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/compiler.h>
33#include <linux/linkage.h>
34#include <linux/list.h>
35#include <linux/notifier.h>
36#include <linux/smp.h>
37#include <linux/bug.h>
38#include <linux/percpu.h>
39#include <linux/spinlock.h>
40#include <linux/rcupdate.h>
41#include <linux/mutex.h>
42#include <linux/ftrace.h>
43#include <asm/kprobes.h>
44
45#ifdef CONFIG_KPROBES
46
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
53#else /* CONFIG_KPROBES */
54#include <asm-generic/kprobes.h>
55typedef int kprobe_opcode_t;
56struct arch_specific_insn {
57 int dummy;
58};
59#endif /* CONFIG_KPROBES */
60
61struct kprobe;
62struct pt_regs;
63struct kretprobe;
64struct kretprobe_instance;
65typedef int (*kprobe_pre_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);
70typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
71 struct pt_regs *);
72
73struct kprobe {
74 struct hlist_node hlist;
75
76 /* list of kprobes for multi-handler support */
77 struct list_head list;
78
79 /*count the number of times this probe was temporarily disarmed */
80 unsigned long nmissed;
81
82 /* location of the probe point */
83 kprobe_opcode_t *addr;
84
85 /* Allow user to indicate symbol name of the probe point */
86 const char *symbol_name;
87
88 /* Offset into the symbol */
89 unsigned int offset;
90
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
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 */
101 kprobe_fault_handler_t fault_handler;
102
103 /* Saved opcode (which has been replaced with breakpoint) */
104 kprobe_opcode_t opcode;
105
106 /* copy of the original instruction */
107 struct arch_specific_insn ainsn;
108
109 /*
110 * Indicates various status flags.
111 * Protected by kprobe_mutex after this kprobe is registered.
112 */
113 u32 flags;
114};
115
116/* Kprobe status flags */
117#define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
118#define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
119#define KPROBE_FLAG_OPTIMIZED 4 /*
120 * probe is really optimized.
121 * NOTE:
122 * this flag is only for optimized_kprobe.
123 */
124#define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */
125
126/* Has this kprobe gone ? */
127static inline int kprobe_gone(struct kprobe *p)
128{
129 return p->flags & KPROBE_FLAG_GONE;
130}
131
132/* Is this kprobe disabled ? */
133static inline int kprobe_disabled(struct kprobe *p)
134{
135 return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
136}
137
138/* Is this kprobe really running optimized path ? */
139static inline int kprobe_optimized(struct kprobe *p)
140{
141 return p->flags & KPROBE_FLAG_OPTIMIZED;
142}
143
144/* Is this kprobe uses ftrace ? */
145static inline int kprobe_ftrace(struct kprobe *p)
146{
147 return p->flags & KPROBE_FLAG_FTRACE;
148}
149
150/*
151 * Function-return probe -
152 * Note:
153 * User needs to provide a handler function, and initialize maxactive.
154 * maxactive - The maximum number of instances of the probed function that
155 * can be active concurrently.
156 * nmissed - tracks the number of times the probed function's return was
157 * ignored, due to maxactive being too low.
