Linux 3.9-rc4
[linux-2.6/cjktty.git] / include / linux / kprobes.h
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1 #ifndef _LINUX_KPROBES_H
2 #define _LINUX_KPROBES_H
3 /*
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
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.
32 #include <linux/linkage.h>
33 #include <linux/list.h>
34 #include <linux/notifier.h>
35 #include <linux/smp.h>
36 #include <linux/bug.h>
37 #include <linux/percpu.h>
38 #include <linux/spinlock.h>
39 #include <linux/rcupdate.h>
40 #include <linux/mutex.h>
41 #include <linux/ftrace.h>
43 #ifdef CONFIG_KPROBES
44 #include <asm/kprobes.h>
46 /* kprobe_status settings */
47 #define KPROBE_HIT_ACTIVE 0x00000001
48 #define KPROBE_HIT_SS 0x00000002
49 #define KPROBE_REENTER 0x00000004
50 #define KPROBE_HIT_SSDONE 0x00000008
52 /* Attach to insert probes on any functions which should be ignored*/
53 #define __kprobes __attribute__((__section__(".kprobes.text")))
55 #else /* CONFIG_KPROBES */
56 typedef int kprobe_opcode_t;
57 struct arch_specific_insn {
58 int dummy;
60 #define __kprobes
62 #endif /* CONFIG_KPROBES */
64 struct kprobe;
65 struct pt_regs;
66 struct kretprobe;
67 struct kretprobe_instance;
68 typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
69 typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
70 typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
71 unsigned long flags);
72 typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
73 int trapnr);
74 typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
75 struct pt_regs *);
77 struct kprobe {
78 struct hlist_node hlist;
80 /* list of kprobes for multi-handler support */
81 struct list_head list;
83 /*count the number of times this probe was temporarily disarmed */
84 unsigned long nmissed;
86 /* location of the probe point */
87 kprobe_opcode_t *addr;
89 /* Allow user to indicate symbol name of the probe point */
90 const char *symbol_name;
92 /* Offset into the symbol */
93 unsigned int offset;
95 /* Called before addr is executed. */
96 kprobe_pre_handler_t pre_handler;
98 /* Called after addr is executed, unless... */
99 kprobe_post_handler_t post_handler;
102 * ... called if executing addr causes a fault (eg. page fault).
103 * Return 1 if it handled fault, otherwise kernel will see it.
105 kprobe_fault_handler_t fault_handler;
108 * ... called if breakpoint trap occurs in probe handler.
109 * Return 1 if it handled break, otherwise kernel will see it.
111 kprobe_break_handler_t break_handler;
113 /* Saved opcode (which has been replaced with breakpoint) */
114 kprobe_opcode_t opcode;
116 /* copy of the original instruction */
117 struct arch_specific_insn ainsn;
120 * Indicates various status flags.
121 * Protected by kprobe_mutex after this kprobe is registered.
123 u32 flags;
126 /* Kprobe status flags */
127 #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
128 #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
129 #define KPROBE_FLAG_OPTIMIZED 4 /*
130 * probe is really optimized.
131 * NOTE:
132 * this flag is only for optimized_kprobe.
134 #define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */
136 /* Has this kprobe gone ? */
137 static inline int kprobe_gone(struct kprobe *p)
139 return p->flags & KPROBE_FLAG_GONE;
142 /* Is this kprobe disabled ? */
143 static inline int kprobe_disabled(struct kprobe *p)
145 return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
148 /* Is this kprobe really running optimized path ? */
149 static inline int kprobe_optimized(struct kprobe *p)
151 return p->flags & KPROBE_FLAG_OPTIMIZED;
154 /* Is this kprobe uses ftrace ? */
155 static inline int kprobe_ftrace(struct kprobe *p)
157 return p->flags & KPROBE_FLAG_FTRACE;
161 * Special probe type that uses setjmp-longjmp type tricks to resume
162 * execution at a specified entry with a matching prototype corresponding
163 * to the probed function - a trick to enable arguments to become
164 * accessible seamlessly by probe handling logic.
165 * Note:
166 * Because of the way compilers allocate stack space for local variables
167 * etc upfront, regardless of sub-scopes within a function, this mirroring
168 * principle currently works only for probes placed on function entry points.
170 struct jprobe {
171 struct kprobe kp;
172 void *entry; /* probe handling code to jump to */
175 /* For backward compatibility with old code using JPROBE_ENTRY() */
176 #define JPROBE_ENTRY(handler) (handler)
179 * Function-return probe -
180 * Note:
181 * User needs to provide a handler function, and initialize maxactive.
182 * maxactive - The maximum number of instances of the probed function that
183 * can be active concurrently.
184 * nmissed - tracks the number of times the probed function's return was
185 * ignored, due to maxactive being too low.
