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/bug.h>
37 #include <linux/percpu.h>
38 #include <linux/spinlock.h>
39 #include <linux/rcupdate.h>
40 #include <linux/mutex.h>
41 #include <linux/ftrace.h>
44 #include <asm/kprobes.h>
46 /* kprobe_status settings */
47 #define KPROBE_HIT_ACTIVE 0x00000001
48 #define KPROBE_HIT_SS 0x00000002
49 #define KPROBE_REENTER 0x00000004
50 #define KPROBE_HIT_SSDONE 0x00000008
53 * If function tracer is enabled and the arch supports full
54 * passing of pt_regs to function tracing, then kprobes can
55 * optimize on top of function tracing.
57 #if defined(CONFIG_FUNCTION_TRACER) && defined(ARCH_SUPPORTS_FTRACE_SAVE_REGS) \
58 && defined(ARCH_SUPPORTS_KPROBES_ON_FTRACE)
59 # define KPROBES_CAN_USE_FTRACE
62 /* Attach to insert probes on any functions which should be ignored*/
63 #define __kprobes __attribute__((__section__(".kprobes.text")))
65 #else /* CONFIG_KPROBES */
66 typedef int kprobe_opcode_t
;
67 struct arch_specific_insn
{
72 #endif /* CONFIG_KPROBES */
77 struct kretprobe_instance
;
78 typedef int (*kprobe_pre_handler_t
) (struct kprobe
*, struct pt_regs
*);
79 typedef int (*kprobe_break_handler_t
) (struct kprobe
*, struct pt_regs
*);
80 typedef void (*kprobe_post_handler_t
) (struct kprobe
*, struct pt_regs
*,
82 typedef int (*kprobe_fault_handler_t
) (struct kprobe
*, struct pt_regs
*,
84 typedef int (*kretprobe_handler_t
) (struct kretprobe_instance
*,
88 struct hlist_node hlist
;
90 /* list of kprobes for multi-handler support */
91 struct list_head list
;
93 /*count the number of times this probe was temporarily disarmed */
94 unsigned long nmissed
;
96 /* location of the probe point */
97 kprobe_opcode_t
*addr
;
99 /* Allow user to indicate symbol name of the probe point */
100 const char *symbol_name
;
102 /* Offset into the symbol */
105 /* Called before addr is executed. */
106 kprobe_pre_handler_t pre_handler
;
108 /* Called after addr is executed, unless... */
109 kprobe_post_handler_t post_handler
;
112 * ... called if executing addr causes a fault (eg. page fault).
113 * Return 1 if it handled fault, otherwise kernel will see it.
115 kprobe_fault_handler_t fault_handler
;
118 * ... called if breakpoint trap occurs in probe handler.
119 * Return 1 if it handled break, otherwise kernel will see it.
121 kprobe_break_handler_t break_handler
;
123 /* Saved opcode (which has been replaced with breakpoint) */
124 kprobe_opcode_t opcode
;
126 /* copy of the original instruction */
127 struct arch_specific_insn ainsn
;
130 * Indicates various status flags.
131 * Protected by kprobe_mutex after this kprobe is registered.
136 /* Kprobe status flags */
137 #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
138 #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
139 #define KPROBE_FLAG_OPTIMIZED 4 /*
140 * probe is really optimized.
142 * this flag is only for optimized_kprobe.
144 #define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */
146 /* Has this kprobe gone ? */
147 static inline int kprobe_gone(struct kprobe
*p
)
149 return p
->flags
& KPROBE_FLAG_GONE
;
152 /* Is this kprobe disabled ? */
153 static inline int kprobe_disabled(struct kprobe
*p
)
155 return p
->flags
& (KPROBE_FLAG_DISABLED
| KPROBE_FLAG_GONE
);
158 /* Is this kprobe really running optimized path ? */
159 static inline int kprobe_optimized(struct kprobe
*p
)
161 return p
->flags
& KPROBE_FLAG_OPTIMIZED
;
164 /* Is this kprobe uses ftrace ? */
165 static inline int kprobe_ftrace(struct kprobe
*p
)
167 return p
->flags
& KPROBE_FLAG_FTRACE
;
171 * Special probe type that uses setjmp-longjmp type tricks to resume
172 * execution at a specified entry with a matching prototype corresponding
173 * to the probed function - a trick to enable arguments to become
174 * accessible seamlessly by probe handling logic.
176 * Because of the way compilers allocate stack space for local variables
177 * etc upfront, regardless of sub-scopes within a function, this mirroring
178 * principle currently works only for probes placed on function entry points.
