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.
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.
31 */
32 #include <linux/compiler.h>
33 #include <linux/linkage.h>
34 #include <linux/list.h>
35 #include <linux/notifier.h>
36 #include <linux/smp.h>
37 #include <linux/bug.h>
38 #include <linux/percpu.h>
39 #include <linux/spinlock.h>
40 #include <linux/rcupdate.h>
41 #include <linux/mutex.h>
42 #include <linux/ftrace.h>
43 #include <asm/kprobes.h>
44
45 #ifdef CONFIG_KPROBES
46
47 /* kprobe_status settings */
48 #define KPROBE_HIT_ACTIVE 0x00000001
49 #define KPROBE_HIT_SS 0x00000002
50 #define KPROBE_REENTER 0x00000004
51 #define KPROBE_HIT_SSDONE 0x00000008
52
53 #else /* CONFIG_KPROBES */
54 #include <asm-generic/kprobes.h>
55 typedef int kprobe_opcode_t;
56 struct arch_specific_insn {
57 int dummy;
58 };
59 #endif /* CONFIG_KPROBES */
60
61 struct kprobe;
62 struct pt_regs;
63 struct kretprobe;
64 struct kretprobe_instance;
65 typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
66 typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
67 unsigned long flags);
68 typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
69 int trapnr);
70 typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
71 struct pt_regs *);
72
73 struct kprobe {
74 struct hlist_node hlist;
75
76 /* list of kprobes for multi-handler support */
77 struct list_head list;
78
79 /*count the number of times this probe was temporarily disarmed */
80 unsigned long nmissed;
81
82 /* location of the probe point */
83 kprobe_opcode_t *addr;
84
85 /* Allow user to indicate symbol name of the probe point */
86 const char *symbol_name;
87
88 /* Offset into the symbol */
89 unsigned int offset;
90
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 /*
98 * ... called if executing addr causes a fault (eg. page fault).
99 * Return 1 if it handled fault, otherwise kernel will see it.
100 */
101 kprobe_fault_handler_t fault_handler;
102
103 /* Saved opcode (which has been replaced with breakpoint) */
104 kprobe_opcode_t opcode;
105
106 /* copy of the original instruction */
107 struct arch_specific_insn ainsn;
108
109 /*
110 * Indicates various status flags.
111 * Protected by kprobe_mutex after this kprobe is registered.
112 */
113 u32 flags;
114 };
115
116 /* Kprobe status flags */
117 #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
118 #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
119 #define KPROBE_FLAG_OPTIMIZED 4 /*
120 * probe is really optimized.
121 * NOTE:
122 * this flag is only for optimized_kprobe.
123 */
124 #define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */
125
126 /* Has this kprobe gone ? */
kprobe_gone(struct kprobe * p)127 static inline int kprobe_gone(struct kprobe *p)
128 {
129 return p->flags & KPROBE_FLAG_GONE;
130 }
131
132 /* Is this kprobe disabled ? */
kprobe_disabled(struct kprobe * p)133 static inline int kprobe_disabled(struct kprobe *p)
134 {
135 return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
136 }
137
138 /* Is this kprobe really running optimized path ? */
kprobe_optimized(struct kprobe * p)139 static inline int kprobe_optimized(struct kprobe *p)
140 {
141 return p->flags & KPROBE_FLAG_OPTIMIZED;
142 }
143
144 /* Is this kprobe uses ftrace ? */
kprobe_ftrace(struct kprobe * p)145 static inline int kprobe_ftrace(struct kprobe *p)
146 {
147 return p->flags & KPROBE_FLAG_FTRACE;
148 }
149
150 /*
151 * Function-return probe -
152 * Note:
153 * User needs to provide a handler function, and initialize maxactive.
154 * maxactive - The maximum number of instances of the probed function that
155 * can be active concurrently.
156 * nmissed - tracks the number of times the probed function's return was
157 * ignored, due to maxactive being too low.
