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/stddef.h>
39 #include <linux/module.h>
40 #include <linux/moduleloader.h>
41 #include <linux/kallsyms.h>
42 #include <linux/freezer.h>
43 #include <linux/seq_file.h>
44 #include <linux/debugfs.h>
45 #include <linux/kdebug.h>
46 #include <asm-generic/sections.h>
47 #include <asm/cacheflush.h>
48 #include <asm/errno.h>
50 #define KPROBE_HASH_BITS 6
51 #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS)
55 * Some oddball architectures like 64bit powerpc have function descriptors
56 * so this must be overridable.
58 #ifndef kprobe_lookup_name
59 #define kprobe_lookup_name(name, addr) \
60 addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name)))
63 static struct hlist_head kprobe_table
[KPROBE_TABLE_SIZE
];
64 static struct hlist_head kretprobe_inst_table
[KPROBE_TABLE_SIZE
];
65 static atomic_t kprobe_count
;
67 DEFINE_MUTEX(kprobe_mutex
); /* Protects kprobe_table */
68 DEFINE_SPINLOCK(kretprobe_lock
); /* Protects kretprobe_inst_table */
69 static DEFINE_PER_CPU(struct kprobe
*, kprobe_instance
) = NULL
;
71 static struct notifier_block kprobe_page_fault_nb
= {
72 .notifier_call
= kprobe_exceptions_notify
,
73 .priority
= 0x7fffffff /* we need to notified first */
76 #ifdef __ARCH_WANT_KPROBES_INSN_SLOT
78 * kprobe->ainsn.insn points to the copy of the instruction to be
79 * single-stepped. x86_64, POWER4 and above have no-exec support and
80 * stepping on the instruction on a vmalloced/kmalloced/data page
81 * is a recipe for disaster
83 #define INSNS_PER_PAGE (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t)))
85 struct kprobe_insn_page
{
86 struct hlist_node hlist
;
87 kprobe_opcode_t
*insns
; /* Page of instruction slots */
88 char slot_used
[INSNS_PER_PAGE
];
93 enum kprobe_slot_state
{
99 static struct hlist_head kprobe_insn_pages
;
100 static int kprobe_garbage_slots
;
101 static int collect_garbage_slots(void);
103 static int __kprobes
check_safety(void)
106 #if defined(CONFIG_PREEMPT) && defined(CONFIG_PM)
107 ret
= freeze_processes();
109 struct task_struct
*p
, *q
;
110 do_each_thread(p
, q
) {
111 if (p
!= current
&& p
->state
== TASK_RUNNING
&&
113 printk("Check failed: %s is running\n",p
->comm
);
117 } while_each_thread(p
, q
);
128 * get_insn_slot() - Find a slot on an executable page for an instruction.
129 * We allocate an executable page if there's no room on existing ones.
131 kprobe_opcode_t __kprobes
*get_insn_slot(void)
133 struct kprobe_insn_page
*kip
;
134 struct hlist_node
*pos
;
137 hlist_for_each_entry(kip
, pos
, &kprobe_insn_pages
, 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
);
162 * Use module_alloc so this page is within +/- 2GB of where the
163 * kernel image and loaded module images reside. This is required
164 * so x86_64 can correctly handle the %rip-relative fixups.
166 kip
->insns
= module_alloc(PAGE_SIZE
);
171 INIT_HLIST_NODE(&kip
->hlist
);
172 hlist_add_head(&kip
->hlist
, &kprobe_insn_pages
);
173 memset(kip
->slot_used
, SLOT_CLEAN
, INSNS_PER_PAGE
);
174 kip
->slot_used
[0] = SLOT_USED
;
180 /* Return 1 if all garbages are collected, otherwise 0. */
181 static int __kprobes
collect_one_slot(struct kprobe_insn_page
*kip
, int idx
)
183 kip
->slot_used
[idx
] = SLOT_CLEAN
;
185 if (kip
->nused
== 0) {
187 * Page is no longer in use. Free it unless
188 * it's the last one. We keep the last one
189 * so as not to have to set it up again the
190 * next time somebody inserts a probe.
