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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 | ||
df019b1d KA |
72 | /* Indicates that the corresponding module has been ref counted */ |
73 | unsigned int mod_refcounted; | |
74 | ||
ea32c65c PP |
75 | /*count the number of times this probe was temporarily disarmed */ |
76 | unsigned long nmissed; | |
77 | ||
1da177e4 LT |
78 | /* location of the probe point */ |
79 | kprobe_opcode_t *addr; | |
80 | ||
3a872d89 | 81 | /* Allow user to indicate symbol name of the probe point */ |
9b3af29b | 82 | const char *symbol_name; |
3a872d89 AM |
83 | |
84 | /* Offset into the symbol */ | |
85 | unsigned int offset; | |
86 | ||
1da177e4 LT |
87 | /* Called before addr is executed. */ |
88 | kprobe_pre_handler_t pre_handler; | |
89 | ||
90 | /* Called after addr is executed, unless... */ | |
91 | kprobe_post_handler_t post_handler; | |
92 | ||
93 | /* ... called if executing addr causes a fault (eg. page fault). | |
94 | * Return 1 if it handled fault, otherwise kernel will see it. */ | |
95 | kprobe_fault_handler_t fault_handler; | |
96 | ||
97 | /* ... called if breakpoint trap occurs in probe handler. | |
98 | * Return 1 if it handled break, otherwise kernel will see it. */ | |
99 | kprobe_break_handler_t break_handler; | |
100 | ||
101 | /* Saved opcode (which has been replaced with breakpoint) */ | |
102 | kprobe_opcode_t opcode; | |
103 | ||
104 | /* copy of the original instruction */ | |
105 | struct arch_specific_insn ainsn; | |
106 | }; | |
107 | ||
108 | /* | |
109 | * Special probe type that uses setjmp-longjmp type tricks to resume | |
110 | * execution at a specified entry with a matching prototype corresponding | |
111 | * to the probed function - a trick to enable arguments to become | |
112 | * accessible seamlessly by probe handling logic. | |
113 | * Note: | |
114 | * Because of the way compilers allocate stack space for local variables | |
115 | * etc upfront, regardless of sub-scopes within a function, this mirroring | |
116 | * principle currently works only for probes placed on function entry points. | |
117 | */ | |
118 | struct jprobe { | |
119 | struct kprobe kp; | |
81eae375 | 120 | void *entry; /* probe handling code to jump to */ |
1da177e4 LT |
121 | }; |
122 | ||
9e367d85 ME |
123 | /* For backward compatibility with old code using JPROBE_ENTRY() */ |
124 | #define JPROBE_ENTRY(handler) (handler) | |
125 | ||
e6584523 AM |
126 | DECLARE_PER_CPU(struct kprobe *, current_kprobe); |
127 | DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
128 | ||
9edddaa2 | 129 | #ifdef CONFIG_KRETPROBES |
4c4308cb CH |
130 | extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, |
131 | struct pt_regs *regs); | |
bf8f6e5b | 132 | extern int arch_trampoline_kprobe(struct kprobe *p); |
9edddaa2 | 133 | #else /* CONFIG_KRETPROBES */ |
b94cce92 HN |
134 | static inline void arch_prepare_kretprobe(struct kretprobe *rp, |
135 | struct pt_regs *regs) | |
136 | { | |
137 | } | |
bf8f6e5b AM |
138 | static inline int arch_trampoline_kprobe(struct kprobe *p) |
139 | { | |
140 | return 0; | |
141 | } | |
9edddaa2 | 142 | #endif /* CONFIG_KRETPROBES */ |
b94cce92 HN |
143 | /* |
144 | * Function-return probe - | |
145 | * Note: | |
146 | * User needs to provide a handler function, and initialize maxactive. | |
147 | * maxactive - The maximum number of instances of the probed function that | |
