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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> | |
187f1882 | 36 | #include <linux/bug.h> |
e6584523 | 37 | #include <linux/percpu.h> |
3516a460 AM |
38 | #include <linux/spinlock.h> |
39 | #include <linux/rcupdate.h> | |
7a7d1cf9 | 40 | #include <linux/mutex.h> |
b94cce92 | 41 | |
00d7c05a | 42 | #ifdef CONFIG_KPROBES |
1da177e4 LT |
43 | #include <asm/kprobes.h> |
44 | ||
ea32c65c PP |
45 | /* kprobe_status settings */ |
46 | #define KPROBE_HIT_ACTIVE 0x00000001 | |
47 | #define KPROBE_HIT_SS 0x00000002 | |
48 | #define KPROBE_REENTER 0x00000004 | |
49 | #define KPROBE_HIT_SSDONE 0x00000008 | |
50 | ||
d0aaff97 | 51 | /* Attach to insert probes on any functions which should be ignored*/ |
fe832a3a | 52 | #define __kprobes __attribute__((__section__(".kprobes.text"))) |
dc19835d MH |
53 | #else /* CONFIG_KPROBES */ |
54 | typedef int kprobe_opcode_t; | |
55 | struct arch_specific_insn { | |
56 | int dummy; | |
57 | }; | |
fe832a3a | 58 | #define __kprobes |
dc19835d | 59 | #endif /* CONFIG_KPROBES */ |
d0aaff97 | 60 | |
1da177e4 LT |
61 | struct kprobe; |
62 | struct pt_regs; | |
b94cce92 HN |
63 | struct kretprobe; |
64 | struct kretprobe_instance; | |
1da177e4 LT |
65 | typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *); |
66 | typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *); | |
67 | typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *, | |
68 | unsigned long flags); | |
69 | typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *, | |
70 | int trapnr); | |
b94cce92 HN |
71 | typedef int (*kretprobe_handler_t) (struct kretprobe_instance *, |
72 | struct pt_regs *); | |
73 | ||
1da177e4 LT |
74 | struct kprobe { |
75 | struct hlist_node hlist; | |
76 | ||
64f562c6 AM |
77 | /* list of kprobes for multi-handler support */ |
78 | struct list_head list; | |
79 | ||
ea32c65c PP |
80 | /*count the number of times this probe was temporarily disarmed */ |
81 | unsigned long nmissed; | |
82 | ||
1da177e4 LT |
83 | /* location of the probe point */ |
84 | kprobe_opcode_t *addr; | |
85 | ||
3a872d89 | 86 | /* Allow user to indicate symbol name of the probe point */ |
9b3af29b | 87 | const char *symbol_name; |
3a872d89 AM |
88 | |
89 | /* Offset into the symbol */ | |
90 | unsigned int offset; | |
91 | ||
1da177e4 LT |
92 | /* Called before addr is executed. */ |
93 | kprobe_pre_handler_t pre_handler; | |
94 | ||
95 | /* Called after addr is executed, unless... */ | |
96 | kprobe_post_handler_t post_handler; | |
97 | ||
cc00e9cf MH |
98 | /* |
99 | * ... called if executing addr causes a fault (eg. page fault). | |
100 | * Return 1 if it handled fault, otherwise kernel will see it. | |
101 | */ | |
1da177e4 LT |
102 | kprobe_fault_handler_t fault_handler; |
103 | ||
cc00e9cf MH |
104 | /* |
105 | * ... called if breakpoint trap occurs in probe handler. | |
106 | * Return 1 if it handled break, otherwise kernel will see it. | |
107 | */ | |
1da177e4 LT |
108 | kprobe_break_handler_t break_handler; |
109 | ||
110 | /* Saved opcode (which has been replaced with breakpoint) */ | |
111 | kprobe_opcode_t opcode; | |
112 | ||
113 | /* copy of the original instruction */ | |
114 | struct arch_specific_insn ainsn; | |
e8386a0c | 115 | |
de5bd88d MH |
116 | /* |
117 | * Indicates various status flags. | |
118 | * Protected by kprobe_mutex after this kprobe is registered. | |
119 | */ | |
e8386a0c | 120 | u32 flags; |
1da177e4 LT |
121 | }; |
122 | ||
e8386a0c MH |
123 | /* Kprobe status flags */ |
124 | #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */ | |
de5bd88d | 125 | #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */ |
afd66255 MH |
126 | #define KPROBE_FLAG_OPTIMIZED 4 /* |
127 | * probe is really optimized. | |
128 | * NOTE: | |
129 | * this flag is only for optimized_kprobe. | |
130 | */ | |
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 | } | |
