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1da177e4 LT |
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. | |
b94cce92 HN |
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. | |
1da177e4 | 31 | */ |
324670b6 | 32 | #include <linux/compiler.h> /* for __kprobes */ |
36dcd67a | 33 | #include <linux/linkage.h> |
1da177e4 LT |
34 | #include <linux/list.h> |
35 | #include <linux/notifier.h> | |
36 | #include <linux/smp.h> | |
187f1882 | 37 | #include <linux/bug.h> |
e6584523 | 38 | #include <linux/percpu.h> |
3516a460 AM |
39 | #include <linux/spinlock.h> |
40 | #include <linux/rcupdate.h> | |
7a7d1cf9 | 41 | #include <linux/mutex.h> |
ae6aa16f | 42 | #include <linux/ftrace.h> |
b94cce92 | 43 | |
00d7c05a | 44 | #ifdef CONFIG_KPROBES |
1da177e4 LT |
45 | #include <asm/kprobes.h> |
46 | ||
ea32c65c PP |
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 | ||
dc19835d MH |
53 | #else /* CONFIG_KPROBES */ |
54 | typedef int kprobe_opcode_t; | |
55 | struct arch_specific_insn { | |
56 | int dummy; | |
57 | }; | |
dc19835d | 58 | #endif /* CONFIG_KPROBES */ |
d0aaff97 | 59 | |
1da177e4 LT |
60 | struct kprobe; |
61 | struct pt_regs; | |
b94cce92 HN |
62 | struct kretprobe; |
63 | struct kretprobe_instance; | |
1da177e4 LT |
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 *, | |
67 | unsigned long flags); | |
68 | typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *, | |
69 | int trapnr); | |
b94cce92 HN |
70 | typedef int (*kretprobe_handler_t) (struct kretprobe_instance *, |
71 | struct pt_regs *); | |
72 | ||
1da177e4 LT |
73 | struct kprobe { |
74 | struct hlist_node hlist; | |
75 | ||
64f562c6 AM |
76 | /* list of kprobes for multi-handler support */ |
77 | struct list_head list; | |
78 | ||
ea32c65c PP |
79 | /*count the number of times this probe was temporarily disarmed */ |
80 | unsigned long nmissed; | |
81 | ||
1da177e4 LT |
82 | /* location of the probe point */ |
83 | kprobe_opcode_t *addr; | |
84 | ||
3a872d89 | 85 | /* Allow user to indicate symbol name of the probe point */ |
9b3af29b | 86 | const char *symbol_name; |
3a872d89 AM |
87 | |
88 | /* Offset into the symbol */ | |
89 | unsigned int offset; | |
90 | ||
1da177e4 LT |
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 | ||
cc00e9cf MH |
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 | */ | |
1da177e4 LT |
101 | kprobe_fault_handler_t fault_handler; |
102 | ||
cc00e9cf MH |
103 | /* |
104 | * ... called if breakpoint trap occurs in probe handler. | |
105 | * Return 1 if it handled break, otherwise kernel will see it. | |
106 | */ | |
1da177e4 LT |
107 | 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; | |
e8386a0c | 114 | |
de5bd88d MH |
115 | /* |
116 | * Indicates various status flags. | |
117 | * Protected by kprobe_mutex after this kprobe is registered. | |
118 | */ | |
e8386a0c | 119 | u32 flags; |
1da177e4 LT |
120 | }; |
121 | ||
e8386a0c MH |
122 | /* Kprobe status flags */ |
123 | #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */ | |
de5bd88d | 124 | #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */ |
afd66255 MH |
125 | #define KPROBE_FLAG_OPTIMIZED 4 /* |
126 | * probe is really optimized. | |
127 | * NOTE: | |
128 | * this flag is only for optimized_kprobe. | |
129 | */ | |
ae6aa16f | 130 | #define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */ |
e8386a0c | 131 | |
de5bd88d | 132 | /* Has this kprobe gone ? */ |
e8386a0c MH |
133 | static inline int kprobe_gone(struct kprobe *p) |
134 | { | |
135 | return p->flags & KPROBE_FLAG_GONE; | |
136 | } | |
137 | ||
de5bd88d MH |
138 | /* Is this kprobe disabled ? */ |
139 | static inline int kprobe_disabled(struct kprobe *p) | |
140 | { | |
141 | return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE); | |
142 | } | |
afd66255 MH |
143 | |
144 | /* Is this kprobe really running optimized path ? */ | |
145 | static inline int kprobe_optimized(struct kprobe *p) | |
146 | { | |
147 | return p->flags & KPROBE_FLAG_OPTIMIZED; | |
148 | } | |
ae6aa16f MH |
149 | |
150 | /* Is this kprobe uses ftrace ? */ | |