188 struct kretprobe {
189 struct kprobe kp;
190 kretprobe_handler_t handler;
191 kretprobe_handler_t entry_handler;
192 int maxactive;
193 int nmissed;
194 size_t data_size;
195 struct hlist_head free_instances;
196 raw_spinlock_t lock;
199 struct kretprobe_instance {
200 struct hlist_node hlist;
201 struct kretprobe *rp;
202 kprobe_opcode_t *ret_addr;
203 struct task_struct *task;
204 char data[0];
207 struct kretprobe_blackpoint {
208 const char *name;
209 void *addr;
212 struct kprobe_blackpoint {
213 const char *name;
214 unsigned long start_addr;
215 unsigned long range;
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)
227 return 1;
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)
241 return 0;
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);
253 BUG();
257 #ifdef CONFIG_KPROBES_SANITY_TEST
258 extern int init_test_probes(void);
259 #else
260 static inline int init_test_probes(void)
262 return 0;
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 kprobe_opcode_t *get_insn_slot(void);
272 extern void free_insn_slot(kprobe_opcode_t *slot, int dirty);
273 extern void kprobes_inc_nmissed_count(struct kprobe *p);
275 #ifdef CONFIG_OPTPROBES
277 * Internal structure for direct jump optimized probe
279 struct optimized_kprobe {
280 struct kprobe kp;
281 struct list_head list; /* list for optimizing queue */
282 struct arch_optimized_insn optinsn;
285 /* Architecture dependent functions for direct jump optimization */
286 extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
287 extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
288 extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op);
289 extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
290 extern void arch_optimize_kprobes(struct list_head *oplist);
291 extern void arch_unoptimize_kprobes(struct list_head *oplist,
292 struct list_head *done_list);
293 extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
294 extern kprobe_opcode_t *get_optinsn_slot(void);
295 extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty);
296 extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
297 unsigned long addr);
299 extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
301 #ifdef CONFIG_SYSCTL
302 extern int sysctl_kprobes_optimization;
303 extern int proc_kprobes_optimization_handler(struct ctl_table *table,
304 int write, void __user *buffer,
305 size_t *length, loff_t *ppos);
306 #endif
308 #endif /* CONFIG_OPTPROBES */
309 #ifdef CONFIG_KPROBES_ON_FTRACE
310 extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
311 struct ftrace_ops *ops, struct pt_regs *regs);
312 extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
313 #endif
316 /* Get the kprobe at this addr (if any) - called with preemption disabled */
317 struct kprobe *get_kprobe(void *addr);
318 void kretprobe_hash_lock(struct task_struct *tsk,
319 struct hlist_head **head, unsigned long *flags);
320 void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
321 struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
323 /* kprobe_running() will just return the current_kprobe on this CPU */
324 static inline struct kprobe *kprobe_running(void)
326 return (__this_cpu_read(current_kprobe));
329 static inline void reset_current_kprobe(void)
331 __this_cpu_write(current_kprobe, NULL);
334 static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
336 return (&__get_cpu_var(kprobe_ctlblk));
339 int register_kprobe(struct kprobe *p);
340 void unregister_kprobe(struct kprobe *p);
341 int register_kprobes(struct kprobe **kps, int num);
342 void unregister_kprobes(struct kprobe **kps, int num);
343 int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
344 int longjmp_break_handler(struct kprobe *, struct pt_regs *);
345 int register_jprobe(struct jprobe *p);
346 void unregister_jprobe(struct jprobe *p);
347 int register_jprobes(struct jprobe **jps, int num);
348 void unregister_jprobes(struct jprobe **jps, int num);
349 void jprobe_return(void);
350 unsigned long arch_deref_entry_point(void *);
352 int register_kretprobe(struct kretprobe *rp);
353 void unregister_kretprobe(struct kretprobe *rp);
354 int register_kretprobes(struct kretprobe **rps, int num);
355 void unregister_kretprobes(struct kretprobe **rps, int num);
357 void kprobe_flush_task(struct task_struct *tk);
358 void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
360 int disable_kprobe(struct kprobe *kp);
361 int enable_kprobe(struct kprobe *kp);
363 void dump_kprobe(struct kprobe *kp);
365 #else /* !CONFIG_KPROBES: */
367 static inline int kprobes_built_in(void)
369 return 0;
371 static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
373 return 0;
375 static inline struct kprobe *get_kprobe(void *addr)
377 return NULL;
379 static inline struct kprobe *kprobe_running(void)
381 return NULL;
383 static inline int register_kprobe(struct kprobe *p)
385 return -ENOSYS;
387 static inline int register_kprobes(struct kprobe **kps, int num)
389 return -ENOSYS;
391 static inline void unregister_kprobe(struct kprobe *p)
394 static inline void unregister_kprobes(struct kprobe **kps, int num)
397 static inline int register_jprobe(struct jprobe *p)
399 return -ENOSYS;
401 static inline int register_jprobes(struct jprobe **jps, int num)
403 return -ENOSYS;
405 static inline void unregister_jprobe(struct jprobe *p)
408 static inline void unregister_jprobes(struct jprobe **jps, int num)
411 static inline void jprobe_return(void)
414 static inline int register_kretprobe(struct kretprobe *rp)
416 return -ENOSYS;
418 static inline int register_kretprobes(struct kretprobe **rps, int num)
420 return -ENOSYS;
422 static inline void unregister_kretprobe(struct kretprobe *rp)
425 static inline void unregister_kretprobes(struct kretprobe **rps, int num)
428 static inline void kprobe_flush_task(struct task_struct *tk)
431 static inline int disable_kprobe(struct kprobe *kp)
433 return -ENOSYS;
435 static inline int enable_kprobe(struct kprobe *kp)
437 return -ENOSYS;
439 #endif /* CONFIG_KPROBES */
440 static inline int disable_kretprobe(struct kretprobe *rp)
442 return disable_kprobe(&rp->kp);
444 static inline int enable_kretprobe(struct kretprobe *rp)
446 return enable_kprobe(&rp->kp);
448 static inline int disable_jprobe(struct jprobe *jp)
450 return disable_kprobe(&jp->kp);
452 static inline int enable_jprobe(struct jprobe *jp)
454 return enable_kprobe(&jp->kp);
457 #endif /* _LINUX_KPROBES_H */