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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> |
ae6aa16f | 41 | #include <linux/ftrace.h> |
b94cce92 | 42 | |
00d7c05a | 43 | #ifdef CONFIG_KPROBES |
1da177e4 LT |
44 | #include <asm/kprobes.h> |
45 | ||
ea32c65c PP |
46 | /* kprobe_status settings */ |
47 | #define KPROBE_HIT_ACTIVE 0x00000001 | |
48 | #define KPROBE_HIT_SS 0x00000002 | |
49 | #define KPROBE_REENTER 0x00000004 | |
50 | #define KPROBE_HIT_SSDONE 0x00000008 | |
51 | ||
ae6aa16f MH |
52 | /* |
53 | * If function tracer is enabled and the arch supports full | |
54 | * passing of pt_regs to function tracing, then kprobes can | |
55 | * optimize on top of function tracing. | |
56 | */ | |
57 | #if defined(CONFIG_FUNCTION_TRACER) && defined(ARCH_SUPPORTS_FTRACE_SAVE_REGS) \ | |
58 | && defined(ARCH_SUPPORTS_KPROBES_ON_FTRACE) | |
59 | # define KPROBES_CAN_USE_FTRACE | |
60 | #endif | |
61 | ||
d0aaff97 | 62 | /* Attach to insert probes on any functions which should be ignored*/ |
fe832a3a | 63 | #define __kprobes __attribute__((__section__(".kprobes.text"))) |
ae6aa16f | 64 | |
dc19835d MH |
65 | #else /* CONFIG_KPROBES */ |
66 | typedef int kprobe_opcode_t; | |
67 | struct arch_specific_insn { | |
68 | int dummy; | |
69 | }; | |
fe832a3a | 70 | #define __kprobes |
ae6aa16f | 71 | |
dc19835d | 72 | #endif /* CONFIG_KPROBES */ |
d0aaff97 | 73 | |
1da177e4 LT |
74 | struct kprobe; |
75 | struct pt_regs; | |
b94cce92 HN |
76 | struct kretprobe; |
77 | struct kretprobe_instance; | |
1da177e4 LT |
78 | typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *); |
79 | typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *); | |
80 | typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *, | |
81 | unsigned long flags); | |
82 | typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *, | |
83 | int trapnr); | |
b94cce92 HN |
84 | typedef int (*kretprobe_handler_t) (struct kretprobe_instance *, |
85 | struct pt_regs *); | |
86 | ||
1da177e4 LT |
87 | struct kprobe { |
88 | struct hlist_node hlist; | |
89 | ||
64f562c6 AM |
90 | /* list of kprobes for multi-handler support */ |
91 | struct list_head list; | |
92 | ||
ea32c65c PP |
93 | /*count the number of times this probe was temporarily disarmed */ |
94 | unsigned long nmissed; | |
95 | ||
1da177e4 LT |
96 | /* location of the probe point */ |
97 | kprobe_opcode_t *addr; | |
98 | ||
3a872d89 | 99 | /* Allow user to indicate symbol name of the probe point */ |
9b3af29b | 100 | const char *symbol_name; |
3a872d89 AM |
101 | |
102 | /* Offset into the symbol */ | |
103 | unsigned int offset; | |
104 | ||
1da177e4 LT |
105 | /* Called before addr is executed. */ |
106 | kprobe_pre_handler_t pre_handler; | |
107 | ||
108 | /* Called after addr is executed, unless... */ | |
109 | kprobe_post_handler_t post_handler; | |
110 | ||
cc00e9cf MH |
111 | /* |
112 | * ... called if executing addr causes a fault (eg. page fault). | |
113 | * Return 1 if it handled fault, otherwise kernel will see it. | |
114 | */ | |
1da177e4 LT |
115 | kprobe_fault_handler_t fault_handler; |
116 | ||
cc00e9cf MH |
117 | /* |
118 | * ... called if breakpoint trap occurs in probe handler. | |
119 | * Return 1 if it handled break, otherwise kernel will see it. | |
120 | */ | |
1da177e4 LT |
121 | kprobe_break_handler_t break_handler; |
122 | ||
123 | /* Saved opcode (which has been replaced with breakpoint) */ | |
