diff options
Diffstat (limited to 'kernel/kprobes.c')
-rw-r--r-- | kernel/kprobes.c | 461 |
1 files changed, 410 insertions, 51 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 78105623d739..612af2d61614 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c | |||
@@ -45,6 +45,7 @@ | |||
45 | #include <linux/kdebug.h> | 45 | #include <linux/kdebug.h> |
46 | #include <linux/memory.h> | 46 | #include <linux/memory.h> |
47 | #include <linux/ftrace.h> | 47 | #include <linux/ftrace.h> |
48 | #include <linux/cpu.h> | ||
48 | 49 | ||
49 | #include <asm-generic/sections.h> | 50 | #include <asm-generic/sections.h> |
50 | #include <asm/cacheflush.h> | 51 | #include <asm/cacheflush.h> |
@@ -280,6 +281,33 @@ void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) | |||
280 | __free_insn_slot(&kprobe_insn_slots, slot, dirty); | 281 | __free_insn_slot(&kprobe_insn_slots, slot, dirty); |
281 | mutex_unlock(&kprobe_insn_mutex); | 282 | mutex_unlock(&kprobe_insn_mutex); |
282 | } | 283 | } |
284 | #ifdef CONFIG_OPTPROBES | ||
285 | /* For optimized_kprobe buffer */ | ||
286 | static DEFINE_MUTEX(kprobe_optinsn_mutex); /* Protects kprobe_optinsn_slots */ | ||
287 | static struct kprobe_insn_cache kprobe_optinsn_slots = { | ||
288 | .pages = LIST_HEAD_INIT(kprobe_optinsn_slots.pages), | ||
289 | /* .insn_size is initialized later */ | ||
290 | .nr_garbage = 0, | ||
291 | }; | ||
292 | /* Get a slot for optimized_kprobe buffer */ | ||
293 | kprobe_opcode_t __kprobes *get_optinsn_slot(void) | ||
294 | { | ||
295 | kprobe_opcode_t *ret = NULL; | ||
296 | |||
297 | mutex_lock(&kprobe_optinsn_mutex); | ||
298 | ret = __get_insn_slot(&kprobe_optinsn_slots); | ||
299 | mutex_unlock(&kprobe_optinsn_mutex); | ||
300 | |||
301 | return ret; | ||
302 | } | ||
303 | |||
304 | void __kprobes free_optinsn_slot(kprobe_opcode_t * slot, int dirty) | ||
305 | { | ||
306 | mutex_lock(&kprobe_optinsn_mutex); | ||
307 | __free_insn_slot(&kprobe_optinsn_slots, slot, dirty); | ||
308 | mutex_unlock(&kprobe_optinsn_mutex); | ||
309 | } | ||
310 | #endif | ||
283 | #endif | 311 | #endif |
284 | 312 | ||
285 | /* We have preemption disabled.. so it is safe to use __ versions */ | 313 | /* We have preemption disabled.. so it is safe to use __ versions */ |
@@ -310,23 +338,324 @@ struct kprobe __kprobes *get_kprobe(void *addr) | |||
310 | if (p->addr == addr) | 338 | if (p->addr == addr) |
311 | return p; | 339 | return p; |
312 | } | 340 | } |
341 | |||
313 | return NULL; | 342 | return NULL; |
314 | } | 343 | } |
315 | 344 | ||
345 | static int __kprobes aggr_pre_handler(struct kprobe *p, struct pt_regs *regs); | ||
346 | |||
347 | /* Return true if the kprobe is an aggregator */ | ||
348 | static inline int kprobe_aggrprobe(struct kprobe *p) | ||
349 | { | ||
350 | return p->pre_handler == aggr_pre_handler; | ||
351 | } | ||
352 | |||
353 | /* | ||
354 | * Keep all fields in the kprobe consistent | ||
355 | */ | ||
356 | static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p) | ||
357 | { | ||
358 | memcpy(&p->opcode, &old_p->opcode, sizeof(kprobe_opcode_t)); | ||
359 | memcpy(&p->ainsn, &old_p->ainsn, sizeof(struct arch_specific_insn)); | ||
360 | } | ||
361 | |||
362 | #ifdef CONFIG_OPTPROBES | ||
363 | /* | ||
364 | * Call all pre_handler on the list, but ignores its return value. | ||
365 | * This must be called from arch-dep optimized caller. | ||
366 | */ | ||
367 | void __kprobes opt_pre_handler(struct kprobe *p, struct pt_regs *regs) | ||
368 | { | ||
369 | struct kprobe *kp; | ||
370 | |||
371 | list_for_each_entry_rcu(kp, &p->list, list) { | ||
372 | if (kp->pre_handler && likely(!kprobe_disabled(kp))) { | ||
373 | set_kprobe_instance(kp); | ||
374 | kp->pre_handler(kp, regs); | ||
375 | } | ||
376 | reset_kprobe_instance(); | ||
377 | } | ||
378 | } | ||
379 | |||
380 | /* Return true(!0) if the kprobe is ready for optimization. */ | ||
381 | static inline int kprobe_optready(struct kprobe *p) | ||
382 | { | ||
383 | struct optimized_kprobe *op; | ||
384 | |||
385 | if (kprobe_aggrprobe(p)) { | ||
