1 #ifndef _LINUX_KPROBES_H
2 #define _LINUX_KPROBES_H
4 * Kernel Probes (KProbes)
5 * include/linux/kprobes.h
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.
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.
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.
21 * Copyright (C) IBM Corporation, 2002, 2004
23 * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
24 * Probes initial implementation ( includes suggestions from
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.
32 #include <linux/linkage.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 #include <linux/mutex.h>
42 #include <asm/kprobes.h>
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
50 /* Attach to insert probes on any functions which should be ignored*/
51 #define __kprobes __attribute__((__section__(".kprobes.text")))
52 #else /* CONFIG_KPROBES */
53 typedef int kprobe_opcode_t
;
54 struct arch_specific_insn
{
58 #endif /* CONFIG_KPROBES */
63 struct kretprobe_instance
;
64 typedef int (*kprobe_pre_handler_t
) (struct kprobe
*, struct pt_regs
*);
65 typedef int (*kprobe_break_handler_t
) (struct kprobe
*, struct pt_regs
*);
66 typedef void (*kprobe_post_handler_t
) (struct kprobe
*, struct pt_regs
*,
68 typedef int (*kprobe_fault_handler_t
) (struct kprobe
*, struct pt_regs
*,
70 typedef int (*kretprobe_handler_t
) (struct kretprobe_instance
*,
74 struct hlist_node hlist
;
76 /* list of kprobes for multi-handler support */
77 struct list_head list
;
79 /*count the number of times this probe was temporarily disarmed */
80 unsigned long nmissed
;
82 /* location of the probe point */
83 kprobe_opcode_t
*addr
;
85 /* Allow user to indicate symbol name of the probe point */
86 const char *symbol_name
;
88 /* Offset into the symbol */
91 /* Called before addr is executed. */
92 kprobe_pre_handler_t pre_handler
;
94 /* Called after addr is executed, unless... */
95 kprobe_post_handler_t post_handler
;
98 * ... called if executing addr causes a fault (eg. page fault).
99 * Return 1 if it handled fault, otherwise kernel will see it.
101 kprobe_fault_handler_t fault_handler
;
104 * ... called if breakpoint trap occurs in probe handler.
105 * Return 1 if it handled break, otherwise kernel will see it.
107 kprobe_break_handler_t break_handler
;
109 /* Saved opcode (which has been replaced with breakpoint) */
110 kprobe_opcode_t opcode
;
112 /* copy of the original instruction */
113 struct arch_specific_insn ainsn
;
116 * Indicates various status flags.
117 * Protected by kprobe_mutex after this kprobe is registered.
122 /* Kprobe status flags */
123 #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
124 #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
126 /* Has this kprobe gone ? */
127 static inline int kprobe_gone(struct kprobe
*p
)
129 return p
->flags
& KPROBE_FLAG_GONE
;
132 /* Is this kprobe disabled ? */
133 static inline int kprobe_disabled(struct kprobe
*p
)
135 return p
->flags
& (KPROBE_FLAG_DISABLED
| KPROBE_FLAG_GONE
);
138 * Special probe type that uses setjmp-longjmp type tricks to resume
139 * execution at a specified entry with a matching prototype corresponding
140 * to the probed function - a trick to enable arguments to become
141 * accessible seamlessly by probe handling logic.
143 * Because of the way compilers allocate stack space for local variables
144 * etc upfront, regardless of sub-scopes within a function, this mirroring
145 * principle currently works only for probes placed on function entry points.
149 void *entry
; /* probe handling code to jump to */
152 /* For backward compatibility with old code using JPROBE_ENTRY() */
153 #define JPROBE_ENTRY(handler) (handler)
156 * Function-return probe -
158 * User needs to provide a handler function, and initialize maxactive.
159 * maxactive - The maximum number of instances of the probed function that
160 * can be active concurrently.
161 * nmissed - tracks the number of times the probed function's return was
162 * ignored, due to maxactive being too low.
