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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 AM |
80 | /* Allow user to indicate symbol name of the probe point */ |
81 | char *symbol_name; | |
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; | |
119 | kprobe_opcode_t *entry; /* probe handling code to jump to */ | |
120 | }; | |
121 | ||
e6584523 AM |
122 | DECLARE_PER_CPU(struct kprobe *, current_kprobe); |
123 | DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); | |
124 | ||
b94cce92 | 125 | #ifdef ARCH_SUPPORTS_KRETPROBES |
b94cce92 | 126 | extern void arch_prepare_kretprobe(struct kretprobe *rp, struct pt_regs *regs); |
b94cce92 | 127 | #else /* ARCH_SUPPORTS_KRETPROBES */ |
b94cce92 HN |
128 | static inline void arch_prepare_kretprobe(struct kretprobe *rp, |
129 | struct pt_regs *regs) | |
130 | { | |
131 | } | |
b94cce92 HN |
132 | #endif /* ARCH_SUPPORTS_KRETPROBES */ |
133 | /* | |
134 | * Function-return probe - | |
135 | * Note: | |
136 | * User needs to provide a handler function, and initialize maxactive. | |
137 | * maxactive - The maximum number of instances of the probed function that | |
138 | * can be active concurrently. | |
139 | * nmissed - tracks the number of times the probed function's return was | |
140 | * ignored, due to maxactive being too low. | |
141 | * | |
142 | */ | |
143 | struct kretprobe { | |
144 | struct kprobe kp; | |
145 | kretprobe_handler_t handler; | |
146 | int maxactive; | |
147 | int nmissed; | |
148 | struct hlist_head free_instances; | |
149 | struct hlist_head used_instances; | |
150 | }; | |
151 | ||
152 | struct kretprobe_instance { | |
153 | struct hlist_node uflist; /* either on free list or used list */ | |
154 | struct hlist_node hlist; | |
155 | struct kretprobe *rp; | |
802eae7c RL |
156 | kprobe_opcode_t *ret_addr; |
157 | struct task_struct *task; | |
b94cce92 HN |
158 | }; |
159 | ||
3516a460 | 160 | extern spinlock_t kretprobe_lock; |
7a7d1cf9 | 161 | extern struct mutex kprobe_mutex; |
1da177e4 | 162 | extern int arch_prepare_kprobe(struct kprobe *p); |
7e1048b1 RL |
163 | extern void arch_arm_kprobe(struct kprobe *p); |
164 | extern void arch_disarm_kprobe(struct kprobe *p); | |
6772926b | 165 | extern int arch_init_kprobes(void); |
1da177e4 | 166 | extern void show_registers(struct pt_regs *regs); |
9ec4b1f3 AM |
167 | extern kprobe_opcode_t *get_insn_slot(void); |
168 | extern void free_insn_slot(kprobe_opcode_t *slot); | |
bf8d5c52 | 169 | extern void kprobes_inc_nmissed_count(struct kprobe *p); |
1da177e4 | 170 | |
d217d545 | 171 | /* Get the kprobe at this addr (if any) - called with preemption disabled */ |
1da177e4 | 172 | struct kprobe *get_kprobe(void *addr); |
b94cce92 | 173 | struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk); |
1da177e4 | 174 | |
e6584523 AM |
175 | /* kprobe_running() will just return the current_kprobe on this CPU */ |
176 | static inline struct kprobe *kprobe_running(void) | |
177 | { | |
178 | return (__get_cpu_var(current_kprobe)); | |
179 | } | |
180 | ||
181 | static inline void reset_current_kprobe(void) | |
182 | { | |
183 | __get_cpu_var(current_kprobe) = NULL; | |
184 | } | |
185 | ||
186 | static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) | |
187 | { | |
188 | return (&__get_cpu_var(kprobe_ctlblk)); | |
189 | } | |
190 | ||
1da177e4 LT |
191 | int register_kprobe(struct kprobe *p); |
192 | void unregister_kprobe(struct kprobe *p); | |
193 | int setjmp_pre_handler(struct kprobe *, struct pt_regs *); | |
194 | int longjmp_break_handler(struct kprobe *, struct pt_regs *); | |
195 | int register_jprobe(struct jprobe *p); | |
196 | void unregister_jprobe(struct jprobe *p); | |
197 | void jprobe_return(void); | |
198 | ||
b94cce92 HN |
199 | int register_kretprobe(struct kretprobe *rp); |
200 | void unregister_kretprobe(struct kretprobe *rp); | |
201 | ||
202 | struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp); | |
b94cce92 HN |
203 | void add_rp_inst(struct kretprobe_instance *ri); |
204 | void kprobe_flush_task(struct task_struct *tk); | |
99219a3f | 205 | void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head); |
b94cce92 | 206 | #else /* CONFIG_KPROBES */ |
00d7c05a KA |
207 | |
208 | #define __kprobes /**/ | |
209 | struct jprobe; | |
210 | struct kretprobe; | |
211 | ||
e6584523 | 212 | static inline struct kprobe *kprobe_running(void) |
1da177e4 | 213 | { |
e6584523 | 214 | return NULL; |
1da177e4 LT |
215 | } |
216 | static inline int register_kprobe(struct kprobe *p) | |
217 | { | |
218 | return -ENOSYS; | |
219 | } | |
220 | static inline void unregister_kprobe(struct kprobe *p) | |
221 | { | |
222 | } | |
223 | static inline int register_jprobe(struct jprobe *p) | |
224 | { | |
225 | return -ENOSYS; | |
226 | } | |
227 | static inline void unregister_jprobe(struct jprobe *p) | |
228 | { | |
229 | } | |
230 | static inline void jprobe_return(void) | |
231 | { | |
232 | } | |
b94cce92 HN |
233 | static inline int register_kretprobe(struct kretprobe *rp) |
234 | { | |
235 | return -ENOSYS; | |
236 | } | |
237 | static inline void unregister_kretprobe(struct kretprobe *rp) | |
238 | { | |
239 | } | |
240 | static inline void kprobe_flush_task(struct task_struct *tk) | |
241 | { | |
242 | } | |
243 | #endif /* CONFIG_KPROBES */ | |
1da177e4 | 244 | #endif /* _LINUX_KPROBES_H */ |