2 * Kernel Probes (KProbes)
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 * Copyright (C) IBM Corporation, 2002, 2004
21 * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
22 * Probes initial implementation (includes suggestions from
24 * 2004-Aug Updated by Prasanna S Panchamukhi <prasanna@in.ibm.com> with
25 * hlists and exceptions notifier as suggested by Andi Kleen.
26 * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
27 * interface to access function arguments.
28 * 2004-Sep Prasanna S Panchamukhi <prasanna@in.ibm.com> Changed Kprobes
29 * exceptions notifier to be first on the priority list.
30 * 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston
31 * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
32 * <prasanna@in.ibm.com> added function-return probes.
34 #include <linux/kprobes.h>
35 #include <linux/hash.h>
36 #include <linux/init.h>
37 #include <linux/slab.h>
38 #include <linux/module.h>
39 #include <linux/moduleloader.h>
40 #include <linux/kallsyms.h>
41 #include <linux/freezer.h>
42 #include <linux/seq_file.h>
43 #include <linux/debugfs.h>
44 #include <asm-generic/sections.h>
45 #include <asm/cacheflush.h>
46 #include <asm/errno.h>
47 #include <asm/kdebug.h>
49 #define KPROBE_HASH_BITS 6
50 #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS)
54 * Some oddball architectures like 64bit powerpc have function descriptors
55 * so this must be overridable.
57 #ifndef kprobe_lookup_name
58 #define kprobe_lookup_name(name, addr) \
59 addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name)))
62 static struct hlist_head kprobe_table
[KPROBE_TABLE_SIZE
];
63 static struct hlist_head kretprobe_inst_table
[KPROBE_TABLE_SIZE
];
64 static atomic_t kprobe_count
;
66 DEFINE_MUTEX(kprobe_mutex
); /* Protects kprobe_table */
67 DEFINE_SPINLOCK(kretprobe_lock
); /* Protects kretprobe_inst_table */
68 static DEFINE_PER_CPU(struct kprobe
*, kprobe_instance
) = NULL
;
70 static struct notifier_block kprobe_page_fault_nb
= {
71 .notifier_call
= kprobe_exceptions_notify
,
72 .priority
= 0x7fffffff /* we need to notified first */
75 #ifdef __ARCH_WANT_KPROBES_INSN_SLOT
77 * kprobe->ainsn.insn points to the copy of the instruction to be
78 * single-stepped. x86_64, POWER4 and above have no-exec support and
79 * stepping on the instruction on a vmalloced/kmalloced/data page
80 * is a recipe for disaster
82 #define INSNS_PER_PAGE (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t)))
84 struct kprobe_insn_page
{
85 struct hlist_node hlist
;
86 kprobe_opcode_t
*insns
; /* Page of instruction slots */
87 char slot_used
[INSNS_PER_PAGE
];
92 enum kprobe_slot_state
{
98 static struct hlist_head kprobe_insn_pages
;
99 static int kprobe_garbage_slots
;
100 static int collect_garbage_slots(void);
102 static int __kprobes
check_safety(void)
105 #if defined(CONFIG_PREEMPT) && defined(CONFIG_PM)
106 ret
= freeze_processes();
108 struct task_struct
*p
, *q
;
109 do_each_thread(p
, q
) {
110 if (p
!= current
&& p
->state
== TASK_RUNNING
&&
112 printk("Check failed: %s is running\n",p
->comm
);
116 } while_each_thread(p
, q
);
127 * get_insn_slot() - Find a slot on an executable page for an instruction.
128 * We allocate an executable page if there's no room on existing ones.
