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/export.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/sysctl.h>
46 #include <linux/kdebug.h>
47 #include <linux/memory.h>
48 #include <linux/ftrace.h>
49 #include <linux/cpu.h>
50 #include <linux/jump_label.h>
52 #include <asm-generic/sections.h>
53 #include <asm/cacheflush.h>
54 #include <asm/errno.h>
55 #include <asm/uaccess.h>
57 #define KPROBE_HASH_BITS 6
58 #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS)
62 * Some oddball architectures like 64bit powerpc have function descriptors
63 * so this must be overridable.
65 #ifndef kprobe_lookup_name
66 #define kprobe_lookup_name(name, addr) \
67 addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name)))
70 static int kprobes_initialized
;
71 static struct hlist_head kprobe_table
[KPROBE_TABLE_SIZE
];
72 static struct hlist_head kretprobe_inst_table
[KPROBE_TABLE_SIZE
];
74 /* NOTE: change this value only with kprobe_mutex held */
75 static bool kprobes_all_disarmed
;
77 /* This protects kprobe_table and optimizing_list */
78 static DEFINE_MUTEX(kprobe_mutex
);
79 static DEFINE_PER_CPU(struct kprobe
*, kprobe_instance
) = NULL
;
81 raw_spinlock_t lock ____cacheline_aligned_in_smp
;
82 } kretprobe_table_locks
[KPROBE_TABLE_SIZE
];
84 static raw_spinlock_t
*kretprobe_table_lock_ptr(unsigned long hash
)
86 return &(kretprobe_table_locks
[hash
].lock
);
89 /* Blacklist -- list of struct kprobe_blacklist_entry */
90 static LIST_HEAD(kprobe_blacklist
);
92 #ifdef __ARCH_WANT_KPROBES_INSN_SLOT
94 * kprobe->ainsn.insn points to the copy of the instruction to be
95 * single-stepped. x86_64, POWER4 and above have no-exec support and
96 * stepping on the instruction on a vmalloced/kmalloced/data page
97 * is a recipe for disaster
99 struct kprobe_insn_page
{
100 struct list_head list
;
101 kprobe_opcode_t
*insns
; /* Page of instruction slots */
102 struct kprobe_insn_cache
*cache
;
108 #define KPROBE_INSN_PAGE_SIZE(slots) \
109 (offsetof(struct kprobe_insn_page, slot_used) + \
110 (sizeof(char) * (slots)))
112 static int slots_per_page(struct kprobe_insn_cache
*c
)
114 return PAGE_SIZE
/(c
->insn_size
* sizeof(kprobe_opcode_t
));
117 enum kprobe_slot_state
{
123 static void *alloc_insn_page(void)
125 return module_alloc(PAGE_SIZE
);
128 static void free_insn_page(void *page
)
130 module_memfree(page
);
133 struct kprobe_insn_cache kprobe_insn_slots
= {
134 .mutex
= __MUTEX_INITIALIZER(kprobe_insn_slots
.mutex
),
135 .alloc
= alloc_insn_page
,
136 .free
= free_insn_page
,
137 .pages
= LIST_HEAD_INIT(kprobe_insn_slots
.pages
),
138 .insn_size
= MAX_INSN_SIZE
,
141 static int collect_garbage_slots(struct kprobe_insn_cache
*c
);
144 * __get_insn_slot() - Find a slot on an executable page for an instruction.
145 * We allocate an executable page if there's no room on existing ones.
147 kprobe_opcode_t
*__get_insn_slot(struct kprobe_insn_cache
*c
)
149 struct kprobe_insn_page
*kip
;
150 kprobe_opcode_t
*slot
= NULL
;
152 mutex_lock(&c
->mutex
);
154 list_for_each_entry(kip
, &c
->pages
, list
) {
155 if (kip
->nused
< slots_per_page(c
)) {
157 for (i
= 0; i
< slots_per_page(c
); i
++) {
158 if (kip
->slot_used
[i
] == SLOT_CLEAN
) {
159 kip
->slot_used
[i
] = SLOT_USED
;
161 slot
= kip
->insns
+ (i
* c
->insn_size
);
165 /* kip->nused is broken. Fix it. */
166 kip
->nused
= slots_per_page(c
);
171 /* If there are any garbage slots, collect it and try again. */
172 if (c
->nr_garbage
&& collect_garbage_slots(c
) == 0)
175 /* All out of space. Need to allocate a new page. */
176 kip
= kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c
)), GFP_KERNEL
);
181 * Use module_alloc so this page is within +/- 2GB of where the
182 * kernel image and loaded module images reside. This is required
183 * so x86_64 can correctly handle the %rip-relative fixups.
185 kip
->insns
= c
->alloc();
190 INIT_LIST_HEAD(&kip
->list
);
191 memset(kip
->slot_used
, SLOT_CLEAN
, slots_per_page(c
));
192 kip
->slot_used
[0] = SLOT_USED
;
196 list_add(&kip
->list
, &c
->pages
);
199 mutex_unlock(&c
->mutex
);
203 /* Return 1 if all garbages are collected, otherwise 0. */
204 static int collect_one_slot(struct kprobe_insn_page
*kip
, int idx
)
206 kip
->slot_used
[idx
] = SLOT_CLEAN
;
208 if (kip
->nused
== 0) {
210 * Page is no longer in use. Free it unless
211 * it's the last one. We keep the last one
212 * so as not to have to set it up again the
213 * next time somebody inserts a probe.
215 if (!list_is_singular(&kip
->list
)) {
216 list_del(&kip
->list
);
217 kip
->cache
->free(kip
->insns
);
225 static int collect_garbage_slots(struct kprobe_insn_cache
*c
)
227 struct kprobe_insn_page
*kip
, *next
;
229 /* Ensure no-one is interrupted on the garbages */
232 list_for_each_entry_safe(kip
, next
, &c
->pages
, list
) {
234 if (kip
->ngarbage
== 0)
236 kip
->ngarbage
= 0; /* we will collect all garbages */
237 for (i
= 0; i
< slots_per_page(c
); i
++) {
238 if (kip
->slot_used
[i
] == SLOT_DIRTY
&&
239 collect_one_slot(kip
, i
))
247 void __free_insn_slot(struct kprobe_insn_cache
*c
,
248 kprobe_opcode_t
*slot
, int dirty
)
250 struct kprobe_insn_page
*kip
;
252 mutex_lock(&c
->mutex
);
253 list_for_each_entry(kip
, &c
->pages
, list
) {
254 long idx
= ((long)slot
- (long)kip
->insns
) /
255 (c
->insn_size
* sizeof(kprobe_opcode_t
));
256 if (idx
>= 0 && idx
< slots_per_page(c
)) {
257 WARN_ON(kip
->slot_used
[idx
] != SLOT_USED
);
259 kip
->slot_used
[idx
] = SLOT_DIRTY
;
261 if (++c
->nr_garbage
> slots_per_page(c
))
262 collect_garbage_slots(c
);
264 collect_one_slot(kip
, idx
);
268 /* Could not free this slot. */
271 mutex_unlock(&c
->mutex
);
274 #ifdef CONFIG_OPTPROBES
275 /* For optimized_kprobe buffer */
276 struct kprobe_insn_cache kprobe_optinsn_slots
= {
277 .mutex
= __MUTEX_INITIALIZER(kprobe_optinsn_slots
.mutex
),
278 .alloc
= alloc_insn_page
,
279 .free
= free_insn_page
,
280 .pages
= LIST_HEAD_INIT(kprobe_optinsn_slots
.pages
),
281 /* .insn_size is initialized later */
287 /* We have preemption disabled.. so it is safe to use __ versions */
288 static inline void set_kprobe_instance(struct kprobe
*kp
)
290 __this_cpu_write(kprobe_instance
, kp
);
293 static inline void reset_kprobe_instance(void)
295 __this_cpu_write(kprobe_instance
, NULL
);
299 * This routine is called either:
300 * - under the kprobe_mutex - during kprobe_[un]register()
302 * - with preemption disabled - from arch/xxx/kernel/kprobes.c
304 struct kprobe
*get_kprobe(void *addr
)
306 struct hlist_head
*head
;
309 head
= &kprobe_table
[hash_ptr(addr
, KPROBE_HASH_BITS
)];
310 hlist_for_each_entry_rcu(p
, head
, hlist
) {
317 NOKPROBE_SYMBOL(get_kprobe
);
319 static int aggr_pre_handler(struct kprobe
*p
, struct pt_regs
*regs
);
321 /* Return true if the kprobe is an aggregator */
322 static inline int kprobe_aggrprobe(struct kprobe
*p
)
324 return p
->pre_handler
== aggr_pre_handler
;
327 /* Return true(!0) if the kprobe is unused */
328 static inline int kprobe_unused(struct kprobe
*p
)
330 return kprobe_aggrprobe(p
) && kprobe_disabled(p
) &&
331 list_empty(&p
->list
);
335 * Keep all fields in the kprobe consistent
337 static inline void copy_kprobe(struct kprobe
*ap
, struct kprobe
*p
)
339 memcpy(&p
->opcode
, &ap
->opcode
, sizeof(kprobe_opcode_t
));
340 memcpy(&p
->ainsn
, &ap
->ainsn
, sizeof(struct arch_specific_insn
));
343 #ifdef CONFIG_OPTPROBES
344 /* NOTE: change this value only with kprobe_mutex held */
345 static bool kprobes_allow_optimization
;
348 * Call all pre_handler on the list, but ignores its return value.
349 * This must be called from arch-dep optimized caller.