124 | kprobe_opcode_t opcode; | |
125 | ||
126 | /* copy of the original instruction */ | |
127 | struct arch_specific_insn ainsn; | |
e8386a0c | 128 | |
de5bd88d MH |
129 | /* |
130 | * Indicates various status flags. | |
131 | * Protected by kprobe_mutex after this kprobe is registered. | |
132 | */ | |
e8386a0c | 133 | u32 flags; |
1da177e4 LT |
134 | }; |
135 | ||
e8386a0c MH |
136 | /* Kprobe status flags */ |
137 | #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */ | |
de5bd88d | 138 | #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */ |
afd66255 MH |
139 | #define KPROBE_FLAG_OPTIMIZED 4 /* |
140 | * probe is really optimized. | |
141 | * NOTE: | |
142 | * this flag is only for optimized_kprobe. | |
143 | */ | |
ae6aa16f | 144 | #define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */ |
e8386a0c | 145 | |
de5bd88d | 146 | /* Has this kprobe gone ? */ |
e8386a0c MH |
147 | static inline int kprobe_gone(struct kprobe *p) |
148 | { | |
149 | return p->flags & KPROBE_FLAG_GONE; | |
150 | } | |
151 | ||
de5bd88d MH |
152 | /* Is this kprobe disabled ? */ |
153 | static inline int kprobe_disabled(struct kprobe *p) | |
154 | { | |
155 | return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE); | |
156 | } | |
afd66255 MH |
157 | |
158 | /* Is this kprobe really running optimized path ? */ | |
159 | static inline int kprobe_optimized(struct kprobe *p) | |
160 | { | |
161 | return p->flags & KPROBE_FLAG_OPTIMIZED; | |
162 | } | |
ae6aa16f MH |
163 | |
164 | /* Is this kprobe uses ftrace ? */ | |
165 | static inline int kprobe_ftrace(struct kprobe *p) | |
166 | { | |
167 | return p->flags & KPROBE_FLAG_FTRACE; | |
168 | } | |
169 | ||
1da177e4 LT |
170 | /* |
171 | * Special probe type that uses setjmp-longjmp type tricks to resume | |
172 | * execution at a specified entry with a matching prototype corresponding | |
173 | * to the probed function - a trick to enable arguments to become | |
174 | * accessible seamlessly by probe handling logic. | |
175 | * Note: | |
176 | * Because of the way compilers allocate stack space for local variables | |
177 | * etc upfront, regardless of sub-scopes within a function, this mirroring | |
178 | * principle currently works only for probes placed on function entry points. | |
179 | */ | |
180 | struct jprobe { | |
181 | struct kprobe kp; | |
81eae375 | 182 | void *entry; /* probe handling code to jump to */ |
1da177e4 LT |
183 | }; |
184 | ||
9e367d85 ME |
185 | /* For backward compatibility with old code using JPROBE_ENTRY() */ |
186 | #define JPROBE_ENTRY(handler) (handler) | |
187 | ||
b94cce92 HN |
188 | /* |
189 | * Function-return probe - | |
190 | * Note: | |
191 | * User needs to provide a handler function, and initialize maxactive. | |
192 | * maxactive - The maximum number of instances of the probed function that | |
193 | * can be active concurrently. | |
194 | * nmissed - tracks the number of times the probed function's return was | |
195 | * ignored, due to maxactive being too low. | |
196 | * | |
197 | */ | |
198 | struct kretprobe { | |
199 | struct kprobe kp; | |
200 | kretprobe_handler_t handler; | |
f47cd9b5 | 201 | kretprobe_handler_t entry_handler; |
b94cce92 HN |
202 | int maxactive; |
203 | int nmissed; | |
f47cd9b5 | 204 | size_t data_size; |
b94cce92 | 205 | struct hlist_head free_instances; |
ec484608 | 206 | raw_spinlock_t lock; |
b94cce92 HN |
207 | }; |
208 | ||
