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
);
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_entry_safe(kip
, pos
, next
, &kprobe_insn_pages
, hlist
) {
218 if (kip
->ngarbage
== 0)
220 kip
->ngarbage
= 0; /* we will collect all garbages */
221 for (i
= 0; i
< INSNS_PER_PAGE
; i
++) {
222 if (kip
->slot_used
[i
] == SLOT_DIRTY
&&
223 collect_one_slot(kip
, i
))
227 kprobe_garbage_slots
= 0;
231 void __kprobes
free_insn_slot(kprobe_opcode_t
* slot
, int dirty
)
233 struct kprobe_insn_page
*kip
;
234 struct hlist_node
*pos
;
236 hlist_for_each_entry(kip
, pos
, &kprobe_insn_pages
, hlist
) {
237 if (kip
->insns
<= slot
&&
238 slot
< kip
->insns
+ (INSNS_PER_PAGE
* MAX_INSN_SIZE
)) {
239 int i
= (slot
- kip
->insns
) / MAX_INSN_SIZE
;
241 kip
->slot_used
[i
] = SLOT_DIRTY
;
244 collect_one_slot(kip
, i
);
249 if (dirty
&& (++kprobe_garbage_slots
> INSNS_PER_PAGE
)) {
250 collect_garbage_slots();
255 /* We have preemption disabled.. so it is safe to use __ versions */
256 static inline void set_kprobe_instance(struct kprobe
*kp
)
258 __get_cpu_var(kprobe_instance
) = kp
;
261 static inline void reset_kprobe_instance(void)
263 __get_cpu_var(kprobe_instance
) = NULL
;
267 * This routine is called either:
268 * - under the kprobe_mutex - during kprobe_[un]register()
270 * - with preemption disabled - from arch/xxx/kernel/kprobes.c
272 struct kprobe __kprobes
*get_kprobe(void *addr
)
274 struct hlist_head
*head
;
275 struct hlist_node
*node
;
278 head
= &kprobe_table
[hash_ptr(addr
, KPROBE_HASH_BITS
)];
279 hlist_for_each_entry_rcu(p
, node
, head
, hlist
) {
287 * Aggregate handlers for multiple kprobes support - these handlers
288 * take care of invoking the individual kprobe handlers on p->list
290 static int __kprobes
aggr_pre_handler(struct kprobe
*p
, struct pt_regs
*regs
)
294 list_for_each_entry_rcu(kp
, &p
->list
, list
) {
295 if (kp
->pre_handler
) {
296 set_kprobe_instance(kp
);
297 if (kp
->pre_handler(kp
, regs
))
300 reset_kprobe_instance();
305 static void __kprobes
aggr_post_handler(struct kprobe
*p
, struct pt_regs
*regs
,
310 list_for_each_entry_rcu(kp
, &p
->list
, list
) {
311 if (kp
->post_handler
) {
312 set_kprobe_instance(kp
);
313 kp
->post_handler(kp
, regs
, flags
);
314 reset_kprobe_instance();
320 static int __kprobes
aggr_fault_handler(struct kprobe
*p
, struct pt_regs
*regs
,
323 struct kprobe
*cur
= __get_cpu_var(kprobe_instance
);
326 * if we faulted "during" the execution of a user specified
327 * probe handler, invoke just that probe's fault handler
329 if (cur
&& cur
->fault_handler
) {
330 if (cur
->fault_handler(cur
, regs
, trapnr
))
336 static int __kprobes
aggr_break_handler(struct kprobe
*p
, struct pt_regs
*regs
)
338 struct kprobe
*cur
= __get_cpu_var(kprobe_instance
);
341 if (cur
&& cur
->break_handler
) {
342 if (cur
->break_handler(cur
, regs
))
345 reset_kprobe_instance();
349 /* Walks the list and increments nmissed count for multiprobe case */
350 void __kprobes
kprobes_inc_nmissed_count(struct kprobe
*p
)
353 if (p
->pre_handler
!= aggr_pre_handler
) {
356 list_for_each_entry_rcu(kp
, &p
->list
, list
)
362 /* Called with kretprobe_lock held */
363 struct kretprobe_instance __kprobes
*get_free_rp_inst(struct kretprobe
*rp
)
365 struct hlist_node
*node
;
