core dump: real_parent ppid

The pr_ppid field reported in core dumps should match what
getppid() would have returned to that process, regardless of
whether a debugger is attached.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/binfmt_elf.c

@@ -1384,7 +1384,7 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 	prstatus->pr_sigpend = p->pending.signal.sig[0];
 	prstatus->pr_sighold = p->blocked.sig[0];
 	prstatus->pr_pid = task_pid_vnr(p);
-	prstatus->pr_ppid = task_pid_vnr(p->parent);
+	prstatus->pr_ppid = task_pid_vnr(p->real_parent);
 	prstatus->pr_pgrp = task_pgrp_vnr(p);
 	prstatus->pr_sid = task_session_vnr(p);
 	if (thread_group_leader(p)) {
@@ -1430,7 +1430,7 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
 	psinfo->pr_psargs[len] = 0;
 
 	psinfo->pr_pid = task_pid_vnr(p);
-	psinfo->pr_ppid = task_pid_vnr(p->parent);
+	psinfo->pr_ppid = task_pid_vnr(p->real_parent);
 	psinfo->pr_pgrp = task_pgrp_vnr(p);
 	psinfo->pr_sid = task_session_vnr(p);