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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 | */ |
36dcd67a | 32 | #include <linux/linkage.h> |
1da177e4 LT |
33 | #include <linux/list.h> |
34 | #include <linux/notifier.h> | |
35 | #include <linux/smp.h> | |
e6584523 | 36 | #include <linux/percpu.h> |
3516a460 AM |
37 | #include <linux/spinlock.h> |
38 | #include <linux/rcupdate.h> | |
7a7d1cf9 | 39 | #include <linux/mutex.h> |
b94cce92 | 40 | |
00d7c05a | 41 | #ifdef CONFIG_KPROBES |
1da177e4 LT |
42 | #include <asm/kprobes.h> |
43 | ||
ea32c65c PP |
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 | |
49 | ||
d0aaff97 | 50 | /* Attach to insert probes on any functions which should be ignored*/ |
fe832a3a | 51 | #define __kprobes __attribute__((__section__(".kprobes.text"))) |
dc19835d MH |
52 | #else /* CONFIG_KPROBES */ |
53 | typedef int kprobe_opcode_t; | |
54 | struct arch_specific_insn { | |
55 | int dummy; | |
56 | }; | |
fe832a3a | 57 | #define __kprobes |
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 | */ | |
e8386a0c | 130 | |
de5bd88d | 131 | /* Has this kprobe gone ? */ |
e8386a0c MH |
132 | static inline int kprobe_gone(struct kprobe *p) |
133 | { | |
134 | return p->flags & KPROBE_FLAG_GONE; | |
135 | } | |
136 | ||
de5bd88d MH |
137 | /* Is this kprobe disabled ? */ |
138 | static inline int kprobe_disabled(struct kprobe *p) | |
139 | { | |
140 | return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE); | |
141 | } | |
afd66255 MH |
142 | |
143 | /* Is this kprobe really running optimized path ? */ | |
144 | static inline int kprobe_optimized(struct kprobe *p) | |
145 | { | |
146 | return p->flags & KPROBE_FLAG_OPTIMIZED; | |
147 | } | |
1da177e4 LT |
148 | /* |
149 | * Special probe type that uses setjmp-longjmp type tricks to resume | |
150 | * execution at a specified entry with a matching prototype corresponding | |
151 | * to the probed function - a trick to enable arguments to become | |
152 | * accessible seamlessly by probe handling logic. | |
153 | * Note: | |
154 | * Because of the way compilers allocate stack space for local variables | |
155 | * etc upfront, regardless of sub-scopes within a function, this mirroring | |
156 | * principle currently works only for probes placed on function entry points. | |
157 | */ | |
158 | struct jprobe { | |
159 | struct kprobe kp; | |
81eae375 | 160 | void *entry; /* probe handling code to jump to */ |
1da177e4 LT |
161 | }; |
162 | ||
9e367d85 ME |
163 | /* For backward compatibility with old code using JPROBE_ENTRY() */ |
164 | #define JPROBE_ENTRY(handler) (handler) | |
165 | ||
b94cce92 HN |
166 | /* |
167 | * Function-return probe - | |
168 | * Note: | |
169 | * User needs to provide a handler function, and initialize maxactive. | |
170 | * maxactive - The maximum number of instances of the probed function that | |
171 | * can be active concurrently. | |
172 | * nmissed - tracks the number of times the probed function's return was | |
173 | * ignored, due to maxactive being too low. | |
174 | * | |
175 | */ | |
176 | struct kretprobe { | |
177 | struct kprobe kp; | |
178 | kretprobe_handler_t handler; | |
f47cd9b5 | 179 | kretprobe_handler_t entry_handler; |
b94cce92 HN |
180 | int maxactive; |
181 | int nmissed; | |
f47cd9b5 | 182 | size_t data_size; |
b94cce92 | 183 | struct hlist_head free_instances; |