151 | static inline int kprobe_ftrace(struct kprobe *p) | |
152 | { | |
153 | return p->flags & KPROBE_FLAG_FTRACE; | |
154 | } | |
155 | ||
1da177e4 LT |
156 | /* |
157 | * Special probe type that uses setjmp-longjmp type tricks to resume | |
158 | * execution at a specified entry with a matching prototype corresponding | |
159 | * to the probed function - a trick to enable arguments to become | |
160 | * accessible seamlessly by probe handling logic. | |
161 | * Note: | |
162 | * Because of the way compilers allocate stack space for local variables | |
163 | * etc upfront, regardless of sub-scopes within a function, this mirroring | |
164 | * principle currently works only for probes placed on function entry points. | |
165 | */ | |
166 | struct jprobe { | |
167 | struct kprobe kp; | |
81eae375 | 168 | void *entry; /* probe handling code to jump to */ |
1da177e4 LT |
169 | }; |
170 | ||
9e367d85 ME |
171 | /* For backward compatibility with old code using JPROBE_ENTRY() */ |
172 | #define JPROBE_ENTRY(handler) (handler) | |
173 | ||
b94cce92 HN |
174 | /* |
175 | * Function-return probe - | |
176 | * Note: | |
177 | * User needs to provide a handler function, and initialize maxactive. | |
178 | * maxactive - The maximum number of instances of the probed function that | |
179 | * can be active concurrently. | |
180 | * nmissed - tracks the number of times the probed function's return was | |
181 | * ignored, due to maxactive being too low. | |
182 | * | |
183 | */ | |
184 | struct kretprobe { | |
185 | struct kprobe kp; | |
186 | kretprobe_handler_t handler; | |
f47cd9b5 | 187 | kretprobe_handler_t entry_handler; |
b94cce92 HN |
188 | int maxactive; |
189 | int nmissed; | |
f47cd9b5 | 190 | size_t data_size; |
b94cce92 | 191 | struct hlist_head free_instances; |
ec484608 | 192 | raw_spinlock_t lock; |
b94cce92 HN |
193 | }; |
194 | ||
195 | struct kretprobe_instance { | |
b94cce92 HN |
196 | struct hlist_node hlist; |
197 | struct kretprobe *rp; | |
802eae7c RL |
198 | kprobe_opcode_t *ret_addr; |
199 | struct task_struct *task; | |
f47cd9b5 | 200 | char data[0]; |
b94cce92 HN |
201 | }; |
202 | ||
f438d914 MH |
203 | struct kretprobe_blackpoint { |
204 | const char *name; | |
205 | void *addr; | |
206 | }; | |
3d8d996e SD |
207 | |
208 | struct kprobe_blackpoint { | |
209 | const char *name; | |
210 | unsigned long start_addr; | |
211 | unsigned long range; | |
212 | }; | |
213 | ||
dc19835d MH |
214 | #ifdef CONFIG_KPROBES |
215 | DECLARE_PER_CPU(struct kprobe *, current_kprobe); | |
216 | DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
217 | ||
b1801812 IM |
218 | /* |
219 | * For #ifdef avoidance: | |
220 | */ | |
221 | static inline int kprobes_built_in(void) | |
222 | { | |
223 | return 1; | |
224 | } | |
225 | ||
dc19835d MH |
226 | #ifdef CONFIG_KRETPROBES |
227 | extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, | |
228 | struct pt_regs *regs); | |
229 | extern int arch_trampoline_kprobe(struct kprobe *p); | |
230 | #else /* CONFIG_KRETPROBES */ | |
231 | static inline void arch_prepare_kretprobe(struct kretprobe *rp, | |
232 | struct pt_regs *regs) | |
233 | { | |
234 | } | |
235 | static inline int arch_trampoline_kprobe(struct kprobe *p) | |
236 | { | |
237 | return 0; | |
238 | } | |
239 | #endif /* CONFIG_KRETPROBES */ | |
240 | ||
f438d914 MH |
241 | extern struct kretprobe_blackpoint kretprobe_blacklist[]; |
242 | ||
0f95b7fc AM |
243 | static inline void kretprobe_assert(struct kretprobe_instance *ri, |
244 | unsigned long orig_ret_address, unsigned long trampoline_address) | |
245 | { | |
246 | if (!orig_ret_address || (orig_ret_address == trampoline_address)) { | |
247 | printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", | |
248 | ri->rp, ri->rp->kp.addr); | |
249 | BUG(); | |
250 | } | |
251 | } | |
252 | ||
8c1c9356 AM |
253 | #ifdef CONFIG_KPROBES_SANITY_TEST |
254 | extern int init_test_probes(void); | |
255 | #else | |
256 | static inline int init_test_probes(void) | |
257 | { | |
258 | return 0; | |