386 | op = container_of(p, struct optimized_kprobe, kp); | ||
387 | return arch_prepared_optinsn(&op->optinsn); | ||
388 | } | ||
389 | |||
390 | return 0; | ||
391 | } | ||
392 | |||
393 | /* | ||
394 | * Return an optimized kprobe whose optimizing code replaces | ||
395 | * instructions including addr (exclude breakpoint). | ||
396 | */ | ||
397 | struct kprobe *__kprobes get_optimized_kprobe(unsigned long addr) | ||
398 | { | ||
399 | int i; | ||
400 | struct kprobe *p = NULL; | ||
401 | struct optimized_kprobe *op; | ||
402 | |||
403 | /* Don't check i == 0, since that is a breakpoint case. */ | ||
404 | for (i = 1; !p && i < MAX_OPTIMIZED_LENGTH; i++) | ||
405 | p = get_kprobe((void *)(addr - i)); | ||
406 | |||
407 | if (p && kprobe_optready(p)) { | ||
408 | op = container_of(p, struct optimized_kprobe, kp); | ||
409 | if (arch_within_optimized_kprobe(op, addr)) | ||
410 | return p; | ||
411 | } | ||
412 | |||
413 | return NULL; | ||
414 | } | ||
415 | |||
416 | /* Optimization staging list, protected by kprobe_mutex */ | ||
417 | static LIST_HEAD(optimizing_list); | ||
418 | |||
419 | static void kprobe_optimizer(struct work_struct *work); | ||
420 | static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer); | ||
421 | #define OPTIMIZE_DELAY 5 | ||
422 | |||
423 | /* Kprobe jump optimizer */ | ||
424 | static __kprobes void kprobe_optimizer(struct work_struct *work) | ||
425 | { | ||
426 | struct optimized_kprobe *op, *tmp; | ||
427 | |||
428 | /* Lock modules while optimizing kprobes */ | ||
429 | mutex_lock(&module_mutex); | ||
430 | mutex_lock(&kprobe_mutex); | ||
431 | if (kprobes_all_disarmed) | ||
432 | goto end; | ||
433 | |||
434 | /* | ||
435 | * Wait for quiesence period to ensure all running interrupts | ||
436 | * are done. Because optprobe may modify multiple instructions | ||
437 | * there is a chance that Nth instruction is interrupted. In that | ||
438 | * case, running interrupt can return to 2nd-Nth byte of jump | ||
439 | * instruction. This wait is for avoiding it. | ||
440 | */ | ||
441 | synchronize_sched(); | ||
442 | |||
443 | /* | ||
444 | * The optimization/unoptimization refers online_cpus via | ||
445 | * stop_machine() and cpu-hotplug modifies online_cpus. | ||
446 | * And same time, text_mutex will be held in cpu-hotplug and here. | ||
447 | * This combination can cause a deadlock (cpu-hotplug try to lock | ||
448 | * text_mutex but stop_machine can not be done because online_cpus | ||
449 | * has been changed) | ||
450 | * To avoid this deadlock, we need to call get_online_cpus() | ||
451 | * for preventing cpu-hotplug outside of text_mutex locking. | ||
452 | */ | ||
453 | get_online_cpus(); | ||
454 | mutex_lock(&text_mutex); | ||
455 | list_for_each_entry_safe(op, tmp, &optimizing_list, list) { | ||
456 | WARN_ON(kprobe_disabled(&op->kp)); | ||
457 | if (arch_optimize_kprobe(op) < 0) | ||
458 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; | ||
459 | list_del_init(&op->list); | ||
460 | } | ||
461 | mutex_unlock(&text_mutex); | ||
462 | put_online_cpus(); | ||
463 | end: | ||
464 | mutex_unlock(&kprobe_mutex); | ||
465 | mutex_unlock(&module_mutex); | ||
466 | } | ||
467 | |||
468 | /* Optimize kprobe if p is ready to be optimized */ | ||
469 | static __kprobes void optimize_kprobe(struct kprobe *p) | ||
470 | { | ||
471 | struct optimized_kprobe *op; | ||
472 | |||
473 | /* Check if the kprobe is disabled or not ready for optimization. */ | ||
474 | if (!kprobe_optready(p) || | ||
475 | (kprobe_disabled(p) || kprobes_all_disarmed)) | ||
476 | return; | ||
477 | |||
478 | /* Both of break_handler and post_handler are not supported. */ | ||
479 | if (p->break_handler || p->post_handler) | ||
480 | return; | ||
481 | |||
482 | op = container_of(p, struct optimized_kprobe, kp); | ||
483 | |||
484 | /* Check there is no other kprobes at the optimized instructions */ | ||
485 | if (arch_check_optimized_kprobe(op) < 0) | ||
486 | return; | ||
487 | |||
488 | /* Check if it is already optimized. */ | ||