ec484608 | 184 | raw_spinlock_t lock; |
b94cce92 HN |
185 | }; |
186 | ||
187 | struct kretprobe_instance { | |
b94cce92 HN |
188 | struct hlist_node hlist; |
189 | struct kretprobe *rp; | |
802eae7c RL |
190 | kprobe_opcode_t *ret_addr; |
191 | struct task_struct *task; | |
f47cd9b5 | 192 | char data[0]; |
b94cce92 HN |
193 | }; |
194 | ||
f438d914 MH |
195 | struct kretprobe_blackpoint { |
196 | const char *name; | |
197 | void *addr; | |
198 | }; | |
3d8d996e SD |
199 | |
200 | struct kprobe_blackpoint { | |
201 | const char *name; | |
202 | unsigned long start_addr; | |
203 | unsigned long range; | |
204 | }; | |
205 | ||
dc19835d MH |
206 | #ifdef CONFIG_KPROBES |
207 | DECLARE_PER_CPU(struct kprobe *, current_kprobe); | |
208 | DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
209 | ||
b1801812 IM |
210 | /* |
211 | * For #ifdef avoidance: | |
212 | */ | |
213 | static inline int kprobes_built_in(void) | |
214 | { | |
215 | return 1; | |
216 | } | |
217 | ||
dc19835d MH |
218 | #ifdef CONFIG_KRETPROBES |
219 | extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, | |
220 | struct pt_regs *regs); | |
221 | extern int arch_trampoline_kprobe(struct kprobe *p); | |
222 | #else /* CONFIG_KRETPROBES */ | |
223 | static inline void arch_prepare_kretprobe(struct kretprobe *rp, | |
224 | struct pt_regs *regs) | |
225 | { | |
226 | } | |
227 | static inline int arch_trampoline_kprobe(struct kprobe *p) | |
228 | { | |
229 | return 0; | |
230 | } | |
231 | #endif /* CONFIG_KRETPROBES */ | |
232 | ||
f438d914 MH |
233 | extern struct kretprobe_blackpoint kretprobe_blacklist[]; |
234 | ||
0f95b7fc AM |
235 | static inline void kretprobe_assert(struct kretprobe_instance *ri, |
236 | unsigned long orig_ret_address, unsigned long trampoline_address) | |
237 | { | |
238 | if (!orig_ret_address || (orig_ret_address == trampoline_address)) { | |
239 | printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", | |
240 | ri->rp, ri->rp->kp.addr); | |
241 | BUG(); | |
242 | } | |
243 | } | |
244 | ||
8c1c9356 AM |
245 | #ifdef CONFIG_KPROBES_SANITY_TEST |
246 | extern int init_test_probes(void); | |
247 | #else | |
248 | static inline int init_test_probes(void) | |
249 | { | |
250 | return 0; | |
251 | } | |
252 | #endif /* CONFIG_KPROBES_SANITY_TEST */ | |
253 | ||
1da177e4 | 254 | extern int arch_prepare_kprobe(struct kprobe *p); |
7e1048b1 RL |
255 | extern void arch_arm_kprobe(struct kprobe *p); |
256 | extern void arch_disarm_kprobe(struct kprobe *p); | |
6772926b | 257 | extern int arch_init_kprobes(void); |
1da177e4 | 258 | extern void show_registers(struct pt_regs *regs); |
9ec4b1f3 | 259 | extern kprobe_opcode_t *get_insn_slot(void); |
b4c6c34a | 260 | extern void free_insn_slot(kprobe_opcode_t *slot, int dirty); |
bf8d5c52 | 261 | extern void kprobes_inc_nmissed_count(struct kprobe *p); |
1da177e4 | 262 | |
afd66255 MH |
263 | #ifdef CONFIG_OPTPROBES |
264 | /* | |
265 | * Internal structure for direct jump optimized probe | |
266 | */ | |
267 | struct optimized_kprobe { | |
268 | struct kprobe kp; | |
269 | struct list_head list; /* list for optimizing queue */ | |
270 | struct arch_optimized_insn optinsn; | |
271 | }; | |
272 | ||
273 | /* Architecture dependent functions for direct jump optimization */ | |
274 | extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn); | |
