remove task_ppid_nr_ns

task_ppid_nr_ns is called in three places.  One of these should never
have called it.  In the other two, using it broke the existing
semantics.  This was presumably accidental.  If the function had not
been there, it would have been much more obvious to the eye that those
patches were changing the behavior.  We don't need this function.

In task_state, the pid of the ptracer is not the ppid of the ptracer.

In do_task_stat, ppid is the tgid of the real_parent, not its pid.
I also moved the call outside of lock_task_sighand, since it doesn't
need it.

In sys_getppid, ppid is the tgid of the real_parent, not its pid.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 65c62e1bfd6f..810eb8fd6500 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -169,7 +169,7 @@ static inline char *task_state(struct task_struct *p, char *buffer)
         ppid = pid_alive(p) ?
                 task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
         tpid = pid_alive(p) && p->ptrace ?
-                task_ppid_nr_ns(rcu_dereference(p->parent), ns) : 0;
+                task_pid_nr_ns(rcu_dereference(p->parent), ns) : 0;
         buffer += sprintf(buffer,
                 "State:\t%s\n"
                 "Tgid:\t%d\n"
@@ -426,6 +426,7 @@ static int do_task_stat(struct task_struct *task, char *buffer, int whole)
         cgtime = gtime = cputime_zero;
 
         rcu_read_lock();
+        ppid = task_tgid_nr_ns(task->real_parent, ns);
         if (lock_task_sighand(task, &flags)) {
                 struct signal_struct *sig = task->signal;
 
@@ -465,7 +466,6 @@ static int do_task_stat(struct task_struct *task, char *buffer, int whole)
 
                 sid = task_session_nr_ns(task, ns);
                 pgid = task_pgrp_nr_ns(task, ns);
-                ppid = task_ppid_nr_ns(task, ns);
 
                 unlock_task_sighand(task, &flags);
         }