tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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.
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.
31 */
32#include <linux/linkage.h>
33#include <linux/list.h>
34#include <linux/notifier.h>
35#include <linux/smp.h>
36#include <linux/percpu.h>
37#include <linux/spinlock.h>
38#include <linux/rcupdate.h>
39#include <linux/mutex.h>
40
41#ifdef CONFIG_KPROBES
42#include <asm/kprobes.h>
43
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
50/* Attach to insert probes on any functions which should be ignored*/
51#define __kprobes __attribute__((__section__(".kprobes.text"))) notrace
52
53struct kprobe;
54struct pt_regs;
55struct kretprobe;
56struct kretprobe_instance;
57typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
58typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
59typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
60 unsigned long flags);
61typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
62 int trapnr);
63typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
64 struct pt_regs *);
65
66struct kprobe {
67 struct hlist_node hlist;
68
69 /* list of kprobes for multi-handler support */
70 struct list_head list;
71
72 /*count the number of times this probe was temporarily disarmed */
73 unsigned long nmissed;
74
75 /* location of the probe point */
76 kprobe_opcode_t *addr;
77
78 /* Allow user to indicate symbol name of the probe point */
79 const char *symbol_name;
80
81 /* Offset into the symbol */
82 unsigned int offset;
83
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;
103
104 /* Indicates various status flags. Protected by kprobe_mutex. */
105 u32 flags;
106};
107
108/* Kprobe status flags */
109#define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
110
111static inline int kprobe_gone(struct kprobe *p)
112{
113 return p->flags & KPROBE_FLAG_GONE;
114}
115
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 */
126struct jprobe {
127 struct kprobe kp;
128 void *entry; /* probe handling code to jump to */
129};
130
131/* For backward compatibility with old code using JPROBE_ENTRY() */
132#define JPROBE_ENTRY(handler) (handler)
133
134DECLARE_PER_CPU(struct kprobe *, current_kprobe);
135DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
136
137#ifdef CONFIG_KRETPROBES
138extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
139 struct pt_regs *regs);
140extern int arch_trampoline_kprobe(struct kprobe *p);
141#else /* CONFIG_KRETPROBES */
142static inline void arch_prepare_kretprobe(struct kretprobe *rp,
143 struct pt_regs *regs)
144{
145}
146static inline int arch_trampoline_kprobe(struct kprobe *p)
147{
148 return 0;
149}
150#endif /* CONFIG_KRETPROBES */
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 */
161struct kretprobe {
162 struct kprobe kp;
163 kretprobe_handler_t handler;
164 kretprobe_handler_t entry_handler;
165 int maxactive;
166 int nmissed;
167 size_t data_size;
168 struct hlist_head free_instances;
169 spinlock_t lock;
170};
171
172struct kretprobe_instance {
173 struct hlist_node hlist;
174 struct kretprobe *rp;
175 kprobe_opcode_t *ret_addr;
176 struct task_struct *task;
177 char data[0];
178};
179
180struct kretprobe_blackpoint {
181 const char *name;
182 void *addr;
183};
184
185struct kprobe_blackpoint {
186 const char *name;
187 unsigned long start_addr;
188 unsigned long range;
189};
190
191extern struct kretprobe_blackpoint kretprobe_blacklist[];
192
193static 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
203#ifdef CONFIG_KPROBES_SANITY_TEST
204extern int init_test_probes(void);
205#else
206static inline int init_test_probes(void)
207{
208 return 0;
209}
210#endif /* CONFIG_KPROBES_SANITY_TEST */
211
212extern int arch_prepare_kprobe(struct kprobe *p);
213extern void arch_arm_kprobe(struct kprobe *p);
214extern void arch_disarm_kprobe(struct kprobe *p);
215extern int arch_init_kprobes(void);
216extern void show_registers(struct pt_regs *regs);
217extern kprobe_opcode_t *get_insn_slot(void);
218extern void free_insn_slot(kprobe_opcode_t *slot, int dirty);
219extern void kprobes_inc_nmissed_count(struct kprobe *p);
220
221/* Get the kprobe at this addr (if any) - called with preemption disabled */
222struct kprobe *get_kprobe(void *addr);
223void kretprobe_hash_lock(struct task_struct *tsk,
224 struct hlist_head **head, unsigned long *flags);
225void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
226struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
227
228/* kprobe_running() will just return the current_kprobe on this CPU */
229static inline struct kprobe *kprobe_running(void)
230{
231 return (__get_cpu_var(current_kprobe));
232}
233
234static inline void reset_current_kprobe(void)
235{
236 __get_cpu_var(current_kprobe) = NULL;
237}
238
239static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
240{
241 return (&__get_cpu_var(kprobe_ctlblk));
242}
243
244int register_kprobe(struct kprobe *p);
245void unregister_kprobe(struct kprobe *p);
246int register_kprobes(struct kprobe **kps, int num);
247void unregister_kprobes(struct kprobe **kps, int num);
248int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
249int longjmp_break_handler(struct kprobe *, struct pt_regs *);
250int register_jprobe(struct jprobe *p);
251void unregister_jprobe(struct jprobe *p);
252int register_jprobes(struct jprobe **jps, int num);
253void unregister_jprobes(struct jprobe **jps, int num);
254void jprobe_return(void);
255unsigned long arch_deref_entry_point(void *);
256
257int register_kretprobe(struct kretprobe *rp);
258void unregister_kretprobe(struct kretprobe *rp);
259int register_kretprobes(struct kretprobe **rps, int num);
260void unregister_kretprobes(struct kretprobe **rps, int num);
261
262void kprobe_flush_task(struct task_struct *tk);
263void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
264
265#else /* CONFIG_KPROBES */
266
267#define __kprobes notrace
268struct jprobe;
269struct kretprobe;
270
271static inline struct kprobe *get_kprobe(void *addr)
272{
273 return NULL;
274}
275static inline struct kprobe *kprobe_running(void)
276{
277 return NULL;
278}
279static inline int register_kprobe(struct kprobe *p)
280{
281 return -ENOSYS;
282}
283static inline int register_kprobes(struct kprobe **kps, int num)
284{
285 return -ENOSYS;
286}
287static inline void unregister_kprobe(struct kprobe *p)
288{
289}
290static inline void unregister_kprobes(struct kprobe **kps, int num)
291{
292}
293static inline int register_jprobe(struct jprobe *p)
294{
295 return -ENOSYS;
296}
297static inline int register_jprobes(struct jprobe **jps, int num)
298{
299 return -ENOSYS;
300}
301static inline void unregister_jprobe(struct jprobe *p)
302{
303}
304static inline void unregister_jprobes(struct jprobe **jps, int num)
305{
306}
307static inline void jprobe_return(void)
308{
309}
310static inline int register_kretprobe(struct kretprobe *rp)
311{
312 return -ENOSYS;
313}
314static inline int register_kretprobes(struct kretprobe **rps, int num)
315{
316 return -ENOSYS;
317}
318static inline void unregister_kretprobe(struct kretprobe *rp)
319{
320}
321static inline void unregister_kretprobes(struct kretprobe **rps, int num)
322{
323}
324static inline void kprobe_flush_task(struct task_struct *tk)
325{
326}
327#endif /* CONFIG_KPROBES */
328#endif /* _LINUX_KPROBES_H */