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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>
51
52#include <asm/sections.h>
53#include <asm/cacheflush.h>
54#include <asm/errno.h>
55#include <linux/uaccess.h>
56
57#define KPROBE_HASH_BITS 6
58#define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS)
59
60
61static int kprobes_initialized;
62static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE];
63static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE];
64
65
66static bool kprobes_all_disarmed;
67
68
69static DEFINE_MUTEX(kprobe_mutex);
70static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
71static struct {
72 raw_spinlock_t lock ____cacheline_aligned_in_smp;
73} kretprobe_table_locks[KPROBE_TABLE_SIZE];
74
75kprobe_opcode_t * __weak kprobe_lookup_name(const char *name,
76 unsigned int __unused)
77{
78 return ((kprobe_opcode_t *)(kallsyms_lookup_name(name)));
79}
80
81static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash)
82{
83 return &(kretprobe_table_locks[hash].lock);
84}
85
86
87static LIST_HEAD(kprobe_blacklist);
88
89#ifdef __ARCH_WANT_KPROBES_INSN_SLOT
90
91
92
93
94
95
96struct kprobe_insn_page {
97 struct list_head list;
98 kprobe_opcode_t *insns;
99 struct kprobe_insn_cache *cache;
100 int nused;
101 int ngarbage;
102 char slot_used[];
103};
104
105#define KPROBE_INSN_PAGE_SIZE(slots) \
106 (offsetof(struct kprobe_insn_page, slot_used) + \
107 (sizeof(char) * (slots)))
108
109static int slots_per_page(struct kprobe_insn_cache *c)
110{
111 return PAGE_SIZE/(c->insn_size * sizeof(kprobe_opcode_t));
112}
113
114enum kprobe_slot_state {
115 SLOT_CLEAN = 0,
116 SLOT_DIRTY = 1,
117 SLOT_USED = 2,
118};
119
120void __weak *alloc_insn_page(void)
121{
122 return module_alloc(PAGE_SIZE);
123}
124
125void __weak free_insn_page(void *page)
126{
127 module_memfree(page);
128}
129
130struct kprobe_insn_cache kprobe_insn_slots = {
131 .mutex = __MUTEX_INITIALIZER(kprobe_insn_slots.mutex),
132 .alloc = alloc_insn_page,
133 .free = free_insn_page,
134 .pages = LIST_HEAD_INIT(kprobe_insn_slots.pages),
135 .insn_size = MAX_INSN_SIZE,
136 .nr_garbage = 0,
137};
138static int collect_garbage_slots(struct kprobe_insn_cache *c);
139
140
141
142
143
144kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c)
145{
146 struct kprobe_insn_page *kip;
147 kprobe_opcode_t *slot = NULL;
148
149
150 mutex_lock(&c->mutex);
151 retry:
152 rcu_read_lock();
153 list_for_each_entry_rcu(kip, &c->pages, list) {
154 if (kip->nused < slots_per_page(c)) {
155 int i;
156 for (i = 0; i < slots_per_page(c); i++) {
157 if (kip->slot_used[i] == SLOT_CLEAN) {
158 kip->slot_used[i] = SLOT_USED;
159 kip->nused++;
160 slot = kip->insns + (i * c->insn_size);
161 rcu_read_unlock();
162 goto out;
163 }
164 }
165
166 kip->nused = slots_per_page(c);
167 WARN_ON(1);
168 }
169 }
170 rcu_read_unlock();
171
172
173 if (c->nr_garbage && collect_garbage_slots(c) == 0)
174 goto retry;
175
176
177 kip = kmalloc(KPROBE_INSN_PAGE_SIZE(slots_per_page(c)), GFP_KERNEL);
178 if (!kip)
179 goto out;
180
181
182
183
184
185
186 kip->insns = c->alloc();
187 if (!kip->insns) {
188 kfree(kip);
189 goto out;
190 }
191 INIT_LIST_HEAD(&kip->list);
192 memset(kip->slot_used, SLOT_CLEAN, slots_per_page(c));
193 kip->slot_used[0] = SLOT_USED;
194 kip->nused = 1;
195 kip->ngarbage = 0;
196 kip->cache = c;
197 list_add_rcu(&kip->list, &c->pages);
198 slot = kip->insns;
199out:
200 mutex_unlock(&c->mutex);
201 return slot;
202}
203
204
205static int collect_one_slot(struct kprobe_insn_page *kip, int idx)
206{
207 kip->slot_used[idx] = SLOT_CLEAN;
208 kip->nused--;
209 if (kip->nused == 0) {
210
211
212
213
214
215
216 if (!list_is_singular(&kip->list)) {
217 list_del_rcu(&kip->list);
218 synchronize_rcu();
219 kip->cache->free(kip->insns);
220 kfree(kip);
221 }
222 return 1;
223 }
224 return 0;
225}
226
227static int collect_garbage_slots(struct kprobe_insn_cache *c)
228{
229 struct kprobe_insn_page *kip, *next;
230
231
232 synchronize_sched();
233
234 list_for_each_entry_safe(kip, next, &c->pages, list) {
235 int i;
236 if (kip->ngarbage == 0)
237 continue;
238 kip->ngarbage = 0;
239 for (i = 0; i < slots_per_page(c); i++) {
240 if (kip->slot_used[i] == SLOT_DIRTY && collect_one_slot(kip, i))
241 break;
242 }
243 }
244 c->nr_garbage = 0;
245 return 0;
246}
247
248void __free_insn_slot(struct kprobe_insn_cache *c,
249 kprobe_opcode_t *slot, int dirty)
250{
251 struct kprobe_insn_page *kip;
252 long idx;
253
254 mutex_lock(&c->mutex);
255 rcu_read_lock();
256 list_for_each_entry_rcu(kip, &c->pages, list) {
257 idx = ((long)slot - (long)kip->insns) /
258 (c->insn_size * sizeof(kprobe_opcode_t));
259 if (idx >= 0 && idx < slots_per_page(c))
260 goto out;
261 }
262
263 WARN_ON(1);
264 kip = NULL;
265out:
266 rcu_read_unlock();
267
268 if (kip) {
269
270 WARN_ON(kip->slot_used[idx] != SLOT_USED);
271 if (dirty) {
272 kip->slot_used[idx] = SLOT_DIRTY;
273 kip->ngarbage++;
274 if (++c->nr_garbage > slots_per_page(c))
275 collect_garbage_slots(c);
276 } else {
277 collect_one_slot(kip, idx);
278 }
279 }
280 mutex_unlock(&c->mutex);
281}
282
283
284
285
286
287
288bool __is_insn_slot_addr(struct kprobe_insn_cache *c, unsigned long addr)
289{
290 struct kprobe_insn_page *kip;
291 bool ret = false;
292
293 rcu_read_lock();
294 list_for_each_entry_rcu(kip, &c->pages, list) {
295 if (addr >= (unsigned long)kip->insns &&
296 addr < (unsigned long)kip->insns + PAGE_SIZE) {
297 ret = true;
298 break;
299 }
300 }
301 rcu_read_unlock();
302
303 return ret;
304}
305
306#ifdef CONFIG_OPTPROBES
307
308struct kprobe_insn_cache kprobe_optinsn_slots = {
309 .mutex = __MUTEX_INITIALIZER(kprobe_optinsn_slots.mutex),
310 .alloc = alloc_insn_page,
311 .free = free_insn_page,
312 .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages),
313
314 .nr_garbage = 0,
315};
316#endif
317#endif
318
319
320static inline void set_kprobe_instance(struct kprobe *kp)
321{
322 __this_cpu_write(kprobe_instance, kp);
323}
324
325static inline void reset_kprobe_instance(void)
326{
327 __this_cpu_write(kprobe_instance, NULL);
328}
329
330
331
332
333
334
335
336struct kprobe *get_kprobe(void *addr)
337{
338 struct hlist_head *head;
339 struct kprobe *p;
340
341 head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)];
342 hlist_for_each_entry_rcu(p, head, hlist) {
343 if (p->addr == addr)
344 return p;
345 }
346
347 return NULL;
348}
349NOKPROBE_SYMBOL(get_kprobe);
350
351static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs);
352
353
354static inline int kprobe_aggrprobe(struct kprobe *p)
355{
356 return p->pre_handler == aggr_pre_handler;
357}
358
359
360static inline int kprobe_unused(struct kprobe *p)
361{
362 return kprobe_aggrprobe(p) && kprobe_disabled(p) &&
363 list_empty(&p->list);
364}
365
366
367
368
369static inline void copy_kprobe(struct kprobe *ap, struct kprobe *p)
370{
371 memcpy(&p->opcode, &ap->opcode, sizeof(kprobe_opcode_t));
372 memcpy(&p->ainsn, &ap->ainsn, sizeof(struct arch_specific_insn));
373}
374
375#ifdef CONFIG_OPTPROBES
376
377static bool kprobes_allow_optimization;
378
379
380
381
