[PATCH 2/2] pid: Use for_each_thread() in do_each_pid_thread()

[Tetsuo Handa]

while_each_pid_thread() is using while_each_thread(), which is unsafe
under RCU lock according to commit 0c740d0afc3bff0a ("introduce
for_each_thread() to replace the buggy while_each_thread()"). Use
for_each_thread() in do_each_pid_thread() which is safe under RCU lock.

Link: http://lkml.kernel.org/r/201702011947.DBD56740.OMVHOLOtSJFFFQ@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
---
 include/linux/pid.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/pid.h b/include/linux/pid.h
index 23705a5..298ead55 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -191,10 +191,10 @@ static inline pid_t pid_nr(struct pid *pid)
 #define do_each_pid_thread(pid, type, task)				\
 	do_each_pid_task(pid, type, task) {				\
 		struct task_struct *tg___ = task;			\
-		do {
+		for_each_thread(tg___, task) {
 
 #define while_each_pid_thread(pid, type, task)				\
-		} while_each_thread(tg___, task);			\
+		}							\
 		task = tg___;						\
 	} while_each_pid_task(pid, type, task)
 #endif /* _LINUX_PID_H */
-- 
1.8.3.1