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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 */
324670b6 32#include <linux/compiler.h> /* for __kprobes */
36dcd67a 33#include <linux/linkage.h>
1da177e4
LT
34#include <linux/list.h>
35#include <linux/notifier.h>
36#include <linux/smp.h>
187f1882 37#include <linux/bug.h>
e6584523 38#include <linux/percpu.h>
3516a460
AM
39#include <linux/spinlock.h>
40#include <linux/rcupdate.h>
7a7d1cf9 41#include <linux/mutex.h>
ae6aa16f 42#include <linux/ftrace.h>
b94cce92 43
00d7c05a 44#ifdef CONFIG_KPROBES
1da177e4
LT
45#include <asm/kprobes.h>
46
ea32c65c
PP
47/* kprobe_status settings */
48#define KPROBE_HIT_ACTIVE 0x00000001
49#define KPROBE_HIT_SS 0x00000002
50#define KPROBE_REENTER 0x00000004
51#define KPROBE_HIT_SSDONE 0x00000008
52
dc19835d
MH
53#else /* CONFIG_KPROBES */
54typedef int kprobe_opcode_t;
55struct arch_specific_insn {
56 int dummy;
57};
dc19835d 58#endif /* CONFIG_KPROBES */
d0aaff97 59
1da177e4
LT
60struct kprobe;
61struct pt_regs;
b94cce92
HN
62struct kretprobe;
63struct kretprobe_instance;
1da177e4
LT
64typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
65typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
66typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
67 unsigned long flags);
68typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
69 int trapnr);
b94cce92
HN
70typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
71 struct pt_regs *);
72
1da177e4
LT
73struct kprobe {
74 struct hlist_node hlist;
75
64f562c6
AM
76 /* list of kprobes for multi-handler support */
77 struct list_head list;
78
ea32c65c
PP
79 /*count the number of times this probe was temporarily disarmed */
80 unsigned long nmissed;
81
1da177e4
LT
82 /* location of the probe point */
83 kprobe_opcode_t *addr;
84
3a872d89 85 /* Allow user to indicate symbol name of the probe point */
9b3af29b 86 const char *symbol_name;
3a872d89
AM
87
88 /* Offset into the symbol */
89 unsigned int offset;
90
1da177e4
LT
91 /* Called before addr is executed. */
92 kprobe_pre_handler_t pre_handler;
93
94 /* Called after addr is executed, unless... */
95 kprobe_post_handler_t post_handler;
96
cc00e9cf
MH
97 /*
98 * ... called if executing addr causes a fault (eg. page fault).
99 * Return 1 if it handled fault, otherwise kernel will see it.
100 */
1da177e4
LT
101 kprobe_fault_handler_t fault_handler;
102
cc00e9cf
MH
103 /*
104 * ... called if breakpoint trap occurs in probe handler.
105 * Return 1 if it handled break, otherwise kernel will see it.
106 */
1da177e4
LT
107 kprobe_break_handler_t break_handler;
108
109 /* Saved opcode (which has been replaced with breakpoint) */
110 kprobe_opcode_t opcode;
111
112 /* copy of the original instruction */
113 struct arch_specific_insn ainsn;
e8386a0c 114
de5bd88d
MH
115 /*
116 * Indicates various status flags.
117 * Protected by kprobe_mutex after this kprobe is registered.
118 */
e8386a0c 119 u32 flags;
1da177e4
LT
120};
121
e8386a0c
MH
122/* Kprobe status flags */
123#define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
de5bd88d 124#define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
afd66255
MH
125#define KPROBE_FLAG_OPTIMIZED 4 /*
126 * probe is really optimized.
127 * NOTE:
128 * this flag is only for optimized_kprobe.
129 */
ae6aa16f 130#define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */
e8386a0c 131
de5bd88d 132/* Has this kprobe gone ? */
e8386a0c
MH
133static inline int kprobe_gone(struct kprobe *p)
134{
135 return p->flags & KPROBE_FLAG_GONE;
136}
137
de5bd88d
MH
138/* Is this kprobe disabled ? */
139static inline int kprobe_disabled(struct kprobe *p)
140{
141 return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
142}
afd66255
MH
143
144/* Is this kprobe really running optimized path ? */
145static inline int kprobe_optimized(struct kprobe *p)
146{
147 return p->flags & KPROBE_FLAG_OPTIMIZED;
148}
ae6aa16f
MH
149
150/* Is this kprobe uses ftrace ? */
151static inline int kprobe_ftrace(struct kprobe *p)
152{
153 return p->flags & KPROBE_FLAG_FTRACE;
154}
155
1da177e4
LT
156/*
157 * Special probe type that uses setjmp-longjmp type tricks to resume
158 * execution at a specified entry with a matching prototype corresponding
159 * to the probed function - a trick to enable arguments to become
160 * accessible seamlessly by probe handling logic.