192 hlist_del(&kip
->hlist
);
193 if (hlist_empty(&kprobe_insn_pages
)) {
194 INIT_HLIST_NODE(&kip
->hlist
);
195 hlist_add_head(&kip
->hlist
,
198 module_free(NULL
, kip
->insns
);
206 static int __kprobes
collect_garbage_slots(void)
208 struct kprobe_insn_page
*kip
;
209 struct hlist_node
*pos
, *next
;
211 /* Ensure no-one is preepmted on the garbages */
212 if (check_safety() != 0)
215 hlist_for_each_entry_safe(kip
, pos
, next
, &kprobe_insn_pages
, hlist
) {
217 if (kip
->ngarbage
== 0)
219 kip
->ngarbage
= 0; /* we will collect all garbages */
220 for (i
= 0; i
< INSNS_PER_PAGE
; i
++) {
221 if (kip
->slot_used
[i
] == SLOT_DIRTY
&&
222 collect_one_slot(kip
, i
))
226 kprobe_garbage_slots
= 0;
230 void __kprobes
free_insn_slot(kprobe_opcode_t
* slot
, int dirty
)
232 struct kprobe_insn_page
*kip
;
233 struct hlist_node
*pos
;
235 hlist_for_each_entry(kip
, pos
, &kprobe_insn_pages
, hlist
) {
236 if (kip
->insns
<= slot
&&
237 slot
< kip
->insns
+ (INSNS_PER_PAGE
* MAX_INSN_SIZE
)) {
238 int i
= (slot
- kip
->insns
) / MAX_INSN_SIZE
;
240 kip
->slot_used
[i
] = SLOT_DIRTY
;
243 collect_one_slot(kip
, i
);
249 if (dirty
&& ++kprobe_garbage_slots
> INSNS_PER_PAGE
)
250 collect_garbage_slots();
254 /* We have preemption disabled.. so it is safe to use __ versions */
255 static inline void set_kprobe_instance(struct kprobe
*kp
)
257 __get_cpu_var(kprobe_instance
) = kp
;
260 static inline void reset_kprobe_instance(void)
262 __get_cpu_var(kprobe_instance
) = NULL
;
266 * This routine is called either:
267 * - under the kprobe_mutex - during kprobe_[un]register()
269 * - with preemption disabled - from arch/xxx/kernel/kprobes.c
271 struct kprobe __kprobes
*get_kprobe(void *addr
)
273 struct hlist_head
*head
;
274 struct hlist_node
*node
;
277 head
= &kprobe_table
[hash_ptr(addr
, KPROBE_HASH_BITS
)];
278 hlist_for_each_entry_rcu(p
, node
, head
, hlist
) {
286 * Aggregate handlers for multiple kprobes support - these handlers
287 * take care of invoking the individual kprobe handlers on p->list
289 static int __kprobes
aggr_pre_handler(struct kprobe
*p
, struct pt_regs
*regs
)
293 list_for_each_entry_rcu(kp
, &p
->list
, list
) {
294 if (kp
->pre_handler
) {
295 set_kprobe_instance(kp
);
296 if (kp
->pre_handler(kp
, regs
))
299 reset_kprobe_instance();
304 static void __kprobes
aggr_post_handler(struct kprobe
*p
, struct pt_regs
*regs
,
309 list_for_each_entry_rcu(kp
, &p
->list
, list
) {
310 if (kp
->post_handler
) {
311 set_kprobe_instance(kp
);
312 kp
->post_handler(kp
, regs
, flags
);
313 reset_kprobe_instance();
318 static int __kprobes
aggr_fault_handler(struct kprobe
*p
, struct pt_regs
*regs
,
321 struct kprobe
*cur
= __get_cpu_var(kprobe_instance
);
324 * if we faulted "during" the execution of a user specified
325 * probe handler, invoke just that probe's fault handler
327 if (cur
&& cur
->fault_handler
) {
328 if (cur
->fault_handler(cur
, regs
, trapnr
))
334 static int __kprobes
aggr_break_handler(struct kprobe
*p
, struct pt_regs
*regs
)
336 struct kprobe
*cur
= __get_cpu_var(kprobe_instance
);
339 if (cur
&& cur
->break_handler
) {
340 if (cur
->break_handler(cur
, regs
))
343 reset_kprobe_instance();
347 /* Walks the list and increments nmissed count for multiprobe case */
348 void __kprobes
kprobes_inc_nmissed_count(struct kprobe
*p
)
351 if (p