366 struct kretprobe_instance
*ri
;
367 hlist_for_each_entry(ri
, node
, &rp
->free_instances
, uflist
)
372 /* Called with kretprobe_lock held */
373 static struct kretprobe_instance __kprobes
*get_used_rp_inst(struct kretprobe
376 struct hlist_node
*node
;
377 struct kretprobe_instance
*ri
;
378 hlist_for_each_entry(ri
, node
, &rp
->used_instances
, uflist
)
383 /* Called with kretprobe_lock held */
384 void __kprobes
add_rp_inst(struct kretprobe_instance
*ri
)
387 * Remove rp inst off the free list -
388 * Add it back when probed function returns
390 hlist_del(&ri
->uflist
);
392 /* Add rp inst onto table */
393 INIT_HLIST_NODE(&ri
->hlist
);
394 hlist_add_head(&ri
->hlist
,
395 &kretprobe_inst_table
[hash_ptr(ri
->task
, KPROBE_HASH_BITS
)]);
397 /* Also add this rp inst to the used list. */
398 INIT_HLIST_NODE(&ri
->uflist
);
399 hlist_add_head(&ri
->uflist
, &ri
->rp
->used_instances
);
402 /* Called with kretprobe_lock held */
403 void __kprobes
recycle_rp_inst(struct kretprobe_instance
*ri
,
404 struct hlist_head
*head
)
406 /* remove rp inst off the rprobe_inst_table */
407 hlist_del(&ri
->hlist
);
409 /* remove rp inst off the used list */
410 hlist_del(&ri
->uflist
);
411 /* put rp inst back onto the free list */
412 INIT_HLIST_NODE(&ri
->uflist
);
413 hlist_add_head(&ri
->uflist
, &ri
->rp
->free_instances
);
416 hlist_add_head(&ri
->hlist
, head
);
419 struct hlist_head __kprobes
*kretprobe_inst_table_head(struct task_struct
*tsk
)
421 return &kretprobe_inst_table
[hash_ptr(tsk
, KPROBE_HASH_BITS
)];
425 * This function is called from finish_task_switch when task tk becomes dead,
426 * so that we can recycle any function-return probe instances associated
427 * with this task. These left over instances represent probed functions
428 * that have been called but will never return.
430 void __kprobes
kprobe_flush_task(struct task_struct
*tk
)
432 struct kretprobe_instance
*ri
;
433 struct hlist_head
*head
, empty_rp
;
434 struct hlist_node
*node
, *tmp
;
435 unsigned long flags
= 0;
437 INIT_HLIST_HEAD(&empty_rp
);
438 spin_lock_irqsave(&kretprobe_lock
, flags
);
439 head
= kretprobe_inst_table_head(tk
);
440 hlist_for_each_entry_safe(ri
, node
, tmp
, head
, hlist
) {
442 recycle_rp_inst(ri
, &empty_rp
);
444 spin_unlock_irqrestore(&kretprobe_lock
, flags
);
446 hlist_for_each_entry_safe(ri
, node
, tmp
, &empty_rp
, hlist
) {
447 hlist_del(&ri
->hlist
);
452 static inline void free_rp_inst(struct kretprobe
*rp
)
454 struct kretprobe_instance
*ri
;
455 while ((ri
= get_free_rp_inst(rp
)) != NULL
) {
456 hlist_del(&ri
->uflist
);
462 * Keep all fields in the kprobe consistent
464 static inline void copy_kprobe(struct kprobe
*old_p
, struct kprobe
*p
)
466 memcpy(&p
->opcode
, &old_p
->opcode
, sizeof(kprobe_opcode_t
));
467 memcpy(&p
->ainsn
, &old_p
->ainsn
, sizeof(struct arch_specific_insn
));
471 * Add the new probe to old_p->list. Fail if this is the
472 * second jprobe at the address - two jprobes can't coexist
474 static int __kprobes
add_new_kprobe(struct kprobe
*old_p
, struct kprobe
*p
)
476 if (p
->break_handler
) {
477 if (old_p
->break_handler
)
479 list_add_tail_rcu(&p
->list
, &old_p
->list
);
480 old_p
->break_handler
= aggr_break_handler
;
482 list_add_rcu(&p
->list
, &old_p
->list
);
483 if (p
