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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 |
d0aaff97 | 52 | |
1da177e4 LT |
53 | struct kprobe; |
54 | struct pt_regs; | |
b94cce92 HN |
55 | struct kretprobe; |
56 | struct kretprobe_instance; | |
1da177e4 LT |
57 | typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *); |
58 | typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *); | |
59 | typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *, | |
60 | unsigned long flags); | |
61 | typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *, | |
62 | int trapnr); | |
b94cce92 HN |
63 | typedef int (*kretprobe_handler_t) (struct kretprobe_instance *, |
64 | struct pt_regs *); | |
65 | ||
1da177e4 LT |
66 | struct kprobe { |
67 | struct hlist_node hlist; | |
68 | ||
64f562c6 AM |
69 | /* list of kprobes for multi-handler support */ |
70 | struct list_head list; | |
71 | ||
ea32c65c PP |
72 | /*count the number of times this probe was temporarily disarmed */ |
73 | unsigned long nmissed; | |
74 | ||
1da177e4 LT |
75 | /* location of the probe point */ |
76 | kprobe_opcode_t *addr; | |
77 | ||
3a872d89 | 78 | /* Allow user to indicate symbol name of the probe point */ |
9b3af29b | 79 | const char *symbol_name; |
3a872d89 AM |
80 | |
81 | /* Offset into the symbol */ | |
82 | unsigned int offset; | |
83 | ||
1da177e4 LT |
84 | /* Called before addr is executed. */ |
85 | kprobe_pre_handler_t pre_handler; | |
86 | ||
87 | /* Called after addr is executed, unless... */ | |
88 | kprobe_post_handler_t post_handler; | |
89 | ||
90 | /* ... called if executing addr causes a fault (eg. page fault). | |
91 | * Return 1 if it handled fault, otherwise kernel will see it. */ | |
92 | kprobe_fault_handler_t fault_handler; | |
93 | ||
94 | /* ... called if breakpoint trap occurs in probe handler. | |
95 | * Return 1 if it handled break, otherwise kernel will see it. */ | |
96 | kprobe_break_handler_t break_handler; | |
97 | ||
98 | /* Saved opcode (which has been replaced with breakpoint) */ | |
99 | kprobe_opcode_t opcode; | |
100 | ||
101 | /* copy of the original instruction */ | |
102 | struct arch_specific_insn ainsn; | |
e8386a0c MH |
103 | |
104 | /* Indicates various status flags. Protected by kprobe_mutex. */ | |
105 | u32 flags; | |
1da177e4 LT |
106 | }; |
107 | ||
e8386a0c MH |
108 | /* Kprobe status flags */ |
109 | #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */ | |
110 | ||
111 | static inline int kprobe_gone(struct kprobe *p) | |
112 | { | |
113 | return p->flags & KPROBE_FLAG_GONE; | |
114 | } | |
115 | ||
1da177e4 LT |
116 | /* |
117 | * Special probe type that uses setjmp-longjmp type tricks to resume | |
118 | * execution at a specified entry with a matching prototype corresponding | |
119 | * to the probed function - a trick to enable arguments to become | |
120 | * accessible seamlessly by probe handling logic. | |
121 | * Note: | |
122 | * Because of the way compilers allocate stack space for local variables | |
123 | * etc upfront, regardless of sub-scopes within a function, this mirroring | |
124 | * principle currently works only for probes placed on function entry points. | |
125 | */ | |
126 | struct jprobe { | |
127 | struct kprobe kp; | |
81eae375 | 128 | void *entry; /* probe handling code to jump to */ |
1da177e4 LT |
129 | }; |
130 | ||
9e367d85 ME |
131 | /* For backward compatibility with old code using JPROBE_ENTRY() */ |
132 | #define JPROBE_ENTRY(handler) (handler) | |
133 | ||
e6584523 AM |
134 | DECLARE_PER_CPU(struct kprobe *, current_kprobe); |
135 | DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
136 | ||
9edddaa2 | 137 | #ifdef CONFIG_KRETPROBES |
4c4308cb CH |
138 | extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, |