130 kprobe_opcode_t __kprobes
*get_insn_slot(void)
132 struct kprobe_insn_page
*kip
;
133 struct hlist_node
*pos
;
136 hlist_for_each(pos
, &kprobe_insn_pages
) {
137 kip
= hlist_entry(pos
, struct kprobe_insn_page
, hlist
);
138 if (kip
->nused
< INSNS_PER_PAGE
) {
140 for (i
= 0; i
< INSNS_PER_PAGE
; i
++) {
141 if (kip
->slot_used
[i
] == SLOT_CLEAN
) {
142 kip
->slot_used
[i
] = SLOT_USED
;
144 return kip
->insns
+ (i
* MAX_INSN_SIZE
);
147 /* Surprise! No unused slots. Fix kip->nused. */
148 kip
->nused
= INSNS_PER_PAGE
;
152 /* If there are any garbage slots, collect it and try again. */
153 if (kprobe_garbage_slots
&& collect_garbage_slots() == 0) {
156 /* All out of space. Need to allocate a new page. Use slot 0. */
157 kip
= kmalloc(sizeof(struct kprobe_insn_page
), GFP_KERNEL
);
163 * Use module_alloc so this page is within +/- 2GB of where the
164 * kernel image and loaded module images reside. This is required
165 * so x86_64 can correctly handle the %rip-relative fixups.
167 kip
->insns
= module_alloc(PAGE_SIZE
);
172 INIT_HLIST_NODE(&kip
->hlist
);
173 hlist_add_head(&kip
->hlist
, &kprobe_insn_pages
);
174 memset(kip
->slot_used
, SLOT_CLEAN
, INSNS_PER_PAGE
);
175 kip
->slot_used
[0] = SLOT_USED
;
181 /* Return 1 if all garbages are collected, otherwise 0. */
182 static int __kprobes
collect_one_slot(struct kprobe_insn_page
*kip
, int idx
)
184 kip
->slot_used
[idx
] = SLOT_CLEAN
;
186 if (kip
->nused
== 0) {
188 * Page is no longer in use. Free it unless
189 * it's the last one. We keep the last one
190 * so as not to have to set it up again the
191 * next time somebody inserts a probe.
193 hlist_del(&kip
->hlist
);
194 if (hlist_empty(&kprobe_insn_pages
)) {
195 INIT_HLIST_NODE(&kip
->hlist
);
196 hlist_add_head(&kip
->hlist
,
199 module_free(NULL
, kip
->insns
);
207 static int __kprobes
collect_garbage_slots(void)
209 struct kprobe_insn_page
*kip
;
210 struct hlist_node
*pos
, *next
;
212 /* Ensure no-one is preepmted on the garbages */
213 if (check_safety() != 0)
216 hlist_for_each_safe(pos
, next
, &kprobe_insn_pages
) {
218 kip
= hlist_entry(pos
, struct kprobe_insn_page
, hlist
);
219 if (kip
->ngarbage
== 0)
221 kip
->ngarbage
= 0; /* we will collect all garbages */
222 for (i
= 0; i
< INSNS_PER_PAGE
; i
++) {
223 if (kip
->slot_used
[i
] == SLOT_DIRTY
&&
224 collect_one_slot(kip
, i
))
228 kprobe_garbage_slots
= 0;
232 void __kprobes
free_insn_slot(kprobe_opcode_t
* slot
, int dirty
)
234 struct kprobe_insn_page
*kip
;
235 struct hlist_node
*pos
;
237 hlist_for_each(pos
, &kprobe_insn_pages
) {
238 kip
= hlist_entry(pos
, struct kprobe_insn_page
, hlist
);
239 if (kip
->insns
<= slot
&&
240 slot
< kip
->insns
+ (INSNS_PER_PAGE
* MAX_INSN_SIZE
)) {
241 int i
= (slot
- kip
->insns
) / MAX_INSN_SIZE
;
243 kip
->slot_used
[i
] = SLOT_DIRTY
;
246 collect_one_slot(kip
, i
);
251 if (dirty
&& (++kprobe_garbage_slots
> INSNS_PER_PAGE
)) {
252 collect_garbage_slots();
257 /* We have preemption disabled.. so it is safe to use __ versions */
258 static inline void set_kprobe_instance(struct kprobe
*kp
)
260 __get_cpu_var(kprobe_instance
) = kp
;
263 static inline void reset_kprobe_instance(void)
265 __get_cpu_var(kprobe_instance
) = NULL
;
269 * This routine is called either:
270 * - under the kprobe_mutex - during kprobe_[un]register()
272 * - with preemption disabled - from arch/xxx/kernel/kprobes.c
274 struct kprobe __kprobes
*get_kprobe(void *addr
)
276 struct hlist_head
*head
;
277 struct hlist_node
*node
;
280 head
= &kprobe_table
[hash_ptr(addr
, KPROBE_HASH_BITS
)];