259 | } | |
260 | #endif /* CONFIG_KPROBES_SANITY_TEST */ | |
261 | ||
1da177e4 | 262 | extern int arch_prepare_kprobe(struct kprobe *p); |
7e1048b1 RL |
263 | extern void arch_arm_kprobe(struct kprobe *p); |
264 | extern void arch_disarm_kprobe(struct kprobe *p); | |
6772926b | 265 | extern int arch_init_kprobes(void); |
1da177e4 | 266 | extern void show_registers(struct pt_regs *regs); |
9ec4b1f3 | 267 | extern kprobe_opcode_t *get_insn_slot(void); |
b4c6c34a | 268 | extern void free_insn_slot(kprobe_opcode_t *slot, int dirty); |
bf8d5c52 | 269 | extern void kprobes_inc_nmissed_count(struct kprobe *p); |
1da177e4 | 270 | |
afd66255 MH |
271 | #ifdef CONFIG_OPTPROBES |
272 | /* | |
273 | * Internal structure for direct jump optimized probe | |
274 | */ | |
275 | struct optimized_kprobe { | |
276 | struct kprobe kp; | |
277 | struct list_head list; /* list for optimizing queue */ | |
278 | struct arch_optimized_insn optinsn; | |
279 | }; | |
280 | ||
281 | /* Architecture dependent functions for direct jump optimization */ | |
282 | extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn); | |
283 | extern int arch_check_optimized_kprobe(struct optimized_kprobe *op); | |
284 | extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op); | |
285 | extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op); | |
cd7ebe22 | 286 | extern void arch_optimize_kprobes(struct list_head *oplist); |
f984ba4e MH |
287 | extern void arch_unoptimize_kprobes(struct list_head *oplist, |
288 | struct list_head *done_list); | |
afd66255 MH |
289 | extern void arch_unoptimize_kprobe(struct optimized_kprobe *op); |
290 | extern kprobe_opcode_t *get_optinsn_slot(void); | |
291 | extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty); | |
292 | extern int arch_within_optimized_kprobe(struct optimized_kprobe *op, | |
293 | unsigned long addr); | |
294 | ||
295 | extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs); | |
b2be84df MH |
296 | |
297 | #ifdef CONFIG_SYSCTL | |
298 | extern int sysctl_kprobes_optimization; | |
299 | extern int proc_kprobes_optimization_handler(struct ctl_table *table, | |
300 | int write, void __user *buffer, | |
301 | size_t *length, loff_t *ppos); | |
302 | #endif | |
303 | ||
afd66255 | 304 | #endif /* CONFIG_OPTPROBES */ |
e7dbfe34 | 305 | #ifdef CONFIG_KPROBES_ON_FTRACE |
ae6aa16f | 306 | extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, |
e5253896 | 307 | struct ftrace_ops *ops, struct pt_regs *regs); |
ae6aa16f MH |
308 | extern int arch_prepare_kprobe_ftrace(struct kprobe *p); |
309 | #endif | |
310 | ||
afd66255 | 311 | |
d217d545 | 312 | /* Get the kprobe at this addr (if any) - called with preemption disabled */ |
1da177e4 | 313 | struct kprobe *get_kprobe(void *addr); |
ef53d9c5 S |
314 | void kretprobe_hash_lock(struct task_struct *tsk, |
315 | struct hlist_head **head, unsigned long *flags); | |
316 | void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags); | |
b94cce92 | 317 | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); |
1da177e4 | 318 | |
e6584523 AM |
319 | /* kprobe_running() will just return the current_kprobe on this CPU */ |
320 | static inline struct kprobe *kprobe_running(void) | |
321 | { | |
b76834bc | 322 | return (__this_cpu_read(current_kprobe)); |
e6584523 AM |
323 | } |
324 | ||
325 | static inline void reset_current_kprobe(void) | |
326 | { | |
b76834bc | 327 | __this_cpu_write(current_kprobe, NULL); |
e6584523 AM |
328 | } |
329 | ||
330 | static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) | |
331 | { | |
332 | return (&__get_cpu_var(kprobe_ctlblk)); | |
333 | } | |
334 | ||
1da177e4 LT |
335 | int register_kprobe(struct kprobe *p); |
336 | void unregister_kprobe(struct kprobe *p); | |
9861668f MH |
337 | int register_kprobes(struct kprobe **kps, int num); |
338 | void unregister_kprobes(struct kprobe **kps, int num); | |
1da177e4 LT |
339 | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); |
340 | int longjmp_break_handler(struct kprobe *, struct pt_regs *); | |
341 | int register_jprobe(struct jprobe *p); | |