->post_handler
&& !old_p
->post_handler
)
484 old_p
->post_handler
= aggr_post_handler
;
489 * Fill in the required fields of the "manager kprobe". Replace the
490 * earlier kprobe in the hlist with the manager kprobe
492 static inline void add_aggr_kprobe(struct kprobe
*ap
, struct kprobe
*p
)
497 ap
->pre_handler
= aggr_pre_handler
;
498 ap
->fault_handler
= aggr_fault_handler
;
500 ap
->post_handler
= aggr_post_handler
;
501 if (p
->break_handler
)
502 ap
->break_handler
= aggr_break_handler
;
504 INIT_LIST_HEAD(&ap
->list
);
505 list_add_rcu(&p
->list
, &ap
->list
);
507 hlist_replace_rcu(&p
->hlist
, &ap
->hlist
);
511 * This is the second or subsequent kprobe at the address - handle
514 static int __kprobes
register_aggr_kprobe(struct kprobe
*old_p
,
520 if (old_p
->pre_handler
== aggr_pre_handler
) {
521 copy_kprobe(old_p
, p
);
522 ret
= add_new_kprobe(old_p
, p
);
524 ap
= kzalloc(sizeof(struct kprobe
), GFP_KERNEL
);
527 add_aggr_kprobe(ap
, old_p
);
529 ret
= add_new_kprobe(ap
, p
);
534 static int __kprobes
in_kprobes_functions(unsigned long addr
)
536 if (addr
>= (unsigned long)__kprobes_text_start
537 && addr
< (unsigned long)__kprobes_text_end
)
542 static int __kprobes
__register_kprobe(struct kprobe
*p
,
543 unsigned long called_from
)
546 struct kprobe
*old_p
;
547 struct module
*probed_mod
;
550 * If we have a symbol_name argument look it up,
551 * and add it to the address. That way the addr
552 * field can either be global or relative to a symbol.
554 if (p
->symbol_name
) {
557 kprobe_lookup_name(p
->symbol_name
, p
->addr
);
562 p
->addr
= (kprobe_opcode_t
*)(((char *)p
->addr
)+ p
->offset
);
564 if ((!kernel_text_address((unsigned long) p
->addr
)) ||
565 in_kprobes_functions((unsigned long) p
->addr
))
568 p
->mod_refcounted
= 0;
569 /* Check are we probing a module */
570 if ((probed_mod
= module_text_address((unsigned long) p
->addr
))) {
571 struct module
*calling_mod
= module_text_address(called_from
);
572 /* We must allow modules to probe themself and
573 * in this case avoid incrementing the module refcount,
574 * so as to allow unloading of self probing modules.
576 if (calling_mod
&& (calling_mod
!= probed_mod
)) {
577 if (unlikely(!try_module_get(probed_mod
)))
579 p
->mod_refcounted
= 1;
585 mutex_lock(&kprobe_mutex
);
586 old_p
= get_kprobe(p
->addr
);
588 ret
= register_aggr_kprobe(old_p
, p
);
590 atomic_inc(&kprobe_count
);
594 if ((ret
= arch_prepare_kprobe(p
)) != 0)
597 INIT_HLIST_NODE(&p
->hlist
);
598 hlist_add_head_rcu(&p
->hlist
,
599 &kprobe_table
[hash_ptr(p
->addr
, KPROBE_HASH_BITS
)]);
601 if (atomic_add_return(1, &kprobe_count
) == \
602 (ARCH_INACTIVE_KPROBE_COUNT
+ 1))
603 register_page_fault_notifier(&kprobe_page_fault_nb
);
608 mutex_unlock(&kprobe_mutex
);
610 if (ret
&& probed_mod
)
611 module_put(probed_mod
);
615 int __kprobes
register_kprobe(struct kprobe
*p
)
617 return __register_kprobe(p
,
618 (unsigned long)__builtin_return_address(0));
621 void __kprobes
unregister_kprobe(struct kprobe
*p
)
624 struct kprobe
*old_p
, *list_p
;
627 mutex_lock(&kprobe_mutex
);
628 old_p
= get_kprobe(p
->addr
);
629 if (unlikely(!old_p
)) {
630 mutex_unlock(&kprobe_mutex
);
634 list_for_each_entry_rcu(list_p
, &old_p
->list
, list
)
636 /* kprobe p is a valid probe */