139 | struct pt_regs *regs); | |
bf8f6e5b | 140 | extern int arch_trampoline_kprobe(struct kprobe *p); |
9edddaa2 | 141 | #else /* CONFIG_KRETPROBES */ |
b94cce92 HN |
142 | static inline void arch_prepare_kretprobe(struct kretprobe *rp, |
143 | struct pt_regs *regs) | |
144 | { | |
145 | } | |
bf8f6e5b AM |
146 | static inline int arch_trampoline_kprobe(struct kprobe *p) |
147 | { | |
148 | return 0; | |
149 | } | |
9edddaa2 | 150 | #endif /* CONFIG_KRETPROBES */ |
b94cce92 HN |
151 | /* |
152 | * Function-return probe - | |
153 | * Note: | |
154 | * User needs to provide a handler function, and initialize maxactive. | |
155 | * maxactive - The maximum number of instances of the probed function that | |
156 | * can be active concurrently. | |
157 | * nmissed - tracks the number of times the probed function's return was | |
158 | * ignored, due to maxactive being too low. | |
159 | * | |
160 | */ | |
161 | struct kretprobe { | |
162 | struct kprobe kp; | |
163 | kretprobe_handler_t handler; | |
f47cd9b5 | 164 | kretprobe_handler_t entry_handler; |
b94cce92 HN |
165 | int maxactive; |
166 | int nmissed; | |
f47cd9b5 | 167 | size_t data_size; |
b94cce92 | 168 | struct hlist_head free_instances; |
ef53d9c5 | 169 | spinlock_t lock; |
b94cce92 HN |
170 | }; |
171 | ||
172 | struct kretprobe_instance { | |
b94cce92 HN |
173 | struct hlist_node hlist; |
174 | struct kretprobe *rp; | |
802eae7c RL |
175 | kprobe_opcode_t *ret_addr; |
176 | struct task_struct *task; | |
f47cd9b5 | 177 | char data[0]; |
b94cce92 HN |
178 | }; |
179 | ||
f438d914 MH |
180 | struct kretprobe_blackpoint { |
181 | const char *name; | |
182 | void *addr; | |
183 | }; | |
3d8d996e SD |
184 | |
185 | struct kprobe_blackpoint { | |
186 | const char *name; | |
187 | unsigned long start_addr; | |
188 | unsigned long range; | |
189 | }; | |
190 | ||
f438d914 MH |
191 | extern struct kretprobe_blackpoint kretprobe_blacklist[]; |
192 | ||
0f95b7fc AM |
193 | static inline void kretprobe_assert(struct kretprobe_instance *ri, |
194 | unsigned long orig_ret_address, unsigned long trampoline_address) | |
195 | { | |
196 | if (!orig_ret_address || (orig_ret_address == trampoline_address)) { | |
197 | printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", | |
198 | ri->rp, ri->rp->kp.addr); | |
199 | BUG(); | |
200 | } | |
201 | } | |
202 | ||
8c1c9356 AM |
203 | #ifdef CONFIG_KPROBES_SANITY_TEST |
204 | extern int init_test_probes(void); | |
205 | #else | |
206 | static inline int init_test_probes(void) | |
207 | { | |
208 | return 0; | |
209 | } | |
210 | #endif /* CONFIG_KPROBES_SANITY_TEST */ | |
211 | ||
1da177e4 | 212 | extern int arch_prepare_kprobe(struct kprobe *p); |
7e1048b1 RL |
213 | extern void arch_arm_kprobe(struct kprobe *p); |
214 | extern void arch_disarm_kprobe(struct kprobe *p); | |
6772926b | 215 | extern int arch_init_kprobes(void); |
1da177e4 | 216 | extern void show_registers(struct pt_regs *regs); |
9ec4b1f3 | 217 | extern kprobe_opcode_t *get_insn_slot(void); |
b4c6c34a | 218 | extern void free_insn_slot(kprobe_opcode_t *slot, int dirty); |
bf8d5c52 | 219 | extern void kprobes_inc_nmissed_count(struct kprobe *p); |
1da177e4 | 220 | |
d217d545 | 221 | /* Get the kprobe at this addr (if any) - called with preemption disabled */ |
1da177e4 | 222 | struct kprobe *get_kprobe(void *addr); |
ef53d9c5 S |
223 | void kretprobe_hash_lock(struct task_struct *tsk, |
224 | struct hlist_head **head, unsigned long *flags); | |
225 | void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags); | |
b94cce92 | 226 | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); |
1da177e4 | 227 | |
e6584523 AM |
228 | /* kprobe_running() will just return the current_kprobe on this CPU */ |
229 | static inline struct kprobe *kprobe_running(void) | |
