Introduce unregister_/register_kretprobes() for kretprobe
batch registration.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
---

 include/linux/kprobes.h |    9 ++++
 kernel/kprobes.c        |  108 +++++++++++++++++++++++++++++++++++++++---------
 2 files changed, 97 insertions(+), 20 deletions(-)

Index: 2.6.25-rc5-mm1/kernel/kprobes.c
===================================================================
--- 2.6.25-rc5-mm1.orig/kernel/kprobes.c
+++ 2.6.25-rc5-mm1/kernel/kprobes.c
@@ -429,6 +429,21 @@ static inline void free_rp_inst(struct k
 	}
 }

+static void __kprobes cleanup_rp_inst(struct kretprobe *rp)
+{
+	unsigned long flags;
+	struct kretprobe_instance *ri;
+	struct hlist_node *pos, *next;
+	/* No race here */
+	spin_lock_irqsave(&kretprobe_lock, flags);
+	hlist_for_each_entry_safe(ri, pos, next, &rp->used_instances, uflist) {
+		ri->rp = NULL;
+		hlist_del(&ri->uflist);
+	}
+	spin_unlock_irqrestore(&kretprobe_lock, flags);
+	free_rp_inst(rp);
+}
+
 /*
  * Keep all fields in the kprobe consistent
  */
@@ -798,7 +813,8 @@ static int __kprobes pre_handler_kretpro
 	return 0;
 }

-int __kprobes register_kretprobe(struct kretprobe *rp)
+static int __kprobes __register_kretprobe(struct kretprobe *rp,
+					  unsigned long called_from)
 {
 	int ret = 0;
 	struct kretprobe_instance *inst;
@@ -844,43 +860,93 @@ int __kprobes register_kretprobe(struct

 	rp->nmissed = 0;
 	/* Establish function entry probe point */
-	if ((ret = __register_kprobe(&rp->kp,
-		(unsigned long)__builtin_return_address(0))) != 0)
+	ret = __register_kprobe(&rp->kp, called_from);
+	if (ret != 0)
 		free_rp_inst(rp);
 	return ret;
 }

+static int __register_kretprobes(struct kretprobe **rps, int num,
+	unsigned long called_from)
+{
+	int ret = 0, i;
+
+	if (num <= 0)
+		return -EINVAL;
+	for (i = 0; i < num; i++) {
+		ret = __register_kretprobe(rps[i], called_from);
+		if (ret < 0 && i > 0) {
+			...
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