382
383void opt_pre_handler(struct kprobe *p, struct pt_regs *regs)
384{
385 struct kprobe *kp;
386
387 list_for_each_entry_rcu(kp, &p->list, list) {
388 if (kp->pre_handler && likely(!kprobe_disabled(kp))) {
389 set_kprobe_instance(kp);
390 kp->pre_handler(kp, regs);
391 }
392 reset_kprobe_instance();
393 }
394}
395NOKPROBE_SYMBOL(opt_pre_handler);
396
397
398static void free_aggr_kprobe(struct kprobe *p)
399{
400 struct optimized_kprobe *op;
401
402 op = container_of(p, struct optimized_kprobe, kp);
403 arch_remove_optimized_kprobe(op);
404 arch_remove_kprobe(p);
405 kfree(op);
406}
407
408
409static inline int kprobe_optready(struct kprobe *p)
410{
411 struct optimized_kprobe *op;
412
413 if (kprobe_aggrprobe(p)) {
414 op = container_of(p, struct optimized_kprobe, kp);
415 return arch_prepared_optinsn(&op->optinsn);
416 }
417
418 return 0;
419}
420
421
422static inline int kprobe_disarmed(struct kprobe *p)
423{
424 struct optimized_kprobe *op;
425
426
427 if (!kprobe_aggrprobe(p))
428 return kprobe_disabled(p);
429
430 op = container_of(p, struct optimized_kprobe, kp);
431
432 return kprobe_disabled(p) && list_empty(&op->list);
433}
434
435
436static int kprobe_queued(struct kprobe *p)
437{
438 struct optimized_kprobe *op;
439
440 if (kprobe_aggrprobe(p)) {
441 op = container_of(p, struct optimized_kprobe, kp);
442 if (!list_empty(&op->list))
443 return 1;
444 }
445 return 0;
446}
447
448
449
450
451
452static struct kprobe *get_optimized_kprobe(unsigned long addr)
453{
454 int i;
455 struct kprobe *p = NULL;
456 struct optimized_kprobe *op;
457
458
459 for (i = 1; !p && i < MAX_OPTIMIZED_LENGTH; i++)
460 p = get_kprobe((void *)(addr - i));
461
462 if (p && kprobe_optready(p)) {
463 op = container_of(p, struct optimized_kprobe, kp);
464 if (arch_within_optimized_kprobe(op, addr))
465 return p;
466 }
467
468 return NULL;
469}
470
471
472static LIST_HEAD(optimizing_list);
473static LIST_HEAD(unoptimizing_list);
474static LIST_HEAD(freeing_list);
475
476static void kprobe_optimizer(struct work_struct *work);
477static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer);
478#define OPTIMIZE_DELAY 5
479
480
481
482
483
484static void do_optimize_kprobes(void)
485{
486
487
488
489
490
491
492
493
494
495
496 lockdep_assert_cpus_held();
497
498
499 if (kprobes_all_disarmed || !kprobes_allow_optimization ||
500 list_empty(&optimizing_list))
501 return;
502
503 mutex_lock(&text_mutex);
504 arch_optimize_kprobes(&optimizing_list);
505 mutex_unlock(&text_mutex);
506}
507
508
509
510
511
512static void do_unoptimize_kprobes(void)
513{
514 struct optimized_kprobe *op, *tmp;
515
516
517 lockdep_assert_cpus_held();
518
519
520 if (list_empty(&unoptimizing_list))
521 return;
522
523 mutex_lock(&text_mutex);
524 arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list);
525
526 list_for_each_entry_safe(op, tmp, &freeing_list, list) {
527
528 if (kprobe_disabled(&op->kp))
529 arch_disarm_kprobe(&op->kp);
530 if (kprobe_unused(&op->kp)) {
531
532
533
534
535
536 hlist_del_rcu(&op->kp.hlist);
537 } else
538 list_del_init(&op->list);
539 }
540 mutex_unlock(&text_mutex);
541}
542
543
544static void do_free_cleaned_kprobes(void)
545{
546 struct optimized_kprobe *op, *tmp;
547
548 list_for_each_entry_safe(op, tmp, &freeing_list, list) {
549 BUG_ON(!kprobe_unused(&op->kp));
550 list_del_init(&op->list);
551 free_aggr_kprobe(&op->kp);
552 }
553}
554
555
556static void kick_kprobe_optimizer(void)
557{
558 schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY);
559}
560
561
562static void kprobe_optimizer(struct work_struct *work)
563{
564 mutex_lock(&kprobe_mutex);
565 cpus_read_lock();
566
567 mutex_lock(&module_mutex);
568
569
570
571
572
573 do_unoptimize_kprobes();
574
575
576
577
578
579
580
581
582
583
584 synchronize_rcu_tasks();
585
586
587 do_optimize_kprobes();
588
589
590 do_free_cleaned_kprobes();
591
592 mutex_unlock(&module_mutex);
593 cpus_read_unlock();
594 mutex_unlock(&kprobe_mutex);
595
596
597 if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list))
598 kick_kprobe_optimizer();
599}
600
601
602void wait_for_kprobe_optimizer(void)
603{
604 mutex_lock(&kprobe_mutex);
605
606 while (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) {
607 mutex_unlock(&kprobe_mutex);
608
609
610 flush_delayed_work(&optimizing_work);
611
612 cpu_relax();
613
614 mutex_lock(&kprobe_mutex);
615 }
616
617 mutex_unlock(&kprobe_mutex);
618}
619
620
621static void optimize_kprobe(struct kprobe *p)
622{
623 struct optimized_kprobe *op;
624
625
626 if (!kprobe_optready(p) || !kprobes_allow_optimization ||
627 (kprobe_disabled(p) || kprobes_all_disarmed))
628 return;
629
630
631 if (p->break_handler || p->post_handler)
632 return;
633
634 op = container_of(p, struct optimized_kprobe, kp);
635
636
637 if (arch_check_optimized_kprobe(op) < 0)
638 return;
639
640
641 if (op->kp.flags & KPROBE_FLAG_OPTIMIZED)
642 return;
643 op->kp.flags |= KPROBE_FLAG_OPTIMIZED;
644
645 if (!list_empty(&op->list))
646
647 list_del_init(&op->list);
648 else {
649 list_add(&op->list, &optimizing_list);
650 kick_kprobe_optimizer();
651 }
652}
653
654
655static void force_unoptimize_kprobe(struct optimized_kprobe *op)
656{
657 lockdep_assert_cpus_held();
658 arch_unoptimize_kprobe(op);
659 if (kprobe_disabled(&op->kp))
660 arch_disarm_kprobe(&op->kp);
661}
662
663
664static void unoptimize_kprobe(struct kprobe *p, bool force)
665{
666 struct optimized_kprobe *op;
667
668 if (!kprobe_aggrprobe(p) || kprobe_disarmed(p))
669 return;
670
671 op = container_of(p, struct optimized_kprobe, kp);
672 if (!kprobe_optimized(p)) {
673
674 if (force && !list_empty(&op->list)) {
675
676
677
678
679
680 list_del_init(&op->list);
681 force_unoptimize_kprobe(op);
682 }
683 return;
684 }
685
686 op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;
687 if (!list_empty(&op->list)) {
688
689 list_del_init(&op->list);
690 return;
691 }
692
693 if (force)
694
695 force_unoptimize_kprobe(op);
696 else {
697 list_add(&op->list, &unoptimizing_list);
698 kick_kprobe_optimizer();
699 }
700}
701
702
703static void reuse_unused_kprobe(struct kprobe *ap)
704{
705 struct optimized_kprobe *op;
706
707 BUG_ON(!kprobe_unused(ap));
708
709
710
711
712 op = container_of(ap, struct optimized_kprobe, kp);
713 if (unlikely(list_empty(&op->list)))
714 printk(KERN_WARNING "Warning: found a stray unused "
715 "aggrprobe@%p\n", ap->addr);
716
717 ap->flags &= ~KPROBE_FLAG_DISABLED;
718
719 BUG_ON(!kprobe_optready(ap));
720 optimize_kprobe(ap);
721}
722
723
724static void kill_optimized_kprobe(struct kprobe *p)
725{
726 struct optimized_kprobe *op;
727
728 op = container_of(p, struct optimized_kprobe, kp);
729 if (!list_empty(&op->list))
730
731 list_del_init(&op->list);
732 op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;
733
734 if (kprobe_unused(p)) {
735
736 list_add(&op->list, &freeing_list);
737
738
739
740
741
742 hlist_del_rcu(&op->kp.hlist);
743 }
744
745
746 arch_remove_optimized_kprobe(op);
747}
748
749static inline
750void __prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p)
751{
752 if (!kprobe_ftrace(p))