1da177e4 LT |
149 | /* |
150 | * Special probe type that uses setjmp-longjmp type tricks to resume | |
151 | * execution at a specified entry with a matching prototype corresponding | |
152 | * to the probed function - a trick to enable arguments to become | |
153 | * accessible seamlessly by probe handling logic. | |
154 | * Note: | |
155 | * Because of the way compilers allocate stack space for local variables | |
156 | * etc upfront, regardless of sub-scopes within a function, this mirroring | |
157 | * principle currently works only for probes placed on function entry points. | |
158 | */ | |
159 | struct jprobe { | |
160 | struct kprobe kp; | |
81eae375 | 161 | void *entry; /* probe handling code to jump to */ |
1da177e4 LT |
162 | }; |
163 | ||
9e367d85 ME |
164 | /* For backward compatibility with old code using JPROBE_ENTRY() */ |
165 | #define JPROBE_ENTRY(handler) (handler) | |
166 | ||
b94cce92 HN |
167 | /* |
168 | * Function-return probe - | |
169 | * Note: | |
170 | * User needs to provide a handler function, and initialize maxactive. | |
171 | * maxactive - The maximum number of instances of the probed function that | |
172 | * can be active concurrently. | |
173 | * nmissed - tracks the number of times the probed function's return was | |
174 | * ignored, due to maxactive being too low. | |
175 | * | |
176 | */ | |
177 | struct kretprobe { | |
178 | struct kprobe kp; | |
179 | kretprobe_handler_t handler; | |
f47cd9b5 | 180 | kretprobe_handler_t entry_handler; |
b94cce92 HN |
181 | int maxactive; |
182 | int nmissed; | |
f47cd9b5 | 183 | size_t data_size; |
b94cce92 | 184 | struct hlist_head free_instances; |
ec484608 | 185 | raw_spinlock_t lock; |
b94cce92 HN |
186 | }; |
187 | ||
188 | struct kretprobe_instance { | |
b94cce92 HN |
189 | struct hlist_node hlist; |
190 | struct kretprobe *rp; | |
802eae7c RL |
191 | kprobe_opcode_t *ret_addr; |
192 | struct task_struct *task; | |
f47cd9b5 | 193 | char data[0]; |
b94cce92 HN |
194 | }; |
195 | ||
f438d914 MH |
196 | struct kretprobe_blackpoint { |
197 | const char *name; | |
198 | void *addr; | |
199 | }; | |
3d8d996e SD |
200 | |
201 | struct kprobe_blackpoint { | |
202 | const char *name; | |
203 | unsigned long start_addr; | |
204 | unsigned long range; | |
205 | }; | |
206 | ||
dc19835d MH |
207 | #ifdef CONFIG_KPROBES |
208 | DECLARE_PER_CPU(struct kprobe *, current_kprobe); | |
209 | DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
210 | ||
b1801812 IM |
211 | /* |
212 | * For #ifdef avoidance: | |
213 | */ | |
214 | static inline int kprobes_built_in(void) | |
215 | { | |
216 | return 1; | |
217 | } | |
218 | ||
dc19835d MH |
219 | #ifdef CONFIG_KRETPROBES |
220 | extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, | |
221 | struct pt_regs *regs); | |
222 | extern int arch_trampoline_kprobe(struct kprobe *p); | |
223 | #else /* CONFIG_KRETPROBES */ | |
224 | static inline void arch_prepare_kretprobe(struct kretprobe *rp, | |
225 | struct pt_regs *regs) | |
226 | { | |
227 | } | |
228 | static inline int arch_trampoline_kprobe(struct kprobe *p) | |
229 | { | |
230 | return 0; | |
231 | } | |
232 | #endif /* CONFIG_KRETPROBES */ | |
233 | ||
f438d914 MH |
234 | extern struct kretprobe_blackpoint kretprobe_blacklist[]; |
235 | ||
0f95b7fc AM |
236 | static inline void kretprobe_assert(struct kretprobe_instance *ri, |
237 | unsigned long orig_ret_address, unsigned long trampoline_address) | |
238 | { | |
239 | if (!orig_ret_address || (orig_ret_address == trampoline_address)) { | |
240 | printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", | |
241 | ri->rp, ri->rp->kp.addr); | |
242 | BUG(); | |
243 | } | |
244 | } | |
245 | ||
8c1c9356 AM |
246 | #ifdef CONFIG_KPROBES_SANITY_TEST |
247 | extern int init_test_probes(void); | |
248 | #else | |
249 | static inline int init_test_probes(void) | |
250 | { | |
251 | return 0; | |