167 kretprobe_handler_t handler
;
168 kretprobe_handler_t entry_handler
;
172 struct hlist_head free_instances
;
176 struct kretprobe_instance
{
177 struct hlist_node hlist
;
178 struct kretprobe
*rp
;
179 kprobe_opcode_t
*ret_addr
;
180 struct task_struct
*task
;
184 struct kretprobe_blackpoint
{
189 struct kprobe_blackpoint
{
191 unsigned long start_addr
;
195 #ifdef CONFIG_KPROBES
196 DECLARE_PER_CPU(struct kprobe
*, current_kprobe
);
197 DECLARE_PER_CPU(struct kprobe_ctlblk
, kprobe_ctlblk
);
200 * For #ifdef avoidance:
202 static inline int kprobes_built_in(void)
207 #ifdef CONFIG_KRETPROBES
208 extern void arch_prepare_kretprobe(struct kretprobe_instance
*ri
,
209 struct pt_regs
*regs
);
210 extern int arch_trampoline_kprobe(struct kprobe
*p
);
211 #else /* CONFIG_KRETPROBES */
212 static inline void arch_prepare_kretprobe(struct kretprobe
*rp
,
213 struct pt_regs
*regs
)
216 static inline int arch_trampoline_kprobe(struct kprobe
*p
)
220 #endif /* CONFIG_KRETPROBES */
222 extern struct kretprobe_blackpoint kretprobe_blacklist
[];
224 static inline void kretprobe_assert(struct kretprobe_instance
*ri
,
225 unsigned long orig_ret_address
, unsigned long trampoline_address
)
227 if (!orig_ret_address
|| (orig_ret_address
== trampoline_address
)) {
228 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
229 ri
->rp
, ri
->rp
->kp
.addr
);
234 #ifdef CONFIG_KPROBES_SANITY_TEST
235 extern int init_test_probes(void);
237 static inline int init_test_probes(void)
241 #endif /* CONFIG_KPROBES_SANITY_TEST */
243 extern int arch_prepare_kprobe(struct kprobe
*p
);
244 extern void arch_arm_kprobe(struct kprobe
*p
);
245 extern void arch_disarm_kprobe(struct kprobe
*p
);
246 extern int arch_init_kprobes(void);
247 extern void show_registers(struct pt_regs
*regs
);
248 extern kprobe_opcode_t
*get_insn_slot(void);
249 extern void free_insn_slot(kprobe_opcode_t
*slot
, int dirty
);
250 extern void kprobes_inc_nmissed_count(struct kprobe
*p
);
252 /* Get the kprobe at this addr (if any) - called with preemption disabled */
253 struct kprobe
*get_kprobe(void *addr
);
254 void kretprobe_hash_lock(struct task_struct
*tsk
,
255 struct hlist_head
**head
, unsigned long *flags
);
256 void kretprobe_hash_unlock(struct task_struct
*tsk
, unsigned long *flags
);
257 struct hlist_head
* kretprobe_inst_table_head(struct task_struct
*tsk
);
259 /* kprobe_running() will just return the current_kprobe on this CPU */
260 static inline struct kprobe
*kprobe_running(void)
262 return (__get_cpu_var(current_kprobe
));
265 static inline void reset_current_kprobe(void)
267 __get_cpu_var(current_kprobe
) = NULL
;
270 static inline struct kprobe_ctlblk
*get_kprobe_ctlblk(void)
272 return (&__get_cpu_var(kprobe_ctlblk
));
275 int register_kprobe(struct kprobe
*p
);
276 void unregister_kprobe(struct kprobe
*p
);
277 int register_kprobes(struct kprobe
**kps
, int num
);
278 void unregister_kprobes(struct kprobe
**kps
, int num
);
279 int setjmp_pre_handler(struct kprobe
*, struct pt_regs
*);
280 int longjmp_break_handler(struct kprobe
*, struct pt_regs
*);
281 int register_jprobe(struct jprobe
*p
);
282 void unregister_jprobe(struct jprobe
*p
);
283 int register_jprobes(struct jprobe
**jps
, int num
);
284 void unregister_jprobes(struct jprobe
**jps
, int num
);
285 void jprobe_return(void);
286 unsigned long arch_deref_entry_point(void *);
288 int register_kretprobe(struct kretprobe
*rp
);
289 void unregister_kretprobe(struct kretprobe
*rp
);
290 int register_kretprobes(struct kretprobe
**rps
, int num
);
291 void unregister_kretprobes(struct kretprobe
**rps
, int num
);
293 void kprobe_flush_task(struct task_struct
*tk
);
294 void recycle_rp_inst(struct kretprobe_instance
*ri
, struct hlist_head
*head
);
296 int disable_kprobe(struct kprobe
*kp
);
297 int enable_kprobe(struct kprobe
*kp
);
299 #else /* !CONFIG_KPROBES: */
301 static inline int kprobes_built_in(void)
305 static inline int kprobe_fault_handler(struct pt_regs
*regs
, int trapnr
)
309 static inline struct kprobe
*get_kprobe(void *addr
)
313 static inline struct kprobe
*kprobe_running(void)
317 static inline int register_kprobe(struct kprobe
*p
)
321 static inline int register_kprobes(struct kprobe
**kps
, int num
)
325 static inline void unregister_kprobe(struct kprobe
*p
)
328 static inline void unregister_kprobes(struct kprobe
**kps
, int num
)
331 static inline int register_jprobe(struct jprobe
*p
)
335 static inline int register_jprobes(struct jprobe
**jps
, int num
)
339 static inline void unregister_jprobe(struct jprobe
*p
)
342 static inline void unregister_jprobes(struct jprobe
**jps
, int num
)
345 static inline void jprobe_return(void)
348 static inline int register_kretprobe(struct kretprobe
*rp
)
352 static inline int register_kretprobes(struct kretprobe
**rps
, int num
)
356 static inline void unregister_kretprobe(struct kretprobe
*rp
)
359 static inline void unregister_kretprobes(struct kretprobe
**rps
, int num
)
362 static inline void kprobe_flush_task(struct task_struct
*tk
)
365 static inline int disable_kprobe(struct kprobe
*kp
)
369 static inline int enable_kprobe(struct kprobe
*kp
)
373 #endif /* CONFIG_KPROBES */
374 static inline int disable_kretprobe(struct kretprobe
*rp
)
376 return disable_kprobe(&rp
->kp
);
378 static inline int enable_kretprobe(struct kretprobe
*rp
)
380 return enable_kprobe(&rp
->kp
);
382 static inline int disable_jprobe(struct jprobe
*jp
)
384 return disable_kprobe(&jp
->kp
);
386 static inline int enable_jprobe(struct jprobe
*jp
)
388 return enable_kprobe(&jp
->kp
);
391 #endif /* _LINUX_KPROBES_H */