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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 | */ |
1da177e4 LT |
32 | #include <linux/list.h> |
33 | #include <linux/notifier.h> | |
34 | #include <linux/smp.h> | |
e6584523 | 35 | #include <linux/percpu.h> |
3516a460 AM |
36 | #include <linux/spinlock.h> |
37 | #include <linux/rcupdate.h> | |
7a7d1cf9 | 38 | #include <linux/mutex.h> |
b94cce92 | 39 | |
00d7c05a | 40 | #ifdef CONFIG_KPROBES |
1da177e4 LT |
41 | #include <asm/kprobes.h> |
42 | ||
ea32c65c PP |
43 | /* kprobe_status settings */ |
44 | #define KPROBE_HIT_ACTIVE 0x00000001 | |
45 | #define KPROBE_HIT_SS 0x00000002 | |
46 | #define KPROBE_REENTER 0x00000004 | |
47 | #define KPROBE_HIT_SSDONE 0x00000008 | |
48 | ||
d0aaff97 PP |
49 | /* Attach to insert probes on any functions which should be ignored*/ |
50 | #define __kprobes __attribute__((__section__(".kprobes.text"))) | |
51 | ||
1da177e4 LT |
52 | struct kprobe; |
53 | struct pt_regs; | |
b94cce92 HN |
54 | struct kretprobe; |
55 | struct kretprobe_instance; | |
1da177e4 LT |
56 | typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *); |
57 | typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *); | |
58 | typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *, | |
59 | unsigned long flags); | |
60 | typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *, | |
61 | int trapnr); | |
b94cce92 HN |
62 | typedef int (*kretprobe_handler_t) (struct kretprobe_instance *, |
63 | struct pt_regs *); | |
64 | ||
1da177e4 LT |
65 | struct kprobe { |
66 | struct hlist_node hlist; | |
67 | ||
64f562c6 AM |
68 | /* list of kprobes for multi-handler support */ |
69 | struct list_head list; | |
70 | ||
df019b1d KA |
71 | /* Indicates that the corresponding module has been ref counted */ |
72 | unsigned int mod_refcounted; | |
73 | ||
ea32c65c PP |
74 | /*count the number of times this probe was temporarily disarmed */ |
75 | unsigned long nmissed; | |
76 | ||
1da177e4 LT |
77 | /* location of the probe point */ |
78 | kprobe_opcode_t *addr; | |
79 | ||
3a872d89 | 80 | /* Allow user to indicate symbol name of the probe point */ |
9b3af29b | 81 | const char *symbol_name; |
3a872d89 AM |
82 | |
83 | /* Offset into the symbol */ | |
84 | unsigned int offset; | |
85 | ||
1da177e4 LT |
86 | /* Called before addr is executed. */ |
87 | kprobe_pre_handler_t pre_handler; | |
88 | ||
89 | /* Called after addr is executed, unless... */ | |
90 | kprobe_post_handler_t post_handler; | |
91 | ||
92 | /* ... called if executing addr causes a fault (eg. page fault). | |
93 | * Return 1 if it handled fault, otherwise kernel will see it. */ | |
94 | kprobe_fault_handler_t fault_handler; | |
95 | ||
96 | /* ... called if breakpoint trap occurs in probe handler. | |
97 | * Return 1 if it handled break, otherwise kernel will see it. */ | |
98 | kprobe_break_handler_t break_handler; | |
99 | ||
100 | /* Saved opcode (which has been replaced with breakpoint) */ | |
101 | kprobe_opcode_t opcode; | |
102 | ||
103 | /* copy of the original instruction */ | |
104 | struct arch_specific_insn ainsn; | |
105 | }; | |
106 | ||
107 | /* | |
108 | * Special probe type that uses setjmp-longjmp type tricks to resume | |
109 | * execution at a specified entry with a matching prototype corresponding | |
110 | * to the probed function - a trick to enable arguments to become | |
111 | * accessible seamlessly by probe handling logic. | |
112 | * Note: | |