489 | if (op->kp.flags & KPROBE_FLAG_OPTIMIZED) | ||
490 | return; | ||
491 | |||
492 | op->kp.flags |= KPROBE_FLAG_OPTIMIZED; | ||
493 | list_add(&op->list, &optimizing_list); | ||
494 | if (!delayed_work_pending(&optimizing_work)) | ||
495 | schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY); | ||
496 | } | ||
497 | |||
498 | /* Unoptimize a kprobe if p is optimized */ | ||
499 | static __kprobes void unoptimize_kprobe(struct kprobe *p) | ||
500 | { | ||
501 | struct optimized_kprobe *op; | ||
502 | |||
503 | if ((p->flags & KPROBE_FLAG_OPTIMIZED) && kprobe_aggrprobe(p)) { | ||
504 | op = container_of(p, struct optimized_kprobe, kp); | ||
505 | if (!list_empty(&op->list)) | ||
506 | /* Dequeue from the optimization queue */ | ||
507 | list_del_init(&op->list); | ||
508 | else | ||
509 | /* Replace jump with break */ | ||
510 | arch_unoptimize_kprobe(op); | ||
511 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; | ||
512 | } | ||
513 | } | ||
514 | |||
515 | /* Remove optimized instructions */ | ||
516 | static void __kprobes kill_optimized_kprobe(struct kprobe *p) | ||
517 | { | ||
518 | struct optimized_kprobe *op; | ||
519 | |||
520 | op = container_of(p, struct optimized_kprobe, kp); | ||
521 | if (!list_empty(&op->list)) { | ||
522 | /* Dequeue from the optimization queue */ | ||
523 | list_del_init(&op->list); | ||
524 | op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED; | ||
525 | } | ||
526 | /* Don't unoptimize, because the target code will be freed. */ | ||
527 | arch_remove_optimized_kprobe(op); | ||
528 | } | ||
529 | |||
530 | /* Try to prepare optimized instructions */ | ||
531 | static __kprobes void prepare_optimized_kprobe(struct kprobe *p) | ||
532 | { | ||
533 | struct optimized_kprobe *op; | ||
534 | |||
535 | op = container_of(p, struct optimized_kprobe, kp); | ||
536 | arch_prepare_optimized_kprobe(op); | ||
537 | } | ||
538 | |||
539 | /* Free optimized instructions and optimized_kprobe */ | ||
540 | static __kprobes void free_aggr_kprobe(struct kprobe *p) | ||
541 | { | ||
542 | struct optimized_kprobe *op; | ||
543 | |||
544 | op = container_of(p, struct optimized_kprobe, kp); | ||
545 | arch_remove_optimized_kprobe(op); | ||
546 | kfree(op); | ||
547 | } | ||
548 | |||
549 | /* Allocate new optimized_kprobe and try to prepare optimized instructions */ | ||
550 | static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p) | ||
551 | { | ||
552 | struct optimized_kprobe *op; | ||
553 | |||
554 | op = kzalloc(sizeof(struct optimized_kprobe), GFP_KERNEL); | ||
555 | if (!op) | ||
556 | return NULL; | ||
557 | |||
558 | INIT_LIST_HEAD(&op->list); | ||
559 | op->kp.addr = p->addr; | ||
560 | arch_prepare_optimized_kprobe(op); | ||
561 | |||
562 | return &op->kp; | ||
563 | } | ||
564 | |||
565 | static void __kprobes init_aggr_kprobe(struct kprobe *ap, struct kprobe *p); | ||
566 | |||
567 | /* | ||
568 | * Prepare an optimized_kprobe and optimize it | ||
569 | * NOTE: p must be a normal registered kprobe | ||
570 | */ | ||
571 | static __kprobes void try_to_optimize_kprobe(struct kprobe *p) | ||
572 | { | ||
573 | struct kprobe *ap; | ||
574 | struct optimized_kprobe *op; | ||
575 | |||
576 | ap = alloc_aggr_kprobe(p); | ||
577 | if (!ap) | ||
578 | return; | ||
579 | |||
580 | op = container_of(ap, struct optimized_kprobe, kp); | ||
581 | if (!arch_prepared_optinsn(&op->optinsn)) { | ||
582 | /* If failed to setup optimizing, fallback to kprobe */ | ||
583 | free_aggr_kprobe(ap); | ||
584 | return; | ||
585 | } | ||
586 | |||
587 | init_aggr_kprobe(ap, p); | ||
588 | optimize_kprobe(ap); | ||
589 | } | ||
590 | |||
591 | static void __kprobes __arm_kprobe(struct kprobe *p) | ||
592 | { | ||
593 | struct kprobe *old_p; | ||
594 | |||
595 | /* Check collision with other optimized kprobes */ | ||
596 | old_p = get_optimized_kprobe((unsigned long)p->addr); | ||
597 | if (unlikely(old_p)) | ||
598 | unoptimize_kprobe(old_p); /* Fallback to unoptimized kprobe */ | ||
599 | |||
600 | arch_arm_kprobe(p); | ||