275 | extern int arch_check_optimized_kprobe(struct optimized_kprobe *op); | |
276 | extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op); | |
277 | extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op); | |
cd7ebe22 | 278 | extern void arch_optimize_kprobes(struct list_head *oplist); |
f984ba4e MH |
279 | extern void arch_unoptimize_kprobes(struct list_head *oplist, |
280 | struct list_head *done_list); | |
afd66255 MH |
281 | extern void arch_unoptimize_kprobe(struct optimized_kprobe *op); |
282 | extern kprobe_opcode_t *get_optinsn_slot(void); | |
283 | extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty); | |
284 | extern int arch_within_optimized_kprobe(struct optimized_kprobe *op, | |
285 | unsigned long addr); | |
286 | ||
287 | extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs); | |
b2be84df MH |
288 | |
289 | #ifdef CONFIG_SYSCTL | |
290 | extern int sysctl_kprobes_optimization; | |
291 | extern int proc_kprobes_optimization_handler(struct ctl_table *table, | |
292 | int write, void __user *buffer, | |
293 | size_t *length, loff_t *ppos); | |
294 | #endif | |
295 | ||
afd66255 MH |
296 | #endif /* CONFIG_OPTPROBES */ |
297 | ||
d217d545 | 298 | /* Get the kprobe at this addr (if any) - called with preemption disabled */ |
1da177e4 | 299 | struct kprobe *get_kprobe(void *addr); |
ef53d9c5 S |
300 | void kretprobe_hash_lock(struct task_struct *tsk, |
301 | struct hlist_head **head, unsigned long *flags); | |
302 | void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags); | |
b94cce92 | 303 | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); |
1da177e4 | 304 | |
e6584523 AM |
305 | /* kprobe_running() will just return the current_kprobe on this CPU */ |
306 | static inline struct kprobe *kprobe_running(void) | |
307 | { | |
b76834bc | 308 | return (__this_cpu_read(current_kprobe)); |
e6584523 AM |
309 | } |
310 | ||
311 | static inline void reset_current_kprobe(void) | |
312 | { | |
b76834bc | 313 | __this_cpu_write(current_kprobe, NULL); |
e6584523 AM |
314 | } |
315 | ||
316 | static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) | |
317 | { | |
318 | return (&__get_cpu_var(kprobe_ctlblk)); | |
319 | } | |
320 | ||
1da177e4 LT |
321 | int register_kprobe(struct kprobe *p); |
322 | void unregister_kprobe(struct kprobe *p); | |
9861668f MH |
323 | int register_kprobes(struct kprobe **kps, int num); |
324 | void unregister_kprobes(struct kprobe **kps, int num); | |
1da177e4 LT |
325 | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); |
326 | int longjmp_break_handler(struct kprobe *, struct pt_regs *); | |
327 | int register_jprobe(struct jprobe *p); | |
328 | void unregister_jprobe(struct jprobe *p); | |
26b31c19 MH |
329 | int register_jprobes(struct jprobe **jps, int num); |
330 | void unregister_jprobes(struct jprobe **jps, int num); | |
1da177e4 | 331 | void jprobe_return(void); |
3d7e3382 | 332 | unsigned long arch_deref_entry_point(void *); |
1da177e4 | 333 | |
b94cce92 HN |
334 | int register_kretprobe(struct kretprobe *rp); |
335 | void unregister_kretprobe(struct kretprobe *rp); | |
4a296e07 MH |
336 | int register_kretprobes(struct kretprobe **rps, int num); |
337 | void unregister_kretprobes(struct kretprobe **rps, int num); | |
b94cce92 | 338 | |
b94cce92 | 339 | void kprobe_flush_task(struct task_struct *tk); |
