Merge patch series "Revert "pid: make __task_pid_nr_ns(ns => NULL) safe for zombie callers""

Commit 006568a ("pid: Add a judgment for ns null in pid_nr_ns")
already added the ns != NULL check in pid_nr_ns(), so we can remove the
same check from __task_pid_nr_ns().

* patches from https://patch.msgid.link/20251015123550.GA9447@redhat.com:
  pid: introduce task_ppid_vnr() helper
  Revert "pid: make __task_pid_nr_ns(ns => NULL) safe for zombie callers"

Link: https://patch.msgid.link/20251015123550.GA9447@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: brauner

fs/pidfs.c

@@ -446,7 +446,7 @@ static long pidfd_info(struct file *file, unsigned int cmd, unsigned long arg)
 	 * the fields are set correctly, or return ESRCH to avoid providing
 	 * incomplete information. */
 
-	kinfo.ppid = task_ppid_nr_ns(task, NULL);
+	kinfo.ppid = task_ppid_vnr(task);
 	kinfo.tgid = task_tgid_vnr(task);
 	kinfo.pid = task_pid_vnr(task);
 	kinfo.mask |= PIDFD_INFO_PID;

include/linux/pid.h

@@ -310,6 +310,11 @@ static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_na
 	return pid;
 }
 
+static inline pid_t task_ppid_vnr(const struct task_struct *tsk)
+{
+	return task_ppid_nr_ns(tsk, NULL);
+}
+
 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
 {
 	return task_ppid_nr_ns(tsk, &init_pid_ns);

kernel/pid.c

@@ -558,8 +558,7 @@ pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
 	rcu_read_lock();
 	if (!ns)
 		ns = task_active_pid_ns(current);
-	if (ns)
-		nr = pid_nr_ns(rcu_dereference(*task_pid_ptr(task, type)), ns);
+	nr = pid_nr_ns(rcu_dereference(*task_pid_ptr(task, type)), ns);
 	rcu_read_unlock();
 
 	return nr;