From a16c3170ef1248b388d4e41467ca004e3ab80e4d Mon Sep 17 00:00:00 2001
From: Masamichi Takagi <masamichi.takagi@riken.jp>
Date: Thu, 4 Sep 2014 17:07:27 +0900
Subject: [PATCH] Correct wait4 when the child is not found

Make wait4 return -ECHILD when pid is specified and it's not found.
---
 kernel/syscall.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/syscall.c b/kernel/syscall.c
index f8a910be..b61c74a4 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -333,7 +333,7 @@ rescan:
 		ihk_mc_spinlock_unlock_noirq(&child_iter->lock);
 	}
 
-	if (empty) {
+	if (empty || (!child && pid != -1)) {
 		ihk_mc_spinlock_unlock_noirq(&proc->ftn->lock);	
 		return -ECHILD;
 	}