The ia64 has its own sys_ptrace implementation and it was 
overlooked when the pid namespaces patches were sent.

Use find_task_by_vpid() in it.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>

---
 arch/ia64/kernel/ptrace.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c
index 2e96f17..a671ef8 100644
--- a/arch/ia64/kernel/ptrace.c
+++ b/arch/ia64/kernel/ptrace.c
@@ -1437,7 +1437,7 @@ sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data)
 	ret = -ESRCH;
 	read_lock(&tasklist_lock);
 	{
-		child = find_task_by_pid(pid);
+		child = find_task_by_vpid(pid);
 		if (child) {
 			if (peek_or_poke)
 				child = find_thread_for_addr(child, addr);
-- 
1.5.3.4