209 | struct kretprobe_instance { | |
b94cce92 HN |
210 | struct hlist_node hlist; |
211 | struct kretprobe *rp; | |
802eae7c RL |
212 | kprobe_opcode_t *ret_addr; |
213 | struct task_struct *task; | |
f47cd9b5 | 214 | char data[0]; |
b94cce92 HN |
215 | }; |
216 | ||
f438d914 MH |
217 | struct kretprobe_blackpoint { |
218 | const char *name; | |
219 | void *addr; | |
220 | }; | |
3d8d996e SD |
221 | |
222 | struct kprobe_blackpoint { | |
223 | const char *name; | |
224 | unsigned long start_addr; | |
225 | unsigned long range; | |
226 | }; | |
227 | ||
dc19835d MH |
228 | #ifdef CONFIG_KPROBES |
229 | DECLARE_PER_CPU(struct kprobe *, current_kprobe); | |
230 | DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
231 | ||
b1801812 IM |
232 | /* |
233 | * For #ifdef avoidance: | |
234 | */ | |
235 | static inline int kprobes_built_in(void) | |
236 | { | |
237 | return 1; | |
238 | } | |
239 | ||
dc19835d MH |
240 | #ifdef CONFIG_KRETPROBES |
241 | extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, | |
242 | struct pt_regs *regs); | |
243 | extern int arch_trampoline_kprobe(struct kprobe *p); | |
244 | #else /* CONFIG_KRETPROBES */ | |
245 | static inline void arch_prepare_kretprobe(struct kretprobe *rp, | |
246 | struct pt_regs *regs) | |
247 | { | |
248 | } | |
249 | static inline int arch_trampoline_kprobe(struct kprobe *p) | |
250 | { | |
251 | return 0; | |
252 | } | |
253 | #endif /* CONFIG_KRETPROBES */ | |
254 | ||
f438d914 MH |
255 | extern struct kretprobe_blackpoint kretprobe_blacklist[]; |
256 | ||
0f95b7fc AM |
257 | static inline void kretprobe_assert(struct kretprobe_instance *ri, |
258 | unsigned long orig_ret_address, unsigned long trampoline_address) | |
259 | { | |
260 | if (!orig_ret_address || (orig_ret_address == trampoline_address)) { | |
261 | printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", | |
262 | ri->rp, ri->rp->kp.addr); | |
263 | BUG(); | |
264 | } | |
265 | } | |
266 | ||
8c1c9356 AM |
267 | #ifdef CONFIG_KPROBES_SANITY_TEST |
268 | extern int init_test_probes(void); | |
269 | #else | |
270 | static inline int init_test_probes(void) | |
271 | { | |
272 | return 0; | |
273 | } | |
274 | #endif /* CONFIG_KPROBES_SANITY_TEST */ | |
275 | ||
1da177e4 | 276 | extern int arch_prepare_kprobe(struct kprobe *p); |
7e1048b1 RL |
277 | extern void arch_arm_kprobe(struct kprobe *p); |
278 | extern void arch_disarm_kprobe(struct kprobe *p); | |
6772926b | 279 | extern int arch_init_kprobes(void); |
1da177e4 | 280 | extern void show_registers(struct pt_regs *regs); |
9ec4b1f3 | 281 | extern kprobe_opcode_t *get_insn_slot(void); |
b4c6c34a | 282 | extern void free_insn_slot(kprobe_opcode_t *slot, int dirty); |
bf8d5c52 | 283 | extern void kprobes_inc_nmissed_count(struct kprobe *p); |
1da177e4 | 284 | |
afd66255 MH |
285 | #ifdef CONFIG_OPTPROBES |
286 | /* | |
287 | * Internal structure for direct jump optimized probe | |
288 | */ | |
289 | struct optimized_kprobe { | |
290 | struct kprobe kp; | |
291 | struct list_head list; /* list for optimizing queue */ | |
292 | struct arch_optimized_insn optinsn; | |
293 | }; | |
294 | ||
295 | /* Architecture dependent functions for direct jump optimization */ | |
296 | extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn); | |
297 | extern int arch_check_optimized_kprobe(struct optimized_kprobe *op); | |
298 | extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op); | |
