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 char data[0];
177 };
178
179 struct kretprobe_blackpoint {
180 const char *name;
181 void *addr;
182 };
183
184 struct kprobe_blacklist_entry {
185 struct list_head list;
186 unsigned long start_addr;
187 unsigned long end_addr;
188 };
189
190 #ifdef CONFIG_KPROBES
191 DECLARE_PER_CPU(struct kprobe *, current_kprobe);
192 DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
193
194 /*
195 * For #ifdef avoidance:
196 */
kprobes_built_in(void)197 static inline int kprobes_built_in(void)
198 {
199 return 1;
200 }
201
202 #ifdef CONFIG_KRETPROBES
203 extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
204 struct pt_regs *regs);
205 extern int arch_trampoline_kprobe(struct kprobe *p);
206 #else /* CONFIG_KRETPROBES */
arch_prepare_kretprobe(struct kretprobe * rp,struct pt_regs * regs)207 static inline void arch_prepare_kretprobe(struct kretprobe *rp,
208 struct pt_regs *regs)
209 {
210 }
arch_trampoline_kprobe(struct kprobe * p)211 static inline int arch_trampoline_kprobe(struct kprobe *p)
212 {
213 return 0;
214 }
215 #endif /* CONFIG_KRETPROBES */
216
217 extern struct kretprobe_blackpoint kretprobe_blacklist[];
218
kretprobe_assert(struct kretprobe_instance * ri,unsigned long orig_ret_address,unsigned long trampoline_address)219 static inline void kretprobe_assert(struct kretprobe_instance *ri,
220 unsigned long orig_ret_address, unsigned long trampoline_address)
221 {
222 if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
223 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
224 ri->rp, ri->rp->kp.addr);
225 BUG();
226 }
227 }
228
229 #ifdef CONFIG_KPROBES_SANITY_TEST
230 extern int init_test_probes(void);
231 #else
init_test_probes(void)232 static inline int init_test_probes(void)
233 {
234 return 0;
235 }
236 #endif /* CONFIG_KPROBES_SANITY_TEST */
237
238 extern int arch_prepare_kprobe(struct kprobe *p);
239 extern void arch_arm_kprobe(struct kprobe *p);
240 extern void arch_disarm_kprobe(struct kprobe *p);
241 extern int arch_init_kprobes(void);
242 extern void show_registers(struct pt_regs *regs);
243 extern void kprobes_inc_nmissed_count(struct kprobe *p);
244 extern bool arch_within_kprobe_blacklist(unsigned long addr);
245 extern bool arch_kprobe_on_func_entry(unsigned long offset);
246 extern bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset);
247
248 extern bool within_kprobe_blacklist(unsigned long addr);
249
250 struct kprobe_insn_cache {
251 struct mutex mutex;
252 void *(*alloc)(void); /* allocate insn page */
253 void (*free)(void *); /* free insn page */
254 struct list_head pages; /* list of kprobe_insn_page */
255 size_t insn_size; /* size of instruction slot */
256 int nr_garbage;
257 };
258
259 #ifdef __ARCH_WANT_KPROBES_INSN_SLOT
260 extern kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c);
261 extern void __free_insn_slot(struct kprobe_insn_cache *c,
262 kprobe_opcode_t *slot, int dirty);
263 /* sleep-less address checking routine */
264 extern bool __is_insn_slot_addr(struct kprobe_insn_cache *c,
265 unsigned long addr);
266
267 #define DEFINE_INSN_CACHE_OPS(__name) \
268 extern struct kprobe_insn_cache kprobe_##__name##_slots; \
269 \
270 static inline kprobe_opcode_t *get_##__name##_slot(void) \
271 { \
272 return __get_insn_slot(&kprobe_##__name##_slots); \
273 } \
274 \
275 static inline void free_##__name##_slot(kprobe_opcode_t *slot, int dirty)\
276 { \
277 __free_insn_slot(&kprobe_##__name##_slots, slot, dirty); \
278 } \
279 \
280 static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
281 { \
282 return __is_insn_slot_addr(&kprobe_##__name##_slots, addr); \
283 }
284 #else /* __ARCH_WANT_KPROBES_INSN_SLOT */
285 #define DEFINE_INSN_CACHE_OPS(__name) \
286 static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
287 { \
288 return 0; \
289 }
290 #endif
291
292 DEFINE_INSN_CACHE_OPS(insn);
293
294 #ifdef CONFIG_OPTPROBES
295 /*
296 * Internal structure for direct jump optimized probe
297 */
298 struct optimized_kprobe {
299 struct kprobe kp;
300 struct list_head list; /* list for optimizing queue */
301 struct arch_optimized_insn optinsn;
302 };
303
304 /* Architecture dependent functions for direct jump optimization */
305 extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
306 extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
307 extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op,
308 struct kprobe *orig);
309 extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
310 extern void arch_optimize_kprobes(struct list_head *oplist);
311 extern void arch_unoptimize_kprobes(struct list_head *oplist,
312 struct list_head *done_list);
313 extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
314 extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
315 unsigned long addr);
316
317 extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
318
319 DEFINE_INSN_CACHE_OPS(optinsn);
320
321 #ifdef CONFIG_SYSCTL
