1 #ifndef _LINUX_KPROBES_H
2 #define _LINUX_KPROBES_H
4 * Kernel Probes (KProbes)
5 * include/linux/kprobes.h
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.
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.
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.
21 * Copyright (C) IBM Corporation, 2002, 2004
23 * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
24 * Probes initial implementation ( includes suggestions from
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.
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>
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
53 #else /* CONFIG_KPROBES */
54 #include <asm-generic/kprobes.h>
55 typedef int kprobe_opcode_t;
56 struct arch_specific_insn {
59 #endif /* CONFIG_KPROBES */
64 struct kretprobe_instance;
65 typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
66 typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
67 typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
69 typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
71 typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
75 struct hlist_node hlist;
77 /* list of kprobes for multi-handler support */
78 struct list_head list;
80 /*count the number of times this probe was temporarily disarmed */
81 unsigned long nmissed;
83 /* location of the probe point */
84 kprobe_opcode_t *addr;
86 /* Allow user to indicate symbol name of the probe point */
87 const char *symbol_name;
89 /* Offset into the symbol */
92 /* Called before addr is executed. */
93 kprobe_pre_handler_t pre_handler;
95 /* Called after addr is executed, unless... */
96 kprobe_post_handler_t post_handler;
99 * ... called if executing addr causes a fault (eg. page fault).
100 * Return 1 if it handled fault, otherwise kernel will see it.
102 kprobe_fault_handler_t fault_handler;
105 * ... called if breakpoint trap occurs in probe handler.
106 * Return 1 if it handled break, otherwise kernel will see it.
108 kprobe_break_handler_t break_handler;
110 /* Saved opcode (which has been replaced with breakpoint) */
111 kprobe_opcode_t opcode;
113 /* copy of the original instruction */
114 struct arch_specific_insn ainsn;
117 * Indicates various status flags.
118 * Protected by kprobe_mutex after this kprobe is registered.
123 /* Kprobe status flags */
124 #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
125 #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
126 #define KPROBE_FLAG_OPTIMIZED 4 /*
127 * probe is really optimized.
129 * this flag is only for optimized_kprobe.
131 #define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */
133 /* Has this kprobe gone ? */
134 static inline int kprobe_gone(struct kprobe *p)
136 return p->flags & KPROBE_FLAG_GONE;
139 /* Is this kprobe disabled ? */
140 static inline int kprobe_disabled(struct kprobe *p)
142 return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
145 /* Is this kprobe really running optimized path ? */
146 static inline int kprobe_optimized(struct kprobe *p)
148 return p->flags & KPROBE_FLAG_OPTIMIZED;
151 /* Is this kprobe uses ftrace ? */
152 static inline int kprobe_ftrace(struct kprobe *p)
154 return p->flags & KPROBE_FLAG_FTRACE;
158 * Special probe type that uses setjmp-longjmp type tricks to resume
159 * execution at a specified entry with a matching prototype corresponding
160 * to the probed function - a trick to enable arguments to become
161 * accessible seamlessly by probe handling logic.
163 * Because of the way compilers allocate stack space for local variables
164 * etc upfront, regardless of sub-scopes within a function, this mirroring
165 * principle currently works only for probes placed on function entry points.
169 void *entry; /* probe handling code to jump to */
172 /* For backward compatibility with old code using JPROBE_ENTRY() */
173 #define JPROBE_ENTRY(handler) (handler)
176 * Function-return probe -
178 * User needs to provide a handler function, and initialize maxactive.
179 * maxactive - The maximum number of instances of the probed function that
180 * can be active concurrently.
181 * nmissed - tracks the number of times the probed function's return was
182 * ignored, due to maxactive being too low.