->pre_handler
!= aggr_pre_handler
) {
354 list_for_each_entry_rcu(kp
, &p
->list
, list
)
360 /* Called with kretprobe_lock held */
361 struct kretprobe_instance __kprobes
*get_free_rp_inst(struct kretprobe
*rp
)
363 struct hlist_node
*node
;
364 struct kretprobe_instance
*ri
;
365 hlist_for_each_entry(ri
, node
, &rp
->free_instances
, uflist
)
370 /* Called with kretprobe_lock held */
371 static struct kretprobe_instance __kprobes
*get_used_rp_inst(struct kretprobe
374 struct hlist_node
*node
;
375 struct kretprobe_instance
*ri
;
376 hlist_for_each_entry(ri
, node
, &rp
->used_instances
, uflist
)
381 /* Called with kretprobe_lock held */
382 void __kprobes
add_rp_inst(struct kretprobe_instance
*ri
)
385 * Remove rp inst off the free list -
386 * Add it back when probed function returns
388 hlist_del(&ri
->uflist
);
390 /* Add rp inst onto table */
391 INIT_HLIST_NODE(&ri
->hlist
);
392 hlist_add_head(&ri
->hlist
,
393 &kretprobe_inst_table
[hash_ptr(ri
->task
, KPROBE_HASH_BITS
)]);
395 /* Also add this rp inst to the used list. */
396 INIT_HLIST_NODE(&ri
->uflist
);
397 hlist_add_head(&ri
->uflist
, &ri
->rp
->used_instances
);
400 /* Called with kretprobe_lock held */
401 void __kprobes
recycle_rp_inst(struct kretprobe_instance
*ri
,
402 struct hlist_head
*head
)
404 /* remove rp inst off the rprobe_inst_table */
405 hlist_del(&ri
->hlist
);
407 /* remove rp inst off the used list */
408 hlist_del(&ri
->uflist
);
409 /* put rp inst back onto the free list */
410 INIT_HLIST_NODE(&ri
->uflist
);
411 hlist_add_head(&ri
->uflist
, &ri
->rp
->free_instances
);
414 hlist_add_head(&ri
->hlist
, head
);
417 struct hlist_head __kprobes
*kretprobe_inst_table_head(struct task_struct
*tsk
)
419 return &kretprobe_inst_table
[hash_ptr(tsk
, KPROBE_HASH_BITS
)];
423 * This function is called from finish_task_switch when task tk becomes dead,
424 * so that we can recycle any function-return probe instances associated
425 * with this task. These left over instances represent probed functions
426 * that have been called but will never return.
428 void __kprobes
kprobe_flush_task(struct task_struct
*tk
)
430 struct kretprobe_instance
*ri
;
431 struct hlist_head
*head
, empty_rp
;
432 struct hlist_node
*node
, *tmp
;
433 unsigned long flags
= 0;
435 INIT_HLIST_HEAD(&empty_rp
);
436 spin_lock_irqsave(&kretprobe_lock
, flags
);
437 head
= kretprobe_inst_table_head(tk
);
438 hlist_for_each_entry_safe(ri
, node
, tmp
, head
, hlist
) {
440 recycle_rp_inst(ri
, &empty_rp
);
442 spin_unlock_irqrestore(&kretprobe_lock
, flags
);
444 hlist_for_each_entry_safe(ri
, node
, tmp
, &empty_rp
, hlist
) {
445 hlist_del(&ri
->hlist
);
450 static inline void free_rp_inst(struct kretprobe
*rp
)
452 struct kretprobe_instance
*ri
;
453 while ((ri
= get_free_rp_inst(rp
)) != NULL
) {
454 hlist_del(&ri
->uflist
);
460 * Keep all fields in the kprobe consistent
462 static inline void copy_kprobe(struct kprobe
*old_p
, struct kprobe
*p
)
464 memcpy(&p
->opcode
, &old_p
->opcode
, sizeof(kprobe_opcode_t
));
465 memcpy(&p
->ainsn
, &old_p
->ainsn
, sizeof(struct arch_specific_insn
));
469 * Add the new probe to old_p->list. Fail if this is the
470 * second jprobe at the address - two jprobes can't coexist
472 static int __kprobes
add_new_kprobe(struct kprobe
*old_p
, struct kprobe
*p
)
474 if (p
->break_handler