638 mutex_unlock(&kprobe_mutex
);
642 if ((old_p
== p
) || ((old_p
->pre_handler
== aggr_pre_handler
) &&
643 (p
->list
.next
== &old_p
->list
) &&
644 (p
->list
.prev
== &old_p
->list
))) {
645 /* Only probe on the hash list */
646 arch_disarm_kprobe(p
);
647 hlist_del_rcu(&old_p
->hlist
);
650 list_del_rcu(&p
->list
);
654 mutex_unlock(&kprobe_mutex
);
657 if (p
->mod_refcounted
&&
658 (mod
= module_text_address((unsigned long)p
->addr
)))
663 list_del_rcu(&p
->list
);
666 arch_remove_kprobe(p
);
668 mutex_lock(&kprobe_mutex
);
669 if (p
->break_handler
)
670 old_p
->break_handler
= NULL
;
671 if (p
->post_handler
){
672 list_for_each_entry_rcu(list_p
, &old_p
->list
, list
){
673 if (list_p
->post_handler
){
679 old_p
->post_handler
= NULL
;
681 mutex_unlock(&kprobe_mutex
);
684 /* Call unregister_page_fault_notifier()
685 * if no probes are active
687 mutex_lock(&kprobe_mutex
);
688 if (atomic_add_return(-1, &kprobe_count
) == \
689 ARCH_INACTIVE_KPROBE_COUNT
)
690 unregister_page_fault_notifier(&kprobe_page_fault_nb
);
691 mutex_unlock(&kprobe_mutex
);
695 static struct notifier_block kprobe_exceptions_nb
= {
696 .notifier_call
= kprobe_exceptions_notify
,
697 .priority
= 0x7fffffff /* we need to be notified first */
701 int __kprobes
register_jprobe(struct jprobe
*jp
)
703 /* Todo: Verify probepoint is a function entry point */
704 jp
->kp
.pre_handler
= setjmp_pre_handler
;
705 jp
->kp
.break_handler
= longjmp_break_handler
;
707 return __register_kprobe(&jp
->kp
,
708 (unsigned long)__builtin_return_address(0));
711 void __kprobes
unregister_jprobe(struct jprobe
*jp
)
713 unregister_kprobe(&jp
->kp
);
716 #ifdef ARCH_SUPPORTS_KRETPROBES
719 * This kprobe pre_handler is registered with every kretprobe. When probe
720 * hits it will set up the return probe.
722 static int __kprobes
pre_handler_kretprobe(struct kprobe
*p
,
723 struct pt_regs
*regs
)
725 struct kretprobe
*rp
= container_of(p
, struct kretprobe
, kp
);
726 unsigned long flags
= 0;
728 /*TODO: consider to only swap the RA after the last pre_handler fired */
729 spin_lock_irqsave(&kretprobe_lock
, flags
);
730 arch_prepare_kretprobe(rp
, regs
);
731 spin_unlock_irqrestore(&kretprobe_lock
, flags
);
735 int __kprobes
register_kretprobe(struct kretprobe
*rp
)
738 struct kretprobe_instance
*inst
;
741 rp
->kp
.pre_handler
= pre_handler_kretprobe
;
742 rp
->kp
.post_handler
= NULL
;
743 rp
->kp
.fault_handler
= NULL
;
744 rp
->kp
.break_handler
= NULL
;
746 /* Pre-allocate memory for max kretprobe instances */
747 if (rp
->maxactive
<= 0) {
748 #ifdef CONFIG_PREEMPT
749 rp
->maxactive
= max(10, 2 * NR_CPUS
);
751 rp
->maxactive
= NR_CPUS
;
754 INIT_HLIST_HEAD(&rp
->used_instances
);
755 INIT_HLIST_HEAD(&rp
->free_instances
);
756 for (i
= 0; i
< rp
->maxactive
; i
++) {
757 inst
= kmalloc(sizeof(struct kretprobe_instance
), GFP_KERNEL
);
762 INIT_HLIST_NODE(&inst
->uflist
);
763 hlist_add_head(&inst
->uflist
, &rp
->free_instances
);
767 /* Establish function entry probe point */
768 if ((ret
= __register_kprobe(&rp
->kp
,
769 (unsigned long)__builtin_return_address(0))) != 0)
774 #else /* ARCH_SUPPORTS_KRETPROBES */
776 int __kprobes
register_kretprobe(struct kretprobe
*rp
)
781 static int __kprobes
pre_handler_kretprobe(struct kprobe
*p
,
782 struct pt_regs
*regs
