved opcode (which has been replaced with breakpoint) */
110 kprobe_opcode_t opcode;
111
112 /* copy of the original instruction */
113 struct arch_specific_insn ainsn;
Masami Hiramatsue8386a02009-01-06 14:41:52 -0800114
Masami Hiramatsude5bd882009-04-06 19:01:02 -0700115 /*
116 * Indicates various status flags.
117 * Protected by kprobe_mutex after this kprobe is registered.
118 */
Masami Hiramatsue8386a02009-01-06 14:41:52 -0800119 u32 flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120};
121
Masami Hiramatsue8386a02009-01-06 14:41:52 -0800122/* Kprobe status flags */
123#define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
Masami Hiramatsude5bd882009-04-06 19:01:02 -0700124#define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
Masami Hiramatsuafd66252010-02-25 08:34:07 -0500125#define KPROBE_FLAG_OPTIMIZED 4 /*
126 * probe is really optimized.
127 * NOTE:
128 * this flag is only for optimized_kprobe.
129 */
Masami Hiramatsue8386a02009-01-06 14:41:52 -0800130
Masami Hiramatsude5bd882009-04-06 19:01:02 -0700131/* Has this kprobe gone ? */
Masami Hiramatsue8386a02009-01-06 14:41:52 -0800132static inline int kprobe_gone(struct kprobe *p)
133{
134 return p->flags & KPROBE_FLAG_GONE;
135}
136
Masami Hiramatsude5bd882009-04-06 19:01:02 -0700137/* Is this kprobe disabled ? */
138static inline int kprobe_disabled(struct kprobe *p)
139{
140 return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
141}
Masami Hiramatsuafd66252010-02-25 08:34:07 -0500142
143/* Is this kprobe really running optimized path ? */
144static inline int kprobe_optimized(struct kprobe *p)
145{
146 return p->flags & KPROBE_FLAG_OPTIMIZED;
147}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148/*
149 * Special probe type that uses setjmp-longjmp type tricks to resume
150 * execution at a specified entry with a matching prototype corresponding
151 * to the probed function - a trick to enable arguments to become
152 * accessible seamlessly by probe handling logic.
153 * Note:
154 * Because of the way compilers allocate stack space for local variables
155 * etc upfront, regardless of sub-scopes within a function, this mirroring
156 * principle currently works only for probes placed on function entry points.
157 */
158struct jprobe {
159 struct kprobe kp;
Michael Ellerman81eae372007-07-19 01:48:09 -0700160 void *entry; /* probe handling code to jump to */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161};
162
Michael Ellerman9e367d82007-07-19 01:48:10 -0700163/* For backward compatibility with old code using JPROBE_ENTRY() */
164#define JPROBE_ENTRY(handler) (handler)
165
Hien Nguyenb94cce92005-06-23 00:09:19 -0700166/*
167 * Function-return probe -
168 * Note:
169 * User needs to provide a handler function, and initialize maxactive.
170 * maxactive - The maximum number of instances of the probed function that
171 * can be active concurrently.
172 * nmissed - tracks the number of times the probed function's return was
173 * ignored, due to maxactive being too low.
174 *
175 */
176struct kretprobe {
177 struct kprobe kp;
178 kretprobe_handler_t handler;
Abhishek Sagarf47cd9b2008-02-06 01:38:22 -0800179 kretprobe_handler_t entry_handler;
Hien Nguyenb94cce92005-06-23 00:09:19 -0700180 int maxactive;
181 int nmissed;
Abhishek Sagarf47cd9b2008-02-06 01:38:22 -0800182 size_t data_size;
Hien Nguyenb94cce92005-06-23 00:09:19 -0700183 struct hlist_head free_instances;
Srinivasa D Sef53d9c2008-07-25 01:46:04 -0700184 spinlock_t lock;
Hien Nguyenb94cce92005-06-23 00:09:19 -0700185};
186
187struct kretprobe_instance {
Hien Nguyenb94cce92005-06-23 00:09:19 -0700188 struct hlist_node hlist;
189 struct kretprobe *rp;
Rusty Lynch802eae72005-06-27 15:17:08 -0700190 kprobe_opcode_t *ret_addr;
191 struct task_struct *task;
Abhishek Sagarf47cd9b2008-02-06 01:38:22 -0800192 char data[0];
Hien Nguyenb94cce92005-06-23 00:09:19 -0700193};
194
Masami Hiramatsuf438d912007-10-16 01:27:49 -0700195struct kretprobe_blackpoint {
196 const char *name;
197 void *addr;
198};
Srinivasa Ds3d8d9962008-04-28 02:14:26 -0700199
200struct kprobe_blackpoint {
201 const char *name;
202 unsigned long start_addr;
203 unsigned long range;
204};
205
Masami Hiramatsudc198352009-01-29 14:25:08 -0800206#ifdef CONFIG_KPROBES
207DECLARE_PER_CPU(struct kprobe *, current_kprobe);
208DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
209
Ingo Molnarb1801812009-02-20 22:42:57 +0100210/*
211 * For #ifdef avoidance:
212 */
213static inline int kprobes_built_in(void)
214{
215 return 1;
216}
217
Masami Hiramatsudc198352009-01-29 14:25:08 -0800218#ifdef CONFIG_KRETPROBES
219extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
220 struct pt_regs *regs);
221extern int arch_trampoline_kprobe(struct kprobe *p);
222#else /* CONFIG_KRETPROBES */
223static inline void arch_prepare_kretprobe(struct kretprobe *rp,
224 struct pt_regs *regs)
225{
226}
227static inline int arch_trampoline_kprobe(struct kprobe *p)
228{
229 return 0;
230}
231#endif /* CONFIG_KRETPROBES */
232
Masami Hiramatsuf438d912007-10-16 01:27:49 -0700233extern struct kretprobe_blackpoint kretprobe_blacklist[];
234
Ananth N Mavinakayanahalli0f95b7f2007-05-08 00:28:27 -0700235static inline void kretprobe_assert(struct kretprobe_instance *ri,
236 unsigned long orig_ret_address, unsigned long trampoline_address)
237{
238 if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
239 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
240 ri->rp, ri->rp->kp.addr);
241 BUG();
242 }
243}
244
Ananth N Mavinakayanahalli8c1c9352008-01-30 13:32:53 +0100245#ifdef CONFIG_KPROBES_SANITY_TEST
246extern int init_test_probes(void);
247#else
248static inline int init_test_probes(void)
249{
250 return 0;
251}
252#endif /* CONFIG_KPROBES_SANITY_TEST */
253
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254extern int arch_prepare_kprobe(struct kprobe *p);
Rusty Lynch7e1048b2005-06-23 00:09:25 -0700255extern void arch_arm_kprobe(struct kprobe *p);
256extern void arch_disarm_kprobe(struct kprobe *p);
Rusty Lynch67729262005-07-05 18:54:50 -0700257extern int arch_init_kprobes(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258extern void show_registers(struct pt_regs *regs);
Ananth N Mavinakayanahalli9ec4b1f2005-06-27 15:17:01 -0700259extern kprobe_opcode_t *get_insn_slot(void);
Masami Hiramatsub4c6c342006-12-06 20:38:11 -0800260extern void free_insn_slot(kprobe_opcode_t *slot, int dirty);
Keshavamurthy Anil Sbf8d5c52005-12-12 00:37:34 -0800261extern void kprobes_inc_nmissed_count(struct kprobe *p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
Masami Hiramatsuafd66252010-02-25 08:34:07 -0500263#ifdef CONFIG_OPTPROBES
264/*
265 * Internal structure for direct jump optimized probe
266 */
267struct optimized_kprobe {
268 struct kprobe kp;
269 struct list_head list; /* list for optimizing queue */
270 struct arch_optimized_insn optinsn;
271};
272
273/* Architecture dependent functions for direct jump optimization */
274extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
275extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
276extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op);
277extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
278extern int arch_optimize_kprobe(struct optimized_kprobe *op);
279extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
280extern kprobe_opcode_t *get_optinsn_slot(void);
281extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty);
282extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
283 unsigned long addr);
284
285extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
286#endif /* CONFIG_OPTPROBES */
287
Ananth N Mavinakayanahallid217d542005-11-07 01:00:14 -0800288/* Get the kprobe at this addr (if any) - called with preemption disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289struct kprobe *get_kprobe(void *addr);
Srinivasa D Sef53d9c2008-07-25 01:46:04 -0700290void kretprobe_hash_lock(struct task_struct *tsk,
291 struct hlist_head **head, unsigned long *flags);
292void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
Hien Nguyenb94cce92005-06-23 00:09:19 -0700293struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294
Ananth N Mavinakayanahallie6584522005-11-07 01:00:07 -0800295/* kprobe_running() will just return the current_kprobe on this CPU */
296static inline struct kprobe *kprobe_running(void)
297{
298 return (__get_cpu_var(current_kprobe));
299}
300
301static inline void reset_current_kprobe(void)
302{
303 __get_cpu_var(current_kprobe) = NULL;
304}
305
306static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
307{
308 return (&__get_cpu_var(kprobe_ctlblk));
309}
310
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311int register_kprobe(struct kprobe *p);
312void unregister_kprobe(struct kprobe *p);
Masami Hiramatsu98616682008-04-28 02:14:28 -0700313int register_kprobes(struct kprobe **kps, int num);
314void unregister_kprobes(struct kprobe **kps, int num);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
316int longjmp_break_handler(struct kprobe *, struct pt_regs *);
317int register_jprobe(struct jprobe *p);
318void unregister_jprobe(struct jprobe *p);
