From d5ecd931c6dde7126e75d7b6df26f921f9aa1e3a Mon Sep 17 00:00:00 2001
From: Masami Hiramatsu <mhiramat@redhat.com>
Date: Mon, 6 Apr 2009 19:00:58 -0700
Subject: [PATCH] --- yaml --- r: 142571 b: refs/heads/master c:
 b918e5e60d775549478e4268155142156a95aa17 h: refs/heads/master i:   142569:
 fcb38a2e589ebf4dc345abf5724930dd5da9c8bc   142567:
 09a01cb61cc845de47489e44ad6e7f14ab238af1 v: v3

---
 [refs]                 |  2 +-
 trunk/kernel/kprobes.c | 60 +++++++++++++++++++++---------------------
 2 files changed, 31 insertions(+), 31 deletions(-)

diff --git a/[refs] b/[refs]
index a630d7ba2e23..d70820d4a962 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 96a6d9aa096aeb758273a8fb6388c279ecef5e7e
+refs/heads/master: b918e5e60d775549478e4268155142156a95aa17
diff --git a/trunk/kernel/kprobes.c b/trunk/kernel/kprobes.c
index 5016bfb682b9..a55bfadfd766 100644
--- a/trunk/kernel/kprobes.c
+++ b/trunk/kernel/kprobes.c
@@ -518,20 +518,20 @@ static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p)
 }
 
 /*
-* Add the new probe to old_p->list. Fail if this is the
+* Add the new probe to ap->list. Fail if this is the
 * second jprobe at the address - two jprobes can't coexist
 */
-static int __kprobes add_new_kprobe(struct kprobe *old_p, struct kprobe *p)
+static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p)
 {
 	if (p->break_handler) {
-		if (old_p->break_handler)
+		if (ap->break_handler)
 			return -EEXIST;
-		list_add_tail_rcu(&p->list, &old_p->list);
-		old_p->break_handler = aggr_break_handler;
+		list_add_tail_rcu(&p->list, &ap->list);
+		ap->break_handler = aggr_break_handler;
 	} else
-		list_add_rcu(&p->list, &old_p->list);
-	if (p->post_handler && !old_p->post_handler)
-		old_p->post_handler = aggr_post_handler;
+		list_add_rcu(&p->list, &ap->list);
+	if (p->post_handler && !ap->post_handler)
+		ap->post_handler = aggr_post_handler;
 	return 0;
 }
 
@@ -544,6 +544,7 @@ static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p)
 	copy_kprobe(p, ap);
 	flush_insn_slot(ap);
 	ap->addr = p->addr;
+	ap->flags = p->flags;
 	ap->pre_handler = aggr_pre_handler;
 	ap->fault_handler = aggr_fault_handler;
 	/* We don't care the kprobe which has gone. */
@@ -566,44 +567,43 @@ static int __kprobes register_aggr_kprobe(struct kprobe *old_p,
 					  struct kprobe *p)
 {
 	int ret = 0;
-	struct kprobe *ap;
+	struct kprobe *ap = old_p;
 
-	if (kprobe_gone(old_p)) {
+	if (old_p->pre_handler != aggr_pre_handler) {
+		/* If old_p is not an aggr_probe, create new aggr_kprobe. */
+		ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL);
+		if (!ap)
+			return -ENOMEM;
+		add_aggr_kprobe(ap, old_p);
+	}
+
+	if (kprobe_gone(ap)) {
 		/*
 		 * Attempting to insert new probe at the same location that
 		 * had a probe in the module vaddr area which already
 		 * freed. So, the instruction slot has already been
 		 * released. We need a new slot for the new probe.
 		 */
-		ret = arch_prepare_kprobe(old_p);
+		ret = arch_prepare_kprobe(ap);
 		if (ret)
+			/*
+			 * Even if fail to allocate new slot, don't need to
+			 * free aggr_probe. It will be used next time, or
+			 * freed by unregister_kprobe.
+			 */
 			return ret;
-	}
-	if (old_p->pre_handler == aggr_pre_handler) {
-		copy_kprobe(old_p, p);
-		ret = add_new_kprobe(old_p, p);
-		ap = old_p;
-	} else {
-		ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL);
-		if (!ap) {
-			if (kprobe_gone(old_p))
-				arch_remove_kprobe(old_p);
-			return -ENOMEM;
-		}
-		add_aggr_kprobe(ap, old_p);
-		copy_kprobe(ap, p);
-		ret = add_new_kprobe(ap, p);
-	}
-	if (kprobe_gone(old_p)) {
+		/* Clear gone flag to prevent allocating new slot again. */
+		ap->flags &= ~KPROBE_FLAG_GONE;
 		/*
 		 * If the old_p has gone, its breakpoint has been disarmed.
 		 * We have to arm it again after preparing real kprobes.
 		 */
-		ap->flags &= ~KPROBE_FLAG_GONE;
 		if (kprobe_enabled)
 			arch_arm_kprobe(ap);
 	}
-	return ret;
+
+	copy_kprobe(ap, p);
+	return add_new_kprobe(ap, p);
 }
 
 static int __kprobes in_kprobes_functions(unsigned long addr)