182 void *entry
; /* probe handling code to jump to */
185 /* For backward compatibility with old code using JPROBE_ENTRY() */
186 #define JPROBE_ENTRY(handler) (handler)
189 * Function-return probe -
191 * User needs to provide a handler function, and initialize maxactive.
192 * maxactive - The maximum number of instances of the probed function that
193 * can be active concurrently.
194 * nmissed - tracks the number of times the probed function's return was
195 * ignored, due to maxactive being too low.
200 kretprobe_handler_t handler
;
201 kretprobe_handler_t entry_handler
;
205 struct hlist_head free_instances
;
209 struct kretprobe_instance
{
210 struct hlist_node hlist
;
211 struct kretprobe
*rp
;
212 kprobe_opcode_t
*ret_addr
;
213 struct task_struct
*task
;
217 struct kretprobe_blackpoint
{
222 struct kprobe_blackpoint
{
224 unsigned long start_addr
;
228 #ifdef CONFIG_KPROBES
229 DECLARE_PER_CPU(struct kprobe
*, current_kprobe
);
230 DECLARE_PER_CPU(struct kprobe_ctlblk
, kprobe_ctlblk
);
233 * For #ifdef avoidance:
235 static inline int kprobes_built_in(void)
240 #ifdef CONFIG_KRETPROBES
241 extern void arch_prepare_kretprobe(struct kretprobe_instance
*ri
,
242 struct pt_regs
*regs
);
243 extern int arch_trampoline_kprobe(struct kprobe
*p
);
244 #else /* CONFIG_KRETPROBES */
245 static inline void arch_prepare_kretprobe(struct kretprobe
*rp
,
246 struct pt_regs
*regs
)
249 static inline int arch_trampoline_kprobe(struct kprobe
*p
)
253 #endif /* CONFIG_KRETPROBES */
255 extern struct kretprobe_blackpoint kretprobe_blacklist
[];
257 static inline void kretprobe_assert(struct kretprobe_instance
*ri
,
258 unsigned long orig_ret_address
, unsigned long trampoline_address
)
260 if (!orig_ret_address
|| (orig_ret_address
== trampoline_address
)) {
261 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
262 ri
->rp
, ri
->rp
->kp
.addr
);
267 #ifdef CONFIG_KPROBES_SANITY_TEST
268 extern int init_test_probes(void);
270 static inline int init_test_probes(void)
274 #endif /* CONFIG_KPROBES_SANITY_TEST */
276 extern int arch_prepare_kprobe(struct kprobe
*p
);
277 extern void arch_arm_kprobe(struct kprobe
*p
);
278 extern void arch_disarm_kprobe(struct kprobe
*p
);
279 extern int arch_init_kprobes(void);
280 extern void show_registers(struct pt_regs
*regs
);
281 extern kprobe_opcode_t
*get_insn_slot(void);
282 extern void free_insn_slot(kprobe_opcode_t
*slot
, int dirty
);
283 extern void kprobes_inc_nmissed_count(struct kprobe
*p
);
285 #ifdef CONFIG_OPTPROBES
287 * Internal structure for direct jump optimized probe
289 struct optimized_kprobe
{
291 struct list_head list
; /* list for optimizing queue */
292 struct arch_optimized_insn optinsn
;
295 /* Architecture dependent functions for direct jump optimization */
296 extern int arch_prepared_optinsn(struct arch_optimized_insn
*optinsn
);
297 extern int arch_check_optimized_kprobe(struct optimized_kprobe
*op
);
298 extern int arch_prepare_optimized_kprobe(struct optimized_kprobe
*op
);
299 extern void arch_remove_optimized_kprobe(struct optimized_kprobe
*op
);
300 extern void arch_optimize_kprobes(struct list_head
*oplist
);
301 extern void arch_unoptimize_kprobes(struct list_head
*oplist
,
302 struct list_head
*done_list
);
303 extern void arch_unoptimize_kprobe(struct optimized_kprobe
*op
);
304 extern kprobe_opcode_t
*get_optinsn_slot(void);
305 extern void free_optinsn_slot(kprobe_opcode_t
*slot
, int dirty
);
306 extern int arch_within_optimized_kprobe(struct optimized_kprobe
*op
,
309 extern void opt_pre_handler(struct kprobe
*p
, struct pt_regs
*regs
);
312 extern int sysctl_kprobes_optimization
;
313 extern int proc_kprobes_optimization_handler(struct ctl_table
*table
,
314 int write
, void __user
*buffer
,
315 size_t *length
, loff_t
*ppos
);
318 #endif /* CONFIG_OPTPROBES */
319 #ifdef KPROBES_CAN_USE_FTRACE