753 arch_prepare_optimized_kprobe(op, p);
754}
755
756
757static void prepare_optimized_kprobe(struct kprobe *p)
758{
759 struct optimized_kprobe *op;
760
761 op = container_of(p, struct optimized_kprobe, kp);
762 __prepare_optimized_kprobe(op, p);
763}
764
765
766static struct kprobe *alloc_aggr_kprobe(struct kprobe *p)
767{
768 struct optimized_kprobe *op;
769
770 op = kzalloc(sizeof(struct optimized_kprobe), GFP_KERNEL);
771 if (!op)
772 return NULL;
773
774 INIT_LIST_HEAD(&op->list);
775 op->kp.addr = p->addr;
776 __prepare_optimized_kprobe(op, p);
777
778 return &op->kp;
779}
780
781static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p);
782
783
784
785
786
787static void try_to_optimize_kprobe(struct kprobe *p)
788{
789 struct kprobe *ap;
790 struct optimized_kprobe *op;
791
792
793 if (kprobe_ftrace(p))
794 return;
795
796
797 cpus_read_lock();
798 jump_label_lock();
799 mutex_lock(&text_mutex);
800
801 ap = alloc_aggr_kprobe(p);
802 if (!ap)
803 goto out;
804
805 op = container_of(ap, struct optimized_kprobe, kp);
806 if (!arch_prepared_optinsn(&op->optinsn)) {
807
808 arch_remove_optimized_kprobe(op);
809 kfree(op);
810 goto out;
811 }
812
813 init_aggr_kprobe(ap, p);
814 optimize_kprobe(ap);
815
816out:
817 mutex_unlock(&text_mutex);
818 jump_label_unlock();
819 cpus_read_unlock();
820}
821
822#ifdef CONFIG_SYSCTL
823static void optimize_all_kprobes(void)
824{
825 struct hlist_head *head;
826 struct kprobe *p;
827 unsigned int i;
828
829 mutex_lock(&kprobe_mutex);
830
831 if (kprobes_allow_optimization)
832 goto out;
833
834 cpus_read_lock();
835 kprobes_allow_optimization = true;
836 for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
837 head = &kprobe_table[i];
838 hlist_for_each_entry_rcu(p, head, hlist)
839 if (!kprobe_disabled(p))
840 optimize_kprobe(p);
841 }
842 cpus_read_unlock();
843 printk(KERN_INFO "Kprobes globally optimized\n");
844out:
845 mutex_unlock(&kprobe_mutex);
846}
847
848static void unoptimize_all_kprobes(void)
849{
850 struct hlist_head *head;
851 struct kprobe *p;
852 unsigned int i;
853
854 mutex_lock(&kprobe_mutex);
855
856 if (!kprobes_allow_optimization) {
857 mutex_unlock(&kprobe_mutex);
858 return;
859 }
860
861 cpus_read_lock();
862 kprobes_allow_optimization = false;
863 for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
864 head = &kprobe_table[i];
865 hlist_for_each_entry_rcu(p, head, hlist) {
866 if (!kprobe_disabled(p))
867 unoptimize_kprobe(p, false);
868 }
869 }
870 cpus_read_unlock();
871 mutex_unlock(&kprobe_mutex);
872
873
874 wait_for_kprobe_optimizer();
875 printk(KERN_INFO "Kprobes globally unoptimized\n");
876}
877
878static DEFINE_MUTEX(kprobe_sysctl_mutex);
879int sysctl_kprobes_optimization;
880int proc_kprobes_optimization_handler(struct ctl_table *table, int write,
881 void __user *buffer, size_t *length,
882 loff_t *ppos)
883{
884 int ret;
885
886 mutex_lock(&kprobe_sysctl_mutex);
887 sysctl_kprobes_optimization = kprobes_allow_optimization ? 1 : 0;
888 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
889
890 if (sysctl_kprobes_optimization)
891 optimize_all_kprobes();
892 else
893 unoptimize_all_kprobes();
894 mutex_unlock(&kprobe_sysctl_mutex);
895
896 return ret;
897}
898#endif
899
900
901static void __arm_kprobe(struct kprobe *p)
902{
903 struct kprobe *_p;
904
905
906 _p = get_optimized_kprobe((unsigned long)p->addr);
907 if (unlikely(_p))
908
909 unoptimize_kprobe(_p, true);
910
911 arch_arm_kprobe(p);
912 optimize_kprobe(p);
913}
914
915
916static void __disarm_kprobe(struct kprobe *p, bool reopt)
917{
918 struct kprobe *_p;
919
920
921 unoptimize_kprobe(p, kprobes_all_disarmed);
922
923 if (!kprobe_queued(p)) {
924 arch_disarm_kprobe(p);
925
926 _p = get_optimized_kprobe((unsigned long)p->addr);
927 if (unlikely(_p) && reopt)
928 optimize_kprobe(_p);
929 }
930
931}
932
933#else
934
935#define optimize_kprobe(p) do {} while (0)
936#define unoptimize_kprobe(p, f) do {} while (0)
937#define kill_optimized_kprobe(p) do {} while (0)
938#define prepare_optimized_kprobe(p) do {} while (0)
939#define try_to_optimize_kprobe(p) do {} while (0)
940#define __arm_kprobe(p) arch_arm_kprobe(p)
941#define __disarm_kprobe(p, o) arch_disarm_kprobe(p)
942#define kprobe_disarmed(p) kprobe_disabled(p)
943#define wait_for_kprobe_optimizer() do {} while (0)
944
945
946static void reuse_unused_kprobe(struct kprobe *ap)
947{
948 printk(KERN_ERR "Error: There should be no unused kprobe here.\n");
949 BUG_ON(kprobe_unused(ap));
950}
951
952static void free_aggr_kprobe(struct kprobe *p)
953{
954 arch_remove_kprobe(p);
955 kfree(p);
956}
957
958static struct kprobe *alloc_aggr_kprobe(struct kprobe *p)
959{
960 return kzalloc(sizeof(struct kprobe), GFP_KERNEL);
961}
962#endif
963
964#ifdef CONFIG_KPROBES_ON_FTRACE
965static struct ftrace_ops kprobe_ftrace_ops __read_mostly = {
966 .func = kprobe_ftrace_handler,
967 .flags = FTRACE_OPS_FL_SAVE_REGS | FTRACE_OPS_FL_IPMODIFY,
968};
969static int kprobe_ftrace_enabled;
970
971
972static int prepare_kprobe(struct kprobe *p)
973{
974 if (!kprobe_ftrace(p))
975 return arch_prepare_kprobe(p);
976
977 return arch_prepare_kprobe_ftrace(p);
978}
979
980
981static int arm_kprobe_ftrace(struct kprobe *p)
982{
983 int ret = 0;
984
985 ret = ftrace_set_filter_ip(&kprobe_ftrace_ops,
986 (unsigned long)p->addr, 0, 0);
987 if (ret) {
988 pr_debug("Failed to arm kprobe-ftrace at %p (%d)\n", p->addr, ret);
989 return ret;
990 }
991
992 if (kprobe_ftrace_enabled == 0) {
993 ret = register_ftrace_function(&kprobe_ftrace_ops);
994 if (ret) {
995 pr_debug("Failed to init kprobe-ftrace (%d)\n", ret);
996 goto err_ftrace;
997 }
998 }
999
1000 kprobe_ftrace_enabled++;
1001 return ret;
1002
1003err_ftrace:
1004
1005
1006
1007
1008
1009 ftrace_set_filter_ip(&kprobe_ftrace_ops, (unsigned long)p->addr, 1, 0);
1010 return ret;
1011}
1012
1013
1014static int disarm_kprobe_ftrace(struct kprobe *p)
1015{
1016 int ret = 0;
1017
1018 if (kprobe_ftrace_enabled == 1) {
1019 ret = unregister_ftrace_function(&kprobe_ftrace_ops);
1020 if (WARN(ret < 0, "Failed to unregister kprobe-ftrace (%d)\n", ret))
1021 return ret;
1022 }
1023
1024 kprobe_ftrace_enabled--;
1025
1026 ret = ftrace_set_filter_ip(&kprobe_ftrace_ops,
1027 (unsigned long)p->addr, 1, 0);
1028 WARN(ret < 0, "Failed to disarm kprobe-ftrace at %p (%d)\n", p->addr, ret);
1029 return ret;
1030}
1031#else
1032#define prepare_kprobe(p) arch_prepare_kprobe(p)
1033#define arm_kprobe_ftrace(p) (-ENODEV)
1034#define disarm_kprobe_ftrace(p) (-ENODEV)
1035#endif
1036
1037
1038static int arm_kprobe(struct kprobe *kp)
1039{
1040 if (unlikely(kprobe_ftrace(kp)))
1041 return arm_kprobe_ftrace(kp);
1042
1043 cpus_read_lock();
1044 mutex_lock(&text_mutex);
1045 __arm_kprobe(kp);
1046 mutex_unlock(&text_mutex);
1047 cpus_read_unlock();
1048
1049 return 0;
1050}
1051
1052
1053static int disarm_kprobe(struct kprobe *kp, bool reopt)
1054{
1055 if (unlikely(kprobe_ftrace(kp)))
1056 return disarm_kprobe_ftrace(kp);
1057
1058 cpus_read_lock();
1059 mutex_lock(&text_mutex);
1060 __disarm_kprobe(kp, reopt);
1061 mutex_unlock(&text_mutex);