158 *
159 */
160 struct kretprobe {
161 struct kprobe kp;
162 kretprobe_handler_t handler;
163 kretprobe_handler_t entry_handler;
164 int maxactive;
165 int nmissed;
166 size_t data_size;
167 struct hlist_head free_instances;
168 raw_spinlock_t lock;
169 };
170
171 struct kretprobe_instance {
172 struct hlist_node hlist;
173 struct kretprobe *rp;
174 kprobe_opcode_t *ret_addr;
175 struct task_struct *task;
176 void *fp;
177 char data[0];
178 };
179
180 struct kretprobe_blackpoint {
181 const char *name;
182 void *addr;
183 };
184
185 struct kprobe_blacklist_entry {
186 struct list_head list;
187 unsigned long start_addr;
188 unsigned long end_addr;
189 };
190
191 #ifdef CONFIG_KPROBES
192 DECLARE_PER_CPU(struct kprobe *, current_kprobe);
193 DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
194
195 /*
196 * For #ifdef avoidance:
197 */
kprobes_built_in(void)198 static inline int kprobes_built_in(void)
199 {
200 return 1;
201 }
202
203 #ifdef CONFIG_KRETPROBES
204 extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
205 struct pt_regs *regs);
206 extern int arch_trampoline_kprobe(struct kprobe *p);
207 #else /* CONFIG_KRETPROBES */
arch_prepare_kretprobe(struct kretprobe * rp,struct pt_regs * regs)208 static inline void arch_prepare_kretprobe(struct kretprobe *rp,
209 struct pt_regs *regs)
210 {
211 }
arch_trampoline_kprobe(struct kprobe * p)212 static inline int arch_trampoline_kprobe(struct kprobe *p)
213 {
214 return 0;
215 }
216 #endif /* CONFIG_KRETPROBES */
217
218 extern struct kretprobe_blackpoint kretprobe_blacklist[];
219
kretprobe_assert(struct kretprobe_instance * ri,unsigned long orig_ret_address,unsigned long trampoline_address)220 static inline void kretprobe_assert(struct kretprobe_instance *ri,
221 unsigned long orig_ret_address, unsigned long trampoline_address)
222 {
223 if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
224 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
225 ri->rp, ri->rp->kp.addr);
226 BUG();
227 }
228 }
229
230 #ifdef CONFIG_KPROBES_SANITY_TEST
231 extern int init_test_probes(void);
232 #else
init_test_probes(void)233 static inline int init_test_probes(void)
234 {
235 return 0;
236 }
237 #endif /* CONFIG_KPROBES_SANITY_TEST */
238
239 extern int arch_prepare_kprobe(struct kprobe *p);
240 extern void arch_arm_kprobe(struct kprobe *p);
241 extern void arch_disarm_kprobe(struct kprobe *p);
242 extern int arch_init_kprobes(void);
243 extern void show_registers(struct pt_regs *regs);
244 extern void kprobes_inc_nmissed_count(struct kprobe *p);
245 extern bool arch_within_kprobe_blacklist(unsigned long addr);
246 extern int arch_populate_kprobe_blacklist(void);
247 extern bool arch_kprobe_on_func_entry(unsigned long offset);
248 extern bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset);
249
250 extern bool within_kprobe_blacklist(unsigned long addr);
251 extern int kprobe_add_ksym_blacklist(unsigned long entry);
252 extern int kprobe_add_area_blacklist(unsigned long start, unsigned long end);
253
254 struct kprobe_insn_cache {
255 struct mutex mutex;
256 void *(*alloc)(void); /* allocate insn page */
257 void (*free)(void *); /* free insn page */
258 struct list_head pages; /* list of kprobe_insn_page */
259 size_t insn_size; /* size of instruction slot */
260 int nr_garbage;
261 };
262
263 #ifdef __ARCH_WANT_KPROBES_INSN_SLOT
264 extern kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c);
265 extern void __free_insn_slot(struct kprobe_insn_cache *c,
266 kprobe_opcode_t *slot, int dirty);