322 extern int sysctl_kprobes_optimization;
323 extern int proc_kprobes_optimization_handler(struct ctl_table *table,
324 int write, void __user *buffer,
325 size_t *length, loff_t *ppos);
326 #endif
327 extern void wait_for_kprobe_optimizer(void);
328 #else
wait_for_kprobe_optimizer(void)329 static inline void wait_for_kprobe_optimizer(void) { }
330 #endif /* CONFIG_OPTPROBES */
331 #ifdef CONFIG_KPROBES_ON_FTRACE
332 extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
333 struct ftrace_ops *ops, struct pt_regs *regs);
334 extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
335 #endif
336
337 int arch_check_ftrace_location(struct kprobe *p);
338
339 /* Get the kprobe at this addr (if any) - called with preemption disabled */
340 struct kprobe *get_kprobe(void *addr);
341 void kretprobe_hash_lock(struct task_struct *tsk,
342 struct hlist_head **head, unsigned long *flags);
343 void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
344 struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
345
346 /* kprobe_running() will just return the current_kprobe on this CPU */
kprobe_running(void)347 static inline struct kprobe *kprobe_running(void)
348 {
349 return (__this_cpu_read(current_kprobe));
350 }
351
reset_current_kprobe(void)352 static inline void reset_current_kprobe(void)
353 {
354 __this_cpu_write(current_kprobe, NULL);
355 }
356
get_kprobe_ctlblk(void)357 static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
358 {
359 return this_cpu_ptr(&kprobe_ctlblk);
360 }
361
362 kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset);
363 int register_kprobe(struct kprobe *p);
364 void unregister_kprobe(struct kprobe *p);
365 int register_kprobes(struct kprobe **kps, int num);
366 void unregister_kprobes(struct kprobe **kps, int num);
367 unsigned long arch_deref_entry_point(void *);
368
369 int register_kretprobe(struct kretprobe *rp);
370 void unregister_kretprobe(struct kretprobe *rp);
371 int register_kretprobes(struct kretprobe **rps, int num);
372 void unregister_kretprobes(struct kretprobe **rps, int num);
373
374 void kprobe_flush_task(struct task_struct *tk);
375 void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
376
377 int disable_kprobe(struct kprobe *kp);
378 int enable_kprobe(struct kprobe *kp);
379
380 void dump_kprobe(struct kprobe *kp);
381
382 #else /* !CONFIG_KPROBES: */
383
kprobes_built_in(void)384 static inline int kprobes_built_in(void)
385 {
386 return 0;
387 }
kprobe_fault_handler(struct pt_regs * regs,int trapnr)388 static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
389 {
390 return 0;
391 }
get_kprobe(void * addr)392 static inline struct kprobe *get_kprobe(void *addr)
393 {
394 return NULL;
395 }
kprobe_running(void)396 static inline struct kprobe *kprobe_running(void)
397 {
398 return NULL;
399 }
register_kprobe(struct kprobe * p)400 static inline int register_kprobe(struct kprobe *p)
401 {
402 return -ENOSYS;
403 }
register_kprobes(struct kprobe ** kps,int num)404 static inline int register_kprobes(struct kprobe **kps, int num)
405 {
406 return -ENOSYS;
407 }
unregister_kprobe(struct kprobe * p)408 static inline void unregister_kprobe(struct kprobe *p)
409 {
410 }
unregister_kprobes(struct kprobe ** kps,int num)411 static inline void unregister_kprobes(struct kprobe **kps, int num)
412 {
413 }
register_kretprobe(struct kretprobe * rp)414 static inline int register_kretprobe(struct kretprobe *rp)
415 {
416 return -ENOSYS;
417 }
register_kretprobes(struct kretprobe ** rps,int num)418 static inline int register_kretprobes(struct kretprobe **rps, int num)
419 {
420 return -ENOSYS;
421 }
unregister_kretprobe(struct kretprobe * rp)422 static inline void unregister_kretprobe(struct kretprobe *rp)
423 {
424 }
unregister_kretprobes(struct kretprobe ** rps,int num)425 static inline void unregister_kretprobes(struct kretprobe **rps, int num)
426 {
427 }
kprobe_flush_task(struct task_struct * tk)428 static inline void kprobe_flush_task(struct task_struct *tk)
429 {
430 }
disable_kprobe(struct kprobe * kp)431 static inline int disable_kprobe(struct kprobe *kp)
432 {
433 return -ENOSYS;
434 }
enable_kprobe(struct kprobe * kp)435 static inline int enable_kprobe(struct kprobe *kp)
436 {
437 return -ENOSYS;
438 }
439 #endif /* CONFIG_KPROBES */
disable_kretprobe(struct kretprobe * rp)440 static inline int disable_kretprobe(struct kretprobe *rp)
441 {
442 return disable_kprobe(&rp->kp);
443 }
enable_kretprobe(struct kretprobe * rp)444 static inline int enable_kretprobe(struct kretprobe *rp)
445 {
446 return enable_kprobe(&rp->kp);
447 }
448
449 #ifndef CONFIG_KPROBES
is_kprobe_insn_slot(unsigned long addr)450 static inline bool is_kprobe_insn_slot(unsigned long addr)
451 {
452 return false;
453 }
454 #endif
455 #ifndef CONFIG_OPTPROBES
is_kprobe_optinsn_slot(unsigned long addr)456 static inline bool is_kprobe_optinsn_slot(unsigned long addr)
457 {
458 return false;
459 }
460 #endif
461
462 #endif /* _LINUX_KPROBES_H */
463