320 extern void kprobe_ftrace_handler(unsigned long ip
, unsigned long parent_ip
,
321 struct ftrace_ops
*ops
, struct pt_regs
*regs
);
322 extern int arch_prepare_kprobe_ftrace(struct kprobe
*p
);
326 /* Get the kprobe at this addr (if any) - called with preemption disabled */
327 struct kprobe
*get_kprobe(void *addr
);
328 void kretprobe_hash_lock(struct task_struct
*tsk
,
329 struct hlist_head
**head
, unsigned long *flags
);
330 void kretprobe_hash_unlock(struct task_struct
*tsk
, unsigned long *flags
);
331 struct hlist_head
* kretprobe_inst_table_head(struct task_struct
*tsk
);
333 /* kprobe_running() will just return the current_kprobe on this CPU */
334 static inline struct kprobe
*kprobe_running(void)
336 return (__this_cpu_read(current_kprobe
));
339 static inline void reset_current_kprobe(void)
341 __this_cpu_write(current_kprobe
, NULL
);
344 static inline struct kprobe_ctlblk
*get_kprobe_ctlblk(void)
346 return (&__get_cpu_var(kprobe_ctlblk
));
349 int register_kprobe(struct kprobe
*p
);
350 void unregister_kprobe(struct kprobe
*p
);
351 int register_kprobes(struct kprobe
**kps
, int num
);
352 void unregister_kprobes(struct kprobe
**kps
, int num
);
353 int setjmp_pre_handler(struct kprobe
*, struct pt_regs
*);
354 int longjmp_break_handler(struct kprobe
*, struct pt_regs
*);
355 int register_jprobe(struct jprobe
*p
);
356 void unregister_jprobe(struct jprobe
*p
);
357 int register_jprobes(struct jprobe
**jps
, int num
);
358 void unregister_jprobes(struct jprobe
**jps
, int num
);
359 void jprobe_return(void);
360 unsigned long arch_deref_entry_point(void *);
362 int register_kretprobe(struct kretprobe
*rp
);
363 void unregister_kretprobe(struct kretprobe
*rp
);
364 int register_kretprobes(struct kretprobe
**rps
, int num
);
365 void unregister_kretprobes(struct kretprobe
**rps
, int num
);
367 void kprobe_flush_task(struct task_struct
*tk
);
368 void recycle_rp_inst(struct kretprobe_instance
*ri
, struct hlist_head
*head
);
370 int disable_kprobe(struct kprobe
*kp
);
371 int enable_kprobe(struct kprobe
*kp
);
373 void dump_kprobe(struct kprobe
*kp
);
375 #else /* !CONFIG_KPROBES: */
377 static inline int kprobes_built_in(void)
381 static inline int kprobe_fault_handler(struct pt_regs
*regs
, int trapnr
)
385 static inline struct kprobe
*get_kprobe(void *addr
)
389 static inline struct kprobe
*kprobe_running(void)
393 static inline int register_kprobe(struct kprobe
*p
)
397 static inline int register_kprobes(struct kprobe
**kps
, int num
)
401 static inline void unregister_kprobe(struct kprobe
*p
)
404 static inline void unregister_kprobes(struct kprobe
**kps
, int num
)
407 static inline int register_jprobe(struct jprobe
*p
)
411 static inline int register_jprobes(struct jprobe
**jps
, int num
)
415 static inline void unregister_jprobe(struct jprobe
*p
)
418 static inline void unregister_jprobes(struct jprobe
**jps
, int num
)
421 static inline void jprobe_return(void)
424 static inline int register_kretprobe(struct kretprobe
*rp
)
428 static inline int register_kretprobes(struct kretprobe
**rps
, int num
)
432 static inline void unregister_kretprobe(struct kretprobe
*rp
)
435 static inline void unregister_kretprobes(struct kretprobe
**rps
, int num
)
438 static inline void kprobe_flush_task(struct task_struct
*tk
)
441 static inline int disable_kprobe(struct kprobe
*kp
)
445 static inline int enable_kprobe(struct kprobe
*kp
)
449 #endif /* CONFIG_KPROBES */
450 static inline int disable_kretprobe(struct kretprobe
*rp
)
452 return disable_kprobe(&rp
->kp
);
454 static inline int enable_kretprobe(struct kretprobe
*rp
)
456 return enable_kprobe(&rp
->kp
);
458 static inline int disable_jprobe(struct jprobe
*jp
)
460 return disable_kprobe(&jp
->kp
);
462 static inline int enable_jprobe(struct jprobe
*jp
)
464 return enable_kprobe(&jp
->kp
);
467 #endif /* _LINUX_KPROBES_H */