transfer_pid() must be never called with pid == PIDTYPE_PID,
new_leader->thread_pid should be changed by exchange_tids().
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
---
kernel/pid.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/kernel/pid.c b/kernel/pid.c
index 62461c7c82b8..de0bf2f8d18b 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -396,8 +396,7 @@ void exchange_tids(struct task_struct *left, struct task_struct *right)
void transfer_pid(struct task_struct *old, struct task_struct *new,
enum pid_type type)
{
- if (type == PIDTYPE_PID)
- new->thread_pid = old->thread_pid;
+ WARN_ON_ONCE(type == PIDTYPE_PID);
hlist_replace_rcu(&old->pid_links[type], &new->pid_links[type]);
}
--
2.25.1.362.g51ebf55
