perf: Fix comments in PERF_MEM_LVL bitmask
[deliverable/linux.git] / include / linux / kprobes.h
CommitLineData
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 */
36dcd67a 32#include <linux/linkage.h>
1da177e4
LT
33#include <linux/list.h>
34#include <linux/notifier.h>
35#include <linux/smp.h>
187f1882 36#include <linux/bug.h>
e6584523 37#include <linux/percpu.h>
3516a460
AM
38#include <linux/spinlock.h>
39#include <linux/rcupdate.h>
7a7d1cf9 40#include <linux/mutex.h>
ae6aa16f 41#include <linux/ftrace.h>
b94cce92 42
00d7c05a 43#ifdef CONFIG_KPROBES
1da177e4
LT
44#include <asm/kprobes.h>
45
ea32c65c
PP
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
51
d0aaff97 52/* Attach to insert probes on any functions which should be ignored*/
fe832a3a 53#define __kprobes __attribute__((__section__(".kprobes.text")))
ae6aa16f 54
dc19835d
MH
55#else /* CONFIG_KPROBES */
56typedef int kprobe_opcode_t;
57struct arch_specific_insn {
58 int dummy;
59};
fe832a3a 60#define __kprobes
ae6aa16f 61
dc19835d 62#endif /* CONFIG_KPROBES */
d0aaff97 63
1da177e4
LT
64struct kprobe;
65struct pt_regs;
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HN
66struct kretprobe;
67struct kretprobe_instance;
1da177e4
LT
68typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
69typedef int (*kprobe_break_handler_t) (struct kprobe *, struct pt_regs *);
70typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
71 unsigned long flags);
72typedef int (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
73 int trapnr);
b94cce92
HN
74typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
75 struct pt_regs *);
76
1da177e4
LT
77struct kprobe {
78 struct hlist_node hlist;
79
64f562c6
AM
80 /* list of kprobes for multi-handler support */
81 struct list_head list;
82
ea32c65c
PP
83 /*count the number of times this probe was temporarily disarmed */
84 unsigned long nmissed;
85
1da177e4
LT
86 /* location of the probe point */
87 kprobe_opcode_t *addr;
88
3a872d89 89 /* Allow user to indicate symbol name of the probe point */
9b3af29b 90 const char *symbol_name;
3a872d89
AM
91
92 /* Offset into the symbol */
93 unsigned int offset;
94
1da177e4
LT
95 /* Called before addr is executed. */
96 kprobe_pre_handler_t pre_handler;
97
98 /* Called after addr is executed, unless... */
99 kprobe_post_handler_t post_handler;
100
cc00e9cf
MH
101 /*
102 * ... called if executing addr causes a fault (eg. page fault).
103 * Return 1 if it handled fault, otherwise kernel will see it.
104 */
1da177e4
LT
105 kprobe_fault_handler_t fault_handler;
106
cc00e9cf
MH
107 /*
108 * ... called if breakpoint trap occurs in probe handler.
109 * Return 1 if it handled break, otherwise kernel will see it.
110 */
1da177e4
LT
111 kprobe_break_handler_t break_handler;
112
113 /* Saved opcode (which has been replaced with breakpoint) */
114 kprobe_opcode_t opcode;
115
116 /* copy of the original instruction */
117 struct arch_specific_insn ainsn;
e8386a0c 118
de5bd88d
MH
119 /*
120 * Indicates various status flags.
121 * Protected by kprobe_mutex after this kprobe is registered.
122 */
e8386a0c 123 u32 flags;
1da177e4
LT
124};
125
e8386a0c
MH
126/* Kprobe status flags */
127#define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
de5bd88d 128#define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
afd66255
MH
129#define KPROBE_FLAG_OPTIMIZED 4 /*
130 * probe is really optimized.
131 * NOTE:
132 * this flag is only for optimized_kprobe.
133 */
ae6aa16f 134#define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */
e8386a0c 135
de5bd88d 136/* Has this kprobe gone ? */
e8386a0c
MH
137static inline int kprobe_gone(struct kprobe *p)
138{
139 return p->flags & KPROBE_FLAG_GONE;
140}
141
de5bd88d
MH
142/* Is this kprobe disabled ? */
143static inline int kprobe_disabled(struct kprobe *p)
144{
145 return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
146}
afd66255
MH
147
148/* Is this kprobe really running optimized path ? */
149static inline int kprobe_optimized(struct kprobe *p)
150{
151 return p->flags & KPROBE_FLAG_OPTIMIZED;
152}
ae6aa16f
MH
153
154/* Is this kprobe uses ftrace ? */
155static inline int kprobe_ftrace(struct kprobe *p)
156{
157 return p->flags & KPROBE_FLAG_FTRACE;
158}
159
1da177e4
LT
160/*
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.
169 */
170struct jprobe {
171 struct kprobe kp;
81eae375 172 void *entry; /* probe handling code to jump to */
1da177e4
LT
173};
174
9e367d85
ME
175/* For backward compatibility with old code using JPROBE_ENTRY() */
176#define JPROBE_ENTRY(handler) (handler)
177
b94cce92
HN
178/*
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.