) {
475 if (old_p
->break_handler
)
477 list_add_tail_rcu(&p
->list
, &old_p
->list
);
478 old_p
->break_handler
= aggr_break_handler
;
480 list_add_rcu(&p
->list
, &old_p
->list
);
481 if (p
->post_handler
&& !old_p
->post_handler
)
482 old_p
->post_handler
= aggr_post_handler
;
487 * Fill in the required fields of the "manager kprobe". Replace the
488 * earlier kprobe in the hlist with the manager kprobe
490 static inline void add_aggr_kprobe(struct kprobe
*ap
, struct kprobe
*p
)
495 ap
->pre_handler
= aggr_pre_handler
;
496 ap
->fault_handler
= aggr_fault_handler
;
498 ap
->post_handler
= aggr_post_handler
;
499 if (p
->break_handler
)
500 ap
->break_handler
= aggr_break_handler
;
502 INIT_LIST_HEAD(&ap
->list
);
503 list_add_rcu(&p
->list
, &ap
->list
);
505 hlist_replace_rcu(&p
->hlist
, &ap
->hlist
);
509 * This is the second or subsequent kprobe at the address - handle
512 static int __kprobes
register_aggr_kprobe(struct kprobe
*old_p
,
518 if (old_p
->pre_handler
== aggr_pre_handler
) {
519 copy_kprobe(old_p
, p
);
520 ret
= add_new_kprobe(old_p
, p
);
522 ap
= kzalloc(sizeof(struct kprobe
), GFP_KERNEL
);
525 add_aggr_kprobe(ap
, old_p
);
527 ret
= add_new_kprobe(ap
, p
);
532 static int __kprobes
in_kprobes_functions(unsigned long addr
)
534 if (addr
>= (unsigned long)__kprobes_text_start
&&
535 addr
< (unsigned long)__kprobes_text_end
)
540 static int __kprobes
__register_kprobe(struct kprobe
*p
,
541 unsigned long called_from
)
544 struct kprobe
*old_p
;
545 struct module
*probed_mod
;
548 * If we have a symbol_name argument look it up,
549 * and add it to the address. That way the addr
550 * field can either be global or relative to a symbol.
552 if (p
->symbol_name
) {
555 kprobe_lookup_name(p
->symbol_name
, p
->addr
);
560 p
->addr
= (kprobe_opcode_t
*)(((char *)p
->addr
)+ p
->offset
);
562 if (!kernel_text_address((unsigned long) p
->addr
) ||
563 in_kprobes_functions((unsigned long) p
->addr
))
566 p
->mod_refcounted
= 0;
569 * Check if are we probing a module.
571 probed_mod
= module_text_address((unsigned long) p
->addr
);
573 struct module
*calling_mod
= module_text_address(called_from
);
575 * We must allow modules to probe themself and in this case
576 * avoid incrementing the module refcount, so as to allow
577 * unloading of self probing modules.
579 if (calling_mod
&& calling_mod
!= probed_mod
) {
580 if (unlikely(!try_module_get(probed_mod
)))
582 p
->mod_refcounted
= 1;
588 mutex_lock(&kprobe_mutex
);
589 old_p
= get_kprobe(p
->addr
);
591 ret
= register_aggr_kprobe(old_p
, p
);
593 atomic_inc(&kprobe_count
);
597 ret
= arch_prepare_kprobe(p
);
601 INIT_HLIST_NODE(&p
->hlist
);
602 hlist_add_head_rcu(&p
->hlist
,
603 &kprobe_table
[hash_ptr(p
->addr
, KPROBE_HASH_BITS
)]);
605 if (atomic_add_return(1, &kprobe_count
) == \
606 (ARCH_INACTIVE_KPROBE_COUNT
+ 1))
607 register_page_fault_notifier(&kprobe_page_fault_nb
);
612 mutex_unlock(&kprobe_mutex
);
614 if (ret
&& probed_mod
)
615 module_put(probed_mod
);
619 int __kprobes
register_kprobe(struct kprobe
*p
)
621 return __register_kprobe(p
, (unsigned long)__builtin_return_address(0));
624 void __kprobes
unregister_kprobe(struct kprobe
*p
)
627 struct kprobe
*old_p
, *list_p
;
630 mutex_lock(&kprobe_mutex
);
631 old_p
= get_kprobe(p
->addr
);
632 if (unlikely(!old_p
)) {