1062 cpus_read_unlock();
1063
1064 return 0;
1065}
1066
1067
1068
1069
1070
1071static int aggr_pre_handler(struct kprobe *p, struct pt_regs *regs)
1072{
1073 struct kprobe *kp;
1074
1075 list_for_each_entry_rcu(kp, &p->list, list) {
1076 if (kp->pre_handler && likely(!kprobe_disabled(kp))) {
1077 set_kprobe_instance(kp);
1078 if (kp->pre_handler(kp, regs))
1079 return 1;
1080 }
1081 reset_kprobe_instance();
1082 }
1083 return 0;
1084}
1085NOKPROBE_SYMBOL(aggr_pre_handler);
1086
1087static void aggr_post_handler(struct kprobe *p, struct pt_regs *regs,
1088 unsigned long flags)
1089{
1090 struct kprobe *kp;
1091
1092 list_for_each_entry_rcu(kp, &p->list, list) {
1093 if (kp->post_handler && likely(!kprobe_disabled(kp))) {
1094 set_kprobe_instance(kp);
1095 kp->post_handler(kp, regs, flags);
1096 reset_kprobe_instance();
1097 }
1098 }
1099}
1100NOKPROBE_SYMBOL(aggr_post_handler);
1101
1102static int aggr_fault_handler(struct kprobe *p, struct pt_regs *regs,
1103 int trapnr)
1104{
1105 struct kprobe *cur = __this_cpu_read(kprobe_instance);
1106
1107
1108
1109
1110
1111 if (cur && cur->fault_handler) {
1112 if (cur->fault_handler(cur, regs, trapnr))
1113 return 1;
1114 }
1115 return 0;
1116}
1117NOKPROBE_SYMBOL(aggr_fault_handler);
1118
1119static int aggr_break_handler(struct kprobe *p, struct pt_regs *regs)
1120{
1121 struct kprobe *cur = __this_cpu_read(kprobe_instance);
1122 int ret = 0;
1123
1124 if (cur && cur->break_handler) {
1125 if (cur->break_handler(cur, regs))
1126 ret = 1;
1127 }
1128 reset_kprobe_instance();
1129 return ret;
1130}
1131NOKPROBE_SYMBOL(aggr_break_handler);
1132
1133
1134void kprobes_inc_nmissed_count(struct kprobe *p)
1135{
1136 struct kprobe *kp;
1137 if (!kprobe_aggrprobe(p)) {
1138 p->nmissed++;
1139 } else {
1140 list_for_each_entry_rcu(kp, &p->list, list)
1141 kp->nmissed++;
1142 }
1143 return;
1144}
1145NOKPROBE_SYMBOL(kprobes_inc_nmissed_count);
1146
1147void recycle_rp_inst(struct kretprobe_instance *ri,
1148 struct hlist_head *head)
1149{
1150 struct kretprobe *rp = ri->rp;
1151
1152
1153 hlist_del(&ri->hlist);
1154 INIT_HLIST_NODE(&ri->hlist);
1155 if (likely(rp)) {
1156 raw_spin_lock(&rp->lock);
1157 hlist_add_head(&ri->hlist, &rp->free_instances);
1158 raw_spin_unlock(&rp->lock);
1159 } else
1160
1161 hlist_add_head(&ri->hlist, head);
1162}
1163NOKPROBE_SYMBOL(recycle_rp_inst);
1164
1165void kretprobe_hash_lock(struct task_struct *tsk,
1166 struct hlist_head **head, unsigned long *flags)
1167__acquires(hlist_lock)
1168{
1169 unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
1170 raw_spinlock_t *hlist_lock;
1171
1172 *head = &kretprobe_inst_table[hash];
1173 hlist_lock = kretprobe_table_lock_ptr(hash);
1174 raw_spin_lock_irqsave(hlist_lock, *flags);
1175}
1176NOKPROBE_SYMBOL(kretprobe_hash_lock);
1177
1178static void kretprobe_table_lock(unsigned long hash,
1179 unsigned long *flags)
1180__acquires(hlist_lock)
1181{
1182 raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
1183 raw_spin_lock_irqsave(hlist_lock, *flags);
1184}
1185NOKPROBE_SYMBOL(kretprobe_table_lock);
1186
1187void kretprobe_hash_unlock(struct task_struct *tsk,
1188 unsigned long *flags)
1189__releases(hlist_lock)
1190{
1191 unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
1192 raw_spinlock_t *hlist_lock;
1193
1194 hlist_lock = kretprobe_table_lock_ptr(hash);
1195 raw_spin_unlock_irqrestore(hlist_lock, *flags);
1196}
1197NOKPROBE_SYMBOL(kretprobe_hash_unlock);
1198
1199static void kretprobe_table_unlock(unsigned long hash,
1200 unsigned long *flags)
1201__releases(hlist_lock)
1202{
1203 raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
1204 raw_spin_unlock_irqrestore(hlist_lock, *flags);
1205}
1206NOKPROBE_SYMBOL(kretprobe_table_unlock);
1207
1208
1209
1210
1211
1212
1213
1214void kprobe_flush_task(struct task_struct *tk)
1215{
1216 struct kretprobe_instance *ri;
1217 struct hlist_head *head, empty_rp;
1218 struct hlist_node *tmp;
1219 unsigned long hash, flags = 0;
1220
1221 if (unlikely(!kprobes_initialized))
1222
1223 return;
1224
1225 INIT_HLIST_HEAD(&empty_rp);
1226 hash = hash_ptr(tk, KPROBE_HASH_BITS);
1227 head = &kretprobe_inst_table[hash];
1228 kretprobe_table_lock(hash, &flags);
1229 hlist_for_each_entry_safe(ri, tmp, head, hlist) {
1230 if (ri->task == tk)
1231 recycle_rp_inst(ri, &empty_rp);
1232 }
1233 kretprobe_table_unlock(hash, &flags);
1234 hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
1235 hlist_del(&ri->hlist);
1236 kfree(ri);
1237 }
1238}
1239NOKPROBE_SYMBOL(kprobe_flush_task);
1240
1241static inline void free_rp_inst(struct kretprobe *rp)
1242{
1243 struct kretprobe_instance *ri;
1244 struct hlist_node *next;
1245
1246 hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) {
1247 hlist_del(&ri->hlist);
1248 kfree(ri);
1249 }
1250}
1251
1252static void cleanup_rp_inst(struct kretprobe *rp)
1253{
1254 unsigned long flags, hash;
1255 struct kretprobe_instance *ri;
1256 struct hlist_node *next;
1257 struct hlist_head *head;
1258
1259
1260 for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) {
1261 kretprobe_table_lock(hash, &flags);
1262 head = &kretprobe_inst_table[hash];
1263 hlist_for_each_entry_safe(ri, next, head, hlist) {
1264 if (ri->rp == rp)
1265 ri->rp = NULL;
1266 }
1267 kretprobe_table_unlock(hash, &flags);
1268 }
1269 free_rp_inst(rp);
1270}
1271NOKPROBE_SYMBOL(cleanup_rp_inst);
1272
1273
1274
1275
1276
1277static int add_new_kprobe(struct kprobe *ap, struct kprobe *p)
1278{
1279 BUG_ON(kprobe_gone(ap) || kprobe_gone(p));
1280
1281 if (p->break_handler || p->post_handler)
1282 unoptimize_kprobe(ap, true);
1283
1284 if (p->break_handler) {
1285 if (ap->break_handler)
1286 return -EEXIST;
1287 list_add_tail_rcu(&p->list, &ap->list);
1288 ap->break_handler = aggr_break_handler;
1289 } else
1290 list_add_rcu(&p->list, &ap->list);
1291 if (p->post_handler && !ap->post_handler)
1292 ap->post_handler = aggr_post_handler;
1293
1294 return 0;
1295}
1296
1297
1298
1299
1300
1301static void init_aggr_kprobe(struct kprobe *ap, struct kprobe *p)
1302{
1303
1304 copy_kprobe(p, ap);
1305 flush_insn_slot(ap);
1306 ap->addr = p->addr;
1307 ap->flags = p->flags & ~KPROBE_FLAG_OPTIMIZED;
1308 ap->pre_handler = aggr_pre_handler;
1309 ap->fault_handler = aggr_fault_handler;
1310
1311 if (p->post_handler && !kprobe_gone(p))
1312 ap->post_handler = aggr_post_handler;
1313 if (p->break_handler && !kprobe_gone(p))
1314 ap->break_handler = aggr_break_handler;
1315
1316 INIT_LIST_HEAD(&ap->list);
1317 INIT_HLIST_NODE(&ap->hlist);
1318
1319 list_add_rcu(&p->list, &ap->list);
1320 hlist_replace_rcu(&p->hlist, &ap->hlist);
1321}
1322
1323
1324
1325
1326
1327static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p)
1328{
1329 int ret = 0;
1330 struct kprobe *ap = orig_p;
1331
1332 cpus_read_lock();
1333
1334
1335 jump_label_lock();
1336 mutex_lock(&text_mutex);
1337
1338 if (!kprobe_aggrprobe(orig_p)) {
1339
1340 ap = alloc_aggr_kprobe(orig_p);
1341 if (!ap) {
1342 ret = -ENOMEM;
1343 goto out;
1344 }
1345 init_aggr_kprobe(ap, orig_p);
1346 } else if (kprobe_unused(ap))
1347
1348 reuse_unused_kprobe(ap);
1349