113 | * Because of the way compilers allocate stack space for local variables | |
114 | * etc upfront, regardless of sub-scopes within a function, this mirroring | |
115 | * principle currently works only for probes placed on function entry points. | |
116 | */ | |
117 | struct jprobe { | |
118 | struct kprobe kp; | |
81eae375 | 119 | void *entry; /* probe handling code to jump to */ |
1da177e4 LT |
120 | }; |
121 | ||
9e367d85 ME |
122 | /* For backward compatibility with old code using JPROBE_ENTRY() */ |
123 | #define JPROBE_ENTRY(handler) (handler) | |
124 | ||
e6584523 AM |
125 | DECLARE_PER_CPU(struct kprobe *, current_kprobe); |
126 | DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
127 | ||
9edddaa2 | 128 | #ifdef CONFIG_KRETPROBES |
4c4308cb CH |
129 | extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, |
130 | struct pt_regs *regs); | |
bf8f6e5b | 131 | extern int arch_trampoline_kprobe(struct kprobe *p); |
9edddaa2 | 132 | #else /* CONFIG_KRETPROBES */ |
b94cce92 HN |
133 | static inline void arch_prepare_kretprobe(struct kretprobe *rp, |
134 | struct pt_regs *regs) | |
135 | { | |
136 | } | |
bf8f6e5b AM |
137 | static inline int arch_trampoline_kprobe(struct kprobe *p) |
138 | { | |
139 | return 0; | |
140 | } | |
9edddaa2 | 141 | #endif /* CONFIG_KRETPROBES */ |
b94cce92 HN |
142 | /* |
143 | * Function-return probe - | |
144 | * Note: | |
145 | * User needs to provide a handler function, and initialize maxactive. | |
146 | * maxactive - The maximum number of instances of the probed function that | |
147 | * can be active concurrently. | |
148 | * nmissed - tracks the number of times the probed function's return was | |
149 | * ignored, due to maxactive being too low. | |
150 | * | |
151 | */ | |
152 | struct kretprobe { | |
153 | struct kprobe kp; | |
154 | kretprobe_handler_t handler; | |
f47cd9b5 | 155 | kretprobe_handler_t entry_handler; |
b94cce92 HN |
156 | int maxactive; |
157 | int nmissed; | |
f47cd9b5 | 158 | size_t data_size; |
b94cce92 HN |
159 | struct hlist_head free_instances; |
160 | struct hlist_head used_instances; | |
161 | }; | |
162 | ||
163 | struct kretprobe_instance { | |
164 | struct hlist_node uflist; /* either on free list or used list */ | |
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 | ||
3516a460 | 204 | extern spinlock_t kretprobe_lock; |
7a7d1cf9 | 205 | extern struct mutex kprobe_mutex; |
1da177e4 | 206 | extern int arch_prepare_kprobe(struct kprobe *p); |
7e1048b1 RL |
207 | extern void arch_arm_kprobe(struct kprobe *p); |
208 | extern void arch_disarm_kprobe(struct kprobe *p); | |
6772926b | 209 | extern int arch_init_kprobes(void); |
1da177e4 | 210 | extern void show_registers(struct pt_regs *regs); |
9ec4b1f3 | 211 | extern kprobe_opcode_t *get_insn_slot(void); |
b4c6c34a | 212 | extern void free_insn_slot(kprobe_opcode_t *slot, int dirty); |
bf8d5c52 | 213 | extern void kprobes_inc_nmissed_count(struct kprobe *p); |
1da177e4 | 214 | |
d217d545 | 215 | /* Get the kprobe at this addr (if any) - called with preemption disabled */ |
1da177e4 | 216 | struct kprobe *get_kprobe(void *addr); |
b94cce92 | 217 | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); |
1da177e4 | 218 | |
e6584523 AM |
219 | /* kprobe_running() will just return the current_kprobe on this CPU */ |
220 | static inline struct kprobe *kprobe_running(void) | |
221 | { | |
222 | return (__get_cpu_var(current_kprobe)); | |
223 | } | |
224 | ||
225 | static inline void reset_current_kprobe(void) | |
226 | { | |
