diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/kprobes.c | 39 |
1 files changed, 3 insertions, 36 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 4b8a4493c54..f9798ff7899 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -64,7 +64,6 @@ static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; -static atomic_t kprobe_count; /* NOTE: change this value only with kprobe_mutex held */ static bool kprobe_enabled; @@ -73,11 +72,6 @@ DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */ DEFINE_SPINLOCK(kretprobe_lock); /* Protects kretprobe_inst_table */ static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL; -static struct notifier_block kprobe_page_fault_nb = { - .notifier_call = kprobe_exceptions_notify, - .priority = 0x7fffffff /* we need to notified first */ -}; - #ifdef __ARCH_WANT_KPROBES_INSN_SLOT /* * kprobe->ainsn.insn points to the copy of the instruction to be @@ -556,8 +550,6 @@ static int __kprobes __register_kprobe(struct kprobe *p, old_p = get_kprobe(p->addr); if (old_p) { ret = register_aggr_kprobe(old_p, p); - if (!ret) - atomic_inc(&kprobe_count); goto out; } @@ -569,13 +561,9 @@ static int __kprobes __register_kprobe(struct kprobe *p, hlist_add_head_rcu(&p->hlist, &kprobe_table[hash_ptr(p->addr, KPROBE_HASH_BITS)]); - if (kprobe_enabled) { - if (atomic_add_return(1, &kprobe_count) == \ - (ARCH_INACTIVE_KPROBE_COUNT + 1)) - register_page_fault_notifier(&kprobe_page_fault_nb); - + if (kprobe_enabled) arch_arm_kprobe(p); - } + out: mutex_unlock(&kprobe_mutex); @@ -658,16 +646,6 @@ valid_p: } mutex_unlock(&kprobe_mutex); } - - /* Call unregister_page_fault_notifier() - * if no probes are active - */ - mutex_lock(&kprobe_mutex); - if (atomic_add_return(-1, &kprobe_count) == \ - ARCH_INACTIVE_KPROBE_COUNT) - unregister_page_fault_notifier(&kprobe_page_fault_nb); - mutex_unlock(&kprobe_mutex); - return; } static struct notifier_block kprobe_exceptions_nb = { @@ -815,7 +793,6 @@ static int __init init_kprobes(void) INIT_HLIST_HEAD(&kprobe_table[i]); INIT_HLIST_HEAD(&kretprobe_inst_table[i]); } - atomic_set(&kprobe_count, 0); /* By default, kprobes are enabled */ kprobe_enabled = true; @@ -921,13 +898,6 @@ static void __kprobes enable_all_kprobes(void) if (kprobe_enabled) goto already_enabled; - /* - * Re-register the page fault notifier only if there are any - * active probes at the time of enabling kprobes globally - */ - if (atomic_read(&kprobe_count) > ARCH_INACTIVE_KPROBE_COUNT) - register_page_fault_notifier(&kprobe_page_fault_nb); - for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; hlist_for_each_entry_rcu(p, node, head, hlist) @@ -968,10 +938,7 @@ static void __kprobes disable_all_kprobes(void) mutex_unlock(&kprobe_mutex); /* Allow all currently running kprobes to complete */ synchronize_sched(); - - mutex_lock(&kprobe_mutex); - /* Unconditionally unregister the page_fault notifier */ - unregister_page_fault_notifier(&kprobe_page_fault_nb); + return; already_disabled: mutex_unlock(&kprobe_mutex); |