351 void opt_pre_handler(struct kprobe
*p
, struct pt_regs
*regs
)
355 list_for_each_entry_rcu(kp
, &p
->list
, list
) {
356 if (kp
->pre_handler
&& likely(!kprobe_disabled(kp
))) {
357 set_kprobe_instance(kp
);
358 kp
->pre_handler(kp
, regs
);
360 reset_kprobe_instance();
363 NOKPROBE_SYMBOL(opt_pre_handler
);
365 /* Free optimized instructions and optimized_kprobe */
366 static void free_aggr_kprobe(struct kprobe
*p
)
368 struct optimized_kprobe
*op
;
370 op
= container_of(p
, struct optimized_kprobe
, kp
);
371 arch_remove_optimized_kprobe(op
);
372 arch_remove_kprobe(p
);
376 /* Return true(!0) if the kprobe is ready for optimization. */
377 static inline int kprobe_optready(struct kprobe
*p
)
379 struct optimized_kprobe
*op
;
381 if (kprobe_aggrprobe(p
)) {
382 op
= container_of(p
, struct optimized_kprobe
, kp
);
383 return arch_prepared_optinsn(&op
->optinsn
);
389 /* Return true(!0) if the kprobe is disarmed. Note: p must be on hash list */
390 static inline int kprobe_disarmed(struct kprobe
*p
)
392 struct optimized_kprobe
*op
;
394 /* If kprobe is not aggr/opt probe, just return kprobe is disabled */
395 if (!kprobe_aggrprobe(p
))
396 return kprobe_disabled(p
);
398 op
= container_of(p
, struct optimized_kprobe
, kp
);
400 return kprobe_disabled(p
) && list_empty(&op
->list
);
403 /* Return true(!0) if the probe is queued on (un)optimizing lists */
404 static int kprobe_queued(struct kprobe
*p
)
406 struct optimized_kprobe
*op
;
408 if (kprobe_aggrprobe(p
)) {
409 op
= container_of(p
, struct optimized_kprobe
, kp
);
410 if (!list_empty(&op
->list
))
417 * Return an optimized kprobe whose optimizing code replaces
418 * instructions including addr (exclude breakpoint).
420 static struct kprobe
*get_optimized_kprobe(unsigned long addr
)
423 struct kprobe
*p
= NULL
;
424 struct optimized_kprobe
*op
;
426 /* Don't check i == 0, since that is a breakpoint case. */
427 for (i
= 1; !p
&& i
< MAX_OPTIMIZED_LENGTH
; i
++)
428 p
= get_kprobe((void *)(addr
- i
));
430 if (p
&& kprobe_optready(p
)) {
431 op
= container_of(p
, struct optimized_kprobe
, kp
);
432 if (arch_within_optimized_kprobe(op
, addr
))
439 /* Optimization staging list, protected by kprobe_mutex */
440 static LIST_HEAD(optimizing_list
);
441 static LIST_HEAD(unoptimizing_list
);
442 static LIST_HEAD(freeing_list
);
444 static void kprobe_optimizer(struct work_struct
*work
);
445 static DECLARE_DELAYED_WORK(optimizing_work
, kprobe_optimizer
);
446 #define OPTIMIZE_DELAY 5
449 * Optimize (replace a breakpoint with a jump) kprobes listed on
452 static void do_optimize_kprobes(void)
454 /* Optimization never be done when disarmed */
455 if (kprobes_all_disarmed
|| !kprobes_allow_optimization
||
456 list_empty(&optimizing_list
))
460 * The optimization/unoptimization refers online_cpus via
461 * stop_machine() and cpu-hotplug modifies online_cpus.
462 * And same time, text_mutex will be held in cpu-hotplug and here.
463 * This combination can cause a deadlock (cpu-hotplug try to lock
464 * text_mutex but stop_machine can not be done because online_cpus
466 * To avoid this deadlock, we need to call get_online_cpus()
467 * for preventing cpu-hotplug outside of text_mutex locking.
470 mutex_lock(&text_mutex
);
471 arch_optimize_kprobes(&optimizing_list
);
472 mutex_unlock(&text_mutex
);
477 * Unoptimize (replace a jump with a breakpoint and remove the breakpoint
478 * if need) kprobes listed on unoptimizing_list.
480 static void do_unoptimize_kprobes(void)
482 struct optimized_kprobe
*op
, *tmp
;
484 /* Unoptimization must be done anytime */
485 if (list_empty(&unoptimizing_list
))
488 /* Ditto to do_optimize_kprobes */
490 mutex_lock(&text_mutex
);
491 arch_unoptimize_kprobes(&unoptimizing_list
, &freeing_list
);
492 /* Loop free_list for disarming */
493 list_for_each_entry_safe(op
, tmp
, &freeing_list
, list
) {
494 /* Disarm probes if marked disabled */
495 if (kprobe_disabled(&op
->kp
))
496 arch_disarm_kprobe(&op
->kp
);
497 if (kprobe_unused(&op
->kp
)) {
499 * Remove unused probes from hash list. After waiting
500 * for synchronization, these probes are reclaimed.
501 * (reclaiming is done by do_free_cleaned_kprobes.)
503 hlist_del_rcu(&op
->kp
.hlist
);
505 list_del_init(&op
->list
);
507 mutex_unlock(&text_mutex
);
511 /* Reclaim all kprobes on the free_list */
512 static void do_free_cleaned_kprobes(void)
514 struct optimized_kprobe
*op
, *tmp
;
516 list_for_each_entry_safe(op
, tmp
, &freeing_list
, list
) {
517 BUG_ON(!kprobe_unused(&op
->kp
));
518 list_del_init(&op
->list
);
519 free_aggr_kprobe(&op
->kp
);
523 /* Start optimizer after OPTIMIZE_DELAY passed */
524 static void kick_kprobe_optimizer(void)
526 schedule_delayed_work(&optimizing_work
, OPTIMIZE_DELAY
);
529 /* Kprobe jump optimizer */
530 static void kprobe_optimizer(struct work_struct
*work
)
532 mutex_lock(&kprobe_mutex
);
533 /* Lock modules while optimizing kprobes */
534 mutex_lock(&module_mutex
);
537 * Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed)
538 * kprobes before waiting for quiesence period.
540 do_unoptimize_kprobes();
543 * Step 2: Wait for quiesence period to ensure all running interrupts
544 * are done. Because optprobe may modify multiple instructions
545 * there is a chance that Nth instruction is interrupted. In that
546 * case, running interrupt can return to 2nd-Nth byte of jump
547 * instruction. This wait is for avoiding it.
551 /* Step 3: Optimize kprobes after quiesence period */
552 do_optimize_kprobes();
554 /* Step 4: Free cleaned kprobes after quiesence period */
555 do_free_cleaned_kprobes();
557 mutex_unlock(&module_mutex
);
558 mutex_unlock(&kprobe_mutex
);
560 /* Step 5: Kick optimizer again if needed */
561 if (!list_empty(&optimizing_list
) || !list_empty(&unoptimizing_list
))
562 kick_kprobe_optimizer();
565 /* Wait for completing optimization and unoptimization */
566 static void wait_for_kprobe_optimizer(void)
568 mutex_lock(&kprobe_mutex
);
570 while (!list_empty(&optimizing_list
) || !list_empty(&unoptimizing_list
)) {
571 mutex_unlock(&kprobe_mutex
);
573 /* this will also make optimizing_work execute immmediately */
574 flush_delayed_work(&optimizing_work
);
575 /* @optimizing_work might not have been queued yet, relax */
578 mutex_lock(&kprobe_mutex
);
581 mutex_unlock(&kprobe_mutex
);
584 /* Optimize kprobe if p is ready to be optimized */
585 static void optimize_kprobe(struct kprobe
*p
)
587 struct optimized_kprobe
*op
;
589 /* Check if the kprobe is disabled or not ready for optimization. */
590 if (!kprobe_optready(p
) || !kprobes_allow_optimization
||
591 (kprobe_disabled(p
) || kprobes_all_disarmed
))
594 /* Both of break_handler and post_handler are not supported. */
595 if (p
->break_handler
|| p
->post_handler
)
598 op
= container_of(p
, struct optimized_kprobe
, kp
);
600 /* Check there is no other kprobes at the optimized instructions */
601 if (arch_check_optimized_kprobe(op
) < 0)
604 /* Check if it is already optimized. */
605 if (op
->kp
.flags
& KPROBE_FLAG_OPTIMIZED
)
607 op
->kp
.flags
|= KPROBE_FLAG_OPTIMIZED
;
609 if (!list_empty(&op
->list
))
610 /* This is under unoptimizing. Just dequeue the probe */
611 list_del_init(&op
->list
);
613 list_add(&op
->list
, &optimizing_list
);
614 kick_kprobe_optimizer();
618 /* Short cut to direct unoptimizing */
619 static void force_unoptimize_kprobe(struct optimized_kprobe
*op
)
622 arch_unoptimize_kprobe(op
);
624 if (kprobe_disabled(&op
->kp
))
625 arch_disarm_kprobe(&op
->kp
);
628 /* Unoptimize a kprobe if p is optimized */
629 static void unoptimize_kprobe(struct kprobe
*p
, bool force
)
631 struct optimized_kprobe
*op
;
633 if (!kprobe_aggrprobe(p
) || kprobe_disarmed(p
))
634 return; /* This is not an optprobe nor optimized */
636 op
= container_of(p
, struct optimized_kprobe
, kp
);
637 if (!kprobe_optimized(p
)) {
638 /* Unoptimized or unoptimizing case */
639 if (force
&& !list_empty(&op
->list
)) {
641 * Only if this is unoptimizing kprobe and forced,
642 * forcibly unoptimize it. (No need to unoptimize
643 * unoptimized kprobe again :)
645 list_del_init(&op
->list
);
646 force_unoptimize_kprobe(op
);
651 op
->kp
.flags
&= ~KPROBE_FLAG_OPTIMIZED
;
652 if (!list_empty(&op
->list
)) {
653 /* Dequeue from the optimization queue */
654 list_del_init(&op
->list
);
657 /* Optimized kprobe case */
659 /* Forcibly update the code: this is a special case */
660 force_unoptimize_kprobe(op
);
662 list_add(&op
->list
, &unoptimizing_list
);
663 kick_kprobe_optimizer();
667 /* Cancel unoptimizing for reusing */
668 static void reuse_unused_kprobe(struct kprobe
*ap
)
670 struct optimized_kprobe
*op
;
672 BUG_ON(!kprobe_unused(ap
));
674 * Unused kprobe MUST be on the way of delayed unoptimizing (means
675 * there is still a relative jump) and disabled.