281 hlist_for_each_entry_rcu(p
, node
, head
, hlist
) {
289 * Aggregate handlers for multiple kprobes support - these handlers
290 * take care of invoking the individual kprobe handlers on p->list
292 static int __kprobes
aggr_pre_handler(struct kprobe
*p
, struct pt_regs
*regs
)
296 list_for_each_entry_rcu(kp
, &p
->list
, list
) {
297 if (kp
->pre_handler
) {
298 set_kprobe_instance(kp
);
299 if (kp
->pre_handler(kp
, regs
))
302 reset_kprobe_instance();
307 static void __kprobes
aggr_post_handler(struct kprobe
*p
, struct pt_regs
*regs
,
312 list_for_each_entry_rcu(kp
, &p
->list
, list
) {
313 if (kp
->post_handler
) {
314 set_kprobe_instance(kp
);
315 kp
->post_handler(kp
, regs
, flags
);
316 reset_kprobe_instance();
322 static int __kprobes
aggr_fault_handler(struct kprobe
*p
, struct pt_regs
*regs
,
325 struct kprobe
*cur
= __get_cpu_var(kprobe_instance
);
328 * if we faulted "during" the execution of a user specified
329 * probe handler, invoke just that probe's fault handler
331 if (cur
&& cur
->fault_handler
) {
332 if (cur
->fault_handler(cur
, regs
, trapnr
))
338 static int __kprobes
aggr_break_handler(struct kprobe
*p
, struct pt_regs
*regs
)
340 struct kprobe
*cur
= __get_cpu_var(kprobe_instance
);
343 if (cur
&& cur
->break_handler
) {
344 if (cur
->break_handler(cur
, regs
))
347 reset_kprobe_instance();
351 /* Walks the list and increments nmissed count for multiprobe case */
352 void __kprobes
kprobes_inc_nmissed_count(struct kprobe
*p
)
355 if (p
->pre_handler
!= aggr_pre_handler
) {
358 list_for_each_entry_rcu(kp
, &p
->list
, list
)
364 /* Called with kretprobe_lock held */
365 struct kretprobe_instance __kprobes
*get_free_rp_inst(struct kretprobe
*rp
)
367 struct hlist_node
*node
;
368 struct kretprobe_instance
*ri
;
369 hlist_for_each_entry(ri
, node
, &rp
->free_instances
, uflist
)
374 /* Called with kretprobe_lock held */
375 static struct kretprobe_instance __kprobes
*get_used_rp_inst(struct kretprobe
378 struct hlist_node
*node
;
379 struct kretprobe_instance
*ri
;
380 hlist_for_each_entry(ri
, node
, &rp
->used_instances
, uflist
)
385 /* Called with kretprobe_lock held */
386 void __kprobes
add_rp_inst(struct kretprobe_instance
*ri
)
389 * Remove rp inst off the free list -
390 * Add it back when probed function returns
392 hlist_del(&ri
->uflist
);
394 /* Add rp inst onto table */
395 INIT_HLIST_NODE(&ri
->hlist
);
396 hlist_add_head(&ri
->hlist
,
397 &kretprobe_inst_table
[hash_ptr(ri
->task
, KPROBE_HASH_BITS
)]);
399 /* Also add this rp inst to the used list. */
400 INIT_HLIST_NODE(&ri
->uflist
);
401 hlist_add_head(&ri
->uflist
, &ri
->rp
->used_instances
);
404 /* Called with kretprobe_lock held */
405 void __kprobes
recycle_rp_inst(struct kretprobe_instance
*ri
,
406 struct hlist_head
*head
)
408 /* remove rp inst off the rprobe_inst_table */
409 hlist_del(&ri
->hlist
);
411 /* remove rp inst off the used list */
412 hlist_del(&ri
->uflist
);
413 /* put rp inst back onto the free list */
414 INIT_HLIST_NODE(&ri
->uflist
);
415 hlist_add_head(&ri
->uflist
, &ri
->rp
->free_instances
);
418 hlist_add_head(&ri
->hlist
, head
);
421 struct hlist_head __kprobes
*kretprobe_inst_table_head(struct task_struct
*tsk
)
423 return &kretprobe_inst_table
[hash_ptr(tsk
, KPROBE_HASH_BITS
)];
427 * This function is called from finish_task_switch when task tk becomes dead,
428 * so that we can recycle any function-return probe instances associated
429 * with this task. These left over instances represent probed functions
430 * that have been called but will never return.