Masami Hiramatsu26b31c12008-04-28 02:14:29 -0700319int register_jprobes(struct jprobe **jps, int num);
320void unregister_jprobes(struct jprobe **jps, int num);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321void jprobe_return(void);
Michael Ellerman3d7e3382007-07-19 01:48:11 -0700322unsigned long arch_deref_entry_point(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323
Hien Nguyenb94cce92005-06-23 00:09:19 -0700324int register_kretprobe(struct kretprobe *rp);
325void unregister_kretprobe(struct kretprobe *rp);
Masami Hiramatsu4a296e02008-04-28 02:14:29 -0700326int register_kretprobes(struct kretprobe **rps, int num);
327void unregister_kretprobes(struct kretprobe **rps, int num);
Hien Nguyenb94cce92005-06-23 00:09:19 -0700328
Hien Nguyenb94cce92005-06-23 00:09:19 -0700329void kprobe_flush_task(struct task_struct *tk);
bibo,mao99219a32006-10-02 02:17:35 -0700330void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
Ananth N Mavinakayanahalli8c1c9352008-01-30 13:32:53 +0100331
Masami Hiramatsude5bd882009-04-06 19:01:02 -0700332int disable_kprobe(struct kprobe *kp);
333int enable_kprobe(struct kprobe *kp);
334
Frederic Weisbecker24851d22009-08-26 23:38:30 +0200335void dump_kprobe(struct kprobe *kp);
336
Ingo Molnarb1801812009-02-20 22:42:57 +0100337#else /* !CONFIG_KPROBES: */
Keshavamurthy Anil S00d7c052005-12-12 00:37:33 -0800338
Ingo Molnarb1801812009-02-20 22:42:57 +0100339static inline int kprobes_built_in(void)
340{
341 return 0;
342}
343static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
344{
345 return 0;
346}
Abhishek Sagar785656a2008-06-21 23:47:39 +0530347static inline struct kprobe *get_kprobe(void *addr)
348{
349 return NULL;
350}
Ananth N Mavinakayanahallie6584522005-11-07 01:00:07 -0800351static inline struct kprobe *kprobe_running(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352{
Ananth N Mavinakayanahallie6584522005-11-07 01:00:07 -0800353 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354}
355static inline int register_kprobe(struct kprobe *p)
356{
357 return -ENOSYS;
358}
Masami Hiramatsu98616682008-04-28 02:14:28 -0700359static inline int register_kprobes(struct kprobe **kps, int num)
360{
361 return -ENOSYS;
362}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363static inline void unregister_kprobe(struct kprobe *p)
364{
365}
Masami Hiramatsu98616682008-04-28 02:14:28 -0700366static inline void unregister_kprobes(struct kprobe **kps, int num)
367{
368}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369static inline int register_jprobe(struct jprobe *p)
370{
371 return -ENOSYS;
372}
Masami Hiramatsu26b31c12008-04-28 02:14:29 -0700373static inline int register_jprobes(struct jprobe **jps, int num)
374{
375 return -ENOSYS;
376}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377static inline void unregister_jprobe(struct jprobe *p)
378{
379}
Masami Hiramatsu26b31c12008-04-28 02:14:29 -0700380static inline void unregister_jprobes(struct jprobe **jps, int num)
381{
382}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383static inline void jprobe_return(void)
384{
385}
Hien Nguyenb94cce92005-06-23 00:09:19 -0700386static inline int register_kretprobe(struct kretprobe *rp)
387{
388 return -ENOSYS;
389}
Masami Hiramatsu4a296e02008-04-28 02:14:29 -0700390static inline int register_kretprobes(struct kretprobe **rps, int num)
391{
392 return -ENOSYS;
393}
Hien Nguyenb94cce92005-06-23 00:09:19 -0700394static inline void unregister_kretprobe(struct kretprobe *rp)
395{
396}
Masami Hiramatsu4a296e02008-04-28 02:14:29 -0700397static inline void unregister_kretprobes(struct kretprobe **rps, int num)
398{
399}
Hien Nguyenb94cce92005-06-23 00:09:19 -0700400static inline void kprobe_flush_task(struct task_struct *tk)
401{
402}
Masami Hiramatsude5bd882009-04-06 19:01:02 -0700403static inline int disable_kprobe(struct kprobe *kp)
404{
405 return -ENOSYS;
406}
407static inline int enable_kprobe(struct kprobe *kp)
408{
409 return -ENOSYS;
410}
Ingo Molnarb1801812009-02-20 22:42:57 +0100411#endif /* CONFIG_KPROBES */
Masami Hiramatsu8f9b1522009-04-06 19:01:02 -0700412static inline int disable_kretprobe(struct kretprobe *rp)
413{
414 return disable_kprobe(&rp->kp);
415}
416static inline int enable_kretprobe(struct kretprobe *rp)
417{
418 return enable_kprobe(&rp->kp);
419}
420static inline int disable_jprobe(struct jprobe *jp)
421{
422 return disable_kprobe(&jp->kp);
423}
424static inline int enable_jprobe(struct jprobe *jp)
425{
426 return enable_kprobe(&jp->kp);
427}
428
Ingo Molnarb1801812009-02-20 22:42:57 +0100429#endif /* _LINUX_KPROBES_H */