677 op
= container_of(ap
, struct optimized_kprobe
, kp
);
678 if (unlikely(list_empty(&op
->list
)))
679 printk(KERN_WARNING
"Warning: found a stray unused "
680 "aggrprobe@%p\n", ap
->addr
);
681 /* Enable the probe again */
682 ap
->flags
&= ~KPROBE_FLAG_DISABLED
;
683 /* Optimize it again (remove from op->list) */
684 BUG_ON(!kprobe_optready(ap
));
688 /* Remove optimized instructions */
689 static void kill_optimized_kprobe(struct kprobe
*p
)
691 struct optimized_kprobe
*op
;
693 op
= container_of(p
, struct optimized_kprobe
, kp
);
694 if (!list_empty(&op
->list
))
695 /* Dequeue from the (un)optimization queue */
696 list_del_init(&op
->list
);
697 op
->kp
.flags
&= ~KPROBE_FLAG_OPTIMIZED
;
699 if (kprobe_unused(p
)) {
700 /* Enqueue if it is unused */
701 list_add(&op
->list
, &freeing_list
);
703 * Remove unused probes from the hash list. After waiting
704 * for synchronization, this probe is reclaimed.
705 * (reclaiming is done by do_free_cleaned_kprobes().)
707 hlist_del_rcu(&op
->kp
.hlist
);
710 /* Don't touch the code, because it is already freed. */
711 arch_remove_optimized_kprobe(op
);
714 /* Try to prepare optimized instructions */
715 static void prepare_optimized_kprobe(struct kprobe
*p
)
717 struct optimized_kprobe
*op
;
719 op
= container_of(p
, struct optimized_kprobe
, kp
);
720 arch_prepare_optimized_kprobe(op
, p
);
723 /* Allocate new optimized_kprobe and try to prepare optimized instructions */
724 static struct kprobe
*alloc_aggr_kprobe(struct kprobe
*p
)
726 struct optimized_kprobe
*op
;
728 op
= kzalloc(sizeof(struct optimized_kprobe
), GFP_KERNEL
);
732 INIT_LIST_HEAD(&op
->list
);
733 op
->kp
.addr
= p
->addr
;
734 arch_prepare_optimized_kprobe(op
, p
);
739 static void init_aggr_kprobe(struct kprobe
*ap
, struct kprobe
*p
);
742 * Prepare an optimized_kprobe and optimize it
743 * NOTE: p must be a normal registered kprobe
745 static void try_to_optimize_kprobe(struct kprobe
*p
)
748 struct optimized_kprobe
*op
;
750 /* Impossible to optimize ftrace-based kprobe */
751 if (kprobe_ftrace(p
))
754 /* For preparing optimization, jump_label_text_reserved() is called */
756 mutex_lock(&text_mutex
);
758 ap
= alloc_aggr_kprobe(p
);
762 op
= container_of(ap
, struct optimized_kprobe
, kp
);
763 if (!arch_prepared_optinsn(&op
->optinsn
)) {
764 /* If failed to setup optimizing, fallback to kprobe */
765 arch_remove_optimized_kprobe(op
);
770 init_aggr_kprobe(ap
, p
);
771 optimize_kprobe(ap
); /* This just kicks optimizer thread */
774 mutex_unlock(&text_mutex
);
779 static void optimize_all_kprobes(void)
781 struct hlist_head
*head
;
785 mutex_lock(&kprobe_mutex
);
786 /* If optimization is already allowed, just return */
787 if (kprobes_allow_optimization
)
790 kprobes_allow_optimization
= true;
791 for (i
= 0; i
< KPROBE_TABLE_SIZE
; i
++) {
792 head
= &kprobe_table
[i
];
793 hlist_for_each_entry_rcu(p
, head
, hlist
)
794 if (!kprobe_disabled(p
))
797 printk(KERN_INFO
"Kprobes globally optimized\n");
799 mutex_unlock(&kprobe_mutex
);
802 static void unoptimize_all_kprobes(void)
804 struct hlist_head
*head
;
808 mutex_lock(&kprobe_mutex
);
809 /* If optimization is already prohibited, just return */
810 if (!kprobes_allow_optimization
) {
811 mutex_unlock(&kprobe_mutex
);
815 kprobes_allow_optimization
= false;
816 for (i
= 0; i
< KPROBE_TABLE_SIZE
; i
++) {
817 head
= &kprobe_table
[i
];
818 hlist_for_each_entry_rcu(p
, head
, hlist
) {
819 if (!kprobe_disabled(p
))
820 unoptimize_kprobe(p
, false);
823 mutex_unlock(&kprobe_mutex
);
825 /* Wait for unoptimizing completion */
826 wait_for_kprobe_optimizer();
827 printk(KERN_INFO
"Kprobes globally unoptimized\n");
830 static DEFINE_MUTEX(kprobe_sysctl_mutex
);
831 int sysctl_kprobes_optimization
;
832 int proc_kprobes_optimization_handler(struct ctl_table
*table
, int write
,
833 void __user
*buffer
, size_t *length
,
838 mutex_lock(&kprobe_sysctl_mutex
);
839 sysctl_kprobes_optimization
= kprobes_allow_optimization
? 1 : 0;
840 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
842 if (sysctl_kprobes_optimization
)
843 optimize_all_kprobes();
845 unoptimize_all_kprobes();
846 mutex_unlock(&kprobe_sysctl_mutex
);
850 #endif /* CONFIG_SYSCTL */
852 /* Put a breakpoint for a probe. Must be called with text_mutex locked */
853 static void __arm_kprobe(struct kprobe
*p
)
857 /* Check collision with other optimized kprobes */
858 _p
= get_optimized_kprobe((unsigned long)p
->addr
);
860 /* Fallback to unoptimized kprobe */
861 unoptimize_kprobe(_p
, true);
864 optimize_kprobe(p
); /* Try to optimize (add kprobe to a list) */
867 /* Remove the breakpoint of a probe. Must be called with text_mutex locked */
868 static void __disarm_kprobe(struct kprobe
*p
, bool reopt
)
872 /* Try to unoptimize */
873 unoptimize_kprobe(p
, kprobes_all_disarmed
);
875 if (!kprobe_queued(p
)) {
876 arch_disarm_kprobe(p
);
877 /* If another kprobe was blocked, optimize it. */
878 _p
= get_optimized_kprobe((unsigned long)p
->addr
);
879 if (unlikely(_p
) && reopt
)
882 /* TODO: reoptimize others after unoptimized this probe */
885 #else /* !CONFIG_OPTPROBES */
887 #define optimize_kprobe(p) do {} while (0)
888 #define unoptimize_kprobe(p, f) do {} while (0)
889 #define kill_optimized_kprobe(p) do {} while (0)
890 #define prepare_optimized_kprobe(p) do {} while (0)
891 #define try_to_optimize_kprobe(p) do {} while (0)
892 #define __arm_kprobe(p) arch_arm_kprobe(p)
893 #define __disarm_kprobe(p, o) arch_disarm_kprobe(p)
894 #define kprobe_disarmed(p) kprobe_disabled(p)
895 #define wait_for_kprobe_optimizer() do {} while (0)
897 /* There should be no unused kprobes can be reused without optimization */
898 static void reuse_unused_kprobe(struct kprobe
*ap
)
900 printk(KERN_ERR
"Error: There should be no unused kprobe here.\n");
901 BUG_ON(kprobe_unused(ap
));
904 static void free_aggr_kprobe(struct kprobe
*p
)
906 arch_remove_kprobe(p
);
910 static struct kprobe
*alloc_aggr_kprobe(struct kprobe
*p
)
912 return kzalloc(sizeof(struct kprobe
), GFP_KERNEL
);
914 #endif /* CONFIG_OPTPROBES */
916 #ifdef CONFIG_KPROBES_ON_FTRACE
917 static struct ftrace_ops kprobe_ftrace_ops __read_mostly
= {
918 .func
= kprobe_ftrace_handler
,
919 .flags
= FTRACE_OPS_FL_SAVE_REGS
| FTRACE_OPS_FL_IPMODIFY
,
921 static int kprobe_ftrace_enabled
;
923 /* Must ensure p->addr is really on ftrace */
924 static int prepare_kprobe(struct kprobe
*p
)
926 if (!kprobe_ftrace(p
))
927 return arch_prepare_kprobe(p
);
929 return arch_prepare_kprobe_ftrace(p
);
932 /* Caller must lock kprobe_mutex */
933 static void arm_kprobe_ftrace(struct kprobe
*p
)
937 ret
= ftrace_set_filter_ip(&kprobe_ftrace_ops
,
938 (unsigned long)p
->addr
, 0, 0);
939 WARN(ret
< 0, "Failed to arm kprobe-ftrace at %p (%d)\n", p
->addr
, ret
);
940 kprobe_ftrace_enabled
++;
941 if (kprobe_ftrace_enabled
== 1) {
942 ret
= register_ftrace_function(&kprobe_ftrace_ops
);
943 WARN(ret
< 0, "Failed to init kprobe-ftrace (%d)\n", ret
);
947 /* Caller must lock kprobe_mutex */
948 static void disarm_kprobe_ftrace(struct kprobe
*p
)
952 kprobe_ftrace_enabled
--;
953 if (kprobe_ftrace_enabled
== 0) {
954 ret
= unregister_ftrace_function(&kprobe_ftrace_ops
);
955 WARN(ret
< 0, "Failed to init kprobe-ftrace (%d)\n", ret
);
957 ret
= ftrace_set_filter_ip(&kprobe_ftrace_ops
,
958 (unsigned long)p
->addr
, 1, 0);
959 WARN(ret
< 0, "Failed to disarm kprobe-ftrace at %p (%d)\n", p
->addr
, ret
);
961 #else /* !CONFIG_KPROBES_ON_FTRACE */
962 #define prepare_kprobe(p) arch_prepare_kprobe(p)
963 #define arm_kprobe_ftrace(p) do {} while (0)
964 #define disarm_kprobe_ftrace(p) do {} while (0)
967 /* Arm a kprobe with text_mutex */
968 static void arm_kprobe(struct kprobe
*kp
)
970 if (unlikely(kprobe_ftrace(kp
))) {
971 arm_kprobe_ftrace(kp
);
975 * Here, since __arm_kprobe() doesn't use stop_machine(),
976 * this doesn't cause deadlock on text_mutex. So, we don't
977 * need get_online_cpus().