230 | { | |
231 | return (__get_cpu_var(current_kprobe)); | |
232 | } | |
233 | ||
234 | static inline void reset_current_kprobe(void) | |
235 | { | |
236 | __get_cpu_var(current_kprobe) = NULL; | |
237 | } | |
238 | ||
239 | static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) | |
240 | { | |
241 | return (&__get_cpu_var(kprobe_ctlblk)); | |
242 | } | |
243 | ||
1da177e4 LT |
244 | int register_kprobe(struct kprobe *p); |
245 | void unregister_kprobe(struct kprobe *p); | |
9861668f MH |
246 | int register_kprobes(struct kprobe **kps, int num); |
247 | void unregister_kprobes(struct kprobe **kps, int num); | |
1da177e4 LT |
248 | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); |
249 | int longjmp_break_handler(struct kprobe *, struct pt_regs *); | |
250 | int register_jprobe(struct jprobe *p); | |
251 | void unregister_jprobe(struct jprobe *p); | |
26b31c19 MH |
252 | int register_jprobes(struct jprobe **jps, int num); |
253 | void unregister_jprobes(struct jprobe **jps, int num); | |
1da177e4 | 254 | void jprobe_return(void); |
3d7e3382 | 255 | unsigned long arch_deref_entry_point(void *); |
1da177e4 | 256 | |
b94cce92 HN |
257 | int register_kretprobe(struct kretprobe *rp); |
258 | void unregister_kretprobe(struct kretprobe *rp); | |
4a296e07 MH |
259 | int register_kretprobes(struct kretprobe **rps, int num); |
260 | void unregister_kretprobes(struct kretprobe **rps, int num); | |
b94cce92 | 261 | |
b94cce92 | 262 | void kprobe_flush_task(struct task_struct *tk); |
99219a3f | 263 | void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); |
8c1c9356 | 264 | |
b94cce92 | 265 | #else /* CONFIG_KPROBES */ |
00d7c05a | 266 | |
36dcd67a | 267 | #define __kprobes notrace |
00d7c05a KA |
268 | struct jprobe; |
269 | struct kretprobe; | |
270 | ||
785656a4 AS |
271 | static inline struct kprobe *get_kprobe(void *addr) |
272 | { | |
273 | return NULL; | |
274 | } | |
e6584523 | 275 | static inline struct kprobe *kprobe_running(void) |
1da177e4 | 276 | { |
e6584523 | 277 | return NULL; |
1da177e4 LT |
278 | } |
279 | static inline int register_kprobe(struct kprobe *p) | |
280 | { | |
281 | return -ENOSYS; | |
282 | } | |
9861668f MH |
283 | static inline int register_kprobes(struct kprobe **kps, int num) |
284 | { | |
285 | return -ENOSYS; | |
286 | } | |
1da177e4 LT |
287 | static inline void unregister_kprobe(struct kprobe *p) |
288 | { | |
289 | } | |
9861668f MH |
290 | static inline void unregister_kprobes(struct kprobe **kps, int num) |
291 | { | |
292 | } | |
1da177e4 LT |
293 | static inline int register_jprobe(struct jprobe *p) |
294 | { | |
295 | return -ENOSYS; | |
296 | } | |
26b31c19 MH |
297 | static inline int register_jprobes(struct jprobe **jps, int num) |
298 | { | |
299 | return -ENOSYS; | |
300 | } | |
1da177e4 LT |
301 | static inline void unregister_jprobe(struct jprobe *p) |
302 | { | |
303 | } | |
26b31c19 MH |
304 | static inline void unregister_jprobes(struct jprobe **jps, int num) |
305 | { | |
306 | } | |
1da177e4 LT |
307 | static inline void jprobe_return(void) |
308 | { | |
309 | } | |
b94cce92 HN |
310 | static inline int register_kretprobe(struct kretprobe *rp) |
311 | { | |
312 | return -ENOSYS; | |
313 | } | |
4a296e07 MH |
314 | static inline int register_kretprobes(struct kretprobe **rps, int num) |
315 | { | |
316 | return -ENOSYS; | |
317 | } | |
b94cce92 HN |
318 | static inline void unregister_kretprobe(struct kretprobe *rp) |
319 | { | |
320 | } | |
4a296e07 MH |
321 | static inline void unregister_kretprobes(struct kretprobe **rps, int num) |
322 | { | |
323 | } | |
b94cce92 HN |
324 | static inline void kprobe_flush_task(struct task_struct *tk) |
325 | { | |
326 | } | |
327 | #endif /* CONFIG_KPROBES */ | |
1da177e4 | 328 | #endif /* _LINUX_KPROBES_H */ |