601 | optimize_kprobe(p); /* Try to optimize (add kprobe to a list) */ | ||
602 | } | ||
603 | |||
604 | static void __kprobes __disarm_kprobe(struct kprobe *p) | ||
605 | { | ||
606 | struct kprobe *old_p; | ||
607 | |||
608 | unoptimize_kprobe(p); /* Try to unoptimize */ | ||
609 | arch_disarm_kprobe(p); | ||
610 | |||
611 | /* If another kprobe was blocked, optimize it. */ | ||
612 | old_p = get_optimized_kprobe((unsigned long)p->addr); | ||
613 | if (unlikely(old_p)) | ||
614 | optimize_kprobe(old_p); | ||
615 | } | ||
616 | |||
617 | #else /* !CONFIG_OPTPROBES */ | ||
618 | |||
619 | #define optimize_kprobe(p) do {} while (0) | ||
620 | #define unoptimize_kprobe(p) do {} while (0) | ||
621 | #define kill_optimized_kprobe(p) do {} while (0) | ||
622 | #define prepare_optimized_kprobe(p) do {} while (0) | ||
623 | #define try_to_optimize_kprobe(p) do {} while (0) | ||
624 | #define __arm_kprobe(p) arch_arm_kprobe(p) | ||
625 | #define __disarm_kprobe(p) arch_disarm_kprobe(p) | ||
626 | |||
627 | static __kprobes void free_aggr_kprobe(struct kprobe *p) | ||
628 | { | ||
629 | kfree(p); | ||
630 | } | ||
631 | |||
632 | static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p) | ||
633 | { | ||
634 | return kzalloc(sizeof(struct kprobe), GFP_KERNEL); | ||
635 | } | ||
636 | #endif /* CONFIG_OPTPROBES */ | ||
637 | |||
316 | /* Arm a kprobe with text_mutex */ | 638 | /* Arm a kprobe with text_mutex */ |
317 | static void __kprobes arm_kprobe(struct kprobe *kp) | 639 | static void __kprobes arm_kprobe(struct kprobe *kp) |
318 | { | 640 | { |
641 | /* | ||
642 | * Here, since __arm_kprobe() doesn't use stop_machine(), | ||
643 | * this doesn't cause deadlock on text_mutex. So, we don't | ||
644 | * need get_online_cpus(). | ||
645 | */ | ||
319 | mutex_lock(&text_mutex); | 646 | mutex_lock(&text_mutex); |
320 | arch_arm_kprobe(kp); | 647 | __arm_kprobe(kp); |
321 | mutex_unlock(&text_mutex); | 648 | mutex_unlock(&text_mutex); |
322 | } | 649 | } |
323 | 650 | ||
324 | /* Disarm a kprobe with text_mutex */ | 651 | /* Disarm a kprobe with text_mutex */ |
325 | static void __kprobes disarm_kprobe(struct kprobe *kp) | 652 | static void __kprobes disarm_kprobe(struct kprobe *kp) |
326 | { | 653 | { |
654 | get_online_cpus(); /* For avoiding text_mutex deadlock */ | ||
327 | mutex_lock(&text_mutex); | 655 | mutex_lock(&text_mutex); |
328 | arch_disarm_kprobe(kp); | 656 | __disarm_kprobe(kp); |
329 | mutex_unlock(&text_mutex); | 657 | mutex_unlock(&text_mutex); |
658 | put_online_cpus(); | ||
330 | } | 659 | } |
331 | 660 | ||
332 | /* | 661 | /* |
@@ -395,7 +724,7 @@ static int __kprobes aggr_break_handler(struct kprobe *p, struct pt_regs *regs) | |||
395 | void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) | 724 | void __kprobes kprobes_inc_nmissed_count(struct kprobe *p) |
396 | { | 725 | { |
397 | struct kprobe *kp; | 726 | struct kprobe *kp; |
398 | if (p->pre_handler != aggr_pre_handler) { | 727 | if (!kprobe_aggrprobe(p)) { |
399 | p->nmissed++; | 728 | p->nmissed++; |
400 | } else { | 729 | } else { |
401 | list_for_each_entry_rcu(kp, &p->list, list) | 730 | list_for_each_entry_rcu(kp, &p->list, list) |
@@ -519,21 +848,16 @@ static void __kprobes cleanup_rp_inst(struct kretprobe *rp) | |||
519 | } | 848 | } |
520 | 849 | ||
521 | /* | 850 | /* |
522 | * Keep all fields in the kprobe consistent | ||
523 | */ | ||
524 | static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p) | ||
525 | { | ||
526 | memcpy(&p->opcode, &old_p->opcode, sizeof(kprobe_opcode_t)); | ||
527 | memcpy(&p->ainsn, &old_p->ainsn, sizeof(struct arch_specific_insn)); | ||
528 | } | ||
529 | |||
530 | /* | ||
531 | * Add the new probe to ap->list. Fail if this is the | 851 | * Add the new probe to ap->list. Fail if this is the |
532 | * second jprobe at the address - two jprobes can't coexist | 852 | * second jprobe at the address - two jprobes can't coexist |
533 | */ | 853 | */ |
534 | static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p) | 854 | static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p) |