186 *
187 */
188struct kretprobe {
189 struct kprobe kp;
190 kretprobe_handler_t handler;
f47cd9b5 191 kretprobe_handler_t entry_handler;
b94cce92
HN
192 int maxactive;
193 int nmissed;
f47cd9b5 194 size_t data_size;
b94cce92 195 struct hlist_head free_instances;
ec484608 196 raw_spinlock_t lock;
b94cce92
HN
197};
198
199struct kretprobe_instance {
b94cce92
HN
200 struct hlist_node hlist;
201 struct kretprobe *rp;
802eae7c
RL
202 kprobe_opcode_t *ret_addr;
203 struct task_struct *task;
f47cd9b5 204 char data[0];
b94cce92
HN
205};
206
f438d914
MH
207struct kretprobe_blackpoint {
208 const char *name;
209 void *addr;
210};
3d8d996e
SD
211
212struct kprobe_blackpoint {
213 const char *name;
214 unsigned long start_addr;
215 unsigned long range;
216};
217
dc19835d
MH
218#ifdef CONFIG_KPROBES
219DECLARE_PER_CPU(struct kprobe *, current_kprobe);
220DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
221
b1801812
IM
222/*
223 * For #ifdef avoidance:
224 */
225static inline int kprobes_built_in(void)
226{
227 return 1;
228}
229
dc19835d
MH
230#ifdef CONFIG_KRETPROBES
231extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
232 struct pt_regs *regs);
233extern int arch_trampoline_kprobe(struct kprobe *p);
234#else /* CONFIG_KRETPROBES */
235static inline void arch_prepare_kretprobe(struct kretprobe *rp,
236 struct pt_regs *regs)
237{
238}
239static inline int arch_trampoline_kprobe(struct kprobe *p)
240{
241 return 0;
242}
243#endif /* CONFIG_KRETPROBES */
244
f438d914
MH
245extern struct kretprobe_blackpoint kretprobe_blacklist[];
246
0f95b7fc
AM
247static inline void kretprobe_assert(struct kretprobe_instance *ri,
248 unsigned long orig_ret_address, unsigned long trampoline_address)
249{
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();
254 }
255}
256
8c1c9356
AM
257#ifdef CONFIG_KPROBES_SANITY_TEST
258extern int init_test_probes(void);
259#else
260static inline int init_test_probes(void)
261{
262 return 0;
263}
264#endif /* CONFIG_KPROBES_SANITY_TEST */
265
1da177e4 266extern int arch_prepare_kprobe(struct kprobe *p);
7e1048b1
RL
267extern void arch_arm_kprobe(struct kprobe *p);
268extern void arch_disarm_kprobe(struct kprobe *p);
6772926b 269extern int arch_init_kprobes(void);
1da177e4 270extern void show_registers(struct pt_regs *regs);
9ec4b1f3 271extern kprobe_opcode_t *get_insn_slot(void);
b4c6c34a 272extern void free_insn_slot(kprobe_opcode_t *slot, int dirty);
bf8d5c52 273extern void kprobes_inc_nmissed_count(struct kprobe *p);
1da177e4 274
afd66255
MH
275#ifdef CONFIG_OPTPROBES
276/*
277 * Internal structure for direct jump optimized probe
278 */
279struct optimized_kprobe {
280 struct kprobe kp;
281 struct list_head list; /* list for optimizing queue */
282 struct arch_optimized_insn optinsn;
283};
284
285/* Architecture dependent functions for direct jump optimization */
286extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
287extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
288extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op);
289extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
cd7ebe22 290extern void arch_optimize_kprobes(struct list_head *oplist);
f984ba4e
MH
291extern void arch_unoptimize_kprobes(struct list_head *oplist,
292 struct list_head *done_list);
afd66255
MH
293extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
294extern kprobe_opcode_t *get_optinsn_slot(void);
295extern void free_optinsn_slot(kprobe_opcode_t *slot, int dirty);
296extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
297 unsigned long addr);
298
299extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
b2be84df
MH
300
301#ifdef CONFIG_SYSCTL
302extern int sysctl_kprobes_optimization;
303extern int proc_kprobes_optimization_handler(struct ctl_table *table,
304 int write, void __user *buffer,
305 size_t *length, loff_t *ppos);
306#endif
307
afd66255 308#endif /* CONFIG_OPTPROBES */
e7dbfe34 309#ifdef CONFIG_KPROBES_ON_FTRACE
ae6aa16f 310extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
e5253896 311 struct ftrace_ops *ops, struct pt_regs *regs);
ae6aa16f
MH
312extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
313#endif
314
afd66255 315
d217d545 316/* Get the kprobe at this addr (if any) - called with preemption disabled */
1da177e4 317struct kprobe *get_kprobe(void *addr);
ef53d9c5
S
318void kretprobe_hash_lock(struct task_struct *tsk,
