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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*/ |
36dcd67a | 51 | #define __kprobes __attribute__((__section__(".kprobes.text"))) notrace |
dc19835d MH |
52 | #else /* CONFIG_KPROBES */ |
53 | typedef int kprobe_opcode_t; | |
54 | struct arch_specific_insn { | |
55 | int dummy; | |
56 | }; | |
57 | #define __kprobes notrace | |
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 MH |
114 | |
115 | /* Indicates various status flags. Protected by kprobe_mutex. */ | |
116 | u32 flags; | |
1da177e4 LT |
117 | }; |
118 | ||
e8386a0c MH |
119 | /* Kprobe status flags */ |
120 | #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */ | |
121 | ||
122 | static inline int kprobe_gone(struct kprobe *p) | |
123 | { | |
124 | return p->flags & KPROBE_FLAG_GONE; | |
125 | } | |
126 | ||
1da177e4 LT |
127 | /* |
128 | * Special probe type that uses setjmp-longjmp type tricks to resume | |
129 | * execution at a specified entry with a matching prototype corresponding | |
130 | * to the probed function - a trick to enable arguments to become | |
131 | * accessible seamlessly by probe handling logic. | |
132 | * Note: | |
133 | * Because of the way compilers allocate stack space for local variables | |
134 | * etc upfront, regardless of sub-scopes within a function, this mirroring | |
135 | * principle currently works only for probes placed on function entry points. | |
136 | */ | |
137 | struct jprobe { | |
138 | struct kprobe kp; | |
81eae375 | 139 | void *entry; /* probe handling code to jump to */ |
1da177e4 LT |
140 | }; |
141 | ||
9e367d85 ME |
142 | /* For backward compatibility with old code using JPROBE_ENTRY() */ |
143 | #define JPROBE_ENTRY(handler) (handler) | |
144 | ||
b94cce92 HN |
145 | /* |
146 | * Function-return probe - | |
147 | * Note: | |
148 | * User needs to provide a handler function, and initialize maxactive. | |
149 | * maxactive - The maximum number of instances of the probed function that | |
150 | * can be active concurrently. | |
151 | * nmissed - tracks the number of times the probed function's return was | |
152 | * ignored, due to maxactive being too low. | |
153 | * | |
154 | */ | |
155 | struct kretprobe { | |
156 | struct kprobe kp; | |
157 | kretprobe_handler_t handler; | |
f47cd9b5 | 158 | kretprobe_handler_t entry_handler; |
b94cce92 HN |
159 | int maxactive; |
160 | int nmissed; | |
f47cd9b5 | 161 | size_t data_size; |
b94cce92 | 162 | struct hlist_head free_instances; |
ef53d9c5 | 163 | spinlock_t lock; |
b94cce92 HN |
164 | }; |
165 | ||
166 | struct kretprobe_instance { | |
b94cce92 HN |
167 | struct hlist_node hlist; |
168 | struct kretprobe *rp; | |
802eae7c RL |
169 | kprobe_opcode_t *ret_addr; |
170 | struct task_struct *task; | |
f47cd9b5 | 171 | char data[0]; |
b94cce92 HN |
172 | }; |
173 | ||
f438d914 MH |
174 | struct kretprobe_blackpoint { |
175 | const char *name; | |
176 | void *addr; | |
177 | }; | |
3d8d996e SD |
178 | |
179 | struct kprobe_blackpoint { | |
180 | const char *name; | |
181 | unsigned long start_addr; | |
182 | unsigned long range; | |
183 | }; | |
184 | ||
dc19835d MH |
185 | #ifdef CONFIG_KPROBES |
186 | DECLARE_PER_CPU(struct kprobe *, current_kprobe); | |
187 | DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
