aboutsummaryrefslogtreecommitdiff
path: root/kernel/kprobes.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/kprobes.c')
-rw-r--r--kernel/kprobes.c39
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);