158 *
159 */
160struct kretprobe {
161 struct kprobe kp;
162 kretprobe_handler_t handler;
163 kretprobe_handler_t entry_handler;
164 int maxactive;
165 int nmissed;
166 size_t data_size;
167 struct hlist_head free_instances;
168 raw_spinlock_t lock;
169};
170
171struct kretprobe_instance {
172 struct hlist_node hlist;
173 struct kretprobe *rp;
174 kprobe_opcode_t *ret_addr;
175 struct task_struct *task;
176 char data[0];
177};
178
179struct kretprobe_blackpoint {
180 const char *name;
181 void *addr;
182};
183
184struct kprobe_blacklist_entry {
185 struct list_head list;
186 unsigned long start_addr;
187 unsigned long end_addr;
188};
189
190#ifdef CONFIG_KPROBES
191DECLARE_PER_CPU(struct kprobe *, current_kprobe);
192DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
193
194/*
195 * For #ifdef avoidance:
196 */
197static inline int kprobes_built_in(void)
198{
199 return 1;
200}
201
202#ifdef CONFIG_KRETPROBES
203extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
204 struct pt_regs *regs);
205extern int arch_trampoline_kprobe(struct kprobe *p);
206#else /* CONFIG_KRETPROBES */
207static inline void arch_prepare_kretprobe(struct kretprobe *rp,
208 struct pt_regs *regs)
209{
210}
211static inline int arch_trampoline_kprobe(struct kprobe *p)
212{
213 return 0;
214}
215#endif /* CONFIG_KRETPROBES */
216
217extern struct kretprobe_blackpoint kretprobe_blacklist[];
218
219static inline void kretprobe_assert(struct kretprobe_instance *ri,
220 unsigned long orig_ret_address, unsigned long trampoline_address)
221{
222 if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
223 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
224 ri->rp, ri->rp->kp.addr);
225 BUG();
226 }
227}
228
229#ifdef CONFIG_KPROBES_SANITY_TEST
230extern int init_test_probes(void);
231#else
232static inline int init_test_probes(void)
233{
234 return 0;
235}
236#endif /* CONFIG_KPROBES_SANITY_TEST */
237
238extern int arch_prepare_kprobe(struct kprobe *p);
239extern void arch_arm_kprobe(struct kprobe *p);
240extern void arch_disarm_kprobe(struct kprobe *p);
241extern int arch_init_kprobes(void);
242extern void show_registers(struct pt_regs *regs);
243extern void kprobes_inc_nmissed_count(struct kprobe *p);
244extern bool arch_within_kprobe_blacklist(unsigned long addr);
245extern int arch_populate_kprobe_blacklist(void);
246extern bool arch_kprobe_on_func_entry(unsigned long offset);
247extern bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset);
248
249extern bool within_kprobe_blacklist(unsigned long addr);
250extern int kprobe_add_ksym_blacklist(unsigned long entry);
251extern int kprobe_add_area_blacklist(unsigned long start, unsigned long end);
252
253struct kprobe_insn_cache {
254 struct mutex mutex;
255 void *(*alloc)(void); /* allocate insn page */
256 void (*free)(void *); /* free insn page */
257 struct list_head pages; /* list of kprobe_insn_page */
258 size_t insn_size; /* size of instruction slot */
259 int nr_garbage;
260};
261
262#ifdef __ARCH_WANT_KPROBES_INSN_SLOT
263extern kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c);
264extern void __free_insn_slot(struct kprobe_insn_cache *c,
265 kprobe_opcode_t *slot, int dirty);
266/* sleep-less address checking routine */
267extern bool __is_insn_slot_addr(struct kprobe_insn_cache *c,
268 unsigned long addr);
269
270#define DEFINE_INSN_CACHE_OPS(__name) \
271extern struct kprobe_insn_cache kprobe_##__name##_slots; \
272 \
273static inline kprobe_opcode_t *get_##__name##_slot(void) \
274{ \
275 return __get_insn_slot(&kprobe_##__name##_slots); \
276} \
277 \
278static inline void free_##__name##_slot(kprobe_opcode_t *slot, int dirty)\
279{ \
280 __free_insn_slot(&kprobe_##__name##_slots, slot, dirty); \
281} \
282 \
283static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
284{ \
285 return __is_insn_slot_addr(&kprobe_##__name##_slots, addr); \
286}
287#else /* __ARCH_WANT_KPROBES_INSN_SLOT */
288#define DEFINE_INSN_CACHE_OPS(__name) \
289static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
290{ \
291 return 0; \
292}
293#endif
294
295DEFINE_INSN_CACHE_OPS(insn);
296
297#ifdef CONFIG_OPTPROBES
298/*
299 * Internal structure for direct jump optimized probe
300 */
301struct optimized_kprobe {
302 struct kprobe kp;
303 struct list_head list; /* list for optimizing queue */
304 struct arch_optimized_insn optinsn;
305};
306
307/* Architecture dependent functions for direct jump optimization */
308extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
309extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
310extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op,
311 struct kprobe *orig);
312extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
313extern void arch_optimize_kprobes(struct list_head *oplist);
314extern void arch_unoptimize_kprobes(struct list_head *oplist,
315 struct list_head *done_list);
316extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
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);
321
322DEFINE_INSN_CACHE_OPS(optinsn);
323
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
330extern void wait_for_kprobe_optimizer(void);
331#else
332static inline void wait_for_kprobe_optimizer(void) { }
333#endif /* CONFIG_OPTPROBES */
334#ifdef CONFIG_KPROBES_ON_FTRACE
335extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
336 struct ftrace_ops *ops, struct pt_regs *regs);
337extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
338#endif
339
340int arch_check_ftrace_location(struct kprobe *p);
341
342/* Get the kprobe at this addr (if any) - called with preemption disabled */
343struct kprobe *get_kprobe(void *addr);
344void kretprobe_hash_lock(struct task_struct *tsk,
345 struct hlist_head **head, unsigned long *flags);
346void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
347struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
348
349/* kprobe_running() will just return the current_kprobe on this CPU */
350static inline struct kprobe *kprobe_running(void)
351{
352 return (__this_cpu_read(current_kprobe));
353}
354
355static inline void reset_current_kprobe(void)
356{
357 __this_cpu_write(current_kprobe, NULL);
358}
359
360static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
361{
362 return this_cpu_ptr(&kprobe_ctlblk);
363}
364
365kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset);
366int register_kprobe(struct kprobe *p);
367void unregister_kprobe(struct kprobe *p);
368int register_kprobes(struct kprobe **kps, int num);
369void unregister_kprobes(struct kprobe **kps, int num);
370unsigned long arch_deref_entry_point(void *);
371
372int register_kretprobe(struct kretprobe *rp);
373void unregister_kretprobe(struct kretprobe *rp);
374int register_kretprobes(struct kretprobe **rps, int num);
375void unregister_kretprobes(struct kretprobe **rps, int num);
376
377void kprobe_flush_task(struct task_struct *tk);
378void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
379
380int disable_kprobe(struct kprobe *kp);
381int enable_kprobe(struct kprobe *kp);
382
383void dump_kprobe(struct kprobe *kp);
384
385void *alloc_insn_page(void);
386void free_insn_page(void *page);
387
388#else /* !CONFIG_KPROBES: */
389
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}
398static inline struct kprobe *get_kprobe(void *addr)
399{
400 return NULL;
401}
402static inline struct kprobe *kprobe_running(void)
403{
404 return NULL;
405}
406static inline int register_kprobe(struct kprobe *p)
407{
408 return -ENOSYS;
409}
410static inline int register_kprobes(struct kprobe **kps, int num)
411{
412 return -ENOSYS;
413}
414static inline void unregister_kprobe(struct kprobe *p)
415{
416}
417static inline void unregister_kprobes(struct kprobe **kps, int num)
418{
419}
420static inline int register_kretprobe(struct kretprobe *rp)
421{
422 return -ENOSYS;
423}
424static inline int register_kretprobes(struct kretprobe **rps, int num)
425{
426 return -ENOSYS;
427}
428static inline void unregister_kretprobe(struct kretprobe *rp)
429{
430}
431static inline void unregister_kretprobes(struct kretprobe **rps, int num)
432{
433}
434static inline void kprobe_flush_task(struct task_struct *tk)
435{
436}
437static inline int disable_kprobe(struct kprobe *kp)
438{
439 return -ENOSYS;
440}
441static inline int enable_kprobe(struct kprobe *kp)
442{
443 return -ENOSYS;
444}
445
446static inline bool within_kprobe_blacklist(unsigned long addr)
447{
448 return true;
449}
450#endif /* CONFIG_KPROBES */
451static inline int disable_kretprobe(struct kretprobe *rp)
452{
453 return disable_kprobe(&rp->kp);
454}
455static inline int enable_kretprobe(struct kretprobe *rp)
456{
457 return enable_kprobe(&rp->kp);
458}
459
460#ifndef CONFIG_KPROBES
461static inline bool is_kprobe_insn_slot(unsigned long addr)
462{
463 return false;
464}
465#endif
466#ifndef CONFIG_OPTPROBES
467static inline bool is_kprobe_optinsn_slot(unsigned long addr)
468{
469 return false;
470}
471#endif
472
473#endif /* _LINUX_KPROBES_H */
474