319 struct hlist_head **head, unsigned long *flags);
320void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
b94cce92 321struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
1da177e4 322
e6584523
AM
323/* kprobe_running() will just return the current_kprobe on this CPU */
324static inline struct kprobe *kprobe_running(void)
325{
b76834bc 326 return (__this_cpu_read(current_kprobe));
e6584523
AM
327}
328
329static inline void reset_current_kprobe(void)
330{
b76834bc 331 __this_cpu_write(current_kprobe, NULL);
e6584523
AM
332}
333
334static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
335{
336 return (&__get_cpu_var(kprobe_ctlblk));
337}
338
1da177e4
LT
339int register_kprobe(struct kprobe *p);
340void unregister_kprobe(struct kprobe *p);
9861668f
MH
341int register_kprobes(struct kprobe **kps, int num);
342void unregister_kprobes(struct kprobe **kps, int num);
1da177e4
LT
343int setjmp_pre_handler(struct kprobe *, struct pt_regs *);
344int longjmp_break_handler(struct kprobe *, struct pt_regs *);
345int register_jprobe(struct jprobe *p);
346void unregister_jprobe(struct jprobe *p);
26b31c19
MH
347int register_jprobes(struct jprobe **jps, int num);
348void unregister_jprobes(struct jprobe **jps, int num);
1da177e4 349void jprobe_return(void);
3d7e3382 350unsigned long arch_deref_entry_point(void *);
1da177e4 351
b94cce92
HN
352int register_kretprobe(struct kretprobe *rp);
353void unregister_kretprobe(struct kretprobe *rp);
4a296e07
MH
354int register_kretprobes(struct kretprobe **rps, int num);
355void unregister_kretprobes(struct kretprobe **rps, int num);
b94cce92 356
b94cce92 357void kprobe_flush_task(struct task_struct *tk);
99219a3f 358void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
8c1c9356 359
de5bd88d
MH
360int disable_kprobe(struct kprobe *kp);
361int enable_kprobe(struct kprobe *kp);
362
24851d24
FW
363void dump_kprobe(struct kprobe *kp);
364
b1801812 365#else /* !CONFIG_KPROBES: */
00d7c05a 366
b1801812
IM
367static inline int kprobes_built_in(void)
368{
369 return 0;
370}
371static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
372{
373 return 0;
374}
785656a4
AS
375static inline struct kprobe *get_kprobe(void *addr)
376{
377 return NULL;
378}
e6584523 379static inline struct kprobe *kprobe_running(void)
1da177e4 380{
e6584523 381 return NULL;
1da177e4
LT
382}
383static inline int register_kprobe(struct kprobe *p)
384{
385 return -ENOSYS;
386}
9861668f
MH
387static inline int register_kprobes(struct kprobe **kps, int num)
388{
389 return -ENOSYS;
390}
1da177e4
LT
391static inline void unregister_kprobe(struct kprobe *p)
392{
393}
9861668f
MH
394static inline void unregister_kprobes(struct kprobe **kps, int num)
395{
396}
1da177e4
LT
397static inline int register_jprobe(struct jprobe *p)
398{
399 return -ENOSYS;
400}
26b31c19
MH
401static inline int register_jprobes(struct jprobe **jps, int num)
402{
403 return -ENOSYS;
404}
1da177e4
LT
405static inline void unregister_jprobe(struct jprobe *p)
406{
407}
26b31c19
MH
408static inline void unregister_jprobes(struct jprobe **jps, int num)
409{
410}
1da177e4
LT
411static inline void jprobe_return(void)
412{
413}
b94cce92
HN
414static inline int register_kretprobe(struct kretprobe *rp)
415{
416 return -ENOSYS;
417}
4a296e07
MH
418static inline int register_kretprobes(struct kretprobe **rps, int num)
419{
420 return -ENOSYS;
421}
b94cce92
HN
422static inline void unregister_kretprobe(struct kretprobe *rp)
423{
424}
4a296e07
MH
425static inline void unregister_kretprobes(struct kretprobe **rps, int num)
426{
427}
b94cce92
HN
428static inline void kprobe_flush_task(struct task_struct *tk)
429{
430}
de5bd88d
MH
431static inline int disable_kprobe(struct kprobe *kp)
432{
433 return -ENOSYS;
434}
435static inline int enable_kprobe(struct kprobe *kp)
436{
437 return -ENOSYS;
438}
b1801812 439#endif /* CONFIG_KPROBES */
8f9b1528
MH
440static inline int disable_kretprobe(struct kretprobe *rp)
441{
442 return disable_kprobe(&rp->kp);
443}
444static inline int enable_kretprobe(struct kretprobe *rp)
445{
446 return enable_kprobe(&rp->kp);
447}
448static inline int disable_jprobe(struct jprobe *jp)
449{
450 return disable_kprobe(&jp->kp);
451}
452static inline int enable_jprobe(struct jprobe *jp)
453{
454 return enable_kprobe(&jp->kp);
455}
456
b1801812 457#endif /* _LINUX_KPROBES_H */
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