267 /* sleep-less address checking routine */
268 extern bool __is_insn_slot_addr(struct kprobe_insn_cache *c,
269 unsigned long addr);
270
271 #define DEFINE_INSN_CACHE_OPS(__name) \
272 extern struct kprobe_insn_cache kprobe_##__name##_slots; \
273 \
274 static inline kprobe_opcode_t *get_##__name##_slot(void) \
275 { \
276 return __get_insn_slot(&kprobe_##__name##_slots); \
277 } \
278 \
279 static inline void free_##__name##_slot(kprobe_opcode_t *slot, int dirty)\
280 { \
281 __free_insn_slot(&kprobe_##__name##_slots, slot, dirty); \
282 } \
283 \
284 static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
285 { \
286 return __is_insn_slot_addr(&kprobe_##__name##_slots, addr); \
287 }
288 #else /* __ARCH_WANT_KPROBES_INSN_SLOT */
289 #define DEFINE_INSN_CACHE_OPS(__name) \
290 static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
291 { \
292 return 0; \
293 }
294 #endif
295
296 DEFINE_INSN_CACHE_OPS(insn);
297
298 #ifdef CONFIG_OPTPROBES
299 /*
300 * Internal structure for direct jump optimized probe
301 */
302 struct optimized_kprobe {
303 struct kprobe kp;
304 struct list_head list; /* list for optimizing queue */
305 struct arch_optimized_insn optinsn;
306 };
307
308 /* Architecture dependent functions for direct jump optimization */
309 extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
310 extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
311 extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op,
312 struct kprobe *orig);
313 extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
314 extern void arch_optimize_kprobes(struct list_head *oplist);
315 extern void arch_unoptimize_kprobes(struct list_head *oplist,
316 struct list_head *done_list);
317 extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
318 extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
319 unsigned long addr);
320
321 extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
322
323 DEFINE_INSN_CACHE_OPS(optinsn);
324
325 #ifdef CONFIG_SYSCTL
326 extern int sysctl_kprobes_optimization;
327 extern int proc_kprobes_optimization_handler(struct ctl_table *table,
328 int write, void __user *buffer,
329 size_t *length, loff_t *ppos);
330 #endif
331 extern void wait_for_kprobe_optimizer(void);
332 #else
wait_for_kprobe_optimizer(void)333 static inline void wait_for_kprobe_optimizer(void) { }
334 #endif /* CONFIG_OPTPROBES */
335 #ifdef CONFIG_KPROBES_ON_FTRACE
336 extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
337 struct ftrace_ops *ops, struct pt_regs *regs);
338 extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
339 #endif
340
341 int arch_check_ftrace_location(struct kprobe *p);
342
343 /* Get the kprobe at this addr (if any) - called with preemption disabled */
344 struct kprobe *get_kprobe(void *addr);
345 void kretprobe_hash_lock(struct task_struct *tsk,
346 struct hlist_head **head, unsigned long *flags);
347 void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
348 struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
349
350 /* kprobe_running() will just return the current_kprobe on this CPU */
kprobe_running(void)351 static inline struct kprobe *kprobe_running(void)
352 {
353 return (__this_cpu_read(current_kprobe));
354 }
355
reset_current_kprobe(void)356 static inline void reset_current_kprobe(void)
357 {
358 __this_cpu_write(current_kprobe, NULL);
359 }
360
get_kprobe_ctlblk(void)361 static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
362 {
363 return this_cpu_ptr(&kprobe_ctlblk);
364 }
365
366 extern struct kprobe kprobe_busy;