161 * Note:
162 * Because of the way compilers allocate stack space for local variables
163 * etc upfront, regardless of sub-scopes within a function, this mirroring
164 * principle currently works only for probes placed on function entry points.
165 */
166struct jprobe {
167 struct kprobe kp;
81eae375 168 void *entry; /* probe handling code to jump to */
1da177e4
LT
169};
170
9e367d85
ME
171/* For backward compatibility with old code using JPROBE_ENTRY() */
172#define JPROBE_ENTRY(handler) (handler)
173
b94cce92
HN
174/*
175 * Function-return probe -
176 * Note:
177 * User needs to provide a handler function, and initialize maxactive.
178 * maxactive - The maximum number of instances of the probed function that
179 * can be active concurrently.
180 * nmissed - tracks the number of times the probed function's return was
181 * ignored, due to maxactive being too low.
182 *
183 */
184struct kretprobe {
185 struct kprobe kp;
186 kretprobe_handler_t handler;
f47cd9b5 187 kretprobe_handler_t entry_handler;
b94cce92
HN
188 int maxactive;
189 int nmissed;
f47cd9b5 190 size_t data_size;
b94cce92 191 struct hlist_head free_instances;
ec484608 192 raw_spinlock_t lock;
b94cce92
HN
193};
194
195struct kretprobe_instance {
b94cce92
HN
196 struct hlist_node hlist;
197 struct kretprobe *rp;
802eae7c
RL
198 kprobe_opcode_t *ret_addr;
199 struct task_struct *task;
f47cd9b5 200 char data[0];
b94cce92
HN
201};
202
f438d914
MH
203struct kretprobe_blackpoint {
204 const char *name;
205 void *addr;
206};
3d8d996e 207
376e2424
MH
208struct kprobe_blacklist_entry {
209 struct list_head list;
3d8d996e 210 unsigned long start_addr;
376e2424 211 unsigned long end_addr;
3d8d996e
SD
212};
213
dc19835d
MH
214#ifdef CONFIG_KPROBES
215DECLARE_PER_CPU(struct kprobe *, current_kprobe);
216DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
217
b1801812
IM
218/*
219 * For #ifdef avoidance:
220 */
221static inline int kprobes_built_in(void)
222{
223 return 1;
224}
225
dc19835d
MH
226#ifdef CONFIG_KRETPROBES
227extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
228 struct pt_regs *regs);
229extern int arch_trampoline_kprobe(struct kprobe *p);
230#else /* CONFIG_KRETPROBES */
231static inline void arch_prepare_kretprobe(struct kretprobe *rp,
232 struct pt_regs *regs)
233{
234}
235static inline int arch_trampoline_kprobe(struct kprobe *p)
236{
237 return 0;
238}
239#endif /* CONFIG_KRETPROBES */
240
f438d914
MH
241extern struct kretprobe_blackpoint kretprobe_blacklist[];
242
0f95b7fc
AM
243static inline void kretprobe_assert(struct kretprobe_instance *ri,
244 unsigned long orig_ret_address, unsigned long trampoline_address)
245{
246 if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
247 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
248 ri->rp, ri->rp->kp.addr);
249 BUG();
250 }
251}
252
8c1c9356
AM
253#ifdef CONFIG_KPROBES_SANITY_TEST
254extern int init_test_probes(void);
255#else
256static inline int init_test_probes(void)
257{
258 return 0;
259}
260#endif /* CONFIG_KPROBES_SANITY_TEST */
261
1da177e4 262extern int arch_prepare_kprobe(struct kprobe *p);
7e1048b1
RL
263extern void arch_arm_kprobe(struct kprobe *p);
264extern void arch_disarm_kprobe(struct kprobe *p);
6772926b 265extern int arch_init_kprobes(void);
1da177e4 266extern void show_registers(struct pt_regs *regs);
bf8d5c52 267extern void kprobes_inc_nmissed_count(struct kprobe *p);
be8f2743 268extern bool arch_within_kprobe_blacklist(unsigned long addr);
1da177e4 269
c802d64a
HC
270struct kprobe_insn_cache {
271 struct mutex mutex;
af96397d
HC
272 void *(*alloc)(void); /* allocate insn page */
273 void (*free)(void *); /* free insn page */
c802d64a
HC