148 | * can be active concurrently. | |
149 | * nmissed - tracks the number of times the probed function's return was | |
150 | * ignored, due to maxactive being too low. | |
151 | * | |
152 | */ | |
153 | struct kretprobe { | |
154 | struct kprobe kp; | |
155 | kretprobe_handler_t handler; | |
f47cd9b5 | 156 | kretprobe_handler_t entry_handler; |
b94cce92 HN |
157 | int maxactive; |
158 | int nmissed; | |
f47cd9b5 | 159 | size_t data_size; |
b94cce92 | 160 | struct hlist_head free_instances; |
ef53d9c5 | 161 | spinlock_t lock; |
b94cce92 HN |
162 | }; |
163 | ||
164 | struct kretprobe_instance { | |
b94cce92 HN |
165 | struct hlist_node hlist; |
166 | struct kretprobe *rp; | |
802eae7c RL |
167 | kprobe_opcode_t *ret_addr; |
168 | struct task_struct *task; | |
f47cd9b5 | 169 | char data[0]; |
b94cce92 HN |
170 | }; |
171 | ||
f438d914 MH |
172 | struct kretprobe_blackpoint { |
173 | const char *name; | |
174 | void *addr; | |
175 | }; | |
3d8d996e SD |
176 | |
177 | struct kprobe_blackpoint { | |
178 | const char *name; | |
179 | unsigned long start_addr; | |
180 | unsigned long range; | |
181 | }; | |
182 | ||
f438d914 MH |
183 | extern struct kretprobe_blackpoint kretprobe_blacklist[]; |
184 | ||
0f95b7fc AM |
185 | static inline void kretprobe_assert(struct kretprobe_instance *ri, |
186 | unsigned long orig_ret_address, unsigned long trampoline_address) | |
187 | { | |
188 | if (!orig_ret_address || (orig_ret_address == trampoline_address)) { | |
189 | printk("kretprobe BUG!: Processing kretprobe %p @ %p\n", | |
190 | ri->rp, ri->rp->kp.addr); | |
191 | BUG(); | |
192 | } | |
193 | } | |
194 | ||
8c1c9356 AM |
195 | #ifdef CONFIG_KPROBES_SANITY_TEST |
196 | extern int init_test_probes(void); | |
197 | #else | |
198 | static inline int init_test_probes(void) | |
199 | { | |
200 | return 0; | |
201 | } | |
202 | #endif /* CONFIG_KPROBES_SANITY_TEST */ | |
203 | ||
1da177e4 | 204 | extern int arch_prepare_kprobe(struct kprobe *p); |
7e1048b1 RL |
205 | extern void arch_arm_kprobe(struct kprobe *p); |
206 | extern void arch_disarm_kprobe(struct kprobe *p); | |
6772926b | 207 | extern int arch_init_kprobes(void); |
1da177e4 | 208 | extern void show_registers(struct pt_regs *regs); |
9ec4b1f3 | 209 | extern kprobe_opcode_t *get_insn_slot(void); |
b4c6c34a | 210 | extern void free_insn_slot(kprobe_opcode_t *slot, int dirty); |
bf8d5c52 | 211 | extern void kprobes_inc_nmissed_count(struct kprobe *p); |
1da177e4 | 212 | |
d217d545 | 213 | /* Get the kprobe at this addr (if any) - called with preemption disabled */ |
1da177e4 | 214 | struct kprobe *get_kprobe(void *addr); |
ef53d9c5 S |
215 | void kretprobe_hash_lock(struct task_struct *tsk, |
216 | struct hlist_head **head, unsigned long *flags); | |
217 | void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags); | |
b94cce92 | 218 | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); |
1da177e4 | 219 | |
e6584523 AM |
220 | /* kprobe_running() will just return the current_kprobe on this CPU */ |
221 | static inline struct kprobe *kprobe_running(void) | |
222 | { | |
223 | return (__get_cpu_var(current_kprobe)); | |
224 | } | |
225 | ||
226 | static inline void reset_current_kprobe(void) | |
227 | { | |
228 | __get_cpu_var(current_kprobe) = NULL; | |
229 | } | |
230 | ||
231 | static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) | |
232 | { | |
233 | return (&__get_cpu_var(kprobe_ctlblk)); | |
234 | } | |