252 | } | |
253 | #endif /* CONFIG_KPROBES_SANITY_TEST */ | |
254 | ||
1da177e4 | 255 | extern int arch_prepare_kprobe(struct kprobe *p); |
7e1048b1 RL |
256 | extern void arch_arm_kprobe(struct kprobe *p); |
257 | extern void arch_disarm_kprobe(struct kprobe *p); | |
6772926b | 258 | extern int arch_init_kprobes(void); |
1da177e4 | 259 | extern void show_registers(struct pt_regs *regs); |
9ec4b1f3 | 260 | extern kprobe_opcode_t *get_insn_slot(void); |
b4c6c34a | 261 | extern void free_insn_slot(kprobe_opcode_t *slot, int dirty); |
bf8d5c52 | 262 | extern void kprobes_inc_nmissed_count(struct kprobe *p); |
1da177e4 | 263 | |
afd66255 MH |
264 | #ifdef CONFIG_OPTPROBES |
265 | /* | |
266 | * Internal structure for direct jump optimized probe | |
267 | */ | |
268 | struct optimized_kprobe { | |
269 | struct kprobe kp; | |
270 | struct list_head list; /* list for optimizing queue */ | |
271 | struct arch_optimized_insn optinsn; | |
272 | }; | |
273 | ||
274 | /* Architecture dependent functions for direct jump optimization */ | |
275 | extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn); | |
276 | extern int arch_check_optimized_kprobe(struct optimized_kprobe *op); | |
277 | extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op); | |
278 | extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op); | |
cd7ebe22 | 279 | extern void arch_optimize_kprobes(struct list_head *oplist); |
f984ba4e MH |
280 | extern void arch_unoptimize_kprobes(struct list_head *oplist, |
281 | struct list_head *done_list); | |
afd66255 MH |
282 | extern void arch_unoptimize_kprobe(struct optimized_kprobe *op); |
283 | extern kprobe_opcode_t *get_optinsn_slot(void); | |
284 | extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty); | |
285 | extern int arch_within_optimized_kprobe(struct optimized_kprobe *op, | |
286 | unsigned long addr); | |
287 | ||
288 | extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs); | |
b2be84df MH |
289 | |
290 | #ifdef CONFIG_SYSCTL | |
291 | extern int sysctl_kprobes_optimization; | |
292 | extern int proc_kprobes_optimization_handler(struct ctl_table *table, | |
293 | int write, void __user *buffer, | |
294 | size_t *length, loff_t *ppos); | |
295 | #endif | |
296 | ||
afd66255 MH |
297 | #endif /* CONFIG_OPTPROBES */ |
298 | ||
d217d545 | 299 | /* Get the kprobe at this addr (if any) - called with preemption disabled */ |
1da177e4 | 300 | struct kprobe *get_kprobe(void *addr); |
ef53d9c5 S |
301 | void kretprobe_hash_lock(struct task_struct *tsk, |
302 | struct hlist_head **head, unsigned long *flags); | |
303 | void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags); | |
b94cce92 | 304 | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); |
1da177e4 | 305 | |
e6584523 AM |
306 | /* kprobe_running() will just return the current_kprobe on this CPU */ |
307 | static inline struct kprobe *kprobe_running(void) | |
308 | { | |
b76834bc | 309 | return (__this_cpu_read(current_kprobe)); |
e6584523 AM |
310 | } |
311 | ||
312 | static inline void reset_current_kprobe(void) | |
313 | { | |
b76834bc | 314 | __this_cpu_write(current_kprobe, NULL); |
e6584523 AM |
315 | } |
316 | ||
317 | static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) | |
318 | { | |
319 | return (&__get_cpu_var(kprobe_ctlblk)); | |
320 | } | |
321 | ||
1da177e4 LT |
322 | int register_kprobe(struct kprobe *p); |
323 | void unregister_kprobe(struct kprobe *p); | |
9861668f MH |
324 | int register_kprobes(struct kprobe **kps, int num); |
325 | void unregister_kprobes(struct kprobe **kps, int num); | |
1da177e4 LT |
326 | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); |
327 | int longjmp_break_handler(struct kprobe *, struct pt_regs *); | |
328 | int register_jprobe(struct jprobe *p); | |
329 | void unregister_jprobe(struct jprobe *p); | |
26b31c19 MH |
330 | int register_jprobes(struct jprobe **jps, int num); |