367 void kprobe_busy_begin(void);
368 void kprobe_busy_end(void);
369
370 kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset);
371 int register_kprobe(struct kprobe *p);
372 void unregister_kprobe(struct kprobe *p);
373 int register_kprobes(struct kprobe **kps, int num);
374 void unregister_kprobes(struct kprobe **kps, int num);
375 unsigned long arch_deref_entry_point(void *);
376
377 int register_kretprobe(struct kretprobe *rp);
378 void unregister_kretprobe(struct kretprobe *rp);
379 int register_kretprobes(struct kretprobe **rps, int num);
380 void unregister_kretprobes(struct kretprobe **rps, int num);
381
382 void kprobe_flush_task(struct task_struct *tk);
383 void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
384
385 int disable_kprobe(struct kprobe *kp);
386 int enable_kprobe(struct kprobe *kp);
387
388 void dump_kprobe(struct kprobe *kp);
389
390 #else /* !CONFIG_KPROBES: */
391
kprobes_built_in(void)392 static inline int kprobes_built_in(void)
393 {
394 return 0;
395 }
kprobe_fault_handler(struct pt_regs * regs,int trapnr)396 static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
397 {
398 return 0;
399 }
get_kprobe(void * addr)400 static inline struct kprobe *get_kprobe(void *addr)
401 {
402 return NULL;
403 }
kprobe_running(void)404 static inline struct kprobe *kprobe_running(void)
405 {
406 return NULL;
407 }
register_kprobe(struct kprobe * p)408 static inline int register_kprobe(struct kprobe *p)
409 {
410 return -ENOSYS;
411 }
register_kprobes(struct kprobe ** kps,int num)412 static inline int register_kprobes(struct kprobe **kps, int num)
413 {
414 return -ENOSYS;
415 }
unregister_kprobe(struct kprobe * p)416 static inline void unregister_kprobe(struct kprobe *p)
417 {
418 }
unregister_kprobes(struct kprobe ** kps,int num)419 static inline void unregister_kprobes(struct kprobe **kps, int num)
420 {
421 }
register_kretprobe(struct kretprobe * rp)422 static inline int register_kretprobe(struct kretprobe *rp)
423 {
424 return -ENOSYS;
425 }
register_kretprobes(struct kretprobe ** rps,int num)426 static inline int register_kretprobes(struct kretprobe **rps, int num)
427 {
428 return -ENOSYS;
429 }
unregister_kretprobe(struct kretprobe * rp)430 static inline void unregister_kretprobe(struct kretprobe *rp)
431 {
432 }
unregister_kretprobes(struct kretprobe ** rps,int num)433 static inline void unregister_kretprobes(struct kretprobe **rps, int num)
434 {
435 }
kprobe_flush_task(struct task_struct * tk)436 static inline void kprobe_flush_task(struct task_struct *tk)
437 {
438 }
disable_kprobe(struct kprobe * kp)439 static inline int disable_kprobe(struct kprobe *kp)
440 {
441 return -ENOSYS;
442 }
enable_kprobe(struct kprobe * kp)443 static inline int enable_kprobe(struct kprobe *kp)
444 {
445 return -ENOSYS;
446 }
447 #endif /* CONFIG_KPROBES */
disable_kretprobe(struct kretprobe * rp)448 static inline int disable_kretprobe(struct kretprobe *rp)
449 {
450 return disable_kprobe(&rp->kp);
451 }
enable_kretprobe(struct kretprobe * rp)452 static inline int enable_kretprobe(struct kretprobe *rp)
453 {
454 return enable_kprobe(&rp->kp);
455 }
456
457 #ifndef CONFIG_KPROBES
is_kprobe_insn_slot(unsigned long addr)458 static inline bool is_kprobe_insn_slot(unsigned long addr)
459 {
460 return false;
461 }
462 #endif
463 #ifndef CONFIG_OPTPROBES
is_kprobe_optinsn_slot(unsigned long addr)464 static inline bool is_kprobe_optinsn_slot(unsigned long addr)
465 {
466 return false;
467 }
468 #endif
469
470 #endif /* _LINUX_KPROBES_H */
471