188 | ||
b1801812 IM |
189 | /* |
190 | * For #ifdef avoidance: | |
191 | */ | |
192 | static inline int kprobes_built_in(void) | |
193 | { | |
194 | return 1; | |
195 | } | |
196 | ||
dc19835d MH |
197 | #ifdef CONFIG_KRETPROBES |
198 | extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, | |
199 | struct pt_regs *regs); | |
200 | extern int arch_trampoline_kprobe(struct kprobe *p); | |
201 | #else /* CONFIG_KRETPROBES */ | |
202 | static inline void arch_prepare_kretprobe(struct kretprobe *rp, | |
203 | struct pt_regs *regs) | |
204 | { | |
205 | } | |
206 | static inline int arch_trampoline_kprobe(struct kprobe *p) | |
207 | { | |
208 | return 0; | |
209 | } | |
210 | #endif /* CONFIG_KRETPROBES */ | |
211 | ||
f438d914 MH |
212 | extern struct kretprobe_blackpoint kretprobe_blacklist[]; |
213 | ||
0f95b7fc AM |
214 | static inline void kretprobe_assert(struct kretprobe_instance *ri, |
215 | unsigned long orig_ret_address, unsigned long trampoline_address) | |
216 | { | |
217 | if (!orig_ret_address || (orig_ret_address == trampoline_address)) { | |
218 | printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", | |
219 | ri->rp, ri->rp->kp.addr); | |
220 | BUG(); | |
221 | } | |
222 | } | |
223 | ||
8c1c9356 AM |
224 | #ifdef CONFIG_KPROBES_SANITY_TEST |
225 | extern int init_test_probes(void); | |
226 | #else | |
227 | static inline int init_test_probes(void) | |
228 | { | |
229 | return 0; | |
230 | } | |
231 | #endif /* CONFIG_KPROBES_SANITY_TEST */ | |
232 | ||
1da177e4 | 233 | extern int arch_prepare_kprobe(struct kprobe *p); |
7e1048b1 RL |
234 | extern void arch_arm_kprobe(struct kprobe *p); |
235 | extern void arch_disarm_kprobe(struct kprobe *p); | |
6772926b | 236 | extern int arch_init_kprobes(void); |
1da177e4 | 237 | extern void show_registers(struct pt_regs *regs); |
9ec4b1f3 | 238 | extern kprobe_opcode_t *get_insn_slot(void); |
b4c6c34a | 239 | extern void free_insn_slot(kprobe_opcode_t *slot, int dirty); |
bf8d5c52 | 240 | extern void kprobes_inc_nmissed_count(struct kprobe *p); |
1da177e4 | 241 | |
d217d545 | 242 | /* Get the kprobe at this addr (if any) - called with preemption disabled */ |
1da177e4 | 243 | struct kprobe *get_kprobe(void *addr); |
ef53d9c5 S |
244 | void kretprobe_hash_lock(struct task_struct *tsk, |
245 | struct hlist_head **head, unsigned long *flags); | |
246 | void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags); | |
b94cce92 | 247 | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); |
1da177e4 | 248 | |
e6584523 AM |
249 | /* kprobe_running() will just return the current_kprobe on this CPU */ |
250 | static inline struct kprobe *kprobe_running(void) | |
251 | { | |
252 | return (__get_cpu_var(current_kprobe)); | |
253 | } | |
254 | ||
255 | static inline void reset_current_kprobe(void) | |
256 | { | |
257 | __get_cpu_var(current_kprobe) = NULL; | |
258 | } | |
259 | ||
260 | static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) | |
261 | { | |
262 | return (&__get_cpu_var(kprobe_ctlblk)); | |
263 | } | |
264 | ||
1da177e4 LT |
265 | int register_kprobe(struct kprobe *p); |
266 | void unregister_kprobe(struct kprobe *p); | |
9861668f MH |
267 | int register_kprobes(struct kprobe **kps, int num); |
268 | void unregister_kprobes(struct kprobe **kps, int num); | |