535 | { | 855 | { |
536 | BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); | 856 | BUG_ON(kprobe_gone(ap) || kprobe_gone(p)); |
857 | |||
858 | if (p->break_handler || p->post_handler) | ||
859 | unoptimize_kprobe(ap); /* Fall back to normal kprobe */ | ||
860 | |||
537 | if (p->break_handler) { | 861 | if (p->break_handler) { |
538 | if (ap->break_handler) | 862 | if (ap->break_handler) |
539 | return -EEXIST; | 863 | return -EEXIST; |
@@ -548,7 +872,7 @@ static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p) | |||
548 | ap->flags &= ~KPROBE_FLAG_DISABLED; | 872 | ap->flags &= ~KPROBE_FLAG_DISABLED; |
549 | if (!kprobes_all_disarmed) | 873 | if (!kprobes_all_disarmed) |
550 | /* Arm the breakpoint again. */ | 874 | /* Arm the breakpoint again. */ |
551 | arm_kprobe(ap); | 875 | __arm_kprobe(ap); |
552 | } | 876 | } |
553 | return 0; | 877 | return 0; |
554 | } | 878 | } |
@@ -557,12 +881,13 @@ static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p) | |||
557 | * Fill in the required fields of the "manager kprobe". Replace the | 881 | * Fill in the required fields of the "manager kprobe". Replace the |
558 | * earlier kprobe in the hlist with the manager kprobe | 882 | * earlier kprobe in the hlist with the manager kprobe |
559 | */ | 883 | */ |
560 | static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p) | 884 | static void __kprobes init_aggr_kprobe(struct kprobe *ap, struct kprobe *p) |
561 | { | 885 | { |
886 | /* Copy p's insn slot to ap */ | ||
562 | copy_kprobe(p, ap); | 887 | copy_kprobe(p, ap); |
563 | flush_insn_slot(ap); | 888 | flush_insn_slot(ap); |
564 | ap->addr = p->addr; | 889 | ap->addr = p->addr; |
565 | ap->flags = p->flags; | 890 | ap->flags = p->flags & ~KPROBE_FLAG_OPTIMIZED; |
566 | ap->pre_handler = aggr_pre_handler; | 891 | ap->pre_handler = aggr_pre_handler; |
567 | ap->fault_handler = aggr_fault_handler; | 892 | ap->fault_handler = aggr_fault_handler; |
568 | /* We don't care the kprobe which has gone. */ | 893 | /* We don't care the kprobe which has gone. */ |
@@ -572,8 +897,9 @@ static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p) | |||
572 | ap->break_handler = aggr_break_handler; | 897 | ap->break_handler = aggr_break_handler; |
573 | 898 | ||
574 | INIT_LIST_HEAD(&ap->list); | 899 | INIT_LIST_HEAD(&ap->list); |
575 | list_add_rcu(&p->list, &ap->list); | 900 | INIT_HLIST_NODE(&ap->hlist); |
576 | 901 | ||
902 | list_add_rcu(&p->list, &ap->list); | ||
577 | hlist_replace_rcu(&p->hlist, &ap->hlist); | 903 | hlist_replace_rcu(&p->hlist, &ap->hlist); |
578 | } | 904 | } |
579 | 905 | ||
@@ -587,12 +913,12 @@ static int __kprobes register_aggr_kprobe(struct kprobe *old_p, | |||
587 | int ret = 0; | 913 | int ret = 0; |
588 | struct kprobe *ap = old_p; | 914 | struct kprobe *ap = old_p; |
589 | 915 | ||
590 | if (old_p->pre_handler != aggr_pre_handler) { | 916 | if (!kprobe_aggrprobe(old_p)) { |
591 | /* If old_p is not an aggr_probe, create new aggr_kprobe. */ | 917 | /* If old_p is not an aggr_kprobe, create new aggr_kprobe. */ |
592 | ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL); | 918 | ap = alloc_aggr_kprobe(old_p); |
593 | if (!ap) | 919 | if (!ap) |
594 | return -ENOMEM; | 920 | return -ENOMEM; |
595 | add_aggr_kprobe(ap, old_p); | 921 | init_aggr_kprobe(ap, old_p); |
596 | } | 922 | } |
597 | 923 | ||
598 | if (kprobe_gone(ap)) { | 924 | if (kprobe_gone(ap)) { |
@@ -611,6 +937,9 @@ static int __kprobes register_aggr_kprobe(struct kprobe *old_p, | |||
611 | */ | 937 | */ |
612 | return ret; | 938 | return ret; |
613 | 939 | ||
940 | /* Prepare optimized instructions if possible. */ | ||
941 | prepare_optimized_kprobe(ap); | ||
942 | |||
614 | /* | 943 | /* |
615 | * Clear gone flag to prevent allocating new slot again, and | 944 | * Clear gone flag to prevent allocating new slot again, and |
616 | * set disabled flag because it is not armed yet. | 945 | * set disabled flag because it is not armed yet. |
@@ -619,6 +948,7 @@ static int __kprobes register_aggr_kprobe(struct kprobe *old_p, | |||
