Index: lib/libc/sys/procctl.2
===================================================================
--- lib/libc/sys/procctl.2
+++ lib/libc/sys/procctl.2
@@ -29,7 +29,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd August 31, 2019
+.Dd October 4, 2019
 .Dt PROCCTL 2
 .Os
 .Sh NAME
@@ -71,7 +71,7 @@
 .Fa cmd
 argument.
 The following commands are supported:
-.Bl -tag -width PROC_TRAPCAP_STATUS
+.Bl -tag -width PROC_LOGSIGEXIT_STATUS
 .It Dv PROC_ASLR_CTL
 Controls the Address Space Layout Randomization (ASLR) in the program
 images created
@@ -112,6 +112,39 @@
 the
 .Dv PROC_ASLR_ACTIVE
 flag is or-ed with the value listed above.
+.It Dv PROC_LOGSIGEXIT_CTL
+Controls the logging of exits due to signals that would normally cause a core
+dump.
+The
+.Va arg
+parameter must point to an integer variable holding one of the following values:
+.Bl -tag -width PROC_LOGSIGEXIT_FORCE_DISABLE
+.It Dv PROC_LOGSIGEXIT_FORCE_ENABLE
+Enables logging of exits due to signals that would normally cause a core dump.
+Logging is done via
+.Xr log 9
+with a log level of
+.Dv LOG_INFO .
+.It Dv PROC_LOGSIGEXIT_FORCE_DISABLE
+Disables the logging of exits due to signals that would normally cause a core
+dump.
+.It Dv PROC_LOGSIGEXIT_NOFORCE
+The logging behavior is delegated to the
+.Xr sysctl 3
+MIB variable
+.Va kern.logsigexit .
+.El
+.It Dv PROC_LOGSIGEXIT_STATUS
+Returns the current status of logging for the target process.
+The
+.Va arg
+parameter must point to an integer variable, where one of the following values
+is written:
+.Bl -tag -width PROC_LOGSIGEXIT_FORCE_DISABLE
+.It Dv PROC_LOGSIGEXIT_FORCE_ENABLE
+.It Dv PROC_LOGSIGEXIT_FORCE_DISABLE
+.It Dv PROC_LOGSIGEXIT_NOFORCE
+.El
 .It Dv PROC_PROTMAX_CTL
 Controls implicit application of PROT_MAX protection equal to the
 .Fa prot
Index: sys/compat/freebsd32/freebsd32_misc.c
===================================================================
--- sys/compat/freebsd32/freebsd32_misc.c
+++ sys/compat/freebsd32/freebsd32_misc.c
@@ -3367,6 +3367,7 @@
 	case PROC_STACKGAP_CTL:
 	case PROC_TRACE_CTL:
 	case PROC_TRAPCAP_CTL:
+	case PROC_LOGSIGEXIT_CTL:
 		error = copyin(PTRIN(uap->data), &flags, sizeof(flags));
 		if (error != 0)
 			return (error);
@@ -3400,6 +3401,7 @@
 	case PROC_STACKGAP_STATUS:
 	case PROC_TRACE_STATUS:
 	case PROC_TRAPCAP_STATUS:
+	case PROC_LOGSIGEXIT_STATUS:
 		data = &flags;
 		break;
 	case PROC_PDEATHSIG_CTL:
@@ -3431,6 +3433,7 @@
 	case PROC_STACKGAP_STATUS:
 	case PROC_TRACE_STATUS:
 	case PROC_TRAPCAP_STATUS:
+	case PROC_LOGSIGEXIT_STATUS:
 		if (error == 0)
 			error = copyout(&flags, uap->data, sizeof(flags));
 		break;
Index: sys/kern/kern_fork.c
===================================================================
--- sys/kern/kern_fork.c
+++ sys/kern/kern_fork.c
@@ -469,7 +469,8 @@
 	p2->p_flag2 = p1->p_flag2 & (P2_ASLR_DISABLE | P2_ASLR_ENABLE |
 	    P2_ASLR_IGNSTART | P2_NOTRACE | P2_NOTRACE_EXEC |
 	    P2_PROTMAX_ENABLE | P2_PROTMAX_DISABLE | P2_TRAPCAP |
-	    P2_STKGAP_DISABLE | P2_STKGAP_DISABLE_EXEC);
+	    P2_STKGAP_DISABLE | P2_STKGAP_DISABLE_EXEC | P2_LOGSIGEXIT_CTL |
+	    P2_LOGSIGEXIT_ENABLE);
 	p2->p_swtick = ticks;
 	if (p1->p_flag & P_PROFIL)
 		startprofclock(p2);
Index: sys/kern/kern_procctl.c
===================================================================
--- sys/kern/kern_procctl.c
+++ sys/kern/kern_procctl.c
@@ -569,6 +569,42 @@
 	return (0);
 }
 
