From ba32f2a51c8f42da730987ff4a6c5915641fa2fd Mon Sep 17 00:00:00 2001
From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Date: Wed, 10 Nov 2010 10:05:58 +0100
Subject: [PATCH] --- yaml --- r: 222159 b: refs/heads/master c:
 89480801a17a3069f45169d40b828c8e511aa005 h: refs/heads/master i:   222157:
 8fecdce847c773057e33fbf054e49193828fea73   222155:
 46bd9492bce36aa35d0cbc71d9d21734d810b070   222151:
 a87918629b951e2878bd3a0c0dc496fe6c84a4ce   222143:
 2aec1e2c6cb6ffe819c8c44309471c44b5cde50b v: v3

---
 [refs]                           |  2 +-
 trunk/arch/s390/kernel/kprobes.c | 29 ++++++++++++++++++++++++++---
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index dd560d490820..72c3112ec4ad 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: adb45839817392102e659c19e5c19aa39530021f
+refs/heads/master: 89480801a17a3069f45169d40b828c8e511aa005
diff --git a/trunk/arch/s390/kernel/kprobes.c b/trunk/arch/s390/kernel/kprobes.c
index 70cf73bdba25..2564793ec2b6 100644
--- a/trunk/arch/s390/kernel/kprobes.c
+++ b/trunk/arch/s390/kernel/kprobes.c
@@ -349,6 +349,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
 	struct hlist_node *node, *tmp;
 	unsigned long flags, orig_ret_address = 0;
 	unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
+	kprobe_opcode_t *correct_ret_addr = NULL;
 
 	INIT_HLIST_HEAD(&empty_rp);
 	kretprobe_hash_lock(current, &head, &flags);
@@ -371,10 +372,32 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
 			/* another task is sharing our hash bucket */
 			continue;
 
-		if (ri->rp && ri->rp->handler)
-			ri->rp->handler(ri, regs);
+		orig_ret_address = (unsigned long)ri->ret_addr;
+
+		if (orig_ret_address != trampoline_address)
+			/*
+			 * This is the real return address. Any other
+			 * instances associated with this task are for
+			 * other calls deeper on the call stack
+			 */
+			break;
+	}
+
+	kretprobe_assert(ri, orig_ret_address, trampoline_address);
+
+	correct_ret_addr = ri->ret_addr;
+	hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
+		if (ri->task != current)
+			/* another task is sharing our hash bucket */
+			continue;
 
 		orig_ret_address = (unsigned long)ri->ret_addr;
+
+		if (ri->rp && ri->rp->handler) {
+			ri->ret_addr = correct_ret_addr;
+			ri->rp->handler(ri, regs);
+		}
+
 		recycle_rp_inst(ri, &empty_rp);
 
 		if (orig_ret_address != trampoline_address) {
@@ -386,7 +409,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
 			break;
 		}
 	}
-	kretprobe_assert(ri, orig_ret_address, trampoline_address);
+
 	regs->psw.addr = orig_ret_address | PSW_ADDR_AMODE;
 
 	reset_current_kprobe();