331 | void unregister_jprobes(struct jprobe **jps, int num); | |
1da177e4 | 332 | void jprobe_return(void); |
3d7e3382 | 333 | unsigned long arch_deref_entry_point(void *); |
1da177e4 | 334 | |
b94cce92 HN |
335 | int register_kretprobe(struct kretprobe *rp); |
336 | void unregister_kretprobe(struct kretprobe *rp); | |
4a296e07 MH |
337 | int register_kretprobes(struct kretprobe **rps, int num); |
338 | void unregister_kretprobes(struct kretprobe **rps, int num); | |
b94cce92 | 339 | |
b94cce92 | 340 | void kprobe_flush_task(struct task_struct *tk); |
99219a3f | 341 | void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); |
8c1c9356 | 342 | |
de5bd88d MH |
343 | int disable_kprobe(struct kprobe *kp); |
344 | int enable_kprobe(struct kprobe *kp); | |
345 | ||
24851d24 FW |
346 | void dump_kprobe(struct kprobe *kp); |
347 | ||
b1801812 | 348 | #else /* !CONFIG_KPROBES: */ |
00d7c05a | 349 | |
b1801812 IM |
350 | static inline int kprobes_built_in(void) |
351 | { | |
352 | return 0; | |
353 | } | |
354 | static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) | |
355 | { | |
356 | return 0; | |
357 | } | |
785656a4 AS |
358 | static inline struct kprobe *get_kprobe(void *addr) |
359 | { | |
360 | return NULL; | |
361 | } | |
e6584523 | 362 | static inline struct kprobe *kprobe_running(void) |
1da177e4 | 363 | { |
e6584523 | 364 | return NULL; |
1da177e4 LT |
365 | } |
366 | static inline int register_kprobe(struct kprobe *p) | |
367 | { | |
368 | return -ENOSYS; | |
369 | } | |
9861668f MH |
370 | static inline int register_kprobes(struct kprobe **kps, int num) |
371 | { | |
372 | return -ENOSYS; | |
373 | } | |
1da177e4 LT |
374 | static inline void unregister_kprobe(struct kprobe *p) |
375 | { | |
376 | } | |
9861668f MH |
377 | static inline void unregister_kprobes(struct kprobe **kps, int num) |
378 | { | |
379 | } | |
1da177e4 LT |
380 | static inline int register_jprobe(struct jprobe *p) |
381 | { | |
382 | return -ENOSYS; | |
383 | } | |
26b31c19 MH |
384 | static inline int register_jprobes(struct jprobe **jps, int num) |
385 | { | |
386 | return -ENOSYS; | |
387 | } | |
1da177e4 LT |
388 | static inline void unregister_jprobe(struct jprobe *p) |
389 | { | |
390 | } | |
26b31c19 MH |
391 | static inline void unregister_jprobes(struct jprobe **jps, int num) |
392 | { | |
393 | } | |
1da177e4 LT |
394 | static inline void jprobe_return(void) |
395 | { | |
396 | } | |
b94cce92 HN |
397 | static inline int register_kretprobe(struct kretprobe *rp) |
398 | { | |
399 | return -ENOSYS; | |
400 | } | |
4a296e07 MH |
401 | static inline int register_kretprobes(struct kretprobe **rps, int num) |
402 | { | |
403 | return -ENOSYS; | |
404 | } | |
b94cce92 HN |
405 | static inline void unregister_kretprobe(struct kretprobe *rp) |
406 | { | |
407 | } | |
4a296e07 MH |
408 | static inline void unregister_kretprobes(struct kretprobe **rps, int num) |
409 | { | |
410 | } | |
b94cce92 HN |
411 | static inline void kprobe_flush_task(struct task_struct *tk) |
412 | { | |
413 | } | |
de5bd88d MH |
414 | static inline int disable_kprobe(struct kprobe *kp) |
415 | { | |
416 | return -ENOSYS; | |
417 | } | |
418 | static inline int enable_kprobe(struct kprobe *kp) | |
419 | { | |
420 | return -ENOSYS; | |
421 | } | |
b1801812 | 422 | #endif /* CONFIG_KPROBES */ |
8f9b1528 MH |
423 | static inline int disable_kretprobe(struct kretprobe *rp) |
424 | { | |
425 | return disable_kprobe(&rp->kp); | |
426 | } | |
427 | static inline int enable_kretprobe(struct kretprobe *rp) | |
428 | { | |
429 | return enable_kprobe(&rp->kp); | |
430 | } | |
431 | static inline int disable_jprobe(struct jprobe *jp) | |
432 | { | |
433 | return disable_kprobe(&jp->kp); | |
434 | } | |
435 | static inline int enable_jprobe(struct jprobe *jp) | |
436 | { | |
437 | return enable_kprobe(&jp->kp); | |
438 | } | |
439 | ||
b1801812 | 440 | #endif /* _LINUX_KPROBES_H */ |