299 | extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op); | |
cd7ebe22 | 300 | extern void arch_optimize_kprobes(struct list_head *oplist); |
f984ba4e MH |
301 | extern void arch_unoptimize_kprobes(struct list_head *oplist, |
302 | struct list_head *done_list); | |
afd66255 MH |
303 | extern void arch_unoptimize_kprobe(struct optimized_kprobe *op); |
304 | extern kprobe_opcode_t *get_optinsn_slot(void); | |
305 | extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty); | |
306 | extern int arch_within_optimized_kprobe(struct optimized_kprobe *op, | |
307 | unsigned long addr); | |
308 | ||
309 | extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs); | |
b2be84df MH |
310 | |
311 | #ifdef CONFIG_SYSCTL | |
312 | extern int sysctl_kprobes_optimization; | |
313 | extern int proc_kprobes_optimization_handler(struct ctl_table *table, | |
314 | int write, void __user *buffer, | |
315 | size_t *length, loff_t *ppos); | |
316 | #endif | |
317 | ||
afd66255 | 318 | #endif /* CONFIG_OPTPROBES */ |
ae6aa16f MH |
319 | #ifdef KPROBES_CAN_USE_FTRACE |
320 | extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, | |
e5253896 | 321 | struct ftrace_ops *ops, struct pt_regs *regs); |
ae6aa16f MH |
322 | extern int arch_prepare_kprobe_ftrace(struct kprobe *p); |
323 | #endif | |
324 | ||
afd66255 | 325 | |
d217d545 | 326 | /* Get the kprobe at this addr (if any) - called with preemption disabled */ |
1da177e4 | 327 | struct kprobe *get_kprobe(void *addr); |
ef53d9c5 S |
328 | void kretprobe_hash_lock(struct task_struct *tsk, |
329 | struct hlist_head **head, unsigned long *flags); | |
330 | void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags); | |
b94cce92 | 331 | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); |
1da177e4 | 332 | |
e6584523 AM |
333 | /* kprobe_running() will just return the current_kprobe on this CPU */ |
334 | static inline struct kprobe *kprobe_running(void) | |
335 | { | |
b76834bc | 336 | return (__this_cpu_read(current_kprobe)); |
e6584523 AM |
337 | } |
338 | ||
339 | static inline void reset_current_kprobe(void) | |
340 | { | |
b76834bc | 341 | __this_cpu_write(current_kprobe, NULL); |
e6584523 AM |
342 | } |
343 | ||
344 | static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) | |
345 | { | |
346 | return (&__get_cpu_var(kprobe_ctlblk)); | |
347 | } | |
348 | ||
1da177e4 LT |
349 | int register_kprobe(struct kprobe *p); |
350 | void unregister_kprobe(struct kprobe *p); | |
9861668f MH |
351 | int register_kprobes(struct kprobe **kps, int num); |
352 | void unregister_kprobes(struct kprobe **kps, int num); | |
1da177e4 LT |
353 | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); |
354 | int longjmp_break_handler(struct kprobe *, struct pt_regs *); | |
355 | int register_jprobe(struct jprobe *p); | |
356 | void unregister_jprobe(struct jprobe *p); | |
26b31c19 MH |
357 | int register_jprobes(struct jprobe **jps, int num); |
358 | void unregister_jprobes(struct jprobe **jps, int num); | |
1da177e4 | 359 | void jprobe_return(void); |
3d7e3382 | 360 | unsigned long arch_deref_entry_point(void *); |
1da177e4 | 361 | |
b94cce92 HN |
362 | int register_kretprobe(struct kretprobe *rp); |
363 | void unregister_kretprobe(struct kretprobe *rp); | |
4a296e07 MH |
364 | int register_kretprobes(struct kretprobe **rps, int num); |
365 | void unregister_kretprobes(struct kretprobe **rps, int num); | |
b94cce92 | 366 | |