979 mutex_lock(&text_mutex
);
981 mutex_unlock(&text_mutex
);
984 /* Disarm a kprobe with text_mutex */
985 static void disarm_kprobe(struct kprobe
*kp
, bool reopt
)
987 if (unlikely(kprobe_ftrace(kp
))) {
988 disarm_kprobe_ftrace(kp
);
992 mutex_lock(&text_mutex
);
993 __disarm_kprobe(kp
, reopt
);
994 mutex_unlock(&text_mutex
);
998 * Aggregate handlers for multiple kprobes support - these handlers
999 * take care of invoking the individual kprobe handlers on p->list
1001 static int aggr_pre_handler(struct kprobe
*p
, struct pt_regs
*regs
)
1005 list_for_each_entry_rcu(kp
, &p
->list
, list
) {
1006 if (kp
->pre_handler
&& likely(!kprobe_disabled(kp
))) {
1007 set_kprobe_instance(kp
);
1008 if (kp
->pre_handler(kp
, regs
))
1011 reset_kprobe_instance();
1015 NOKPROBE_SYMBOL(aggr_pre_handler
);
1017 static void aggr_post_handler(struct kprobe
*p
, struct pt_regs
*regs
,
1018 unsigned long flags
)
1022 list_for_each_entry_rcu(kp
, &p
->list
, list
) {
1023 if (kp
->post_handler
&& likely(!kprobe_disabled(kp
))) {
1024 set_kprobe_instance(kp
);
1025 kp
->post_handler(kp
, regs
, flags
);
1026 reset_kprobe_instance();
1030 NOKPROBE_SYMBOL(aggr_post_handler
);
1032 static int aggr_fault_handler(struct kprobe
*p
, struct pt_regs
*regs
,
1035 struct kprobe
*cur
= __this_cpu_read(kprobe_instance
);
1038 * if we faulted "during" the execution of a user specified
1039 * probe handler, invoke just that probe's fault handler
1041 if (cur
&& cur
->fault_handler
) {
1042 if (cur
->fault_handler(cur
, regs
, trapnr
))
1047 NOKPROBE_SYMBOL(aggr_fault_handler
);
1049 static int aggr_break_handler(struct kprobe
*p
, struct pt_regs
*regs
)
1051 struct kprobe
*cur
= __this_cpu_read(kprobe_instance
);
1054 if (cur
&& cur
->break_handler
) {
1055 if (cur
->break_handler(cur
, regs
))
1058 reset_kprobe_instance();
1061 NOKPROBE_SYMBOL(aggr_break_handler
);
1063 /* Walks the list and increments nmissed count for multiprobe case */
1064 void kprobes_inc_nmissed_count(struct kprobe
*p
)
1067 if (!kprobe_aggrprobe(p
)) {
1070 list_for_each_entry_rcu(kp
, &p
->list
, list
)
1075 NOKPROBE_SYMBOL(kprobes_inc_nmissed_count
);
1077 void recycle_rp_inst(struct kretprobe_instance
*ri
,
1078 struct hlist_head
*head
)
1080 struct kretprobe
*rp
= ri
->rp
;
1082 /* remove rp inst off the rprobe_inst_table */
1083 hlist_del(&ri
->hlist
);
1084 INIT_HLIST_NODE(&ri
->hlist
);
1086 raw_spin_lock(&rp
->lock
);
1087 hlist_add_head(&ri
->hlist
, &rp
->free_instances
);
1088 raw_spin_unlock(&rp
->lock
);
1091 hlist_add_head(&ri
->hlist
, head
);
1093 NOKPROBE_SYMBOL(recycle_rp_inst
);
1095 void kretprobe_hash_lock(struct task_struct
*tsk
,
1096 struct hlist_head
**head
, unsigned long *flags
)
1097 __acquires(hlist_lock
)
1099 unsigned long hash
= hash_ptr(tsk
, KPROBE_HASH_BITS
);
1100 raw_spinlock_t
*hlist_lock
;
1102 *head
= &kretprobe_inst_table
[hash
];
1103 hlist_lock
= kretprobe_table_lock_ptr(hash
);
1104 raw_spin_lock_irqsave(hlist_lock
, *flags
);
1106 NOKPROBE_SYMBOL(kretprobe_hash_lock
);
1108 static void kretprobe_table_lock(unsigned long hash
,
1109 unsigned long *flags
)
1110 __acquires(hlist_lock
)
1112 raw_spinlock_t
*hlist_lock
= kretprobe_table_lock_ptr(hash
);
1113 raw_spin_lock_irqsave(hlist_lock
, *flags
);
1115 NOKPROBE_SYMBOL(kretprobe_table_lock
);
1117 void kretprobe_hash_unlock(struct task_struct
*tsk
,
1118 unsigned long *flags
)
1119 __releases(hlist_lock
)
1121 unsigned long hash
= hash_ptr(tsk
, KPROBE_HASH_BITS
);
1122 raw_spinlock_t
*hlist_lock
;
1124 hlist_lock
= kretprobe_table_lock_ptr(hash
);
1125 raw_spin_unlock_irqrestore(hlist_lock
, *flags
);
1127 NOKPROBE_SYMBOL(kretprobe_hash_unlock
);
1129 static void kretprobe_table_unlock(unsigned long hash
,
1130 unsigned long *flags
)
1131 __releases(hlist_lock
)
1133 raw_spinlock_t
*hlist_lock
= kretprobe_table_lock_ptr(hash
);
1134 raw_spin_unlock_irqrestore(hlist_lock
, *flags
);
1136 NOKPROBE_SYMBOL(kretprobe_table_unlock
);
1139 * This function is called from finish_task_switch when task tk becomes dead,
1140 * so that we can recycle any function-return probe instances associated
1141 * with this task. These left over instances represent probed functions
1142 * that have been called but will never return.