432 void __kprobes
kprobe_flush_task(struct task_struct
*tk
)
434 struct kretprobe_instance
*ri
;
435 struct hlist_head
*head
, empty_rp
;
436 struct hlist_node
*node
, *tmp
;
437 unsigned long flags
= 0;
439 INIT_HLIST_HEAD(&empty_rp
);
440 spin_lock_irqsave(&kretprobe_lock
, flags
);
441 head
= kretprobe_inst_table_head(tk
);
442 hlist_for_each_entry_safe(ri
, node
, tmp
, head
, hlist
) {
444 recycle_rp_inst(ri
, &empty_rp
);
446 spin_unlock_irqrestore(&kretprobe_lock
, flags
);
448 hlist_for_each_entry_safe(ri
, node
, tmp
, &empty_rp
, hlist
) {
449 hlist_del(&ri
->hlist
);
454 static inline void free_rp_inst(struct kretprobe
*rp
)
456 struct kretprobe_instance
*ri
;
457 while ((ri
= get_free_rp_inst(rp
)) != NULL
) {
458 hlist_del(&ri
->uflist
);
464 * Keep all fields in the kprobe consistent
466 static inline void copy_kprobe(struct kprobe
*old_p
, struct kprobe
*p
)
468 memcpy(&p
->opcode
, &old_p
->opcode
, sizeof(kprobe_opcode_t
));
469 memcpy(&p
->ainsn
, &old_p
->ainsn
, sizeof(struct arch_specific_insn
));
473 * Add the new probe to old_p->list. Fail if this is the
474 * second jprobe at the address - two jprobes can't coexist
476 static int __kprobes
add_new_kprobe(struct kprobe
*old_p
, struct kprobe
*p
)
478 if (p
->break_handler
) {
479 if (old_p
->break_handler
)
481 list_add_tail_rcu(&p
->list
, &old_p
->list
);
482 old_p
->break_handler
= aggr_break_handler
;
484 list_add_rcu(&p
->list
, &old_p
->list
);
485 if (p
->post_handler
&& !old_p
->post_handler
)
486 old_p
->post_handler
= aggr_post_handler
;
491 * Fill in the required fields of the "manager kprobe". Replace the
492 * earlier kprobe in the hlist with the manager kprobe
494 static inline void add_aggr_kprobe(struct kprobe
*ap
, struct kprobe
*p
)
499 ap
->pre_handler
= aggr_pre_handler
;
500 ap
->fault_handler
= aggr_fault_handler
;
502 ap
->post_handler
= aggr_post_handler
;
503 if (p
->break_handler
)
504 ap
->break_handler
= aggr_break_handler
;
506 INIT_LIST_HEAD(&ap
->list
);
507 list_add_rcu(&p
->list
, &ap
->list
);
509 hlist_replace_rcu(&p
->hlist
, &ap
->hlist
);
513 * This is the second or subsequent kprobe at the address - handle
516 static int __kprobes
register_aggr_kprobe(struct kprobe
*old_p
,
522 if (old_p
->pre_handler
== aggr_pre_handler
) {
523 copy_kprobe(old_p
, p
);
524 ret
= add_new_kprobe(old_p
, p
);
526 ap
= kzalloc(sizeof(struct kprobe
), GFP_KERNEL
);
529 add_aggr_kprobe(ap
, old_p
);
531 ret
= add_new_kprobe(ap
, p
);
536 static int __kprobes
in_kprobes_functions(unsigned long addr
)
538 if (addr
>= (unsigned long)__kprobes_text_start
539 && addr
< (unsigned long)__kprobes_text_end
)
544 static int __kprobes
__register_kprobe(struct kprobe
*p
,
545 unsigned long called_from
)
548 struct kprobe
*old_p
;
549 struct module
*probed_mod
;
552 * If we have a symbol_name argument look it up,
553 * and add it to the address. That way the addr
554 * field can either be global or relative to a symbol.