342 | void unregister_jprobe(struct jprobe *p); | |
26b31c19 MH |
343 | int register_jprobes(struct jprobe **jps, int num); |
344 | void unregister_jprobes(struct jprobe **jps, int num); | |
1da177e4 | 345 | void jprobe_return(void); |
3d7e3382 | 346 | unsigned long arch_deref_entry_point(void *); |
1da177e4 | 347 | |
b94cce92 HN |
348 | int register_kretprobe(struct kretprobe *rp); |
349 | void unregister_kretprobe(struct kretprobe *rp); | |
4a296e07 MH |
350 | int register_kretprobes(struct kretprobe **rps, int num); |
351 | void unregister_kretprobes(struct kretprobe **rps, int num); | |
b94cce92 | 352 | |
b94cce92 | 353 | void kprobe_flush_task(struct task_struct *tk); |
99219a3f | 354 | void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); |
8c1c9356 | 355 | |
de5bd88d MH |
356 | int disable_kprobe(struct kprobe *kp); |
357 | int enable_kprobe(struct kprobe *kp); | |
358 | ||
24851d24 FW |
359 | void dump_kprobe(struct kprobe *kp); |
360 | ||
b1801812 | 361 | #else /* !CONFIG_KPROBES: */ |
00d7c05a | 362 | |
b1801812 IM |
363 | static inline int kprobes_built_in(void) |
364 | { | |
365 | return 0; | |
366 | } | |
367 | static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) | |
368 | { | |
369 | return 0; | |
370 | } | |
785656a4 AS |
371 | static inline struct kprobe *get_kprobe(void *addr) |
372 | { | |
373 | return NULL; | |
374 | } | |
e6584523 | 375 | static inline struct kprobe *kprobe_running(void) |
1da177e4 | 376 | { |
e6584523 | 377 | return NULL; |
1da177e4 LT |
378 | } |
379 | static inline int register_kprobe(struct kprobe *p) | |
380 | { | |
381 | return -ENOSYS; | |
382 | } | |
9861668f MH |
383 | static inline int register_kprobes(struct kprobe **kps, int num) |
384 | { | |
385 | return -ENOSYS; | |
386 | } | |
1da177e4 LT |
387 | static inline void unregister_kprobe(struct kprobe *p) |
388 | { | |
389 | } | |
9861668f MH |
390 | static inline void unregister_kprobes(struct kprobe **kps, int num) |
391 | { | |
392 | } | |
1da177e4 LT |
393 | static inline int register_jprobe(struct jprobe *p) |
394 | { | |
395 | return -ENOSYS; | |
396 | } | |
26b31c19 MH |
397 | static inline int register_jprobes(struct jprobe **jps, int num) |
398 | { | |
399 | return -ENOSYS; | |
400 | } | |
1da177e4 LT |
401 | static inline void unregister_jprobe(struct jprobe *p) |
402 | { | |
403 | } | |
26b31c19 MH |
404 | static inline void unregister_jprobes(struct jprobe **jps, int num) |
405 | { | |
406 | } | |
1da177e4 LT |
407 | static inline void jprobe_return(void) |
408 | { | |
409 | } | |
b94cce92 HN |
410 | static inline int register_kretprobe(struct kretprobe *rp) |
411 | { | |
412 | return -ENOSYS; | |
413 | } | |
4a296e07 MH |
414 | static inline int register_kretprobes(struct kretprobe **rps, int num) |
415 | { | |
416 | return -ENOSYS; | |
417 | } | |
b94cce92 HN |
418 | static inline void unregister_kretprobe(struct kretprobe *rp) |
419 | { | |
420 | } | |
4a296e07 MH |
421 | static inline void unregister_kretprobes(struct kretprobe **rps, int num) |
422 | { | |
423 | } | |
b94cce92 HN |
424 | static inline void kprobe_flush_task(struct task_struct *tk) |
425 | { | |
426 | } | |
de5bd88d MH |
427 | static inline int disable_kprobe(struct kprobe *kp) |
428 | { | |
429 | return -ENOSYS; | |
430 | } | |
431 | static inline int enable_kprobe(struct kprobe *kp) | |
432 | { | |
433 | return -ENOSYS; | |
434 | } | |
b1801812 | 435 | #endif /* CONFIG_KPROBES */ |
8f9b1528 MH |
436 | static inline int disable_kretprobe(struct kretprobe *rp) |
437 | { | |
438 | return disable_kprobe(&rp->kp); | |
439 | } | |
440 | static inline int enable_kretprobe(struct kretprobe *rp) | |
441 | { | |
442 | return enable_kprobe(&rp->kp); | |
443 | } | |
444 | static inline int disable_jprobe(struct jprobe *jp) | |
445 | { | |
446 | return disable_kprobe(&jp->kp); | |
447 | } | |
448 | static inline int enable_jprobe(struct jprobe *jp) | |
449 | { | |
450 | return enable_kprobe(&jp->kp); | |
451 | } | |
452 | ||
b1801812 | 453 | #endif /* _LINUX_KPROBES_H */ |