1144 void kprobe_flush_task(struct task_struct
*tk
)
1146 struct kretprobe_instance
*ri
;
1147 struct hlist_head
*head
, empty_rp
;
1148 struct hlist_node
*tmp
;
1149 unsigned long hash
, flags
= 0;
1151 if (unlikely(!kprobes_initialized
))
1152 /* Early boot. kretprobe_table_locks not yet initialized. */
1155 INIT_HLIST_HEAD(&empty_rp
);
1156 hash
= hash_ptr(tk
, KPROBE_HASH_BITS
);
1157 head
= &kretprobe_inst_table
[hash
];
1158 kretprobe_table_lock(hash
, &flags
);
1159 hlist_for_each_entry_safe(ri
, tmp
, head
, hlist
) {
1161 recycle_rp_inst(ri
, &empty_rp
);
1163 kretprobe_table_unlock(hash
, &flags
);
1164 hlist_for_each_entry_safe(ri
, tmp
, &empty_rp
, hlist
) {
1165 hlist_del(&ri
->hlist
);
1169 NOKPROBE_SYMBOL(kprobe_flush_task
);
1171 static inline void free_rp_inst(struct kretprobe
*rp
)
1173 struct kretprobe_instance
*ri
;
1174 struct hlist_node
*next
;
1176 hlist_for_each_entry_safe(ri
, next
, &rp
->free_instances
, hlist
) {
1177 hlist_del(&ri
->hlist
);
1182 static void cleanup_rp_inst(struct kretprobe
*rp
)
1184 unsigned long flags
, hash
;
1185 struct kretprobe_instance
*ri
;
1186 struct hlist_node
*next
;
1187 struct hlist_head
*head
;
1190 for (hash
= 0; hash
< KPROBE_TABLE_SIZE
; hash
++) {
1191 kretprobe_table_lock(hash
, &flags
);
1192 head
= &kretprobe_inst_table
[hash
];
1193 hlist_for_each_entry_safe(ri
, next
, head
, hlist
) {
1197 kretprobe_table_unlock(hash
, &flags
);
1201 NOKPROBE_SYMBOL(cleanup_rp_inst
);
1204 * Add the new probe to ap->list. Fail if this is the
1205 * second jprobe at the address - two jprobes can't coexist
1207 static int add_new_kprobe(struct kprobe
*ap
, struct kprobe
*p
)
1209 BUG_ON(kprobe_gone(ap
) || kprobe_gone(p
));
1211 if (p
->break_handler
|| p
->post_handler
)
1212 unoptimize_kprobe(ap
, true); /* Fall back to normal kprobe */
1214 if (p
->break_handler
) {
1215 if (ap
->break_handler
)
1217 list_add_tail_rcu(&p
->list
, &ap
->list
);
1218 ap
->break_handler
= aggr_break_handler
;
1220 list_add_rcu(&p
->list
, &ap
->list
);
1221 if (p
->post_handler
&& !ap
->post_handler
)
1222 ap
->post_handler
= aggr_post_handler
;
1228 * Fill in the required fields of the "manager kprobe". Replace the
1229 * earlier kprobe in the hlist with the manager kprobe
1231 static void init_aggr_kprobe(struct kprobe
*ap
, struct kprobe
*p
)
1233 /* Copy p's insn slot to ap */
1235 flush_insn_slot(ap
);
1237 ap
->flags
= p
->flags
& ~KPROBE_FLAG_OPTIMIZED
;
1238 ap
->pre_handler
= aggr_pre_handler
;
1239 ap
->fault_handler
= aggr_fault_handler
;
1240 /* We don't care the kprobe which has gone. */
1241 if (p
->post_handler
&& !kprobe_gone(p
))
1242 ap
->post_handler
= aggr_post_handler
;
1243 if (p
->break_handler
&& !kprobe_gone(p
))
1244 ap
->break_handler
= aggr_break_handler
;
1246 INIT_LIST_HEAD(&ap
->list
);
1247 INIT_HLIST_NODE(&ap
->hlist
);
1249 list_add_rcu(&p
->list
, &ap
->list
);
1250 hlist_replace_rcu(&p
->hlist
, &ap
->hlist
);
1254 * This is the second or subsequent kprobe at the address - handle
1257 static int register_aggr_kprobe(struct kprobe
*orig_p
, struct kprobe
*p
)
1260 struct kprobe
*ap
= orig_p
;
1262 /* For preparing optimization, jump_label_text_reserved() is called */
1265 * Get online CPUs to avoid text_mutex deadlock.with stop machine,
1266 * which is invoked by unoptimize_kprobe() in add_new_kprobe()
1269 mutex_lock(&text_mutex
);
1271 if (!kprobe_aggrprobe(orig_p
)) {
1272 /* If orig_p is not an aggr_kprobe, create new aggr_kprobe. */
1273 ap
= alloc_aggr_kprobe(orig_p
);
1278 init_aggr_kprobe(ap
, orig_p
);
1279 } else if (kprobe_unused(ap
))
1280 /* This probe is going to die. Rescue it */
1281 reuse_unused_kprobe(ap
);
1283 if (kprobe_gone(ap
)) {
1285 * Attempting to insert new probe at the same location that
1286 * had a probe in the module vaddr area which already
1287 * freed. So, the instruction slot has already been
1288 * released. We need a new slot for the new probe.
1290 ret
= arch_prepare_kprobe(ap
);
1293 * Even if fail to allocate new slot, don't need to
1294 * free aggr_probe. It will be used next time, or
1295 * freed by unregister_kprobe.
1299 /* Prepare optimized instructions if possible. */
1300 prepare_optimized_kprobe(ap
);
1303 * Clear gone flag to prevent allocating new slot again, and
1304 * set disabled flag because it is not armed yet.
1306 ap
->flags
= (ap
->flags
& ~KPROBE_FLAG_GONE
)
1307 | KPROBE_FLAG_DISABLED
;
1310 /* Copy ap's insn slot to p */
1312 ret
= add_new_kprobe(ap
, p
);
1315 mutex_unlock(&text_mutex
);
1317 jump_label_unlock();
1319 if (ret
== 0 && kprobe_disabled(ap
) && !kprobe_disabled(p
)) {
1320 ap
->flags
&= ~KPROBE_FLAG_DISABLED
;
1321 if (!kprobes_all_disarmed
)
1322 /* Arm the breakpoint again. */
1328 bool __weak
arch_within_kprobe_blacklist(unsigned long addr
)
1330 /* The __kprobes marked functions and entry code must not be probed */
1331 return addr
>= (unsigned long)__kprobes_text_start
&&
1332 addr
< (unsigned long)__kprobes_text_end
;
1335 bool within_kprobe_blacklist(unsigned long addr
)
1337 struct kprobe_blacklist_entry
*ent
;
1339 if (arch_within_kprobe_blacklist(addr
))
1342 * If there exists a kprobe_blacklist, verify and
1343 * fail any probe registration in the prohibited area
1345 list_for_each_entry(ent
, &kprobe_blacklist
, list
) {
1346 if (addr
>= ent
->start_addr
&& addr
< ent
->end_addr
)
1354 * If we have a symbol_name argument, look it up and add the offset field
1355 * to it. This way, we can specify a relative address to a symbol.
1356 * This returns encoded errors if it fails to look up symbol or invalid
1357 * combination of parameters.
1359 static kprobe_opcode_t
*kprobe_addr(struct kprobe
*p
)
1361 kprobe_opcode_t
*addr
= p
->addr
;
1363 if ((p
->symbol_name
&& p
->addr
) ||
1364 (!p
->symbol_name
&& !p
->addr
))
1367 if (p
->symbol_name
) {
1368 kprobe_lookup_name(p
->symbol_name
, addr
);
1370 return ERR_PTR(-ENOENT
);
1373 addr
= (kprobe_opcode_t
*)(((char *)addr
) + p
->offset
);
1378 return ERR_PTR(-EINVAL
);
1381 /* Check passed kprobe is valid and return kprobe in kprobe_table. */
1382 static struct kprobe
*__get_valid_kprobe(struct kprobe
*p
)
1384 struct kprobe
*ap
, *list_p
;
1386 ap
= get_kprobe(p
->addr
);
1391 list_for_each_entry_rcu(list_p
, &ap
->list
, list
)
1393 /* kprobe p is a valid probe */
1401 /* Return error if the kprobe is being re-registered */
1402 static inline int check_kprobe_rereg(struct kprobe
*p
)
1406 mutex_lock(&kprobe_mutex
);
1407 if (__get_valid_kprobe(p
))
1409 mutex_unlock(&kprobe_mutex
);
1414 int __weak
arch_check_ftrace_location(struct kprobe
*p
)
1416 unsigned long ftrace_addr
;
1418 ftrace_addr
= ftrace_location((unsigned long)p
->addr
);
1420 #ifdef CONFIG_KPROBES_ON_FTRACE
1421 /* Given address is not on the instruction boundary */
1422 if ((unsigned long)p
->addr
!= ftrace_addr
)
1424 p
->flags
|= KPROBE_FLAG_FTRACE
;
1425 #else /* !CONFIG_KPROBES_ON_FTRACE */
1432 static int check_kprobe_address_safe(struct kprobe
*p
,
1433 struct module
**probed_mod
)
1437 ret
= arch_check_ftrace_location(p
);
1443 /* Ensure it is not in reserved area nor out of text */
1444 if (!kernel_text_address((unsigned long) p
->addr
) ||
1445 within_kprobe_blacklist((unsigned long) p
->addr
) ||
1446 jump_label_text_reserved(p
->addr
, p
->addr
)) {
1451 /* Check if are we probing a module */
1452 *probed_mod
= __module_text_address((unsigned long) p
->addr
);
1455 * We must hold a refcount of the probed module while updating
1456 * its code to prohibit unexpected unloading.
1458 if (unlikely(!try_module_get(*probed_mod
))) {
1464 * If the module freed .init.text, we couldn't insert
1467 if (within_module_init((unsigned long)p
->addr
, *probed_mod
) &&
1468 (*probed_mod
)->state
!= MODULE_STATE_COMING
) {
1469 module_put(*probed_mod
);
1476 jump_label_unlock();
1481 int register_kprobe(struct kprobe
*p
)
1484 struct kprobe
*old_p
;
1485 struct module
*probed_mod
;
1486 kprobe_opcode_t
*addr
;
1488 /* Adjust probe address from symbol */
1489 addr
= kprobe_addr(p
);
1491 return PTR_ERR(addr
);
1494 ret
= check_kprobe_rereg(p
);
1498 /* User can pass only KPROBE_FLAG_DISABLED to register_kprobe */
1499 p
->flags
&= KPROBE_FLAG_DISABLED
;
1501 INIT_LIST_HEAD(&p
->list
);
1503 ret
= check_kprobe_address_safe(p
, &probed_mod
);
1507 mutex_lock(&kprobe_mutex
);
1509 old_p
= get_kprobe(p
->addr
);
1511 /* Since this may unoptimize old_p, locking text_mutex. */
1512 ret
= register_aggr_kprobe(old_p
, p
);
1516 mutex_lock(&text_mutex
); /* Avoiding text modification */
1517 ret
= prepare_kprobe(p
);
1518 mutex_unlock(&text_mutex
);
1522 INIT_HLIST_NODE(&p
->hlist
);
1523 hlist_add_head_rcu(&p
->hlist
,
1524 &kprobe_table
[hash_ptr(p
->addr
, KPROBE_HASH_BITS
)]);
1526 if (!kprobes_all_disarmed
&& !kprobe_disabled(p
))
1529 /* Try to optimize kprobe */
1530 try_to_optimize_kprobe(p
);
1533 mutex_unlock(&kprobe_mutex
);
1536 module_put(probed_mod
);
1540 EXPORT_SYMBOL_GPL(register_kprobe
);
1542 /* Check if all probes on the aggrprobe are disabled */
1543 static int aggr_kprobe_disabled(struct kprobe
*ap
)
1547 list_for_each_entry_rcu(kp
, &ap
->list
, list
)
1548 if (!kprobe_disabled(kp
))
1550 * There is an active probe on the list.
