diff options
| -rw-r--r-- | include/linux/kprobes.h | 9 | ||||
| -rw-r--r-- | kernel/kprobes.c | 124 |
2 files changed, 96 insertions, 37 deletions
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index cd507ab4fed7..2ba7df645a84 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -234,6 +234,8 @@ static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) int register_kprobe(struct kprobe *p); void unregister_kprobe(struct kprobe *p); +int register_kprobes(struct kprobe **kps, int num); +void unregister_kprobes(struct kprobe **kps, int num); int setjmp_pre_handler(struct kprobe *, struct pt_regs *); int longjmp_break_handler(struct kprobe *, struct pt_regs *); int register_jprobe(struct jprobe *p); @@ -261,9 +263,16 @@ static inline int register_kprobe(struct kprobe *p) { return -ENOSYS; } +static inline int register_kprobes(struct kprobe **kps, int num) +{ + return -ENOSYS; +} static inline void unregister_kprobe(struct kprobe *p) { } +static inline void unregister_kprobes(struct kprobe **kps, int num) +{ +} static inline int register_jprobe(struct jprobe *p) { return -ENOSYS; diff --git a/kernel/kprobes.c b/kernel/kprobes.c index f02a4311768b..76275fc025a5 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -580,6 +580,7 @@ static int __kprobes __register_kprobe(struct kprobe *p, } p->nmissed = 0; + INIT_LIST_HEAD(&p->list); mutex_lock(&kprobe_mutex); old_p = get_kprobe(p->addr); if (old_p) { @@ -606,35 +607,28 @@ out: return ret; } -int __kprobes register_kprobe(struct kprobe *p) -{ - return __register_kprobe(p, (unsigned long)__builtin_return_address(0)); -} - -void __kprobes unregister_kprobe(struct kprobe *p) +/* + * Unregister a kprobe without a scheduler synchronization. + */ +static int __kprobes __unregister_kprobe_top(struct kprobe *p) { - struct module *mod; struct kprobe *old_p, *list_p; - int cleanup_p; - mutex_lock(&kprobe_mutex); old_p = get_kprobe(p->addr); - if (unlikely(!old_p)) { - mutex_unlock(&kprobe_mutex); - return; - } + if (unlikely(!old_p)) + return -EINVAL; + if (p != old_p) { list_for_each_entry_rcu(list_p, &old_p->list, list) if (list_p == p) /* kprobe p is a valid probe */ goto valid_p; - mutex_unlock(&kprobe_mutex); - return; + return -EINVAL; } valid_p: if (old_p == p || (old_p->pre_handler == aggr_pre_handler && - p->list.next == &old_p->list && p->list.prev == &old_p->list)) { + list_is_singular(&old_p->list))) { /* * Only probe on the hash list. Disarm only if kprobes are * enabled - otherwise, the breakpoint would already have @@ -643,43 +637,97 @@ valid_p: if (kprobe_enabled) arch_disarm_kprobe(p); hlist_del_rcu(&old_p->hlist); - cleanup_p = 1; } else { + if (p->break_handler) + old_p->break_handler = NULL; + if (p->post_handler) { + list_for_each_entry_rcu(list_p, &old_p->list, list) { + if ((list_p != p) && (list_p->post_handler)) + goto noclean; + } + old_p->post_handler = NULL; + } +noclean: list_del_rcu(&p->list); - cleanup_p = 0; } + return 0; +} - mutex_unlock(&kprobe_mutex); +static void __kprobes __unregister_kprobe_bottom(struct kprobe *p) +{ + struct module *mod; + struct kprobe *old_p; - synchronize_sched(); if (p->mod_refcounted) { mod = module_text_address((unsigned long)p->addr); if (mod) module_put(mod); } - if (cleanup_p) { - if (p != old_p) { - list_del_rcu(&p->list); + if (list_empty(&p->list) || list_is_singular(&p->list)) { + if (!list_empty(&p->list)) { + /* "p" is the last child of an aggr_kprobe */ + old_p = list_entry(p->list.next, struct kprobe, list); + list_del(&p->list); kfree(old_p); } arch_remove_kprobe(p); - } else { - mutex_lock(&kprobe_mutex); - if (p->break_handler) - old_p->break_handler = NULL; - if (p->post_handler){ - list_for_each_entry_rcu(list_p, &old_p->list, list){ - if (list_p->post_handler){ - cleanup_p = 2; - break; - } - } - if (cleanup_p == 0) - old_p->post_handler = NULL; + } +} + +static int __register_kprobes(struct kprobe **kps, int num, + unsigned long called_from) +{ + int i, ret = 0; + + if (num <= 0) + return -EINVAL; + for (i = 0; i < num; i++) { + ret = __register_kprobe(kps[i], called_from); + if (ret < 0 && i > 0) { + unregister_kprobes(kps, i); + break; } - mutex_unlock(&kprobe_mutex); } + return ret; +} + +/* + * Registration and unregistration functions for kprobe. + */ +int __kprobes register_kprobe(struct kprobe *p) +{ + return __register_kprobes(&p, 1, + (unsigned long)__builtin_return_address(0)); +} + +void __kprobes unregister_kprobe(struct kprobe *p) +{ + unregister_kprobes(&p, 1); +} + +int __kprobes register_kprobes(struct kprobe **kps, int num) +{ + return __register_kprobes(kps, num, + (unsigned long)__builtin_return_address(0)); +} + +void __kprobes unregister_kprobes(struct kprobe **kps, int num) +{ + int i; + + if (num <= 0) + return; + mutex_lock(&kprobe_mutex); + for (i = 0; i < num; i++) + if (__unregister_kprobe_top(kps[i]) < 0) + kps[i]->addr = NULL; + mutex_unlock(&kprobe_mutex); + + synchronize_sched(); + for (i = 0; i < num; i++) + if (kps[i]->addr) + __unregister_kprobe_bottom(kps[i]); } static struct notifier_block kprobe_exceptions_nb = { @@ -1118,6 +1166,8 @@ module_init(init_kprobes); EXPORT_SYMBOL_GPL(register_kprobe); EXPORT_SYMBOL_GPL(unregister_kprobe); +EXPORT_SYMBOL_GPL(register_kprobes); +EXPORT_SYMBOL_GPL(unregister_kprobes); EXPORT_SYMBOL_GPL(register_jprobe); EXPORT_SYMBOL_GPL(unregister_jprobe); #ifdef CONFIG_KPROBES |