633 mutex_unlock(&kprobe_mutex
);
637 list_for_each_entry_rcu(list_p
, &old_p
->list
, list
)
639 /* kprobe p is a valid probe */
641 mutex_unlock(&kprobe_mutex
);
646 (old_p
->pre_handler
== aggr_pre_handler
&&
647 p
->list
.next
== &old_p
->list
&& p
->list
.prev
== &old_p
->list
)) {
648 /* Only probe on the hash list */
649 arch_disarm_kprobe(p
);
650 hlist_del_rcu(&old_p
->hlist
);
653 list_del_rcu(&p
->list
);
657 mutex_unlock(&kprobe_mutex
);
660 if (p
->mod_refcounted
) {
661 mod
= module_text_address((unsigned long)p
->addr
);
668 list_del_rcu(&p
->list
);
671 arch_remove_kprobe(p
);
673 mutex_lock(&kprobe_mutex
);
674 if (p
->break_handler
)
675 old_p
->break_handler
= NULL
;
676 if (p
->post_handler
){
677 list_for_each_entry_rcu(list_p
, &old_p
->list
, list
){
678 if (list_p
->post_handler
){
684 old_p
->post_handler
= NULL
;
686 mutex_unlock(&kprobe_mutex
);
689 /* Call unregister_page_fault_notifier()
690 * if no probes are active
692 mutex_lock(&kprobe_mutex
);
693 if (atomic_add_return(-1, &kprobe_count
) == \
694 ARCH_INACTIVE_KPROBE_COUNT
)
695 unregister_page_fault_notifier(&kprobe_page_fault_nb
);
696 mutex_unlock(&kprobe_mutex
);
700 static struct notifier_block kprobe_exceptions_nb
= {
701 .notifier_call
= kprobe_exceptions_notify
,
702 .priority
= 0x7fffffff /* we need to be notified first */
706 int __kprobes
register_jprobe(struct jprobe
*jp
)
708 /* Todo: Verify probepoint is a function entry point */
709 jp
->kp
.pre_handler
= setjmp_pre_handler
;
710 jp
->kp
.break_handler
= longjmp_break_handler
;
712 return __register_kprobe(&jp
->kp
,
713 (unsigned long)__builtin_return_address(0));
716 void __kprobes
unregister_jprobe(struct jprobe
*jp
)
718 unregister_kprobe(&jp
->kp
);
721 #ifdef ARCH_SUPPORTS_KRETPROBES
724 * This kprobe pre_handler is registered with every kretprobe. When probe
725 * hits it will set up the return probe.
727 static int __kprobes
pre_handler_kretprobe(struct kprobe
*p
,
728 struct pt_regs
*regs
)
730 struct kretprobe
*rp
= container_of(p
, struct kretprobe
, kp
);
731 unsigned long flags
= 0;
733 /*TODO: consider to only swap the RA after the last pre_handler fired */
734 spin_lock_irqsave(&kretprobe_lock
, flags
);
735 arch_prepare_kretprobe(rp
, regs
);
736 spin_unlock_irqrestore(&kretprobe_lock
, flags
);
740 int __kprobes
register_kretprobe(struct kretprobe
*rp
)
743 struct kretprobe_instance
*inst
;
746 rp
->kp
.pre_handler
= pre_handler_kretprobe
;
747 rp
->kp
.post_handler
= NULL
;
748 rp
->kp
.fault_handler
= NULL
;
749 rp
->kp
.break_handler
= NULL
;
751 /* Pre-allocate memory for max kretprobe instances */
752 if (rp
->maxactive
<= 0) {
753 #ifdef CONFIG_PREEMPT
754 rp
->maxactive
= max(10, 2 * NR_CPUS
);
756 rp
->maxactive
= NR_CPUS
;
759 INIT_HLIST_HEAD(&rp
->used_instances
);
760 INIT_HLIST_HEAD(&rp
->free_instances
);
761 for (i
= 0; i
< rp
->maxactive
; i
++) {
762 inst
= kmalloc(sizeof(struct kretprobe_instance
), GFP_KERNEL
);
767 INIT_HLIST_NODE(&inst
->uflist
);
768 hlist_add_head(&inst
->uflist
, &rp
->free_instances
);
772 /* Establish function entry probe point */
773 if ((ret
= __register_kprobe(&rp
->kp
,
774 (unsigned long)__builtin_return_address(0))) != 0)
779 #else /* ARCH_SUPPORTS_KRETPROBES */
781 int __kprobes
register_kretprobe(struct kretprobe
*rp
)
786 static int __kprobes