+static int
+logsigexit_ctl(struct thread *td, struct proc *p, int state)
+{
+
+	PROC_LOCK_ASSERT(p, MA_OWNED);
+
+	switch (state) {
+	case PROC_LOGSIGEXIT_CTL_NOFORCE:
+		p->p_flag2 &= ~(P2_LOGSIGEXIT_CTL | P2_LOGSIGEXIT_ENABLE);
+		break;
+	case PROC_LOGSIGEXIT_CTL_FORCE_ENABLE:
+		p->p_flag2 |= P2_LOGSIGEXIT_CTL | P2_LOGSIGEXIT_ENABLE;
+		break;
+	case PROC_LOGSIGEXIT_CTL_FORCE_DISABLE:
+		p->p_flag2 |= P2_LOGSIGEXIT_CTL;
+		p->p_flag2 &= ~P2_LOGSIGEXIT_ENABLE;
+		break;
+	default:
+		return (EINVAL);
+	}
+	return (0);
+}
+
+static int
+logsigexit_status(struct thread *td, struct proc *p, int *data)
+{
+
+	if ((p->p_flag2 & P2_LOGSIGEXIT_CTL) == 0)
+		*data = PROC_LOGSIGEXIT_CTL_NOFORCE;
+	else if ((p->p_flag2 & P2_LOGSIGEXIT_ENABLE) != 0)
+		*data = PROC_LOGSIGEXIT_CTL_FORCE_ENABLE;
+	else
+		*data = PROC_LOGSIGEXIT_CTL_FORCE_DISABLE;
+	return (0);
+}
+
 #ifndef _SYS_SYSPROTO_H_
 struct procctl_args {
 	idtype_t idtype;
@@ -600,6 +636,7 @@
 	case PROC_STACKGAP_CTL:
 	case PROC_TRACE_CTL:
 	case PROC_TRAPCAP_CTL:
+	case PROC_LOGSIGEXIT_CTL:
 		error = copyin(uap->data, &flags, sizeof(flags));
 		if (error != 0)
 			return (error);
@@ -631,6 +668,7 @@
 	case PROC_STACKGAP_STATUS:
 	case PROC_TRACE_STATUS:
 	case PROC_TRAPCAP_STATUS:
+	case PROC_LOGSIGEXIT_STATUS:
 		data = &flags;
 		break;
 	case PROC_PDEATHSIG_CTL:
@@ -661,6 +699,7 @@
 	case PROC_STACKGAP_STATUS:
 	case PROC_TRACE_STATUS:
 	case PROC_TRAPCAP_STATUS:
+	case PROC_LOGSIGEXIT_STATUS:
 		if (error == 0)
 			error = copyout(&flags, uap->data, sizeof(flags));
 		break;
@@ -710,6 +749,10 @@
 		return (trapcap_ctl(td, p, *(int *)data));
 	case PROC_TRAPCAP_STATUS:
 		return (trapcap_status(td, p, data));
+	case PROC_LOGSIGEXIT_CTL:
+		return (logsigexit_ctl(td, p, *(int *)data));
+	case PROC_LOGSIGEXIT_STATUS:
+		return (logsigexit_status(td, p, data));
 	default:
 		return (EINVAL);
 	}
@@ -772,6 +815,7 @@
 	case PROC_REAP_KILL:
 	case PROC_TRACE_CTL:
 	case PROC_TRAPCAP_CTL:
+	case PROC_LOGSIGEXIT_CTL:
 		sx_slock(&proctree_lock);
 		tree_locked = true;
 		break;
@@ -788,6 +832,7 @@
 	case PROC_STACKGAP_STATUS:
 	case PROC_TRACE_STATUS:
 	case PROC_TRAPCAP_STATUS:
+	case PROC_LOGSIGEXIT_STATUS:
 		tree_locked = false;
 		break;
 	default:
Index: sys/kern/kern_sig.c
===================================================================
--- sys/kern/kern_sig.c
+++ sys/kern/kern_sig.c
@@ -3119,9 +3119,15 @@
 sigexit(struct thread *td, int sig)
 {
 	struct proc *p = td->td_proc;
+	bool logexit;
 