1551 * We can't disable this ap.
1558 /* Disable one kprobe: Make sure called under kprobe_mutex is locked */
1559 static struct kprobe
*__disable_kprobe(struct kprobe
*p
)
1561 struct kprobe
*orig_p
;
1563 /* Get an original kprobe for return */
1564 orig_p
= __get_valid_kprobe(p
);
1565 if (unlikely(orig_p
== NULL
))
1568 if (!kprobe_disabled(p
)) {
1569 /* Disable probe if it is a child probe */
1571 p
->flags
|= KPROBE_FLAG_DISABLED
;
1573 /* Try to disarm and disable this/parent probe */
1574 if (p
== orig_p
|| aggr_kprobe_disabled(orig_p
)) {
1576 * If kprobes_all_disarmed is set, orig_p
1577 * should have already been disarmed, so
1578 * skip unneed disarming process.
1580 if (!kprobes_all_disarmed
)
1581 disarm_kprobe(orig_p
, true);
1582 orig_p
->flags
|= KPROBE_FLAG_DISABLED
;
1590 * Unregister a kprobe without a scheduler synchronization.
1592 static int __unregister_kprobe_top(struct kprobe
*p
)
1594 struct kprobe
*ap
, *list_p
;
1596 /* Disable kprobe. This will disarm it if needed. */
1597 ap
= __disable_kprobe(p
);
1603 * This probe is an independent(and non-optimized) kprobe
1604 * (not an aggrprobe). Remove from the hash list.
1608 /* Following process expects this probe is an aggrprobe */
1609 WARN_ON(!kprobe_aggrprobe(ap
));
1611 if (list_is_singular(&ap
->list
) && kprobe_disarmed(ap
))
1613 * !disarmed could be happen if the probe is under delayed
1618 /* If disabling probe has special handlers, update aggrprobe */
1619 if (p
->break_handler
&& !kprobe_gone(p
))
1620 ap
->break_handler
= NULL
;
1621 if (p
->post_handler
&& !kprobe_gone(p
)) {
1622 list_for_each_entry_rcu(list_p
, &ap
->list
, list
) {
1623 if ((list_p
!= p
) && (list_p
->post_handler
))
1626 ap
->post_handler
= NULL
;
1630 * Remove from the aggrprobe: this path will do nothing in
1631 * __unregister_kprobe_bottom().
1633 list_del_rcu(&p
->list
);
1634 if (!kprobe_disabled(ap
) && !kprobes_all_disarmed
)
1636 * Try to optimize this probe again, because post
1637 * handler may have been changed.
1639 optimize_kprobe(ap
);
1644 BUG_ON(!kprobe_disarmed(ap
));
1645 hlist_del_rcu(&ap
->hlist
);
1649 static void __unregister_kprobe_bottom(struct kprobe
*p
)
1653 if (list_empty(&p
->list
))
1654 /* This is an independent kprobe */
1655 arch_remove_kprobe(p
);
1656 else if (list_is_singular(&p
->list
)) {
1657 /* This is the last child of an aggrprobe */
1658 ap
= list_entry(p
->list
.next
, struct kprobe
, list
);
1660 free_aggr_kprobe(ap
);
1662 /* Otherwise, do nothing. */
1665 int register_kprobes(struct kprobe
**kps
, int num
)
1671 for (i
= 0; i
< num
; i
++) {
1672 ret
= register_kprobe(kps
[i
]);
1675 unregister_kprobes(kps
, i
);
1681 EXPORT_SYMBOL_GPL(register_kprobes
);
1683 void unregister_kprobe(struct kprobe
*p
)
1685 unregister_kprobes(&p
, 1);
1687 EXPORT_SYMBOL_GPL(unregister_kprobe
);
1689 void unregister_kprobes(struct kprobe
**kps
, int num
)
1695 mutex_lock(&kprobe_mutex
);
1696 for (i
= 0; i
< num
; i
++)
1697 if (__unregister_kprobe_top(kps
[i
]) < 0)
1698 kps
[i
]->addr
= NULL
;
1699 mutex_unlock(&kprobe_mutex
);
1701 synchronize_sched();
1702 for (i
= 0; i
< num
; i
++)
1704 __unregister_kprobe_bottom(kps
[i
]);
1706 EXPORT_SYMBOL_GPL(unregister_kprobes
);
1708 static struct notifier_block kprobe_exceptions_nb
= {
1709 .notifier_call
= kprobe_exceptions_notify
,
1710 .priority
= 0x7fffffff /* we need to be notified first */
1713 unsigned long __weak
arch_deref_entry_point(void *entry
)
1715 return (unsigned long)entry
;
1718 int register_jprobes(struct jprobe
**jps
, int num
)
1725 for (i
= 0; i
< num
; i
++) {
1726 unsigned long addr
, offset
;
1728 addr
= arch_deref_entry_point(jp
->entry
);
1730 /* Verify probepoint is a function entry point */
1731 if (kallsyms_lookup_size_offset(addr
, NULL
, &offset
) &&
1733 jp
->kp
.pre_handler
= setjmp_pre_handler
;
1734 jp
->kp
.break_handler
= longjmp_break_handler
;
1735 ret
= register_kprobe(&jp
->kp
);
1741 unregister_jprobes(jps
, i
);
1747 EXPORT_SYMBOL_GPL(register_jprobes
);
1749 int register_jprobe(struct jprobe
*jp
)
1751 return register_jprobes(&jp
, 1);
1753 EXPORT_SYMBOL_GPL(register_jprobe
);
1755 void unregister_jprobe(struct jprobe
*jp
)
1757 unregister_jprobes(&jp
, 1);
1759 EXPORT_SYMBOL_GPL(unregister_jprobe
);
1761 void unregister_jprobes(struct jprobe
**jps
, int num
)
1767 mutex_lock(&kprobe_mutex
);
1768 for (i
= 0; i
< num
; i
++)
1769 if (__unregister_kprobe_top(&jps
[i
]->kp
) < 0)
1770 jps
[i
]->kp
.addr
= NULL
;
1771 mutex_unlock(&kprobe_mutex
);
1773 synchronize_sched();
1774 for (i
= 0; i
< num
; i
++) {
1775 if (jps
[i
]->kp
.addr
)
1776 __unregister_kprobe_bottom(&jps
[i
]->kp
);
1779 EXPORT_SYMBOL_GPL(unregister_jprobes
);
1781 #ifdef CONFIG_KRETPROBES
1783 * This kprobe pre_handler is registered with every kretprobe. When probe
1784 * hits it will set up the return probe.