619 | | KPROBE_FLAG_DISABLED; | 948 | | KPROBE_FLAG_DISABLED; |
620 | } | 949 | } |
621 | 950 | ||
951 | /* Copy ap's insn slot to p */ | ||
622 | copy_kprobe(ap, p); | 952 | copy_kprobe(ap, p); |
623 | return add_new_kprobe(ap, p); | 953 | return add_new_kprobe(ap, p); |
624 | } | 954 | } |
@@ -769,27 +1099,34 @@ int __kprobes register_kprobe(struct kprobe *p) | |||
769 | p->nmissed = 0; | 1099 | p->nmissed = 0; |
770 | INIT_LIST_HEAD(&p->list); | 1100 | INIT_LIST_HEAD(&p->list); |
771 | mutex_lock(&kprobe_mutex); | 1101 | mutex_lock(&kprobe_mutex); |
1102 | |||
1103 | get_online_cpus(); /* For avoiding text_mutex deadlock. */ | ||
1104 | mutex_lock(&text_mutex); | ||
1105 | |||
772 | old_p = get_kprobe(p->addr); | 1106 | old_p = get_kprobe(p->addr); |
773 | if (old_p) { | 1107 | if (old_p) { |
1108 | /* Since this may unoptimize old_p, locking text_mutex. */ | ||
774 | ret = register_aggr_kprobe(old_p, p); | 1109 | ret = register_aggr_kprobe(old_p, p); |
775 | goto out; | 1110 | goto out; |
776 | } | 1111 | } |
777 | 1112 | ||
778 | mutex_lock(&text_mutex); | ||
779 | ret = arch_prepare_kprobe(p); | 1113 | ret = arch_prepare_kprobe(p); |
780 | if (ret) | 1114 | if (ret) |
781 | goto out_unlock_text; | 1115 | goto out; |
782 | 1116 | ||
783 | INIT_HLIST_NODE(&p->hlist); | 1117 | INIT_HLIST_NODE(&p->hlist); |
784 | hlist_add_head_rcu(&p->hlist, | 1118 | hlist_add_head_rcu(&p->hlist, |
785 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); | 1119 | &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); |
786 | 1120 | ||
787 | if (!kprobes_all_disarmed && !kprobe_disabled(p)) | 1121 | if (!kprobes_all_disarmed && !kprobe_disabled(p)) |
788 | arch_arm_kprobe(p); | 1122 | __arm_kprobe(p); |
1123 | |||
1124 | /* Try to optimize kprobe */ | ||
1125 | try_to_optimize_kprobe(p); | ||
789 | 1126 | ||
790 | out_unlock_text: | ||
791 | mutex_unlock(&text_mutex); | ||
792 | out: | 1127 | out: |
1128 | mutex_unlock(&text_mutex); | ||
1129 | put_online_cpus(); | ||
793 | mutex_unlock(&kprobe_mutex); | 1130 | mutex_unlock(&kprobe_mutex); |
794 | 1131 | ||
795 | if (probed_mod) | 1132 | if (probed_mod) |
@@ -811,7 +1148,7 @@ static int __kprobes __unregister_kprobe_top(struct kprobe *p) | |||
811 | return -EINVAL; | 1148 | return -EINVAL; |
812 | 1149 | ||
813 | if (old_p == p || | 1150 | if (old_p == p || |
814 | (old_p->pre_handler == aggr_pre_handler && | 1151 | (kprobe_aggrprobe(old_p) && |
815 | list_is_singular(&old_p->list))) { | 1152 | list_is_singular(&old_p->list))) { |
816 | /* | 1153 | /* |
817 | * Only probe on the hash list. Disarm only if kprobes are | 1154 | * Only probe on the hash list. Disarm only if kprobes are |
@@ -819,7 +1156,7 @@ static int __kprobes __unregister_kprobe_top(struct kprobe *p) | |||
819 | * already have been removed. We save on flushing icache. | 1156 | * already have been removed. We save on flushing icache. |
820 | */ | 1157 | */ |
821 | if (!kprobes_all_disarmed && !kprobe_disabled(old_p)) | 1158 | if (!kprobes_all_disarmed && !kprobe_disabled(old_p)) |
822 | disarm_kprobe(p); | 1159 | disarm_kprobe(old_p); |
823 | hlist_del_rcu(&old_p->hlist); | 1160 | hlist_del_rcu(&old_p->hlist); |
824 | } else { | 1161 | } else { |
825 | if (p->break_handler && !kprobe_gone(p)) | 1162 | if (p->break_handler && !kprobe_gone(p)) |
@@ -835,8 +1172,13 @@ noclean: | |||
835 | list_del_rcu(&p->list); | 1172 | list_del_rcu(&p->list); |
836 | if (!kprobe_disabled(old_p)) { | 1173 | if (!kprobe_disabled(old_p)) { |
837 | try_to_disable_aggr_kprobe(old_p); | 1174 | try_to_disable_aggr_kprobe(old_p); |
838 | if (!kprobes_all_disarmed && kprobe_disabled(old_p)) | 1175 | if (!kprobes_all_disarmed) { |
839 | disarm_kprobe(old_p); | 1176 | if (kprobe_disabled(old_p)) |
1177 | disarm_kprobe(old_p); | ||
1178 | else | ||
1179 | /* Try to optimize this probe again */ | ||
1180 | optimize_kprobe(old_p); | ||
1181 | } | ||
840 | } | 1182 | } |
841 | } | 1183 | } |
842 | return 0; | 1184 | return 0; |
@@ -853,7 +1195,7 @@ static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) | |||