99219a3f | 340 | void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); |
8c1c9356 | 341 | |
de5bd88d MH |
342 | int disable_kprobe(struct kprobe *kp); |
343 | int enable_kprobe(struct kprobe *kp); | |
344 | ||
24851d24 FW |
345 | void dump_kprobe(struct kprobe *kp); |
346 | ||
b1801812 | 347 | #else /* !CONFIG_KPROBES: */ |
00d7c05a | 348 | |
b1801812 IM |
349 | static inline int kprobes_built_in(void) |
350 | { | |
351 | return 0; | |
352 | } | |
353 | static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) | |
354 | { | |
355 | return 0; | |
356 | } | |
785656a4 AS |
357 | static inline struct kprobe *get_kprobe(void *addr) |
358 | { | |
359 | return NULL; | |
360 | } | |
e6584523 | 361 | static inline struct kprobe *kprobe_running(void) |
1da177e4 | 362 | { |
e6584523 | 363 | return NULL; |
1da177e4 LT |
364 | } |
365 | static inline int register_kprobe(struct kprobe *p) | |
366 | { | |
367 | return -ENOSYS; | |
368 | } | |
9861668f MH |
369 | static inline int register_kprobes(struct kprobe **kps, int num) |
370 | { | |
371 | return -ENOSYS; | |
372 | } | |
1da177e4 LT |
373 | static inline void unregister_kprobe(struct kprobe *p) |
374 | { | |
375 | } | |
9861668f MH |
376 | static inline void unregister_kprobes(struct kprobe **kps, int num) |
377 | { | |
378 | } | |
1da177e4 LT |
379 | static inline int register_jprobe(struct jprobe *p) |
380 | { | |
381 | return -ENOSYS; | |
382 | } | |
26b31c19 MH |
383 | static inline int register_jprobes(struct jprobe **jps, int num) |
384 | { | |
385 | return -ENOSYS; | |
386 | } | |
1da177e4 LT |
387 | static inline void unregister_jprobe(struct jprobe *p) |
388 | { | |
389 | } | |
26b31c19 MH |
390 | static inline void unregister_jprobes(struct jprobe **jps, int num) |
391 | { | |
392 | } | |
1da177e4 LT |
393 | static inline void jprobe_return(void) |
394 | { | |
395 | } | |
b94cce92 HN |
396 | static inline int register_kretprobe(struct kretprobe *rp) |
397 | { | |
398 | return -ENOSYS; | |
399 | } | |
4a296e07 MH |
400 | static inline int register_kretprobes(struct kretprobe **rps, int num) |
401 | { | |
402 | return -ENOSYS; | |
403 | } | |
b94cce92 HN |
404 | static inline void unregister_kretprobe(struct kretprobe *rp) |
405 | { | |
406 | } | |
4a296e07 MH |
407 | static inline void unregister_kretprobes(struct kretprobe **rps, int num) |
408 | { | |
409 | } | |
b94cce92 HN |
410 | static inline void kprobe_flush_task(struct task_struct *tk) |
411 | { | |
412 | } | |
de5bd88d MH |
413 | static inline int disable_kprobe(struct kprobe *kp) |
414 | { | |
415 | return -ENOSYS; | |
416 | } | |
417 | static inline int enable_kprobe(struct kprobe *kp) | |
418 | { | |
419 | return -ENOSYS; | |
420 | } | |
b1801812 | 421 | #endif /* CONFIG_KPROBES */ |
8f9b1528 MH |
422 | static inline int disable_kretprobe(struct kretprobe *rp) |
423 | { | |
424 | return disable_kprobe(&rp->kp); | |
425 | } | |
426 | static inline int enable_kretprobe(struct kretprobe *rp) | |
427 | { | |
428 | return enable_kprobe(&rp->kp); | |
429 | } | |
430 | static inline int disable_jprobe(struct jprobe *jp) | |
431 | { | |
432 | return disable_kprobe(&jp->kp); | |
433 | } | |
434 | static inline int enable_jprobe(struct jprobe *jp) | |
435 | { | |
436 | return enable_kprobe(&jp->kp); | |
437 | } | |
438 | ||
b1801812 | 439 | #endif /* _LINUX_KPROBES_H */ |