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-rw-r--r--kernel/kprobes.c128
1 files changed, 72 insertions, 56 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 8c3aa14..ab99caf 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;
}