556 if (p
->symbol_name
) {
559 kprobe_lookup_name(p
->symbol_name
, p
->addr
);
564 p
->addr
= (kprobe_opcode_t
*)(((char *)p
->addr
)+ p
->offset
);
566 if ((!kernel_text_address((unsigned long) p
->addr
)) ||
567 in_kprobes_functions((unsigned long) p
->addr
))
570 p
->mod_refcounted
= 0;
571 /* Check are we probing a module */
572 if ((probed_mod
= module_text_address((unsigned long) p
->addr
))) {
573 struct module
*calling_mod
= module_text_address(called_from
);
574 /* We must allow modules to probe themself and
575 * in this case avoid incrementing the module refcount,
576 * so as to allow unloading of self probing modules.
578 if (calling_mod
&& (calling_mod
!= probed_mod
)) {
579 if (unlikely(!try_module_get(probed_mod
)))
581 p
->mod_refcounted
= 1;
587 mutex_lock(&kprobe_mutex
);
588 old_p
= get_kprobe(p
->addr
);
590 ret
= register_aggr_kprobe(old_p
, p
);
592 atomic_inc(&kprobe_count
);
596 if ((ret
= arch_prepare_kprobe(p
)) != 0)
599 INIT_HLIST_NODE(&p
->hlist
);
600 hlist_add_head_rcu(&p
->hlist
,
601 &kprobe_table
[hash_ptr(p
->addr
, KPROBE_HASH_BITS
)]);
603 if (atomic_add_return(1, &kprobe_count
) == \
604 (ARCH_INACTIVE_KPROBE_COUNT
+ 1))
605 register_page_fault_notifier(&kprobe_page_fault_nb
);
610 mutex_unlock(&kprobe_mutex
);
612 if (ret
&& probed_mod
)
613 module_put(probed_mod
);
617 int __kprobes
register_kprobe(struct kprobe
*p
)
619 return __register_kprobe(p
,
620 (unsigned long)__builtin_return_address(0));
623 void __kprobes
unregister_kprobe(struct kprobe
*p
)
626 struct kprobe
*old_p
, *list_p
;
629 mutex_lock(&kprobe_mutex
);
630 old_p
= get_kprobe(p
->addr
);
631 if (unlikely(!old_p
)) {
632 mutex_unlock(&kprobe_mutex
);
636 list_for_each_entry_rcu(list_p
, &old_p
->list
, list
)
638 /* kprobe p is a valid probe */
640 mutex_unlock(&kprobe_mutex
);
644 if ((old_p
== p
) || ((old_p
->pre_handler
== aggr_pre_handler
) &&
645 (p
->list
.next
== &old_p
->list
) &&
646 (p
->list
.prev
== &old_p
->list
))) {
647 /* Only probe on the hash list */
648 arch_disarm_kprobe(p
);
649 hlist_del_rcu(&old_p
->hlist
);
652 list_del_rcu(&p
->list
);
656 mutex_unlock(&kprobe_mutex
);
659 if (p
->mod_refcounted
&&
660 (mod
= module_text_address((unsigned long)p
->addr
)))
665 list_del_rcu(&p
->list
);
668 arch_remove_kprobe(p
);
670 mutex_lock(&kprobe_mutex
);
671 if (p
->break_handler
)
672 old_p
->break_handler
= NULL
;
673 if (p
->post_handler
){
674 list_for_each_entry_rcu(list_p
, &old_p
->list
, list
){
675 if (list_p
->post_handler
){
681 old_p
->post_handler
= NULL
;
683 mutex_unlock(&kprobe_mutex
);
686 /* Call unregister_page_fault_notifier()
687 * if no probes are active
689 mutex_lock(&kprobe_mutex
);
690 if (atomic_add_return(-1, &kprobe_count
) == \
691 ARCH_INACTIVE_KPROBE_COUNT
)