235 | ||
1da177e4 LT |
236 | int register_kprobe(struct kprobe *p); |
237 | void unregister_kprobe(struct kprobe *p); | |
9861668f MH |
238 | int register_kprobes(struct kprobe **kps, int num); |
239 | void unregister_kprobes(struct kprobe **kps, int num); | |
1da177e4 LT |
240 | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); |
241 | int longjmp_break_handler(struct kprobe *, struct pt_regs *); | |
242 | int register_jprobe(struct jprobe *p); | |
243 | void unregister_jprobe(struct jprobe *p); | |
26b31c19 MH |
244 | int register_jprobes(struct jprobe **jps, int num); |
245 | void unregister_jprobes(struct jprobe **jps, int num); | |
1da177e4 | 246 | void jprobe_return(void); |
3d7e3382 | 247 | unsigned long arch_deref_entry_point(void *); |
1da177e4 | 248 | |
b94cce92 HN |
249 | int register_kretprobe(struct kretprobe *rp); |
250 | void unregister_kretprobe(struct kretprobe *rp); | |
4a296e07 MH |
251 | int register_kretprobes(struct kretprobe **rps, int num); |
252 | void unregister_kretprobes(struct kretprobe **rps, int num); | |
b94cce92 | 253 | |
b94cce92 | 254 | void kprobe_flush_task(struct task_struct *tk); |
99219a3f | 255 | void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); |
8c1c9356 | 256 | |
b94cce92 | 257 | #else /* CONFIG_KPROBES */ |
00d7c05a | 258 | |
36dcd67a | 259 | #define __kprobes notrace |
00d7c05a KA |
260 | struct jprobe; |
261 | struct kretprobe; | |
262 | ||
785656a4 AS |
263 | static inline struct kprobe *get_kprobe(void *addr) |
264 | { | |
265 | return NULL; | |
266 | } | |
e6584523 | 267 | static inline struct kprobe *kprobe_running(void) |
1da177e4 | 268 | { |
e6584523 | 269 | return NULL; |
1da177e4 LT |
270 | } |
271 | static inline int register_kprobe(struct kprobe *p) | |
272 | { | |
273 | return -ENOSYS; | |
274 | } | |
9861668f MH |
275 | static inline int register_kprobes(struct kprobe **kps, int num) |
276 | { | |
277 | return -ENOSYS; | |
278 | } | |
1da177e4 LT |
279 | static inline void unregister_kprobe(struct kprobe *p) |
280 | { | |
281 | } | |
9861668f MH |
282 | static inline void unregister_kprobes(struct kprobe **kps, int num) |
283 | { | |
284 | } | |
1da177e4 LT |
285 | static inline int register_jprobe(struct jprobe *p) |
286 | { | |
287 | return -ENOSYS; | |
288 | } | |
26b31c19 MH |
289 | static inline int register_jprobes(struct jprobe **jps, int num) |
290 | { | |
291 | return -ENOSYS; | |
292 | } | |
1da177e4 LT |
293 | static inline void unregister_jprobe(struct jprobe *p) |
294 | { | |
295 | } | |
26b31c19 MH |
296 | static inline void unregister_jprobes(struct jprobe **jps, int num) |
297 | { | |
298 | } | |
1da177e4 LT |
299 | static inline void jprobe_return(void) |
300 | { | |
301 | } | |
b94cce92 HN |
302 | static inline int register_kretprobe(struct kretprobe *rp) |
303 | { | |
304 | return -ENOSYS; | |
305 | } | |
4a296e07 MH |
306 | static inline int register_kretprobes(struct kretprobe **rps, int num) |
307 | { | |
308 | return -ENOSYS; | |
309 | } | |
b94cce92 HN |
310 | static inline void unregister_kretprobe(struct kretprobe *rp) |
311 | { | |
312 | } | |
4a296e07 MH |
313 | static inline void unregister_kretprobes(struct kretprobe **rps, int num) |
314 | { | |
315 | } | |
b94cce92 HN |
316 | static inline void kprobe_flush_task(struct task_struct *tk) |
317 | { | |
318 | } | |
319 | #endif /* CONFIG_KPROBES */ | |
1da177e4 | 320 | #endif /* _LINUX_KPROBES_H */ |