853 | old_p = list_entry(p->list.next, struct kprobe, list); | 1195 | old_p = list_entry(p->list.next, struct kprobe, list); |
854 | list_del(&p->list); | 1196 | list_del(&p->list); |
855 | arch_remove_kprobe(old_p); | 1197 | arch_remove_kprobe(old_p); |
856 | kfree(old_p); | 1198 | free_aggr_kprobe(old_p); |
857 | } | 1199 | } |
858 | } | 1200 | } |
859 | 1201 | ||
@@ -1149,7 +1491,7 @@ static void __kprobes kill_kprobe(struct kprobe *p) | |||
1149 | struct kprobe *kp; | 1491 | struct kprobe *kp; |
1150 | 1492 | ||
1151 | p->flags |= KPROBE_FLAG_GONE; | 1493 | p->flags |= KPROBE_FLAG_GONE; |
1152 | if (p->pre_handler == aggr_pre_handler) { | 1494 | if (kprobe_aggrprobe(p)) { |
1153 | /* | 1495 | /* |
1154 | * If this is an aggr_kprobe, we have to list all the | 1496 | * If this is an aggr_kprobe, we have to list all the |
1155 | * chained probes and mark them GONE. | 1497 | * chained probes and mark them GONE. |
@@ -1158,6 +1500,7 @@ static void __kprobes kill_kprobe(struct kprobe *p) | |||
1158 | kp->flags |= KPROBE_FLAG_GONE; | 1500 | kp->flags |= KPROBE_FLAG_GONE; |
1159 | p->post_handler = NULL; | 1501 | p->post_handler = NULL; |
1160 | p->break_handler = NULL; | 1502 | p->break_handler = NULL; |
1503 | kill_optimized_kprobe(p); | ||
1161 | } | 1504 | } |
1162 | /* | 1505 | /* |
1163 | * Here, we can remove insn_slot safely, because no thread calls | 1506 | * Here, we can remove insn_slot safely, because no thread calls |
@@ -1267,6 +1610,11 @@ static int __init init_kprobes(void) | |||
1267 | } | 1610 | } |
1268 | } | 1611 | } |
1269 | 1612 | ||
1613 | #if defined(CONFIG_OPTPROBES) && defined(__ARCH_WANT_KPROBES_INSN_SLOT) | ||
1614 | /* Init kprobe_optinsn_slots */ | ||
1615 | kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; | ||
1616 | #endif | ||
1617 | |||
1270 | /* By default, kprobes are armed */ | 1618 | /* By default, kprobes are armed */ |
1271 | kprobes_all_disarmed = false; | 1619 | kprobes_all_disarmed = false; |
1272 | 1620 | ||
@@ -1285,7 +1633,7 @@ static int __init init_kprobes(void) | |||
1285 | 1633 | ||
1286 | #ifdef CONFIG_DEBUG_FS | 1634 | #ifdef CONFIG_DEBUG_FS |
1287 | static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p, | 1635 | static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p, |
1288 | const char *sym, int offset,char *modname) | 1636 | const char *sym, int offset, char *modname, struct kprobe *pp) |
1289 | { | 1637 | { |
1290 | char *kprobe_type; | 1638 | char *kprobe_type; |
1291 | 1639 | ||
@@ -1295,19 +1643,21 @@ static void __kprobes report_probe(struct seq_file *pi, struct kprobe *p, | |||
1295 | kprobe_type = "j"; | 1643 | kprobe_type = "j"; |
1296 | else | 1644 | else |
1297 | kprobe_type = "k"; | 1645 | kprobe_type = "k"; |
1646 | |||
1298 | if (sym) | 1647 | if (sym) |
1299 | seq_printf(pi, "%p %s %s+0x%x %s %s%s\n", | 1648 | seq_printf(pi, "%p %s %s+0x%x %s ", |
1300 | p->addr, kprobe_type, sym, offset, | 1649 | p->addr, kprobe_type, sym, offset, |
1301 | (modname ? modname : " "), | 1650 | (modname ? modname : " ")); |
1302 | (kprobe_gone(p) ? "[GONE]" : ""), | ||
1303 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? | ||
1304 | "[DISABLED]" : "")); | ||
1305 | else | 1651 | else |
1306 | seq_printf(pi, "%p %s %p %s%s\n", | 1652 | seq_printf(pi, "%p %s %p ", |
1307 | p->addr, kprobe_type, p->addr, | 1653 | p->addr, kprobe_type, p->addr); |
1308 | (kprobe_gone(p) ? "[GONE]" : ""), | 1654 | |
1309 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? | 1655 | if (!pp) |
1310 | "[DISABLED]" : "")); | 1656 | pp = p; |
1657 | seq_printf(pi, "%s%s%s\n", | ||
1658 | (kprobe_gone(p) ? "[GONE]" : ""), | ||
1659 | ((kprobe_disabled(p) && !kprobe_gone(p)) ? "[DISABLED]" : ""), | ||
1660 | (kprobe_optimized(pp) ? "[OPTIMIZED]" : "")); | ||
1311 | } | 1661 | } |
1312 | 1662 | ||
1313 | static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos) | 1663 | static void __kprobes *kprobe_seq_start(struct seq_file *f, loff_t *pos) |