692 unregister_page_fault_notifier(&kprobe_page_fault_nb
);
693 mutex_unlock(&kprobe_mutex
);
697 static struct notifier_block kprobe_exceptions_nb
= {
698 .notifier_call
= kprobe_exceptions_notify
,
699 .priority
= 0x7fffffff /* we need to be notified first */
703 int __kprobes
register_jprobe(struct jprobe
*jp
)
705 /* Todo: Verify probepoint is a function entry point */
706 jp
->kp
.pre_handler
= setjmp_pre_handler
;
707 jp
->kp
.break_handler
= longjmp_break_handler
;
709 return __register_kprobe(&jp
->kp
,
710 (unsigned long)__builtin_return_address(0));
713 void __kprobes
unregister_jprobe(struct jprobe
*jp
)
715 unregister_kprobe(&jp
->kp
);
718 #ifdef ARCH_SUPPORTS_KRETPROBES
721 * This kprobe pre_handler is registered with every kretprobe. When probe
722 * hits it will set up the return probe.
724 static int __kprobes
pre_handler_kretprobe(struct kprobe
*p
,
725 struct pt_regs
*regs
)
727 struct kretprobe
*rp
= container_of(p
, struct kretprobe
, kp
);
728 unsigned long flags
= 0;
730 /*TODO: consider to only swap the RA after the last pre_handler fired */
731 spin_lock_irqsave(&kretprobe_lock
, flags
);
732 arch_prepare_kretprobe(rp
, regs
);
733 spin_unlock_irqrestore(&kretprobe_lock
, flags
);
737 int __kprobes
register_kretprobe(struct kretprobe
*rp
)
740 struct kretprobe_instance
*inst
;
743 rp
->kp
.pre_handler
= pre_handler_kretprobe
;
744 rp
->kp
.post_handler
= NULL
;
745 rp
->kp
.fault_handler
= NULL
;
746 rp
->kp
.break_handler
= NULL
;
748 /* Pre-allocate memory for max kretprobe instances */
749 if (rp
->maxactive
<= 0) {
750 #ifdef CONFIG_PREEMPT
751 rp
->maxactive
= max(10, 2 * NR_CPUS
);
753 rp
->maxactive
= NR_CPUS
;
756 INIT_HLIST_HEAD(&rp
->used_instances
);
757 INIT_HLIST_HEAD(&rp
->free_instances
);
758 for (i
= 0; i
< rp
->maxactive
; i
++) {
759 inst
= kmalloc(sizeof(struct kretprobe_instance
), GFP_KERNEL
);
764 INIT_HLIST_NODE(&inst
->uflist
);
765 hlist_add_head(&inst
->uflist
, &rp
->free_instances
);
769 /* Establish function entry probe point */
770 if ((ret
= __register_kprobe(&rp
->kp
,
771 (unsigned long)__builtin_return_address(0))) != 0)
776 #else /* ARCH_SUPPORTS_KRETPROBES */
778 int __kprobes
register_kretprobe(struct kretprobe
*rp
)
783 static int __kprobes
pre_handler_kretprobe(struct kprobe
*p
,
784 struct pt_regs
*regs
)
789 #endif /* ARCH_SUPPORTS_KRETPROBES */
791 void __kprobes
unregister_kretprobe(struct kretprobe
*rp
)
794 struct kretprobe_instance
*ri
;
796 unregister_kprobe(&rp
->kp
);
798 spin_lock_irqsave(&kretprobe_lock
, flags
);
799 while ((ri
= get_used_rp_inst(rp
)) != NULL
) {
801 hlist_del(&ri
->uflist
);
803 spin_unlock_irqrestore(&kretprobe_lock
, flags
);
807 static int __init
init_kprobes(void)
811 /* FIXME allocate the probe table, currently defined statically */
812 /* initialize all list heads */