274 struct list_head pages; /* list of kprobe_insn_page */
275 size_t insn_size; /* size of instruction slot */
276 int nr_garbage;
277};
278
279extern kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c);
280extern void __free_insn_slot(struct kprobe_insn_cache *c,
281 kprobe_opcode_t *slot, int dirty);
282
283#define DEFINE_INSN_CACHE_OPS(__name) \
284extern struct kprobe_insn_cache kprobe_##__name##_slots; \
285 \
286static inline kprobe_opcode_t *get_##__name##_slot(void) \
287{ \
288 return __get_insn_slot(&kprobe_##__name##_slots); \
289} \
290 \
291static inline void free_##__name##_slot(kprobe_opcode_t *slot, int dirty)\
292{ \
293 __free_insn_slot(&kprobe_##__name##_slots, slot, dirty); \
294} \
295
296DEFINE_INSN_CACHE_OPS(insn);
297
afd66255
MH
298#ifdef CONFIG_OPTPROBES
299/*
300 * Internal structure for direct jump optimized probe
301 */
302struct optimized_kprobe {
303 struct kprobe kp;
304 struct list_head list; /* list for optimizing queue */
305 struct arch_optimized_insn optinsn;
306};
307
308/* Architecture dependent functions for direct jump optimization */
309extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
310extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
311extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op);
312extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
cd7ebe22 313extern void arch_optimize_kprobes(struct list_head *oplist);
f984ba4e
MH
314extern void arch_unoptimize_kprobes(struct list_head *oplist,
315 struct list_head *done_list);
afd66255 316extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
afd66255
MH
317extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
318 unsigned long addr);
319
320extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
b2be84df 321
c802d64a
HC
322DEFINE_INSN_CACHE_OPS(optinsn);
323
b2be84df
MH
324#ifdef CONFIG_SYSCTL
325extern int sysctl_kprobes_optimization;
326extern int proc_kprobes_optimization_handler(struct ctl_table *table,
327 int write, void __user *buffer,
328 size_t *length, loff_t *ppos);
329#endif
330
afd66255 331#endif /* CONFIG_OPTPROBES */
e7dbfe34 332#ifdef CONFIG_KPROBES_ON_FTRACE
ae6aa16f 333extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
e5253896 334 struct ftrace_ops *ops, struct pt_regs *regs);
ae6aa16f
MH
335extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
336#endif
337
afd66255 338
d217d545 339/* Get the kprobe at this addr (if any) - called with preemption disabled */
1da177e4 340struct kprobe *get_kprobe(void *addr);
ef53d9c5
S
341void kretprobe_hash_lock(struct task_struct *tsk,
342 struct hlist_head **head, unsigned long *flags);
343void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
b94cce92 344struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
1da177e4 345
e6584523
AM
346/* kprobe_running() will just return the current_kprobe on this CPU */
347static inline struct kprobe *kprobe_running(void)
348{
b76834bc 349 return (__this_cpu_read(current_kprobe));
e6584523
AM
350}
351
352static inline void reset_current_kprobe(void)
353{
b76834bc 354 __this_cpu_write(current_kprobe, NULL);
e6584523
AM
355}
356
357static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
358{
bdffd893 359 return this_cpu_ptr(&kprobe_ctlblk);
e6584523
AM
360}
361
1da177e4
LT
362int register_kprobe(struct kprobe *p);
363void unregister_kprobe(struct kprobe *p);
9861668f
MH
364int register_kprobes(struct kprobe **kps, int num);
365void unregister_kprobes(struct kprobe **kps, int num);
1da177e4
LT
366int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
367int longjmp_break_handler(struct kprobe *, struct pt_regs *);
368int register_jprobe(struct jprobe *p);
369void unregister_jprobe(struct jprobe *p);