1350 if (kprobe_gone(ap)) {
1351
1352
1353
1354
1355
1356
1357 ret = arch_prepare_kprobe(ap);
1358 if (ret)
1359
1360
1361
1362
1363
1364 goto out;
1365
1366
1367 prepare_optimized_kprobe(ap);
1368
1369
1370
1371
1372
1373 ap->flags = (ap->flags & ~KPROBE_FLAG_GONE)
1374 | KPROBE_FLAG_DISABLED;
1375 }
1376
1377
1378 copy_kprobe(ap, p);
1379 ret = add_new_kprobe(ap, p);
1380
1381out:
1382 mutex_unlock(&text_mutex);
1383 jump_label_unlock();
1384 cpus_read_unlock();
1385
1386 if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) {
1387 ap->flags &= ~KPROBE_FLAG_DISABLED;
1388 if (!kprobes_all_disarmed) {
1389
1390 ret = arm_kprobe(ap);
1391 if (ret) {
1392 ap->flags |= KPROBE_FLAG_DISABLED;
1393 list_del_rcu(&p->list);
1394 synchronize_sched();
1395 }
1396 }
1397 }
1398 return ret;
1399}
1400
1401bool __weak arch_within_kprobe_blacklist(unsigned long addr)
1402{
1403
1404 return addr >= (unsigned long)__kprobes_text_start &&
1405 addr < (unsigned long)__kprobes_text_end;
1406}
1407
1408bool within_kprobe_blacklist(unsigned long addr)
1409{
1410 struct kprobe_blacklist_entry *ent;
1411
1412 if (arch_within_kprobe_blacklist(addr))
1413 return true;
1414
1415
1416
1417
1418 list_for_each_entry(ent, &kprobe_blacklist, list) {
1419 if (addr >= ent->start_addr && addr < ent->end_addr)
1420 return true;
1421 }
1422
1423 return false;
1424}
1425
1426
1427
1428
1429
1430
1431
1432static kprobe_opcode_t *_kprobe_addr(kprobe_opcode_t *addr,
1433 const char *symbol_name, unsigned int offset)
1434{
1435 if ((symbol_name && addr) || (!symbol_name && !addr))
1436 goto invalid;
1437
1438 if (symbol_name) {
1439 addr = kprobe_lookup_name(symbol_name, offset);
1440 if (!addr)
1441 return ERR_PTR(-ENOENT);
1442 }
1443
1444 addr = (kprobe_opcode_t *)(((char *)addr) + offset);
1445 if (addr)
1446 return addr;
1447
1448invalid:
1449 return ERR_PTR(-EINVAL);
1450}
1451
1452static kprobe_opcode_t *kprobe_addr(struct kprobe *p)
1453{
1454 return _kprobe_addr(p->addr, p->symbol_name, p->offset);
1455}
1456
1457
1458static struct kprobe *__get_valid_kprobe(struct kprobe *p)
1459{
1460 struct kprobe *ap, *list_p;
1461
1462 ap = get_kprobe(p->addr);
1463 if (unlikely(!ap))
1464 return NULL;
1465
1466 if (p != ap) {
1467 list_for_each_entry_rcu(list_p, &ap->list, list)
1468 if (list_p == p)
1469
1470 goto valid;
1471 return NULL;
1472 }
1473valid:
1474 return ap;
1475}
1476
1477
1478static inline int check_kprobe_rereg(struct kprobe *p)
1479{
1480 int ret = 0;
1481
1482 mutex_lock(&kprobe_mutex);
1483 if (__get_valid_kprobe(p))
1484 ret = -EINVAL;
1485 mutex_unlock(&kprobe_mutex);
1486
1487 return ret;
1488}
1489
1490int __weak arch_check_ftrace_location(struct kprobe *p)
1491{
1492 unsigned long ftrace_addr;
1493
1494 ftrace_addr = ftrace_location((unsigned long)p->addr);
1495 if (ftrace_addr) {
1496#ifdef CONFIG_KPROBES_ON_FTRACE
1497
1498 if ((unsigned long)p->addr != ftrace_addr)
1499 return -EILSEQ;
1500 p->flags |= KPROBE_FLAG_FTRACE;
1501#else
1502 return -EINVAL;
1503#endif
1504 }
1505 return 0;
1506}
1507
1508static int check_kprobe_address_safe(struct kprobe *p,
1509 struct module **probed_mod)
1510{
1511 int ret;
1512
1513 ret = arch_check_ftrace_location(p);
1514 if (ret)
1515 return ret;
1516 jump_label_lock();
1517 preempt_disable();
1518
1519
1520 if (!kernel_text_address((unsigned long) p->addr) ||
1521 within_kprobe_blacklist((unsigned long) p->addr) ||
1522 jump_label_text_reserved(p->addr, p->addr)) {
1523 ret = -EINVAL;
1524 goto out;
1525 }
1526
1527
1528 *probed_mod = __module_text_address((unsigned long) p->addr);
1529 if (*probed_mod) {
1530
1531
1532
1533
1534 if (unlikely(!try_module_get(*probed_mod))) {
1535 ret = -ENOENT;
1536 goto out;
1537 }
1538
1539
1540
1541
1542
1543 if (within_module_init((unsigned long)p->addr, *probed_mod) &&
1544 (*probed_mod)->state != MODULE_STATE_COMING) {
1545 module_put(*probed_mod);
1546 *probed_mod = NULL;
1547 ret = -ENOENT;
1548 }
1549 }
1550out:
1551 preempt_enable();
1552 jump_label_unlock();
1553
1554 return ret;
1555}
1556
1557int register_kprobe(struct kprobe *p)
1558{
1559 int ret;
1560 struct kprobe *old_p;
1561 struct module *probed_mod;
1562 kprobe_opcode_t *addr;
1563
1564
1565 addr = kprobe_addr(p);
1566 if (IS_ERR(addr))
1567 return PTR_ERR(addr);
1568 p->addr = addr;
1569
1570 ret = check_kprobe_rereg(p);
1571 if (ret)
1572 return ret;
1573
1574
1575 p->flags &= KPROBE_FLAG_DISABLED;
1576 p->nmissed = 0;
1577 INIT_LIST_HEAD(&p->list);
1578
1579 ret = check_kprobe_address_safe(p, &probed_mod);
1580 if (ret)
1581 return ret;
1582
1583 mutex_lock(&kprobe_mutex);
1584
1585 old_p = get_kprobe(p->addr);
1586 if (old_p) {
1587
1588 ret = register_aggr_kprobe(old_p, p);
1589 goto out;
1590 }
1591
1592 cpus_read_lock();
1593
1594 mutex_lock(&text_mutex);
1595 ret = prepare_kprobe(p);
1596 mutex_unlock(&text_mutex);
1597 cpus_read_unlock();
1598 if (ret)
1599 goto out;
1600
1601 INIT_HLIST_NODE(&p->hlist);
1602 hlist_add_head_rcu(&p->hlist,
1603 &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]);
1604
1605 if (!kprobes_all_disarmed && !kprobe_disabled(p)) {
1606 ret = arm_kprobe(p);
1607 if (ret) {
1608 hlist_del_rcu(&p->hlist);
1609 synchronize_sched();
1610 goto out;
1611 }
1612 }
1613
1614
1615 try_to_optimize_kprobe(p);
1616out:
1617 mutex_unlock(&kprobe_mutex);
1618
1619 if (probed_mod)
1620 module_put(probed_mod);
1621
1622 return ret;
1623}
1624EXPORT_SYMBOL_GPL(register_kprobe);
1625
1626
1627static int aggr_kprobe_disabled(struct kprobe *ap)
1628{
1629 struct kprobe *kp;
1630
1631 list_for_each_entry_rcu(kp, &ap->list, list)
1632 if (!kprobe_disabled(kp))
1633
1634
1635
1636
1637 return 0;
1638
1639 return 1;
1640}
1641
1642
1643static struct kprobe *__disable_kprobe(struct kprobe *p)
1644{
1645 struct kprobe *orig_p;
1646 int ret;
1647
1648
1649 orig_p = __get_valid_kprobe(p);
1650 if (unlikely(orig_p == NULL))
1651 return ERR_PTR(-EINVAL);
1652
1653 if (!kprobe_disabled(p)) {
1654
1655 if (p != orig_p)
1656 p->flags |= KPROBE_FLAG_DISABLED;
1657
1658
1659 if (p == orig_p || aggr_kprobe_disabled(orig_p)) {
1660
1661
1662
1663
1664
1665 if (!kprobes_all_disarmed) {
1666 ret = disarm_kprobe(orig_p, true);
1667 if (ret) {
1668 p->flags &= ~KPROBE_FLAG_DISABLED;
1669 return ERR_PTR(ret);
1670 }
1671 }
1672 orig_p->flags |= KPROBE_FLAG_DISABLED;
1673 }
1674 }
1675
1676 return orig_p;
1677}
1678
1679
1680
1681
1682static int __unregister_kprobe_top(struct kprobe *p)
1683{
1684 struct kprobe *ap, *list_p;
1685
1686
1687 ap = __disable_kprobe(p);
1688 if (IS_ERR(ap))
1689 return PTR_ERR(ap);
1690
1691 if (ap == p)
1692
1693
1694
1695
1696 goto disarmed;
1697
1698
1699 WARN_ON(!kprobe_aggrprobe(ap));
1700
1701 if (list_is_singular(&ap->list) && kprobe_disarmed(ap))
1702
1703
1704
1705
1706 goto disarmed;
1707 else {
1708
1709 if (p->break_handler && !kprobe_gone(p))
1710 ap->break_handler = NULL;
1711 if (p->post_handler && !kprobe_gone(p)) {
1712 list_for_each_entry_rcu(list_p, &ap->list, list) {
1713 if ((list_p != p) && (list_p->post_handler))
1714 goto noclean;
1715 }
1716 ap->post_handler = NULL;
1717 }
1718noclean:
1719
1720
1721
1722
1723 list_del_rcu(&p->list);
1724 if (!kprobe_disabled(ap) && !kprobes_all_disarmed)
1725
1726
1727
1728
1729 optimize_kprobe(ap);
1730 }
1731 return 0;
1732
1733disarmed:
1734 BUG_ON(!kprobe_disarmed(ap));
1735 hlist_del_rcu(&ap->hlist);
1736 return 0;
1737}
1738
1739static void __unregister_kprobe_bottom(struct kprobe *p)
1740{
1741 struct kprobe *ap;
1742
1743 if (list_empty(&p->list))
1744
1745 arch_remove_kprobe(p);
1746 else if (list_is_singular(&p->list)) {
1747
1748 ap = list_entry(p->list.next, struct kprobe, list);
1749 list_del(&p->list);
1750 free_aggr_kprobe(ap);
1751 }
1752
1753}
1754
1755int register_kprobes(struct kprobe **kps, int num)
1756{
1757 int i, ret = 0;
1758
1759 if (num <= 0)
1760 return -EINVAL;
1761 for (i = 0; i < num; i++) {
1762 ret = register_kprobe(kps[i]);
1763 if (ret < 0) {
1764 if (i > 0)
1765 unregister_kprobes(kps, i);
1766 break;
1767 }
1768 }
1769 return ret;
1770}
1771EXPORT_SYMBOL_GPL(register_kprobes);
1772
1773void unregister_kprobe(struct kprobe *p)
1774{
1775 unregister_kprobes(&p, 1);
1776}
1777EXPORT_SYMBOL_GPL(unregister_kprobe);
1778
1779void unregister_kprobes(struct kprobe **kps, int num)
1780{
1781 int i;
1782
1783 if (num <= 0)
1784 return;
1785 mutex_lock(&kprobe_mutex);
1786 for (i = 0; i < num; i++)
1787 if (__unregister_kprobe_top(kps[i]) < 0)
1788 kps[i]->addr = NULL;
1789 mutex_unlock(&kprobe_mutex);
1790
1791 synchronize_sched();
1792 for (i = 0; i < num; i++)
1793 if (kps[i]->addr)
1794 __unregister_kprobe_bottom(kps[i]);
1795}
1796EXPORT_SYMBOL_GPL(unregister_kprobes);
1797
1798int __weak kprobe_exceptions_notify(struct notifier_block *self,
1799 unsigned long val, void *data)
1800{
1801 return NOTIFY_DONE;
1802}
1803NOKPROBE_SYMBOL(kprobe_exceptions_notify);
1804
1805static struct notifier_block kprobe_exceptions_nb = {
1806 .notifier_call = kprobe_exceptions_notify,
1807 .priority = 0x7fffffff
1808};
1809
1810unsigned long __weak arch_deref_entry_point(void *entry)
1811{
1812 return (unsigned long)entry;
1813}
1814
1815#if 0
1816int register_jprobes(struct jprobe **jps, int num)
1817{
1818 int ret = 0, i;
1819
1820 if (num <= 0)
1821 return -EINVAL;
1822
1823 for (i = 0; i < num; i++) {
1824 ret = register_jprobe(jps[i]);
1825
1826 if (ret < 0) {
1827 if (i > 0)
1828 unregister_jprobes(jps, i);
1829 break;
1830 }
1831 }
1832
1833 return ret;
1834}
1835EXPORT_SYMBOL_GPL(register_jprobes);
1836
1837int register_jprobe(struct jprobe *jp)
1838{
1839 unsigned long addr, offset;
1840 struct kprobe *kp = &jp->kp;
1841
1842
1843
1844
1845
1846 addr = arch_deref_entry_point(jp->entry);
1847
1848 if (kallsyms_lookup_size_offset(addr, NULL, &offset) && offset == 0 &&
1849 kprobe_on_func_entry(kp->addr, kp->symbol_name, kp->offset)) {
1850 kp->pre_handler = setjmp_pre_handler;
1851 kp->break_handler = longjmp_break_handler;
1852 return register_kprobe(kp);
1853 }
1854
1855 return -EINVAL;
1856}
1857EXPORT_SYMBOL_GPL(register_jprobe);
1858
1859void unregister_jprobe(struct jprobe *jp)
1860{
1861 unregister_jprobes(&jp, 1);
1862}
1863EXPORT_SYMBOL_GPL(unregister_jprobe);
1864
1865void unregister_jprobes(struct jprobe **jps, int num)
1866{
1867 int i;
1868
1869 if (num <= 0)
1870 return;
1871 mutex_lock(&kprobe_mutex);
1872 for (i = 0; i < num; i++)
1873 if (__unregister_kprobe_top(&jps[i]->kp) < 0)
1874 jps[i]->kp.addr = NULL;
1875 mutex_unlock(&kprobe_mutex);
1876
1877 synchronize_sched();
1878 for (i = 0; i < num; i++) {
1879 if (jps[i]->kp.addr)
1880 __unregister_kprobe_bottom(&jps[i]->kp);
1881 }
1882}
1883EXPORT_SYMBOL_GPL(unregister_jprobes);
1884#endif
1885
1886#ifdef CONFIG_KRETPROBES
1887
1888
1889
1890
1891static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs)
1892{
1893 struct kretprobe *rp = container_of(p, struct kretprobe, kp);
1894 unsigned long hash, flags = 0;
1895 struct kretprobe_instance *ri;
1896
1897
1898
1899
1900
1901
1902
1903 if (unlikely(in_nmi())) {
1904 rp->nmissed++;
1905 return 0;
1906 }
1907
1908
1909 hash = hash_ptr(current, KPROBE_HASH_BITS);
1910 raw_spin_lock_irqsave(&rp->lock, flags);
1911 if (!hlist_empty(&rp->free_instances)) {
1912 ri = hlist_entry(rp->free_instances.first,
1913 struct kretprobe_instance, hlist);
1914 hlist_del(&ri->hlist);
1915 raw_spin_unlock_irqrestore(&rp->lock, flags);
1916
1917 ri->rp = rp;
1918 ri->task = current;
1919
1920 if (rp->entry_handler && rp->entry_handler(ri, regs)) {
1921 raw_spin_lock_irqsave(&rp->lock, flags);
1922 hlist_add_head(&ri->hlist, &rp->free_instances);
1923 raw_spin_unlock_irqrestore(&rp->lock, flags);
1924 return 0;
1925 }
1926
1927 arch_prepare_kretprobe(ri, regs);
1928
1929
1930 INIT_HLIST_NODE(&ri->hlist);
1931 kretprobe_table_lock(hash, &flags);
1932 hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]);
1933 kretprobe_table_unlock(hash, &flags);
1934 } else {
1935 rp->nmissed++;
1936 raw_spin_unlock_irqrestore(&rp->lock, flags);
1937 }
1938 return 0;
1939}
1940NOKPROBE_SYMBOL(pre_handler_kretprobe);
1941
1942bool __weak arch_kprobe_on_func_entry(unsigned long offset)
1943{
1944 return !offset;
1945}
1946
1947bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset)
1948{
1949 kprobe_opcode_t *kp_addr = _kprobe_addr(addr, sym, offset);
1950
1951 if (IS_ERR(kp_addr))
1952 return false;
1953
1954 if (!kallsyms_lookup_size_offset((unsigned long)kp_addr, NULL, &offset) ||
1955 !arch_kprobe_on_func_entry(offset))
1956 return false;
1957
1958 return true;
1959}
1960
1961int register_kretprobe(struct kretprobe *rp)
1962{
1963 int ret = 0;
1964 struct kretprobe_instance *inst;
1965 int i;
1966 void *addr;
1967
1968 if (!kprobe_on_func_entry(rp->kp.addr, rp->kp.symbol_name, rp->kp.offset))
1969 return -EINVAL;
1970
1971 if (kretprobe_blacklist_size) {
1972 addr = kprobe_addr(&rp->kp);
1973 if (IS_ERR(addr))
1974 return PTR_ERR(addr);
1975
1976 for (i = 0; kretprobe_blacklist[i].name != NULL; i++) {
1977 if (kretprobe_blacklist[i].addr == addr)
1978 return -EINVAL;
1979 }
1980 }
1981
1982 rp->kp.pre_handler = pre_handler_kretprobe;
1983 rp->kp.post_handler = NULL;
1984 rp->kp.fault_handler = NULL;
1985 rp->kp.break_handler = NULL;
1986
1987
1988 if (rp->maxactive <= 0) {
1989#ifdef CONFIG_PREEMPT
1990 rp->maxactive = max_t(unsigned int, 10, 2*num_possible_cpus());
1991#else
1992 rp->maxactive = num_possible_cpus();
1993#endif
1994 }
1995 raw_spin_lock_init(&rp->lock);
1996 INIT_HLIST_HEAD(&rp->free_instances);
1997 for (i = 0; i < rp->maxactive; i++) {
1998 inst = kmalloc(sizeof(struct kretprobe_instance) +
1999 rp->data_size, GFP_KERNEL);
2000 if (inst == NULL) {
2001 free_rp_inst(rp);
2002 return -ENOMEM;
2003 }
2004 INIT_HLIST_NODE(&inst->hlist);
2005 hlist_add_head(&inst->hlist, &rp->free_instances);
2006 }
2007
2008 rp->nmissed = 0;
2009
2010 ret = register_kprobe(&rp->kp);
2011 if (ret != 0)
2012 free_rp_inst(rp);
2013 return ret;
2014}
2015EXPORT_SYMBOL_GPL(register_kretprobe);
2016
2017int register_kretprobes(struct kretprobe **rps, int num)
2018{
2019 int ret = 0, i;
2020
2021 if (num <= 0)
2022 return -EINVAL;
2023 for (i = 0; i < num; i++) {
2024 ret = register_kretprobe(rps[i]);