813 for (i
= 0; i
< KPROBE_TABLE_SIZE
; i
++) {
814 INIT_HLIST_HEAD(&kprobe_table
[i
]);
815 INIT_HLIST_HEAD(&kretprobe_inst_table
[i
]);
817 atomic_set(&kprobe_count
, 0);
819 err
= arch_init_kprobes();
821 err
= register_die_notifier(&kprobe_exceptions_nb
);
826 #ifdef CONFIG_DEBUG_FS
827 static void __kprobes
report_probe(struct seq_file
*pi
, struct kprobe
*p
,
828 const char *sym
, int offset
,char *modname
)
832 if (p
->pre_handler
== pre_handler_kretprobe
)
834 else if (p
->pre_handler
== setjmp_pre_handler
)
839 seq_printf(pi
, "%p %s %s+0x%x %s\n", p
->addr
, kprobe_type
,
840 sym
, offset
, (modname
? modname
: " "));
842 seq_printf(pi
, "%p %s %p\n", p
->addr
, kprobe_type
, p
->addr
);
845 static void __kprobes
*kprobe_seq_start(struct seq_file
*f
, loff_t
*pos
)
847 return (*pos
< KPROBE_TABLE_SIZE
) ? pos
: NULL
;
850 static void __kprobes
*kprobe_seq_next(struct seq_file
*f
, void *v
, loff_t
*pos
)
853 if (*pos
>= KPROBE_TABLE_SIZE
)
858 static void __kprobes
kprobe_seq_stop(struct seq_file
*f
, void *v
)
863 static int __kprobes
show_kprobe_addr(struct seq_file
*pi
, void *v
)
865 struct hlist_head
*head
;
866 struct hlist_node
*node
;
867 struct kprobe
*p
, *kp
;
868 const char *sym
= NULL
;
869 unsigned int i
= *(loff_t
*) v
;
870 unsigned long size
, offset
= 0;
871 char *modname
, namebuf
[128];
873 head
= &kprobe_table
[i
];
875 hlist_for_each_entry_rcu(p
, node
, head
, hlist
) {
876 sym
= kallsyms_lookup((unsigned long)p
->addr
, &size
,
877 &offset
, &modname
, namebuf
);
878 if (p
->pre_handler
== aggr_pre_handler
) {
879 list_for_each_entry_rcu(kp
, &p
->list
, list
)
880 report_probe(pi
, kp
, sym
, offset
, modname
);
882 report_probe(pi
, p
, sym
, offset
, modname
);
888 static struct seq_operations kprobes_seq_ops
= {
889 .start
= kprobe_seq_start
,
890 .next
= kprobe_seq_next
,
891 .stop
= kprobe_seq_stop
,
892 .show
= show_kprobe_addr
895 static int __kprobes
kprobes_open(struct inode
*inode
, struct file
*filp
)
897 return seq_open(filp
, &kprobes_seq_ops
);
900 static struct file_operations debugfs_kprobes_operations
= {
901 .open
= kprobes_open
,
904 .release
= seq_release
,
907 static int __kprobes
debugfs_kprobe_init(void)
909 struct dentry
*dir
, *file
;
911 dir
= debugfs_create_dir("kprobes", NULL
);
915 file
= debugfs_create_file("list", 0444, dir
, 0 ,
916 &debugfs_kprobes_operations
);
925 late_initcall(debugfs_kprobe_init
);
926 #endif /* CONFIG_DEBUG_FS */
928 module_init(init_kprobes
);
930 EXPORT_SYMBOL_GPL(register_kprobe
);
931 EXPORT_SYMBOL_GPL(unregister_kprobe
);
932 EXPORT_SYMBOL_GPL(register_jprobe
);
933 EXPORT_SYMBOL_GPL(unregister_jprobe
);
934 EXPORT_SYMBOL_GPL(jprobe_return
);
935 EXPORT_SYMBOL_GPL(register_kretprobe
);
936 EXPORT_SYMBOL_GPL(unregister_kretprobe
);