227 | __get_cpu_var(current_kprobe) = NULL; | |
228 | } | |
229 | ||
230 | static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) | |
231 | { | |
232 | return (&__get_cpu_var(kprobe_ctlblk)); | |
233 | } | |
234 | ||
1da177e4 LT |
235 | int register_kprobe(struct kprobe *p); |
236 | void unregister_kprobe(struct kprobe *p); | |
9861668f MH |
237 | int register_kprobes(struct kprobe **kps, int num); |
238 | void unregister_kprobes(struct kprobe **kps, int num); | |
1da177e4 LT |
239 | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); |
240 | int longjmp_break_handler(struct kprobe *, struct pt_regs *); | |
241 | int register_jprobe(struct jprobe *p); | |
242 | void unregister_jprobe(struct jprobe *p); | |
26b31c19 MH |
243 | int register_jprobes(struct jprobe **jps, int num); |
244 | void unregister_jprobes(struct jprobe **jps, int num); | |
1da177e4 | 245 | void jprobe_return(void); |
3d7e3382 | 246 | unsigned long arch_deref_entry_point(void *); |
1da177e4 | 247 | |
b94cce92 HN |
248 | int register_kretprobe(struct kretprobe *rp); |
249 | void unregister_kretprobe(struct kretprobe *rp); | |
4a296e07 MH |
250 | int register_kretprobes(struct kretprobe **rps, int num); |
251 | void unregister_kretprobes(struct kretprobe **rps, int num); | |
b94cce92 | 252 | |
b94cce92 | 253 | void kprobe_flush_task(struct task_struct *tk); |
99219a3f | 254 | void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); |
8c1c9356 | 255 | |
b94cce92 | 256 | #else /* CONFIG_KPROBES */ |
00d7c05a KA |
257 | |
258 | #define __kprobes /**/ | |
259 | struct jprobe; | |
260 | struct kretprobe; | |
261 | ||
e6584523 | 262 | static inline struct kprobe *kprobe_running(void) |
1da177e4 | 263 | { |
e6584523 | 264 | return NULL; |
1da177e4 LT |
265 | } |
266 | static inline int register_kprobe(struct kprobe *p) | |
267 | { | |
268 | return -ENOSYS; | |
269 | } | |
9861668f MH |
270 | static inline int register_kprobes(struct kprobe **kps, int num) |
271 | { | |
272 | return -ENOSYS; | |
273 | } | |
1da177e4 LT |
274 | static inline void unregister_kprobe(struct kprobe *p) |
275 | { | |
276 | } | |
9861668f MH |
277 | static inline void unregister_kprobes(struct kprobe **kps, int num) |
278 | { | |
279 | } | |
1da177e4 LT |
280 | static inline int register_jprobe(struct jprobe *p) |
281 | { | |
282 | return -ENOSYS; | |
283 | } | |
26b31c19 MH |
284 | static inline int register_jprobes(struct jprobe **jps, int num) |
285 | { | |
286 | return -ENOSYS; | |
287 | } | |
1da177e4 LT |
288 | static inline void unregister_jprobe(struct jprobe *p) |
289 | { | |
290 | } | |
26b31c19 MH |
291 | static inline void unregister_jprobes(struct jprobe **jps, int num) |
292 | { | |
293 | } | |
1da177e4 LT |
294 | static inline void jprobe_return(void) |
295 | { | |
296 | } | |
b94cce92 HN |
297 | static inline int register_kretprobe(struct kretprobe *rp) |
298 | { | |
299 | return -ENOSYS; | |
300 | } | |
4a296e07 MH |
301 | static inline int register_kretprobes(struct kretprobe **rps, int num) |
302 | { | |
303 | return -ENOSYS; | |
304 | } | |
b94cce92 HN |
305 | static inline void unregister_kretprobe(struct kretprobe *rp) |
306 | { | |
307 | } | |
4a296e07 MH |
308 | static inline void unregister_kretprobes(struct kretprobe **rps, int num) |
309 | { | |
310 | } | |
b94cce92 HN |
311 | static inline void kprobe_flush_task(struct task_struct *tk) |
312 | { | |
313 | } | |
314 | #endif /* CONFIG_KPROBES */ | |
1da177e4 | 315 | #endif /* _LINUX_KPROBES_H */ |