@@ -1343,11 +1693,11 @@ static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) | |||
1343 | hlist_for_each_entry_rcu(p, node, head, hlist) { | 1693 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
1344 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, | 1694 | sym = kallsyms_lookup((unsigned long)p->addr, NULL, |
1345 | &offset, &modname, namebuf); | 1695 | &offset, &modname, namebuf); |
1346 | if (p->pre_handler == aggr_pre_handler) { | 1696 | if (kprobe_aggrprobe(p)) { |
1347 | list_for_each_entry_rcu(kp, &p->list, list) | 1697 | list_for_each_entry_rcu(kp, &p->list, list) |
1348 | report_probe(pi, kp, sym, offset, modname); | 1698 | report_probe(pi, kp, sym, offset, modname, p); |
1349 | } else | 1699 | } else |
1350 | report_probe(pi, p, sym, offset, modname); | 1700 | report_probe(pi, p, sym, offset, modname, NULL); |
1351 | } | 1701 | } |
1352 | preempt_enable(); | 1702 | preempt_enable(); |
1353 | return 0; | 1703 | return 0; |
@@ -1425,12 +1775,13 @@ int __kprobes enable_kprobe(struct kprobe *kp) | |||
1425 | goto out; | 1775 | goto out; |
1426 | } | 1776 | } |
1427 | 1777 | ||
1428 | if (!kprobes_all_disarmed && kprobe_disabled(p)) | ||
1429 | arm_kprobe(p); | ||
1430 | |||
1431 | p->flags &= ~KPROBE_FLAG_DISABLED; | ||
1432 | if (p != kp) | 1778 | if (p != kp) |
1433 | kp->flags &= ~KPROBE_FLAG_DISABLED; | 1779 | kp->flags &= ~KPROBE_FLAG_DISABLED; |
1780 | |||
1781 | if (!kprobes_all_disarmed && kprobe_disabled(p)) { | ||
1782 | p->flags &= ~KPROBE_FLAG_DISABLED; | ||
1783 | arm_kprobe(p); | ||
1784 | } | ||
1434 | out: | 1785 | out: |
1435 | mutex_unlock(&kprobe_mutex); | 1786 | mutex_unlock(&kprobe_mutex); |
1436 | return ret; | 1787 | return ret; |
@@ -1450,12 +1801,13 @@ static void __kprobes arm_all_kprobes(void) | |||
1450 | if (!kprobes_all_disarmed) | 1801 | if (!kprobes_all_disarmed) |
1451 | goto already_enabled; | 1802 | goto already_enabled; |
1452 | 1803 | ||
1804 | /* Arming kprobes doesn't optimize kprobe itself */ | ||
1453 | mutex_lock(&text_mutex); | 1805 | mutex_lock(&text_mutex); |
1454 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { | 1806 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
1455 | head = &kprobe_table[i]; | 1807 | head = &kprobe_table[i]; |
1456 | hlist_for_each_entry_rcu(p, node, head, hlist) | 1808 | hlist_for_each_entry_rcu(p, node, head, hlist) |
1457 | if (!kprobe_disabled(p)) | 1809 | if (!kprobe_disabled(p)) |
1458 | arch_arm_kprobe(p); | 1810 | __arm_kprobe(p); |
1459 | } | 1811 | } |
1460 | mutex_unlock(&text_mutex); | 1812 | mutex_unlock(&text_mutex); |
1461 | 1813 | ||
@@ -1482,16 +1834,23 @@ static void __kprobes disarm_all_kprobes(void) | |||
1482 | 1834 | ||
1483 | kprobes_all_disarmed = true; | 1835 | kprobes_all_disarmed = true; |
1484 | printk(KERN_INFO "Kprobes globally disabled\n"); | 1836 | printk(KERN_INFO "Kprobes globally disabled\n"); |
1837 | |||
1838 | /* | ||
1839 | * Here we call get_online_cpus() for avoiding text_mutex deadlock, | ||
1840 | * because disarming may also unoptimize kprobes. | ||
1841 | */ | ||
1842 | get_online_cpus(); | ||
1485 | mutex_lock(&text_mutex); | 1843 | mutex_lock(&text_mutex); |
1486 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { | 1844 | for (i = 0; i < KPROBE_TABLE_SIZE; i++) { |
1487 | head = &kprobe_table[i]; | 1845 | head = &kprobe_table[i]; |
1488 | hlist_for_each_entry_rcu(p, node, head, hlist) { | 1846 | hlist_for_each_entry_rcu(p, node, head, hlist) { |
1489 | if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) | 1847 | if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p)) |
1490 | arch_disarm_kprobe(p); | 1848 | __disarm_kprobe(p); |
1491 | } | 1849 | } |
1492 | } | 1850 | } |
1493 | 1851 | ||
1494 | mutex_unlock(&text_mutex); | 1852 | mutex_unlock(&text_mutex); |
1853 | put_online_cpus(); | ||
1495 | mutex_unlock(&kprobe_mutex); | 1854 | mutex_unlock(&kprobe_mutex); |
1496 | /* Allow all currently running kprobes to complete */ | 1855 | /* Allow all currently running kprobes to complete */ |
1497 | synchronize_sched(); | 1856 | synchronize_sched(); |