187 kretprobe_handler_t handler;
188 kretprobe_handler_t entry_handler;
192 struct hlist_head free_instances;
196 #define KRETPROBE_MAX_DATA_SIZE 4096
198 struct kretprobe_instance {
199 struct hlist_node hlist;
200 struct kretprobe *rp;
201 kprobe_opcode_t *ret_addr;
202 struct task_struct *task;
207 struct kretprobe_blackpoint {
212 struct kprobe_blacklist_entry {
213 struct list_head list;
214 unsigned long start_addr;
215 unsigned long end_addr;
218 #ifdef CONFIG_KPROBES
219 DECLARE_PER_CPU(struct kprobe *, current_kprobe);
220 DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
223 * For #ifdef avoidance:
225 static inline int kprobes_built_in(void)
230 #ifdef CONFIG_KRETPROBES
231 extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
232 struct pt_regs *regs);
233 extern int arch_trampoline_kprobe(struct kprobe *p);
234 #else /* CONFIG_KRETPROBES */
235 static inline void arch_prepare_kretprobe(struct kretprobe *rp,
236 struct pt_regs *regs)
239 static inline int arch_trampoline_kprobe(struct kprobe *p)
243 #endif /* CONFIG_KRETPROBES */
245 extern struct kretprobe_blackpoint kretprobe_blacklist[];
247 static inline void kretprobe_assert(struct kretprobe_instance *ri,
248 unsigned long orig_ret_address, unsigned long trampoline_address)
250 if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
251 printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
252 ri->rp, ri->rp->kp.addr);
257 #ifdef CONFIG_KPROBES_SANITY_TEST
258 extern int init_test_probes(void);
260 static inline int init_test_probes(void)
264 #endif /* CONFIG_KPROBES_SANITY_TEST */
266 extern int arch_prepare_kprobe(struct kprobe *p);
267 extern void arch_arm_kprobe(struct kprobe *p);
268 extern void arch_disarm_kprobe(struct kprobe *p);
269 extern int arch_init_kprobes(void);
270 extern void show_registers(struct pt_regs *regs);
271 extern void kprobes_inc_nmissed_count(struct kprobe *p);
272 extern bool arch_within_kprobe_blacklist(unsigned long addr);
273 extern bool arch_kprobe_on_func_entry(unsigned long offset);
274 extern bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset);
276 extern bool within_kprobe_blacklist(unsigned long addr);
278 struct kprobe_insn_cache {
280 void *(*alloc)(void); /* allocate insn page */
281 void (*free)(void *); /* free insn page */
282 struct list_head pages; /* list of kprobe_insn_page */
283 size_t insn_size; /* size of instruction slot */
287 #ifdef __ARCH_WANT_KPROBES_INSN_SLOT
288 extern kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c);
289 extern void __free_insn_slot(struct kprobe_insn_cache *c,
290 kprobe_opcode_t *slot, int dirty);
291 /* sleep-less address checking routine */
292 extern bool __is_insn_slot_addr(struct kprobe_insn_cache *c,
295 #define DEFINE_INSN_CACHE_OPS(__name) \
296 extern struct kprobe_insn_cache kprobe_##__name##_slots; \
298 static inline kprobe_opcode_t *get_##__name##_slot(void) \
300 return __get_insn_slot(&kprobe_##__name##_slots); \
303 static inline void free_##__name##_slot(kprobe_opcode_t *slot, int dirty)\
305 __free_insn_slot(&kprobe_##__name##_slots, slot, dirty); \
308 static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
310 return __is_insn_slot_addr(&kprobe_##__name##_slots, addr); \
312 #else /* __ARCH_WANT_KPROBES_INSN_SLOT */
313 #define DEFINE_INSN_CACHE_OPS(__name) \
314 static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
320 DEFINE_INSN_CACHE_OPS(insn);
322 #ifdef CONFIG_OPTPROBES
324 * Internal structure for direct jump optimized probe
326 struct optimized_kprobe {
328 struct list_head list; /* list for optimizing queue */
329 struct arch_optimized_insn optinsn;
332 /* Architecture dependent functions for direct jump optimization */
333 extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
334 extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
335 extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op,
336 struct kprobe *orig);
337 extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
338 extern void arch_optimize_kprobes(struct list_head *oplist);
339 extern void arch_unoptimize_kprobes(struct list_head *oplist,
340 struct list_head *done_list);
341 extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
342 extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
345 extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
347 DEFINE_INSN_CACHE_OPS(optinsn);
350 extern int sysctl_kprobes_optimization;
351 extern int proc_kprobes_optimization_handler(struct ctl_table *table,