1da177e4 LT |
269 | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); |
270 | int longjmp_break_handler(struct kprobe *, struct pt_regs *); | |
271 | int register_jprobe(struct jprobe *p); | |
272 | void unregister_jprobe(struct jprobe *p); | |
26b31c19 MH |
273 | int register_jprobes(struct jprobe **jps, int num); |
274 | void unregister_jprobes(struct jprobe **jps, int num); | |
1da177e4 | 275 | void jprobe_return(void); |
3d7e3382 | 276 | unsigned long arch_deref_entry_point(void *); |
1da177e4 | 277 | |
b94cce92 HN |
278 | int register_kretprobe(struct kretprobe *rp); |
279 | void unregister_kretprobe(struct kretprobe *rp); | |
4a296e07 MH |
280 | int register_kretprobes(struct kretprobe **rps, int num); |
281 | void unregister_kretprobes(struct kretprobe **rps, int num); | |
b94cce92 | 282 | |
b94cce92 | 283 | void kprobe_flush_task(struct task_struct *tk); |
99219a3f | 284 | void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); |
8c1c9356 | 285 | |
b1801812 | 286 | #else /* !CONFIG_KPROBES: */ |
00d7c05a | 287 | |
b1801812 IM |
288 | static inline int kprobes_built_in(void) |
289 | { | |
290 | return 0; | |
291 | } | |
292 | static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) | |
293 | { | |
294 | return 0; | |
295 | } | |
785656a4 AS |
296 | static inline struct kprobe *get_kprobe(void *addr) |
297 | { | |
298 | return NULL; | |
299 | } | |
e6584523 | 300 | static inline struct kprobe *kprobe_running(void) |
1da177e4 | 301 | { |
e6584523 | 302 | return NULL; |
1da177e4 LT |
303 | } |
304 | static inline int register_kprobe(struct kprobe *p) | |
305 | { | |
306 | return -ENOSYS; | |
307 | } | |
9861668f MH |
308 | static inline int register_kprobes(struct kprobe **kps, int num) |
309 | { | |
310 | return -ENOSYS; | |
311 | } | |
1da177e4 LT |
312 | static inline void unregister_kprobe(struct kprobe *p) |
313 | { | |
314 | } | |
9861668f MH |
315 | static inline void unregister_kprobes(struct kprobe **kps, int num) |
316 | { | |
317 | } | |
1da177e4 LT |
318 | static inline int register_jprobe(struct jprobe *p) |
319 | { | |
320 | return -ENOSYS; | |
321 | } | |
26b31c19 MH |
322 | static inline int register_jprobes(struct jprobe **jps, int num) |
323 | { | |
324 | return -ENOSYS; | |
325 | } | |
1da177e4 LT |
326 | static inline void unregister_jprobe(struct jprobe *p) |
327 | { | |
328 | } | |
26b31c19 MH |
329 | static inline void unregister_jprobes(struct jprobe **jps, int num) |
330 | { | |
331 | } | |
1da177e4 LT |
332 | static inline void jprobe_return(void) |
333 | { | |
334 | } | |
b94cce92 HN |
335 | static inline int register_kretprobe(struct kretprobe *rp) |
336 | { | |
337 | return -ENOSYS; | |
338 | } | |
4a296e07 MH |
339 | static inline int register_kretprobes(struct kretprobe **rps, int num) |
340 | { | |
341 | return -ENOSYS; | |
342 | } | |
b94cce92 HN |
343 | static inline void unregister_kretprobe(struct kretprobe *rp) |
344 | { | |
345 | } | |
4a296e07 MH |
346 | static inline void unregister_kretprobes(struct kretprobe **rps, int num) |
347 | { | |
348 | } | |
b94cce92 HN |
349 | static inline void kprobe_flush_task(struct task_struct *tk) |
350 | { | |
351 | } | |
b1801812 IM |
352 | #endif /* CONFIG_KPROBES */ |
353 | #endif /* _LINUX_KPROBES_H */ |