2025 if (ret < 0) {
2026 if (i > 0)
2027 unregister_kretprobes(rps, i);
2028 break;
2029 }
2030 }
2031 return ret;
2032}
2033EXPORT_SYMBOL_GPL(register_kretprobes);
2034
2035void unregister_kretprobe(struct kretprobe *rp)
2036{
2037 unregister_kretprobes(&rp, 1);
2038}
2039EXPORT_SYMBOL_GPL(unregister_kretprobe);
2040
2041void unregister_kretprobes(struct kretprobe **rps, int num)
2042{
2043 int i;
2044
2045 if (num <= 0)
2046 return;
2047 mutex_lock(&kprobe_mutex);
2048 for (i = 0; i < num; i++)
2049 if (__unregister_kprobe_top(&rps[i]->kp) < 0)
2050 rps[i]->kp.addr = NULL;
2051 mutex_unlock(&kprobe_mutex);
2052
2053 synchronize_sched();
2054 for (i = 0; i < num; i++) {
2055 if (rps[i]->kp.addr) {
2056 __unregister_kprobe_bottom(&rps[i]->kp);
2057 cleanup_rp_inst(rps[i]);
2058 }
2059 }
2060}
2061EXPORT_SYMBOL_GPL(unregister_kretprobes);
2062
2063#else
2064int register_kretprobe(struct kretprobe *rp)
2065{
2066 return -ENOSYS;
2067}
2068EXPORT_SYMBOL_GPL(register_kretprobe);
2069
2070int register_kretprobes(struct kretprobe **rps, int num)
2071{
2072 return -ENOSYS;
2073}
2074EXPORT_SYMBOL_GPL(register_kretprobes);
2075
2076void unregister_kretprobe(struct kretprobe *rp)
2077{
2078}
2079EXPORT_SYMBOL_GPL(unregister_kretprobe);
2080
2081void unregister_kretprobes(struct kretprobe **rps, int num)
2082{
2083}
2084EXPORT_SYMBOL_GPL(unregister_kretprobes);
2085
2086static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs)
2087{
2088 return 0;
2089}
2090NOKPROBE_SYMBOL(pre_handler_kretprobe);
2091
2092#endif
2093
2094
2095static void kill_kprobe(struct kprobe *p)
2096{
2097 struct kprobe *kp;
2098
2099 p->flags |= KPROBE_FLAG_GONE;
2100 if (kprobe_aggrprobe(p)) {
2101
2102
2103
2104
2105 list_for_each_entry_rcu(kp, &p->list, list)
2106 kp->flags |= KPROBE_FLAG_GONE;
2107 p->post_handler = NULL;
2108 p->break_handler = NULL;
2109 kill_optimized_kprobe(p);
2110 }
2111
2112
2113
2114
2115 arch_remove_kprobe(p);
2116}
2117
2118
2119int disable_kprobe(struct kprobe *kp)
2120{
2121 int ret = 0;
2122 struct kprobe *p;
2123
2124 mutex_lock(&kprobe_mutex);
2125
2126
2127 p = __disable_kprobe(kp);
2128 if (IS_ERR(p))
2129 ret = PTR_ERR(p);
2130
2131 mutex_unlock(&kprobe_mutex);
2132 return ret;
2133}
2134EXPORT_SYMBOL_GPL(disable_kprobe);
2135
2136
2137int enable_kprobe(struct kprobe *kp)
2138{
2139 int ret = 0;
2140 struct kprobe *p;
2141
2142 mutex_lock(&kprobe_mutex);
2143
2144
2145 p = __get_valid_kprobe(kp);
2146 if (unlikely(p == NULL)) {
2147 ret = -EINVAL;
2148 goto out;
2149 }
2150
2151 if (kprobe_gone(kp)) {
2152
2153 ret = -EINVAL;
2154 goto out;
2155 }
2156
2157 if (p != kp)
2158 kp->flags &= ~KPROBE_FLAG_DISABLED;
2159
2160 if (!kprobes_all_disarmed && kprobe_disabled(p)) {
2161 p->flags &= ~KPROBE_FLAG_DISABLED;
2162 ret = arm_kprobe(p);
2163 if (ret)
2164 p->flags |= KPROBE_FLAG_DISABLED;
2165 }
2166out:
2167 mutex_unlock(&kprobe_mutex);
2168 return ret;
2169}
2170EXPORT_SYMBOL_GPL(enable_kprobe);
2171
2172void dump_kprobe(struct kprobe *kp)
2173{
2174 printk(KERN_WARNING "Dumping kprobe:\n");
2175 printk(KERN_WARNING "Name: %s\nAddress: %p\nOffset: %x\n",
2176 kp->symbol_name, kp->addr, kp->offset);
2177}
2178NOKPROBE_SYMBOL(dump_kprobe);
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188static int __init populate_kprobe_blacklist(unsigned long *start,
2189 unsigned long *end)
2190{
2191 unsigned long *iter;
2192 struct kprobe_blacklist_entry *ent;
2193 unsigned long entry, offset = 0, size = 0;
2194
2195 for (iter = start; iter < end; iter++) {
2196 entry = arch_deref_entry_point((void *)*iter);
2197
2198 if (!kernel_text_address(entry) ||
2199 !kallsyms_lookup_size_offset(entry, &size, &offset)) {
2200 pr_err("Failed to find blacklist at %p\n",
2201 (void *)entry);
2202 continue;
2203 }
2204
2205 ent = kmalloc(sizeof(*ent), GFP_KERNEL);
2206 if (!ent)
2207 return -ENOMEM;
2208 ent->start_addr = entry;
2209 ent->end_addr = entry + size;
2210 INIT_LIST_HEAD(&ent->list);
2211 list_add_tail(&ent->list, &kprobe_blacklist);
2212 }
2213 return 0;
2214}
2215
2216
2217static int kprobes_module_callback(struct notifier_block *nb,
2218 unsigned long val, void *data)
2219{
2220 struct module *mod = data;
2221 struct hlist_head *head;
2222 struct kprobe *p;
2223 unsigned int i;
2224 int checkcore = (val == MODULE_STATE_GOING);
2225
2226 if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE)
2227 return NOTIFY_DONE;
2228
2229
2230
2231
2232
2233
2234
2235 mutex_lock(&kprobe_mutex);
2236 for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
2237 head = &kprobe_table[i];
2238 hlist_for_each_entry_rcu(p, head, hlist)
2239 if (within_module_init((unsigned long)p->addr, mod) ||
2240 (checkcore &&
2241 within_module_core((unsigned long)p->addr, mod))) {
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253 kill_kprobe(p);
2254 }
2255 }
2256 mutex_unlock(&kprobe_mutex);
2257 return NOTIFY_DONE;
2258}
2259
2260static struct notifier_block kprobe_module_nb = {
2261 .notifier_call = kprobes_module_callback,
2262 .priority = 0
2263};
2264
2265
2266extern unsigned long __start_kprobe_blacklist[];
2267extern unsigned long __stop_kprobe_blacklist[];
2268
2269static int __init init_kprobes(void)
2270{
2271 int i, err = 0;
2272
2273
2274
2275 for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
2276 INIT_HLIST_HEAD(&kprobe_table[i]);
2277 INIT_HLIST_HEAD(&kretprobe_inst_table[i]);
2278 raw_spin_lock_init(&(kretprobe_table_locks[i].lock));
2279 }
2280
2281 err = populate_kprobe_blacklist(__start_kprobe_blacklist,
2282 __stop_kprobe_blacklist);
2283 if (err) {
2284 pr_err("kprobes: failed to populate blacklist: %d\n", err);
2285 pr_err("Please take care of using kprobes.\n");
2286 }
2287
2288 if (kretprobe_blacklist_size) {
2289
2290 for (i = 0; kretprobe_blacklist[i].name != NULL; i++) {
2291 kretprobe_blacklist[i].addr =
2292 kprobe_lookup_name(kretprobe_blacklist[i].name, 0);
2293 if (!kretprobe_blacklist[i].addr)
2294 printk("kretprobe: lookup failed: %s\n",
2295 kretprobe_blacklist[i].name);
2296 }
2297 }
2298
2299#if defined(CONFIG_OPTPROBES)
2300#if defined(__ARCH_WANT_KPROBES_INSN_SLOT)
2301
2302 kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE;
2303#endif
2304
2305 kprobes_allow_optimization = true;
2306#endif
2307
2308
2309 kprobes_all_disarmed = false;
2310
2311 err = arch_init_kprobes();
2312 if (!err)
2313 err = register_die_notifier(&kprobe_exceptions_nb);
2314 if (!err)
2315 err = register_module_notifier(&kprobe_module_nb);
2316
2317 kprobes_initialized = (err == 0);
2318
2319 if (!err)
2320 init_test_probes();
2321 return err;
2322}
2323
2324#ifdef CONFIG_DEBUG_FS
2325static void report_probe(struct seq_file *pi, struct kprobe *p,
2326 const char *sym, int offset, char *modname, struct kprobe *pp)
2327{
2328 char *kprobe_type;
2329
2330 if (p->pre_handler == pre_handler_kretprobe)
2331 kprobe_type = "r";
2332 else if (p->pre_handler == setjmp_pre_handler)
2333 kprobe_type = "j";
2334 else
2335 kprobe_type = "k";
2336
2337 if (sym)
2338 seq_printf(pi, "%p %s %s+0x%x %s ",
2339 p->addr, kprobe_type, sym, offset,
2340 (modname ? modname : " "));
