From 5d520d7fab2231498382006524ba2adaa085d141 Mon Sep 17 00:00:00 2001
From: Dmitry Chagin <dchagin@FreeBSD.org>
Date: Tue, 30 Apr 2019 17:18:05 +0000
Subject: [PATCH] Follow the FreeBSD and implement PDEATH_SIG prctl ops in the
 Linuxulator. It was first introduced in r163734 and missied by me in r283383.

MFC after:	1 week
---
 sys/compat/linux/linux_emul.c |  1 -
 sys/compat/linux/linux_emul.h |  1 -
 sys/compat/linux/linux_misc.c | 21 +++++++++++----------
 3 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/sys/compat/linux/linux_emul.c b/sys/compat/linux/linux_emul.c
index b30fb09b86bf..e88eb554aed1 100644
--- a/sys/compat/linux/linux_emul.c
+++ b/sys/compat/linux/linux_emul.c
@@ -127,7 +127,6 @@ linux_proc_init(struct thread *td, struct thread *newtd, int flags)
 
 		em->em_tid = p->p_pid;
 		em->flags = 0;
-		em->pdeath_signal = 0;
 		em->robust_futexes = NULL;
 		em->child_clear_tid = NULL;
 		em->child_set_tid = NULL;
diff --git a/sys/compat/linux/linux_emul.h b/sys/compat/linux/linux_emul.h
index 3784d6a061a3..fb445de5db98 100644
--- a/sys/compat/linux/linux_emul.h
+++ b/sys/compat/linux/linux_emul.h
@@ -40,7 +40,6 @@ struct linux_emuldata {
 	int    *child_set_tid;	/* in clone(): Child's TID to set on clone */
 	int    *child_clear_tid;/* in clone(): Child's TID to clear on exit */
 
-	int	pdeath_signal;		/* parent death signal */
 	int	flags;			/* thread emuldata flags */
 	int	em_tid;			/* thread id */
 
diff --git a/sys/compat/linux/linux_misc.c b/sys/compat/linux/linux_misc.c
index f888a2640d1f..a05c6a59be66 100644
--- a/sys/compat/linux/linux_misc.c
+++ b/sys/compat/linux/linux_misc.c
@@ -51,6 +51,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/namei.h>
 #include <sys/priv.h>
 #include <sys/proc.h>
+#include <sys/procctl.h>
 #include <sys/reboot.h>
 #include <sys/racct.h>
 #include <sys/random.h>
@@ -1993,7 +1994,6 @@ linux_prctl(struct thread *td, struct linux_prctl_args *args)
 	int error = 0, max_size;
 	struct proc *p = td->td_proc;
 	char comm[LINUX_MAX_COMM_LEN];
-	struct linux_emuldata *em;
 	int pdeath_signal;
 
 #ifdef DEBUG
@@ -2007,17 +2007,18 @@ linux_prctl(struct thread *td, struct linux_prctl_args *args)
 	case LINUX_PR_SET_PDEATHSIG:
 		if (!LINUX_SIG_VALID(args->arg2))
 			return (EINVAL);
-		em = em_find(td);
-		KASSERT(em != NULL, ("prctl: emuldata not found.\n"));
-		em->pdeath_signal = args->arg2;
-		break;
+		pdeath_signal = linux_to_bsd_signal(args->arg2);
+		return (kern_procctl(td, P_PID, 0, PROC_PDEATHSIG_CTL,
+		    &pdeath_signal));
 	case LINUX_PR_GET_PDEATHSIG:
-		em = em_find(td);
-		KASSERT(em != NULL, ("prctl: emuldata not found.\n"));
-		pdeath_signal = em->pdeath_signal;
-		error = copyout(&pdeath_signal,
+		error = kern_procctl(td, P_PID, 0, PROC_PDEATHSIG_STATUS,
+		    &pdeath_signal);
+		if (error != 0)
+			return (error);
+		pdeath_signal = bsd_to_linux_signal(pdeath_signal);
+		return (copyout(&pdeath_signal,
 		    (void *)(register_t)args->arg2,
-		    sizeof(pdeath_signal));
+		    sizeof(pdeath_signal)));
 		break;
 	case LINUX_PR_GET_KEEPCAPS:
 		/*