352 int write, void __user *buffer,
353 size_t *length, loff_t *ppos);
355 extern void wait_for_kprobe_optimizer(void);
356 bool optprobe_queued_unopt(struct optimized_kprobe *op);
357 bool kprobe_disarmed(struct kprobe *p);
359 static inline void wait_for_kprobe_optimizer(void) { }
360 #endif /* CONFIG_OPTPROBES */
361 #ifdef CONFIG_KPROBES_ON_FTRACE
362 extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
363 struct ftrace_ops *ops, struct pt_regs *regs);
364 extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
367 int arch_check_ftrace_location(struct kprobe *p);
369 /* Get the kprobe at this addr (if any) - called with preemption disabled */
370 struct kprobe *get_kprobe(void *addr);
371 void kretprobe_hash_lock(struct task_struct *tsk,
372 struct hlist_head **head, unsigned long *flags);
373 void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
374 struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
376 /* kprobe_running() will just return the current_kprobe on this CPU */
377 static inline struct kprobe *kprobe_running(void)
379 return (__this_cpu_read(current_kprobe));
382 static inline void reset_current_kprobe(void)
384 __this_cpu_write(current_kprobe, NULL);
387 static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
389 return this_cpu_ptr(&kprobe_ctlblk);
392 extern struct kprobe kprobe_busy;
393 void kprobe_busy_begin(void);
394 void kprobe_busy_end(void);
396 kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset);
397 int register_kprobe(struct kprobe *p);
398 void unregister_kprobe(struct kprobe *p);
399 int register_kprobes(struct kprobe **kps, int num);
400 void unregister_kprobes(struct kprobe **kps, int num);
401 int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
402 int longjmp_break_handler(struct kprobe *, struct pt_regs *);
403 int register_jprobe(struct jprobe *p);
404 void unregister_jprobe(struct jprobe *p);
405 int register_jprobes(struct jprobe **jps, int num);
406 void unregister_jprobes(struct jprobe **jps, int num);
407 void jprobe_return(void);
408 unsigned long arch_deref_entry_point(void *);
410 int register_kretprobe(struct kretprobe *rp);
411 void unregister_kretprobe(struct kretprobe *rp);
412 int register_kretprobes(struct kretprobe **rps, int num);
413 void unregister_kretprobes(struct kretprobe **rps, int num);
415 void kprobe_flush_task(struct task_struct *tk);
416 void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
418 int disable_kprobe(struct kprobe *kp);
419 int enable_kprobe(struct kprobe *kp);
421 void dump_kprobe(struct kprobe *kp);
423 #else /* !CONFIG_KPROBES: */
425 static inline int kprobes_built_in(void)
429 static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
433 static inline struct kprobe *get_kprobe(void *addr)
437 static inline struct kprobe *kprobe_running(void)
441 static inline int register_kprobe(struct kprobe *p)
445 static inline int register_kprobes(struct kprobe **kps, int num)
449 static inline void unregister_kprobe(struct kprobe *p)
452 static inline void unregister_kprobes(struct kprobe **kps, int num)
455 static inline int register_jprobe(struct jprobe *p)
459 static inline int register_jprobes(struct jprobe **jps, int num)
463 static inline void unregister_jprobe(struct jprobe *p)
466 static inline void unregister_jprobes(struct jprobe **jps, int num)
469 static inline void jprobe_return(void)
472 static inline int register_kretprobe(struct kretprobe *rp)
476 static inline int register_kretprobes(struct kretprobe **rps, int num)
480 static inline void unregister_kretprobe(struct kretprobe *rp)
483 static inline void unregister_kretprobes(struct kretprobe **rps, int num)
486 static inline void kprobe_flush_task(struct task_struct *tk)
489 static inline int disable_kprobe(struct kprobe *kp)
493 static inline int enable_kprobe(struct kprobe *kp)
497 #endif /* CONFIG_KPROBES */
498 static inline int disable_kretprobe(struct kretprobe *rp)
500 return disable_kprobe(&rp->kp);
502 static inline int enable_kretprobe(struct kretprobe *rp)
504 return enable_kprobe(&rp->kp);
506 static inline int disable_jprobe(struct jprobe *jp)
508 return disable_kprobe(&jp->kp);
510 static inline int enable_jprobe(struct jprobe *jp)
512 return enable_kprobe(&jp->kp);
515 #ifndef CONFIG_KPROBES
516 static inline bool is_kprobe_insn_slot(unsigned long addr)
521 #ifndef CONFIG_OPTPROBES
522 static inline bool is_kprobe_optinsn_slot(unsigned long addr)
528 #endif /* _LINUX_KPROBES_H */