2341 else
2342 seq_printf(pi, "%p %s %p ",
2343 p->addr, kprobe_type, p->addr);
2344
2345 if (!pp)
2346 pp = p;
2347 seq_printf(pi, "%s%s%s%s\n",
2348 (kprobe_gone(p) ? "[GONE]" : ""),
2349 ((kprobe_disabled(p) && !kprobe_gone(p)) ? "[DISABLED]" : ""),
2350 (kprobe_optimized(pp) ? "[OPTIMIZED]" : ""),
2351 (kprobe_ftrace(pp) ? "[FTRACE]" : ""));
2352}
2353
2354static void *kprobe_seq_start(struct seq_file *f, loff_t *pos)
2355{
2356 return (*pos < KPROBE_TABLE_SIZE) ? pos : NULL;
2357}
2358
2359static void *kprobe_seq_next(struct seq_file *f, void *v, loff_t *pos)
2360{
2361 (*pos)++;
2362 if (*pos >= KPROBE_TABLE_SIZE)
2363 return NULL;
2364 return pos;
2365}
2366
2367static void kprobe_seq_stop(struct seq_file *f, void *v)
2368{
2369
2370}
2371
2372static int show_kprobe_addr(struct seq_file *pi, void *v)
2373{
2374 struct hlist_head *head;
2375 struct kprobe *p, *kp;
2376 const char *sym = NULL;
2377 unsigned int i = *(loff_t *) v;
2378 unsigned long offset = 0;
2379 char *modname, namebuf[KSYM_NAME_LEN];
2380
2381 head = &kprobe_table[i];
2382 preempt_disable();
2383 hlist_for_each_entry_rcu(p, head, hlist) {
2384 sym = kallsyms_lookup((unsigned long)p->addr, NULL,
2385 &offset, &modname, namebuf);
2386 if (kprobe_aggrprobe(p)) {
2387 list_for_each_entry_rcu(kp, &p->list, list)
2388 report_probe(pi, kp, sym, offset, modname, p);
2389 } else
2390 report_probe(pi, p, sym, offset, modname, NULL);
2391 }
2392 preempt_enable();
2393 return 0;
2394}
2395
2396static const struct seq_operations kprobes_seq_ops = {
2397 .start = kprobe_seq_start,
2398 .next = kprobe_seq_next,
2399 .stop = kprobe_seq_stop,
2400 .show = show_kprobe_addr
2401};
2402
2403static int kprobes_open(struct inode *inode, struct file *filp)
2404{
2405 return seq_open(filp, &kprobes_seq_ops);
2406}
2407
2408static const struct file_operations debugfs_kprobes_operations = {
2409 .open = kprobes_open,
2410 .read = seq_read,
2411 .llseek = seq_lseek,
2412 .release = seq_release,
2413};
2414
2415
2416static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos)
2417{
2418 return seq_list_start(&kprobe_blacklist, *pos);
2419}
2420
2421static void *kprobe_blacklist_seq_next(struct seq_file *m, void *v, loff_t *pos)
2422{
2423 return seq_list_next(v, &kprobe_blacklist, pos);
2424}
2425
2426static int kprobe_blacklist_seq_show(struct seq_file *m, void *v)
2427{
2428 struct kprobe_blacklist_entry *ent =
2429 list_entry(v, struct kprobe_blacklist_entry, list);
2430
2431 seq_printf(m, "0x%px-0x%px\t%ps\n", (void *)ent->start_addr,
2432 (void *)ent->end_addr, (void *)ent->start_addr);
2433 return 0;
2434}
2435
2436static const struct seq_operations kprobe_blacklist_seq_ops = {
2437 .start = kprobe_blacklist_seq_start,
2438 .next = kprobe_blacklist_seq_next,
2439 .stop = kprobe_seq_stop,
2440 .show = kprobe_blacklist_seq_show,
2441};
2442
2443static int kprobe_blacklist_open(struct inode *inode, struct file *filp)
2444{
2445 return seq_open(filp, &kprobe_blacklist_seq_ops);
2446}
2447
2448static const struct file_operations debugfs_kprobe_blacklist_ops = {
2449 .open = kprobe_blacklist_open,
2450 .read = seq_read,
2451 .llseek = seq_lseek,
2452 .release = seq_release,
2453};
2454
2455static int arm_all_kprobes(void)
2456{
2457 struct hlist_head *head;
2458 struct kprobe *p;
2459 unsigned int i, total = 0, errors = 0;
2460 int err, ret = 0;
2461
2462 mutex_lock(&kprobe_mutex);
2463
2464
2465 if (!kprobes_all_disarmed)
2466 goto already_enabled;
2467
2468
2469
2470
2471
2472
2473 kprobes_all_disarmed = false;
2474
2475 for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
2476 head = &kprobe_table[i];
2477
2478 hlist_for_each_entry_rcu(p, head, hlist) {
2479 if (!kprobe_disabled(p)) {
2480 err = arm_kprobe(p);
2481 if (err) {
2482 errors++;
2483 ret = err;
2484 }
2485 total++;
2486 }
2487 }
2488 }
2489
2490 if (errors)
2491 pr_warn("Kprobes globally enabled, but failed to arm %d out of %d probes\n",
2492 errors, total);
2493 else
2494 pr_info("Kprobes globally enabled\n");
2495
2496already_enabled:
2497 mutex_unlock(&kprobe_mutex);
2498 return ret;
2499}
2500
2501static int disarm_all_kprobes(void)
2502{
2503 struct hlist_head *head;
2504 struct kprobe *p;
2505 unsigned int i, total = 0, errors = 0;
2506 int err, ret = 0;
2507
2508 mutex_lock(&kprobe_mutex);
2509
2510
2511 if (kprobes_all_disarmed) {
2512 mutex_unlock(&kprobe_mutex);
2513 return 0;
2514 }
2515
2516 kprobes_all_disarmed = true;
2517
2518 for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
2519 head = &kprobe_table[i];
2520
2521 hlist_for_each_entry_rcu(p, head, hlist) {
2522 if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) {
2523 err = disarm_kprobe(p, false);
2524 if (err) {
2525 errors++;
2526 ret = err;
2527 }
2528 total++;
2529 }
2530 }
2531 }
2532
2533 if (errors)
2534 pr_warn("Kprobes globally disabled, but failed to disarm %d out of %d probes\n",
2535 errors, total);
2536 else
2537 pr_info("Kprobes globally disabled\n");
2538
2539 mutex_unlock(&kprobe_mutex);
2540
2541
2542 wait_for_kprobe_optimizer();
2543
2544 return ret;
2545}
2546
2547
2548
2549
2550
2551
2552static ssize_t read_enabled_file_bool(struct file *file,
2553 char __user *user_buf, size_t count, loff_t *ppos)
2554{
2555 char buf[3];
2556
2557 if (!kprobes_all_disarmed)
2558 buf[0] = '1';
2559 else
2560 buf[0] = '0';
2561 buf[1] = '\n';
2562 buf[2] = 0x00;
2563 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
2564}
2565
2566static ssize_t write_enabled_file_bool(struct file *file,
2567 const char __user *user_buf, size_t count, loff_t *ppos)
2568{
2569 char buf[32];
2570 size_t buf_size;
2571 int ret = 0;
2572
2573 buf_size = min(count, (sizeof(buf)-1));
2574 if (copy_from_user(buf, user_buf, buf_size))
2575 return -EFAULT;
2576
2577 buf[buf_size] = '\0';
2578 switch (buf[0]) {
2579 case 'y':
2580 case 'Y':
2581 case '1':
2582 ret = arm_all_kprobes();
2583 break;
2584 case 'n':
2585 case 'N':
2586 case '0':
2587 ret = disarm_all_kprobes();
2588 break;
2589 default:
2590 return -EINVAL;
2591 }
2592
2593 if (ret)
2594 return ret;
2595
2596 return count;
2597}
2598
2599static const struct file_operations fops_kp = {
2600 .read = read_enabled_file_bool,
2601 .write = write_enabled_file_bool,
2602 .llseek = default_llseek,
2603};
2604
2605static int __init debugfs_kprobe_init(void)
2606{
2607 struct dentry *dir, *file;
2608 unsigned int value = 1;
2609
2610 dir = debugfs_create_dir("kprobes", NULL);
2611 if (!dir)
2612 return -ENOMEM;
2613
2614 file = debugfs_create_file("list", 0444, dir, NULL,
2615 &debugfs_kprobes_operations);
2616 if (!file)
2617 goto error;
2618
2619 file = debugfs_create_file("enabled", 0600, dir,
2620 &value, &fops_kp);
2621 if (!file)
2622 goto error;
2623
2624 file = debugfs_create_file("blacklist", 0444, dir, NULL,
2625 &debugfs_kprobe_blacklist_ops);
2626 if (!file)
2627 goto error;
2628
2629 return 0;
2630
2631error:
2632 debugfs_remove(dir);
2633 return -ENOMEM;
2634}
2635
2636late_initcall(debugfs_kprobe_init);
2637#endif
2638
2639module_init(init_kprobes);
2640
2641
2642EXPORT_SYMBOL_GPL(jprobe_return);
2643