b94cce92 | 367 | void kprobe_flush_task(struct task_struct *tk); |
99219a3f | 368 | void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); |
8c1c9356 | 369 | |
de5bd88d MH |
370 | int disable_kprobe(struct kprobe *kp); |
371 | int enable_kprobe(struct kprobe *kp); | |
372 | ||
24851d24 FW |
373 | void dump_kprobe(struct kprobe *kp); |
374 | ||
b1801812 | 375 | #else /* !CONFIG_KPROBES: */ |
00d7c05a | 376 | |
b1801812 IM |
377 | static inline int kprobes_built_in(void) |
378 | { | |
379 | return 0; | |
380 | } | |
381 | static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) | |
382 | { | |
383 | return 0; | |
384 | } | |
785656a4 AS |
385 | static inline struct kprobe *get_kprobe(void *addr) |
386 | { | |
387 | return NULL; | |
388 | } | |
e6584523 | 389 | static inline struct kprobe *kprobe_running(void) |
1da177e4 | 390 | { |
e6584523 | 391 | return NULL; |
1da177e4 LT |
392 | } |
393 | static inline int register_kprobe(struct kprobe *p) | |
394 | { | |
395 | return -ENOSYS; | |
396 | } | |
9861668f MH |
397 | static inline int register_kprobes(struct kprobe **kps, int num) |
398 | { | |
399 | return -ENOSYS; | |
400 | } | |
1da177e4 LT |
401 | static inline void unregister_kprobe(struct kprobe *p) |
402 | { | |
403 | } | |
9861668f MH |
404 | static inline void unregister_kprobes(struct kprobe **kps, int num) |
405 | { | |
406 | } | |
1da177e4 LT |
407 | static inline int register_jprobe(struct jprobe *p) |
408 | { | |
409 | return -ENOSYS; | |
410 | } | |
26b31c19 MH |
411 | static inline int register_jprobes(struct jprobe **jps, int num) |
412 | { | |
413 | return -ENOSYS; | |
414 | } | |
1da177e4 LT |
415 | static inline void unregister_jprobe(struct jprobe *p) |
416 | { | |
417 | } | |
26b31c19 MH |
418 | static inline void unregister_jprobes(struct jprobe **jps, int num) |
419 | { | |
420 | } | |
1da177e4 LT |
421 | static inline void jprobe_return(void) |
422 | { | |
423 | } | |
b94cce92 HN |
424 | static inline int register_kretprobe(struct kretprobe *rp) |
425 | { | |
426 | return -ENOSYS; | |
427 | } | |
4a296e07 MH |
428 | static inline int register_kretprobes(struct kretprobe **rps, int num) |
429 | { | |
430 | return -ENOSYS; | |
431 | } | |
b94cce92 HN |
432 | static inline void unregister_kretprobe(struct kretprobe *rp) |
433 | { | |
434 | } | |
4a296e07 MH |
435 | static inline void unregister_kretprobes(struct kretprobe **rps, int num) |
436 | { | |
437 | } | |
b94cce92 HN |
438 | static inline void kprobe_flush_task(struct task_struct *tk) |
439 | { | |
440 | } | |
de5bd88d MH |
441 | static inline int disable_kprobe(struct kprobe *kp) |
442 | { | |
443 | return -ENOSYS; | |
444 | } | |
445 | static inline int enable_kprobe(struct kprobe *kp) | |
446 | { | |
447 | return -ENOSYS; | |
448 | } | |
b1801812 | 449 | #endif /* CONFIG_KPROBES */ |
8f9b1528 MH |
450 | static inline int disable_kretprobe(struct kretprobe *rp) |
451 | { | |
452 | return disable_kprobe(&rp->kp); | |
453 | } | |
454 | static inline int enable_kretprobe(struct kretprobe *rp) | |
455 | { | |
456 | return enable_kprobe(&rp->kp); | |
457 | } | |
458 | static inline int disable_jprobe(struct jprobe *jp) | |
459 | { | |
460 | return disable_kprobe(&jp->kp); | |
461 | } | |
462 | static inline int enable_jprobe(struct jprobe *jp) | |
463 | { | |
464 | return enable_kprobe(&jp->kp); | |
465 | } | |
466 | ||
b1801812 | 467 | #endif /* _LINUX_KPROBES_H */ |