pre_handler_kretprobe(struct kprobe
*p
,
787 struct pt_regs
*regs
)
792 #endif /* ARCH_SUPPORTS_KRETPROBES */
794 void __kprobes
unregister_kretprobe(struct kretprobe
*rp
)
797 struct kretprobe_instance
*ri
;
799 unregister_kprobe(&rp
->kp
);
801 spin_lock_irqsave(&kretprobe_lock
, flags
);
802 while ((ri
= get_used_rp_inst(rp
)) != NULL
) {
804 hlist_del(&ri
->uflist
);
806 spin_unlock_irqrestore(&kretprobe_lock
, flags
);
810 static int __init
init_kprobes(void)
814 /* FIXME allocate the probe table, currently defined statically */
815 /* initialize all list heads */
816 for (i
= 0; i
< KPROBE_TABLE_SIZE
; i
++) {
817 INIT_HLIST_HEAD(&kprobe_table
[i
]);
818 INIT_HLIST_HEAD(&kretprobe_inst_table
[i
]);
820 atomic_set(&kprobe_count
, 0);
822 err
= arch_init_kprobes();
824 err
= register_die_notifier(&kprobe_exceptions_nb
);
829 #ifdef CONFIG_DEBUG_FS
830 static void __kprobes
report_probe(struct seq_file
*pi
, struct kprobe
*p
,
831 const char *sym
, int offset
,char *modname
)
835 if (p
->pre_handler
== pre_handler_kretprobe
)
837 else if (p
->pre_handler
== setjmp_pre_handler
)
842 seq_printf(pi
, "%p %s %s+0x%x %s\n", p
->addr
, kprobe_type
,
843 sym
, offset
, (modname
? modname
: " "));
845 seq_printf(pi
, "%p %s %p\n", p
->addr
, kprobe_type
, p
->addr
);
848 static void __kprobes
*kprobe_seq_start(struct seq_file
*f
, loff_t
*pos
)
850 return (*pos
< KPROBE_TABLE_SIZE
) ? pos
: NULL
;
853 static void __kprobes
*kprobe_seq_next(struct seq_file
*f
, void *v
, loff_t
*pos
)
856 if (*pos
>= KPROBE_TABLE_SIZE
)
861 static void __kprobes
kprobe_seq_stop(struct seq_file
*f
, void *v
)
866 static int __kprobes
show_kprobe_addr(struct seq_file
*pi
, void *v
)
868 struct hlist_head
*head
;
869 struct hlist_node
*node
;
870 struct kprobe
*p
, *kp
;
871 const char *sym
= NULL
;
872 unsigned int i
= *(loff_t
*) v
;
873 unsigned long offset
= 0;
874 char *modname
, namebuf
[128];
876 head
= &kprobe_table
[i
];
878 hlist_for_each_entry_rcu(p
, node
, head
, hlist
) {
879 sym
= kallsyms_lookup((unsigned long)p
->addr
, NULL
,
880 &offset
, &modname
, namebuf
);
881 if (p
->pre_handler
== aggr_pre_handler
) {
882 list_for_each_entry_rcu(kp
, &p
->list
, list
)
883 report_probe(pi
, kp
, sym
, offset
, modname
);
885 report_probe(pi
, p
, sym
, offset
, modname
);
891 static struct seq_operations kprobes_seq_ops
= {
892 .start
= kprobe_seq_start
,
893 .next
= kprobe_seq_next
,
894 .stop
= kprobe_seq_stop
,
895 .show
= show_kprobe_addr
898 static int __kprobes
kprobes_open(struct inode
*inode
, struct file
*filp
)
900 return seq_open(filp
, &kprobes_seq_ops
);
903 static struct file_operations debugfs_kprobes_operations
= {
904 .open
= kprobes_open
,
907 .release
= seq_release
,
910 static int __kprobes
debugfs_kprobe_init(void)
912 struct dentry
*dir
, *file
;
914 dir
= debugfs_create_dir("kprobes", NULL
);
918 file
= debugfs_create_file("list", 0444, dir
, NULL
,
919 &debugfs_kprobes_operations
);
928 late_initcall(debugfs_kprobe_init
);
929 #endif /* CONFIG_DEBUG_FS */
931 module_init(init_kprobes
);
933 EXPORT_SYMBOL_GPL(register_kprobe
);
934 EXPORT_SYMBOL_GPL(unregister_kprobe
);
935 EXPORT_SYMBOL_GPL(register_jprobe
);
936 EXPORT_SYMBOL_GPL(unregister_jprobe
);
937 EXPORT_SYMBOL_GPL(jprobe_return
);
938 EXPORT_SYMBOL_GPL(register_kretprobe
);
939 EXPORT_SYMBOL_GPL(unregister_kretprobe
);