1786 static int pre_handler_kretprobe(struct kprobe
*p
, struct pt_regs
*regs
)
1788 struct kretprobe
*rp
= container_of(p
, struct kretprobe
, kp
);
1789 unsigned long hash
, flags
= 0;
1790 struct kretprobe_instance
*ri
;
1793 * To avoid deadlocks, prohibit return probing in NMI contexts,
1794 * just skip the probe and increase the (inexact) 'nmissed'
1795 * statistical counter, so that the user is informed that
1796 * something happened:
1798 if (unlikely(in_nmi())) {
1803 /* TODO: consider to only swap the RA after the last pre_handler fired */
1804 hash
= hash_ptr(current
, KPROBE_HASH_BITS
);
1805 raw_spin_lock_irqsave(&rp
->lock
, flags
);
1806 if (!hlist_empty(&rp
->free_instances
)) {
1807 ri
= hlist_entry(rp
->free_instances
.first
,
1808 struct kretprobe_instance
, hlist
);
1809 hlist_del(&ri
->hlist
);
1810 raw_spin_unlock_irqrestore(&rp
->lock
, flags
);
1815 if (rp
->entry_handler
&& rp
->entry_handler(ri
, regs
)) {
1816 raw_spin_lock_irqsave(&rp
->lock
, flags
);
1817 hlist_add_head(&ri
->hlist
, &rp
->free_instances
);
1818 raw_spin_unlock_irqrestore(&rp
->lock
, flags
);
1822 arch_prepare_kretprobe(ri
, regs
);
1824 /* XXX(hch): why is there no hlist_move_head? */
1825 INIT_HLIST_NODE(&ri
->hlist
);
1826 kretprobe_table_lock(hash
, &flags
);
1827 hlist_add_head(&ri
->hlist
, &kretprobe_inst_table
[hash
]);
1828 kretprobe_table_unlock(hash
, &flags
);
1831 raw_spin_unlock_irqrestore(&rp
->lock
, flags
);
1835 NOKPROBE_SYMBOL(pre_handler_kretprobe
);
1837 int register_kretprobe(struct kretprobe
*rp
)
1840 struct kretprobe_instance
*inst
;
1844 if (kretprobe_blacklist_size
) {
1845 addr
= kprobe_addr(&rp
->kp
);
1847 return PTR_ERR(addr
);
1849 for (i
= 0; kretprobe_blacklist
[i
].name
!= NULL
; i
++) {
1850 if (kretprobe_blacklist
[i
].addr
== addr
)
1855 rp
->kp
.pre_handler
= pre_handler_kretprobe
;
1856 rp
->kp
.post_handler
= NULL
;
1857 rp
->kp
.fault_handler
= NULL
;
1858 rp
->kp
.break_handler
= NULL
;
1860 /* Pre-allocate memory for max kretprobe instances */
1861 if (rp
->maxactive
<= 0) {
1862 #ifdef CONFIG_PREEMPT
1863 rp
->maxactive
= max_t(unsigned int, 10, 2*num_possible_cpus());
1865 rp
->maxactive
= num_possible_cpus();
1868 raw_spin_lock_init(&rp
->lock
);
1869 INIT_HLIST_HEAD(&rp
->free_instances
);
1870 for (i
= 0; i
< rp
->maxactive
; i
++) {
1871 inst
= kmalloc(sizeof(struct kretprobe_instance
) +
1872 rp
->data_size
, GFP_KERNEL
);
1877 INIT_HLIST_NODE(&inst
->hlist
);
1878 hlist_add_head(&inst
->hlist
, &rp
->free_instances
);
1882 /* Establish function entry probe point */
1883 ret
= register_kprobe(&rp
->kp
);
1888 EXPORT_SYMBOL_GPL(register_kretprobe
);
1890 int register_kretprobes(struct kretprobe
**rps
, int num
)
1896 for (i
= 0; i
< num
; i
++) {
1897 ret
= register_kretprobe(rps
[i
]);
1900 unregister_kretprobes(rps
, i
);
1906 EXPORT_SYMBOL_GPL(register_kretprobes
);
1908 void unregister_kretprobe(struct kretprobe
*rp
)
1910 unregister_kretprobes(&rp
, 1);
1912 EXPORT_SYMBOL_GPL(unregister_kretprobe
);
1914 void unregister_kretprobes(struct kretprobe
**rps
, int num
)
1920 mutex_lock(&kprobe_mutex
);
1921 for (i
= 0; i
< num
; i
++)
1922 if (__unregister_kprobe_top(&rps
[i
]->kp
) < 0)
1923 rps
[i
]->kp
.addr
= NULL
;
1924 mutex_unlock(&kprobe_mutex
);
1926 synchronize_sched();
1927 for (i
= 0; i
< num
; i
++) {
1928 if (rps
[i
]->kp
.addr
) {
1929 __unregister_kprobe_bottom(&rps
[i
]->kp
);
1930 cleanup_rp_inst(rps
[i
]);
1934 EXPORT_SYMBOL_GPL(unregister_kretprobes
);
1936 #else /* CONFIG_KRETPROBES */
1937 int register_kretprobe(struct kretprobe
*rp
)
1941 EXPORT_SYMBOL_GPL(register_kretprobe
);
1943 int register_kretprobes(struct kretprobe
**rps
, int num
)
1947 EXPORT_SYMBOL_GPL(register_kretprobes
);
1949 void unregister_kretprobe(struct kretprobe
*rp
)
1952 EXPORT_SYMBOL_GPL(unregister_kretprobe
);
1954 void unregister_kretprobes(struct kretprobe
**rps
, int num
)
1957 EXPORT_SYMBOL_GPL(unregister_kretprobes
);
1959 static int pre_handler_kretprobe(struct kprobe
*p
, struct pt_regs
*regs
)
1963 NOKPROBE_SYMBOL(pre_handler_kretprobe
);
1965 #endif /* CONFIG_KRETPROBES */
1967 /* Set the kprobe gone and remove its instruction buffer. */
1968 static void kill_kprobe(struct kprobe
*p
)
1972 p
->flags
|= KPROBE_FLAG_GONE
;
1973 if (kprobe_aggrprobe(p
)) {
1975 * If this is an aggr_kprobe, we have to list all the
1976 * chained probes and mark them GONE.
1978 list_for_each_entry_rcu(kp
, &p
->list
, list
)
1979 kp
->flags
|= KPROBE_FLAG_GONE
;
1980 p
->post_handler
= NULL
;
1981 p
->break_handler
= NULL
;
1982 kill_optimized_kprobe(p
);
1985 * Here, we can remove insn_slot safely, because no thread calls
1986 * the original probed function (which will be freed soon) any more.
1988 arch_remove_kprobe(p
);
1991 /* Disable one kprobe */
1992 int disable_kprobe(struct kprobe
*kp
)
1996 mutex_lock(&kprobe_mutex
);
1998 /* Disable this kprobe */
1999 if (__disable_kprobe(kp
) == NULL
)
2002 mutex_unlock(&kprobe_mutex
);
2005 EXPORT_SYMBOL_GPL(disable_kprobe
);
2007 /* Enable one kprobe */
2008 int enable_kprobe(struct kprobe
*kp
)
2013 mutex_lock(&kprobe_mutex
);
2015 /* Check whether specified probe is valid. */
2016 p
= __get_valid_kprobe(kp
);
2017 if (unlikely(p
== NULL
)) {
2022 if (kprobe_gone(kp
)) {
2023 /* This kprobe has gone, we couldn't enable it. */
2029 kp
->flags
&= ~KPROBE_FLAG_DISABLED
;
2031 if (!kprobes_all_disarmed
&& kprobe_disabled(p
)) {
2032 p
->flags
&= ~KPROBE_FLAG_DISABLED
;
2036 mutex_unlock(&kprobe_mutex
);
2039 EXPORT_SYMBOL_GPL(enable_kprobe
);
2041 void dump_kprobe(struct kprobe
*kp
)
2043 printk(KERN_WARNING
"Dumping kprobe:\n");
2044 printk(KERN_WARNING
"Name: %s\nAddress: %p\nOffset: %x\n",
2045 kp
->symbol_name
, kp
->addr
, kp
->offset
);
2047 NOKPROBE_SYMBOL(dump_kprobe
);
2050 * Lookup and populate the kprobe_blacklist.
2052 * Unlike the kretprobe blacklist, we'll need to determine
2053 * the range of addresses that belong to the said functions,
2054 * since a kprobe need not necessarily be at the beginning
2057 static int __init
populate_kprobe_blacklist(unsigned long *start
,
2060 unsigned long *iter
;
2061 struct kprobe_blacklist_entry
*ent
;
2062 unsigned long entry
, offset
= 0, size
= 0;
2064 for (iter
= start
; iter
< end
; iter
++) {
2065 entry
= arch_deref_entry_point((void *)*iter
);
2067 if (!kernel_text_address(entry
) ||
2068 !kallsyms_lookup_size_offset(entry
, &size
, &offset
)) {
2069 pr_err("Failed to find blacklist at %p\n",
2074 ent
= kmalloc(sizeof(*ent
), GFP_KERNEL
);
2077 ent
->start_addr
= entry
;
2078 ent
->end_addr
= entry
+ size
;
2079 INIT_LIST_HEAD(&ent
->list
);
2080 list_add_tail(&ent
->list
, &kprobe_blacklist
);
2085 /* Module notifier call back, checking kprobes on the module */
2086 static int kprobes_module_callback(struct notifier_block
*nb
,
2087 unsigned long val
, void *data
)
2089 struct module
*mod
= data
;
2090 struct hlist_head
*head
;
2093 int checkcore
= (val
== MODULE_STATE_GOING
);
2095 if (val
!= MODULE_STATE_GOING
&& val
!= MODULE_STATE_LIVE
)
2099 * When MODULE_STATE_GOING was notified, both of module .text and
2100 * .init.text sections would be freed. When MODULE_STATE_LIVE was
2101 * notified, only .init.text section would be freed. We need to
2102 * disable kprobes which have been inserted in the sections.
2104 mutex_lock(&kprobe_mutex
);
2105 for (i
= 0; i
< KPROBE_TABLE_SIZE
; i
++) {
2106 head
= &kprobe_table
[i
];
2107 hlist_for_each_entry_rcu(p
, head
, hlist
)
2108 if (within_module_init((unsigned long)p
->addr
, mod
) ||
2110 within_module_core((unsigned long)p
->addr
, mod
))) {
2112 * The vaddr this probe is installed will soon
2113 * be vfreed buy not synced to disk. Hence,
2114 * disarming the breakpoint isn't needed.