)
787 #endif /* ARCH_SUPPORTS_KRETPROBES */
789 void __kprobes
unregister_kretprobe(struct kretprobe
*rp
)
792 struct kretprobe_instance
*ri
;
794 unregister_kprobe(&rp
->kp
);
796 spin_lock_irqsave(&kretprobe_lock
, flags
);
797 while ((ri
= get_used_rp_inst(rp
)) != NULL
) {
799 hlist_del(&ri
->uflist
);
801 spin_unlock_irqrestore(&kretprobe_lock
, flags
);
805 static int __init
init_kprobes(void)
809 /* FIXME allocate the probe table, currently defined statically */
810 /* initialize all list heads */
811 for (i
= 0; i
< KPROBE_TABLE_SIZE
; i
++) {
812 INIT_HLIST_HEAD(&kprobe_table
[i
]);
813 INIT_HLIST_HEAD(&kretprobe_inst_table
[i
]);
815 atomic_set(&kprobe_count
, 0);
817 err
= arch_init_kprobes();
819 err
= register_die_notifier(&kprobe_exceptions_nb
);
824 #ifdef CONFIG_DEBUG_FS
825 static void __kprobes
report_probe(struct seq_file
*pi
, struct kprobe
*p
,
826 const char *sym
, int offset
,char *modname
)
830 if (p
->pre_handler
== pre_handler_kretprobe
)
832 else if (p
->pre_handler
== setjmp_pre_handler
)
837 seq_printf(pi
, "%p %s %s+0x%x %s\n", p
->addr
, kprobe_type
,
838 sym
, offset
, (modname
? modname
: " "));
840 seq_printf(pi
, "%p %s %p\n", p
->addr
, kprobe_type
, p
->addr
);
843 static void __kprobes
*kprobe_seq_start(struct seq_file
*f
, loff_t
*pos
)
845 return (*pos
< KPROBE_TABLE_SIZE
) ? pos
: NULL
;
848 static void __kprobes
*kprobe_seq_next(struct seq_file
*f
, void *v
, loff_t
*pos
)
851 if (*pos
>= KPROBE_TABLE_SIZE
)
856 static void __kprobes
kprobe_seq_stop(struct seq_file
*f
, void *v
)
861 static int __kprobes
show_kprobe_addr(struct seq_file
*pi
, void *v
)
863 struct hlist_head
*head
;
864 struct hlist_node
*node
;
865 struct kprobe
*p
, *kp
;
866 const char *sym
= NULL
;
867 unsigned int i
= *(loff_t
*) v
;
868 unsigned long offset
= 0;
869 char *modname
, namebuf
[128];
871 head
= &kprobe_table
[i
];
873 hlist_for_each_entry_rcu(p
, node
, head
, hlist
) {
874 sym
= kallsyms_lookup((unsigned long)p
->addr
, NULL
,
875 &offset
, &modname
, namebuf
);
876 if (p
->pre_handler
== aggr_pre_handler
) {
877 list_for_each_entry_rcu(kp
, &p
->list
, list
)
878 report_probe(pi
, kp
, sym
, offset
, modname
);
880 report_probe(pi
, p
, sym
, offset
, modname
);
886 static struct seq_operations kprobes_seq_ops
= {
887 .start
= kprobe_seq_start
,
888 .next
= kprobe_seq_next
,
889 .stop
= kprobe_seq_stop
,
890 .show
= show_kprobe_addr
893 static int __kprobes
kprobes_open(struct inode
*inode
, struct file
*filp
)
895 return seq_open(filp
, &kprobes_seq_ops
);
898 static struct file_operations debugfs_kprobes_operations
= {
899 .open
= kprobes_open
,
902 .release
= seq_release
,
905 static int __kprobes
debugfs_kprobe_init(void)
907 struct dentry
*dir
, *file
;
909 dir
= debugfs_create_dir("kprobes", NULL
);
913 file
= debugfs_create_file("list", 0444, dir
, NULL
,
914 &debugfs_kprobes_operations
);
923 late_initcall(debugfs_kprobe_init
);
924 #endif /* CONFIG_DEBUG_FS */
926 module_init(init_kprobes
);
928 EXPORT_SYMBOL_GPL(register_kprobe
);
929 EXPORT_SYMBOL_GPL(unregister_kprobe
);
930 EXPORT_SYMBOL_GPL(register_jprobe
);
931 EXPORT_SYMBOL_GPL(unregister_jprobe
);
932 EXPORT_SYMBOL_GPL(jprobe_return
);
933 EXPORT_SYMBOL_GPL(register_kretprobe
);
934 EXPORT_SYMBOL_GPL(unregister_kretprobe
);