diff options
| -rw-r--r-- | kernel/kprobes.c | 128 |
1 files changed, 72 insertions, 56 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 8c3aa145220..ab99caf2b16 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1039,23 +1039,6 @@ static int __kprobes register_aggr_kprobe(struct kprobe *orig_p, return add_new_kprobe(ap, p); } -/* Try to disable aggr_kprobe, and return 1 if succeeded.*/ -static int __kprobes try_to_disable_aggr_kprobe(struct kprobe *p) -{ - struct kprobe *kp; - - list_for_each_entry_rcu(kp, &p->list, list) { - if (!kprobe_disabled(kp)) - /* - * There is an active probe on the list. - * We can't disable aggr_kprobe. - */ - return 0; - } - p->flags |= KPROBE_FLAG_DISABLED; - return 1; -} - static int __kprobes in_kprobes_functions(unsigned long addr) { struct kprobe_blackpoint *kb; @@ -1228,6 +1211,47 @@ fail_with_jump_label: } EXPORT_SYMBOL_GPL(register_kprobe); +/* Check if all probes on the aggrprobe are disabled */ +static int __kprobes aggr_kprobe_disabled(struct kprobe *ap) +{ + struct kprobe *kp; + + list_for_each_entry_rcu(kp, &ap->list, list) + if (!kprobe_disabled(kp)) + /* + * There is an active probe on the list. + * We can't disable this ap. + */ + return 0; + + return 1; +} + +/* Disable one kprobe: Make sure called under kprobe_mutex is locked */ +static struct kprobe *__kprobes __disable_kprobe(struct kprobe *p) +{ + struct kprobe *orig_p; + + /* Get an original kprobe for return */ + orig_p = __get_valid_kprobe(p); + if (unlikely(orig_p == NULL)) + return NULL; + + if (!kprobe_disabled(p)) { + /* Disable probe if it is a child probe */ + if (p != orig_p) + p->flags |= KPROBE_FLAG_DISABLED; + + /* Try to disarm and disable this/parent probe */ + if (p == orig_p || aggr_kprobe_disabled(orig_p)) { + disarm_kprobe(orig_p); + orig_p->flags |= KPROBE_FLAG_DISABLED; + } + } + + return orig_p; +} + /* * Unregister a kprobe without a scheduler synchronization. */ @@ -1235,22 +1259,26 @@ static int __kprobes __unregister_kprobe_top(struct kprobe *p) { struct kprobe *ap, *list_p; - ap = __get_valid_kprobe(p); + /* Disable kprobe. This will disarm it if needed. */ + ap = __disable_kprobe(p); if (ap == NULL) return -EINVAL; - if (ap == p || - (kprobe_aggrprobe(ap) && - list_is_singular(&ap->list))) { + if (ap == p) /* - * Only probe on the hash list. Disarm only if kprobes are - * enabled and not gone - otherwise, the breakpoint would - * already have been removed. We save on flushing icache. + * This probe is an independent(and non-optimized) kprobe + * (not an aggrprobe). Remove from the hash list. */ - if (!kprobes_all_disarmed && !kprobe_disabled(ap)) - disarm_kprobe(ap); - hlist_del_rcu(&ap->hlist); - } else { + goto disarmed; + + /* Following process expects this probe is an aggrprobe */ + WARN_ON(!kprobe_aggrprobe(ap)); + + if (list_is_singular(&ap->list)) + /* This probe is the last child of aggrprobe */ + goto disarmed; + else { + /* If disabling probe has special handlers, update aggrprobe */ if (p->break_handler && !kprobe_gone(p)) ap->break_handler = NULL; if (p->post_handler && !kprobe_gone(p)) { @@ -1261,19 +1289,23 @@ static int __kprobes __unregister_kprobe_top(struct kprobe *p) ap->post_handler = NULL; } noclean: + /* + * Remove from the aggrprobe: this path will do nothing in + * __unregister_kprobe_bottom(). + */ list_del_rcu(&p->list); - if (!kprobe_disabled(ap)) { - try_to_disable_aggr_kprobe(ap); - if (!kprobes_all_disarmed) { - if (kprobe_disabled(ap)) - disarm_kprobe(ap); - else - /* Try to optimize this probe again */ - optimize_kprobe(ap); - } - } + if (!kprobe_disabled(ap) && !kprobes_all_disarmed) + /* + * Try to optimize this probe again, because post + * handler may have been changed. + */ + optimize_kprobe(ap); } return 0; + +disarmed: + hlist_del_rcu(&ap->hlist); + return 0; } static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) @@ -1606,29 +1638,13 @@ static void __kprobes kill_kprobe(struct kprobe *p) int __kprobes disable_kprobe(struct kprobe *kp) { int ret = 0; - struct kprobe *p; mutex_lock(&kprobe_mutex); - /* Check whether specified probe is valid. */ - p = __get_valid_kprobe(kp); - if (unlikely(p == NULL)) { + /* Disable this kprobe */ + if (__disable_kprobe(kp) == NULL) ret = -EINVAL; - goto out; - } - - /* If the probe is already disabled (or gone), just return */ - if (kprobe_disabled(kp)) - goto out; - kp->flags |= KPROBE_FLAG_DISABLED; - if (p != kp) - /* When kp != p, p is always enabled. */ - try_to_disable_aggr_kprobe(p); - - if (!kprobes_all_disarmed && kprobe_disabled(p)) - disarm_kprobe(p); -out: mutex_unlock(&kprobe_mutex); return ret; } |