2119 mutex_unlock(&kprobe_mutex
);
2123 static struct notifier_block kprobe_module_nb
= {
2124 .notifier_call
= kprobes_module_callback
,
2128 /* Markers of _kprobe_blacklist section */
2129 extern unsigned long __start_kprobe_blacklist
[];
2130 extern unsigned long __stop_kprobe_blacklist
[];
2132 static int __init
init_kprobes(void)
2136 /* FIXME allocate the probe table, currently defined statically */
2137 /* initialize all list heads */
2138 for (i
= 0; i
< KPROBE_TABLE_SIZE
; i
++) {
2139 INIT_HLIST_HEAD(&kprobe_table
[i
]);
2140 INIT_HLIST_HEAD(&kretprobe_inst_table
[i
]);
2141 raw_spin_lock_init(&(kretprobe_table_locks
[i
].lock
));
2144 err
= populate_kprobe_blacklist(__start_kprobe_blacklist
,
2145 __stop_kprobe_blacklist
);
2147 pr_err("kprobes: failed to populate blacklist: %d\n", err
);
2148 pr_err("Please take care of using kprobes.\n");
2151 if (kretprobe_blacklist_size
) {
2152 /* lookup the function address from its name */
2153 for (i
= 0; kretprobe_blacklist
[i
].name
!= NULL
; i
++) {
2154 kprobe_lookup_name(kretprobe_blacklist
[i
].name
,
2155 kretprobe_blacklist
[i
].addr
);
2156 if (!kretprobe_blacklist
[i
].addr
)
2157 printk("kretprobe: lookup failed: %s\n",
2158 kretprobe_blacklist
[i
].name
);
2162 #if defined(CONFIG_OPTPROBES)
2163 #if defined(__ARCH_WANT_KPROBES_INSN_SLOT)
2164 /* Init kprobe_optinsn_slots */
2165 kprobe_optinsn_slots
.insn_size
= MAX_OPTINSN_SIZE
;
2167 /* By default, kprobes can be optimized */
2168 kprobes_allow_optimization
= true;
2171 /* By default, kprobes are armed */
2172 kprobes_all_disarmed
= false;
2174 err
= arch_init_kprobes();
2176 err
= register_die_notifier(&kprobe_exceptions_nb
);
2178 err
= register_module_notifier(&kprobe_module_nb
);
2180 kprobes_initialized
= (err
== 0);
2187 #ifdef CONFIG_DEBUG_FS
2188 static void report_probe(struct seq_file
*pi
, struct kprobe
*p
,
2189 const char *sym
, int offset
, char *modname
, struct kprobe
*pp
)
2193 if (p
->pre_handler
== pre_handler_kretprobe
)
2195 else if (p
->pre_handler
== setjmp_pre_handler
)
2201 seq_printf(pi
, "%p %s %s+0x%x %s ",
2202 p
->addr
, kprobe_type
, sym
, offset
,
2203 (modname
? modname
: " "));
2205 seq_printf(pi
, "%p %s %p ",
2206 p
->addr
, kprobe_type
, p
->addr
);
2210 seq_printf(pi
, "%s%s%s%s\n",
2211 (kprobe_gone(p
) ? "[GONE]" : ""),
2212 ((kprobe_disabled(p
) && !kprobe_gone(p
)) ? "[DISABLED]" : ""),
2213 (kprobe_optimized(pp
) ? "[OPTIMIZED]" : ""),
2214 (kprobe_ftrace(pp
) ? "[FTRACE]" : ""));
2217 static void *kprobe_seq_start(struct seq_file
*f
, loff_t
*pos
)
2219 return (*pos
< KPROBE_TABLE_SIZE
) ? pos
: NULL
;
2222 static void *kprobe_seq_next(struct seq_file
*f
, void *v
, loff_t
*pos
)
2225 if (*pos
>= KPROBE_TABLE_SIZE
)
2230 static void kprobe_seq_stop(struct seq_file
*f
, void *v
)
2235 static int show_kprobe_addr(struct seq_file
*pi
, void *v
)
2237 struct hlist_head
*head
;
2238 struct kprobe
*p
, *kp
;
2239 const char *sym
= NULL
;
2240 unsigned int i
= *(loff_t
*) v
;
2241 unsigned long offset
= 0;
2242 char *modname
, namebuf
[KSYM_NAME_LEN
];
2244 head
= &kprobe_table
[i
];
2246 hlist_for_each_entry_rcu(p
, head
, hlist
) {
2247 sym
= kallsyms_lookup((unsigned long)p
->addr
, NULL
,
2248 &offset
, &modname
, namebuf
);
2249 if (kprobe_aggrprobe(p
)) {
2250 list_for_each_entry_rcu(kp
, &p
->list
, list
)
2251 report_probe(pi
, kp
, sym
, offset
, modname
, p
);
2253 report_probe(pi
, p
, sym
, offset
, modname
, NULL
);
2259 static const struct seq_operations kprobes_seq_ops
= {
2260 .start
= kprobe_seq_start
,
2261 .next
= kprobe_seq_next
,
2262 .stop
= kprobe_seq_stop
,
2263 .show
= show_kprobe_addr
2266 static int kprobes_open(struct inode
*inode
, struct file
*filp
)
2268 return seq_open(filp
, &kprobes_seq_ops
);
2271 static const struct file_operations debugfs_kprobes_operations
= {
2272 .open
= kprobes_open
,
2274 .llseek
= seq_lseek
,
2275 .release
= seq_release
,
2278 /* kprobes/blacklist -- shows which functions can not be probed */
2279 static void *kprobe_blacklist_seq_start(struct seq_file
*m
, loff_t
*pos
)
2281 return seq_list_start(&kprobe_blacklist
, *pos
);
2284 static void *kprobe_blacklist_seq_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
2286 return seq_list_next(v
, &kprobe_blacklist
, pos
);
2289 static int kprobe_blacklist_seq_show(struct seq_file
*m
, void *v
)
2291 struct kprobe_blacklist_entry
*ent
=
2292 list_entry(v
, struct kprobe_blacklist_entry
, list
);
2294 seq_printf(m
, "0x%p-0x%p\t%ps\n", (void *)ent
->start_addr
,
2295 (void *)ent
->end_addr
, (void *)ent
->start_addr
);
2299 static const struct seq_operations kprobe_blacklist_seq_ops
= {
2300 .start
= kprobe_blacklist_seq_start
,
2301 .next
= kprobe_blacklist_seq_next
,
2302 .stop
= kprobe_seq_stop
, /* Reuse void function */
2303 .show
= kprobe_blacklist_seq_show
,
2306 static int kprobe_blacklist_open(struct inode
*inode
, struct file
*filp
)
2308 return seq_open(filp
, &kprobe_blacklist_seq_ops
);
2311 static const struct file_operations debugfs_kprobe_blacklist_ops
= {
2312 .open
= kprobe_blacklist_open
,
2314 .llseek
= seq_lseek
,
2315 .release
= seq_release
,
2318 static void arm_all_kprobes(void)
2320 struct hlist_head
*head
;
2324 mutex_lock(&kprobe_mutex
);
2326 /* If kprobes are armed, just return */
2327 if (!kprobes_all_disarmed
)
2328 goto already_enabled
;
2331 * optimize_kprobe() called by arm_kprobe() checks
2332 * kprobes_all_disarmed, so set kprobes_all_disarmed before
2335 kprobes_all_disarmed
= false;
2336 /* Arming kprobes doesn't optimize kprobe itself */
2337 for (i
= 0; i
< KPROBE_TABLE_SIZE
; i
++) {
2338 head
= &kprobe_table
[i
];
2339 hlist_for_each_entry_rcu(p
, head
, hlist
)
2340 if (!kprobe_disabled(p
))
2344 printk(KERN_INFO
"Kprobes globally enabled\n");
2347 mutex_unlock(&kprobe_mutex
);
2351 static void disarm_all_kprobes(void)
2353 struct hlist_head
*head
;
2357 mutex_lock(&kprobe_mutex
);
2359 /* If kprobes are already disarmed, just return */
2360 if (kprobes_all_disarmed
) {
2361 mutex_unlock(&kprobe_mutex
);
2365 kprobes_all_disarmed
= true;
2366 printk(KERN_INFO
"Kprobes globally disabled\n");
2368 for (i
= 0; i
< KPROBE_TABLE_SIZE
; i
++) {
2369 head
= &kprobe_table
[i
];
2370 hlist_for_each_entry_rcu(p
, head
, hlist
) {
2371 if (!arch_trampoline_kprobe(p
) && !kprobe_disabled(p
))
2372 disarm_kprobe(p
, false);
2375 mutex_unlock(&kprobe_mutex
);
2377 /* Wait for disarming all kprobes by optimizer */
2378 wait_for_kprobe_optimizer();
2382 * XXX: The debugfs bool file interface doesn't allow for callbacks
2383 * when the bool state is switched. We can reuse that facility when
2386 static ssize_t
read_enabled_file_bool(struct file
*file
,
2387 char __user
*user_buf
, size_t count
, loff_t
*ppos
)
2391 if (!kprobes_all_disarmed
)
2397 return simple_read_from_buffer(user_buf
, count
, ppos
, buf
, 2);
2400 static ssize_t
write_enabled_file_bool(struct file
*file
,
2401 const char __user
*user_buf
, size_t count
, loff_t
*ppos
)
2406 buf_size
= min(count
, (sizeof(buf
)-1));
2407 if (copy_from_user(buf
, user_buf
, buf_size
))
2410 buf
[buf_size
] = '\0';
2420 disarm_all_kprobes();
2429 static const struct file_operations fops_kp
= {
2430 .read
= read_enabled_file_bool
,
2431 .write
= write_enabled_file_bool
,
2432 .llseek
= default_llseek
,
2435 static int __init
debugfs_kprobe_init(void)
2437 struct dentry
*dir
, *file
;
2438 unsigned int value
= 1;
2440 dir
= debugfs_create_dir("kprobes", NULL
);
2444 file
= debugfs_create_file("list", 0444, dir
, NULL
,
2445 &debugfs_kprobes_operations
);
2449 file
= debugfs_create_file("enabled", 0600, dir
,
2454 file
= debugfs_create_file("blacklist", 0444, dir
, NULL
,
2455 &debugfs_kprobe_blacklist_ops
);
2462 debugfs_remove(dir
);
2466 late_initcall(debugfs_kprobe_init
);
2467 #endif /* CONFIG_DEBUG_FS */
2469 module_init(init_kprobes
);
2471 /* defined in arch/.../kernel/kprobes.c */
2472 EXPORT_SYMBOL_GPL(jprobe_return
);