26b31c19
MH
370int register_jprobes(struct jprobe **jps, int num);
371void unregister_jprobes(struct jprobe **jps, int num);
1da177e4 372void jprobe_return(void);
3d7e3382 373unsigned long arch_deref_entry_point(void *);
1da177e4 374
b94cce92
HN
375int register_kretprobe(struct kretprobe *rp);
376void unregister_kretprobe(struct kretprobe *rp);
4a296e07
MH
377int register_kretprobes(struct kretprobe **rps, int num);
378void unregister_kretprobes(struct kretprobe **rps, int num);
b94cce92 379
b94cce92 380void kprobe_flush_task(struct task_struct *tk);
99219a3f 381void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
8c1c9356 382
de5bd88d
MH
383int disable_kprobe(struct kprobe *kp);
384int enable_kprobe(struct kprobe *kp);
385
24851d24
FW
386void dump_kprobe(struct kprobe *kp);
387
b1801812 388#else /* !CONFIG_KPROBES: */
00d7c05a 389
b1801812
IM
390static inline int kprobes_built_in(void)
391{
392 return 0;
393}
394static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
395{
396 return 0;
397}
785656a4
AS
398static inline struct kprobe *get_kprobe(void *addr)
399{
400 return NULL;
401}
e6584523 402static inline struct kprobe *kprobe_running(void)
1da177e4 403{
e6584523 404 return NULL;
1da177e4
LT
405}
406static inline int register_kprobe(struct kprobe *p)
407{
408 return -ENOSYS;
409}
9861668f
MH
410static inline int register_kprobes(struct kprobe **kps, int num)
411{
412 return -ENOSYS;
413}
1da177e4
LT
414static inline void unregister_kprobe(struct kprobe *p)
415{
416}
9861668f
MH
417static inline void unregister_kprobes(struct kprobe **kps, int num)
418{
419}
1da177e4
LT
420static inline int register_jprobe(struct jprobe *p)
421{
422 return -ENOSYS;
423}
26b31c19
MH
424static inline int register_jprobes(struct jprobe **jps, int num)
425{
426 return -ENOSYS;
427}
1da177e4
LT
428static inline void unregister_jprobe(struct jprobe *p)
429{
430}
26b31c19
MH
431static inline void unregister_jprobes(struct jprobe **jps, int num)
432{
433}
1da177e4
LT
434static inline void jprobe_return(void)
435{
436}
b94cce92
HN
437static inline int register_kretprobe(struct kretprobe *rp)
438{
439 return -ENOSYS;
440}
4a296e07
MH
441static inline int register_kretprobes(struct kretprobe **rps, int num)
442{
443 return -ENOSYS;
444}
b94cce92
HN
445static inline void unregister_kretprobe(struct kretprobe *rp)
446{
447}
4a296e07
MH
448static inline void unregister_kretprobes(struct kretprobe **rps, int num)
449{
450}
b94cce92
HN
451static inline void kprobe_flush_task(struct task_struct *tk)
452{
453}
de5bd88d
MH
454static inline int disable_kprobe(struct kprobe *kp)
455{
456 return -ENOSYS;
457}
458static inline int enable_kprobe(struct kprobe *kp)
459{
460 return -ENOSYS;
461}
b1801812 462#endif /* CONFIG_KPROBES */
8f9b1528
MH
463static inline int disable_kretprobe(struct kretprobe *rp)
464{
465 return disable_kprobe(&rp->kp);
466}
467static inline int enable_kretprobe(struct kretprobe *rp)
468{
469 return enable_kprobe(&rp->kp);
470}
471static inline int disable_jprobe(struct jprobe *jp)
472{
473 return disable_kprobe(&jp->kp);
474}
475static inline int enable_jprobe(struct jprobe *jp)
476{
477 return enable_kprobe(&jp->kp);
478}
479
376e2424
MH
480#ifdef CONFIG_KPROBES
481/*
482 * Blacklist ganerating macro. Specify functions which is not probed
483 * by using this macro.
484 */
485#define __NOKPROBE_SYMBOL(fname) \
486static unsigned long __used \
487 __attribute__((section("_kprobe_blacklist"))) \
488 _kbl_addr_##fname = (unsigned long)fname;
489#define NOKPROBE_SYMBOL(fname) __NOKPROBE_SYMBOL(fname)
490#else
491#define NOKPROBE_SYMBOL(fname)
492#endif
493
b1801812 494#endif /* _LINUX_KPROBES_H */