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	p->p_acflag |= AXSIG;
+	if ((p->p_flag2 & P2_LOGSIGEXIT_CTL) == 0)
+		logexit = kern_logsigexit != 0;
+	else
+		logexit = (p->p_flag2 & P2_LOGSIGEXIT_ENABLE) != 0;
+
 	/*
 	 * We must be single-threading to generate a core dump.  This
 	 * ensures that the registers in the core file are up-to-date.
@@ -3143,7 +3149,7 @@
 		 */
 		if (coredump(td) == 0)
 			sig |= WCOREFLAG;
-		if (kern_logsigexit)
+		if (logexit)
 			log(LOG_INFO,
 			    "pid %d (%s), jid %d, uid %d: exited on "
 			    "signal %d%s\n", p->p_pid, p->p_comm,
Index: sys/sys/proc.h
===================================================================
--- sys/sys/proc.h
+++ sys/sys/proc.h
@@ -765,6 +765,8 @@
 #define	P2_PROTMAX_DISABLE 0x00000400	/* Force disable implied PROT_MAX. */
 #define	P2_STKGAP_DISABLE 0x00000800	/* Disable stack gap for MAP_STACK */
 #define	P2_STKGAP_DISABLE_EXEC 0x00001000 /* Stack gap disabled after exec */
+#define	P2_LOGSIGEXIT_ENABLE 0x00002000 /* Disable logging on sigexit */
+#define	P2_LOGSIGEXIT_CTL 0x00004000 /* Override kern.logsigexit */
 
 /* Flags protected by proctree_lock, kept in p_treeflags. */
 #define	P_TREE_ORPHANED		0x00000001	/* Reparented, on orphan list */
Index: sys/sys/procctl.h
===================================================================
--- sys/sys/procctl.h
+++ sys/sys/procctl.h
@@ -63,6 +63,8 @@
 #define	PROC_PROTMAX_STATUS	16	/* query implicit PROT_MAX status */
 #define	PROC_STACKGAP_CTL	17	/* en/dis stack gap on MAP_STACK */
 #define	PROC_STACKGAP_STATUS	18	/* query stack gap */
+#define	PROC_LOGSIGEXIT_CTL	19	/* en/dis logging on sigexit */
+#define	PROC_LOGSIGEXIT_STATUS	20	/* query logging on sigexit */
 
 /* Operations for PROC_SPROTECT (passed in integer arg). */
 #define	PPROT_OP(x)	((x) & 0xf)
@@ -141,6 +143,10 @@
 #define	PROC_STACKGAP_ENABLE_EXEC	0x0004
 #define	PROC_STACKGAP_DISABLE_EXEC	0x0008
 
+#define	PROC_LOGSIGEXIT_CTL_NOFORCE		1
+#define	PROC_LOGSIGEXIT_CTL_FORCE_ENABLE	2
+#define	PROC_LOGSIGEXIT_CTL_FORCE_DISABLE	3
+
 #ifndef _KERNEL
 __BEGIN_DECLS
 int	procctl(idtype_t, id_t, int, void *);
Index: usr.bin/proccontrol/proccontrol.1
===================================================================
--- usr.bin/proccontrol/proccontrol.1
+++ usr.bin/proccontrol/proccontrol.1
@@ -28,7 +28,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 28, 2019
+.Dd October 4, 2019
 .Dt PROCCONTROL 1
 .Os
 .Sh NAME
@@ -56,7 +56,7 @@
 Possible values for
 .Ar mode
 are:
-.Bl -tag -width trapcap
+.Bl -tag -width logsigexit
 .It Ar aslr
 Control the Address Space Layout Randomization.
 Only applicable to the new process spawned.
@@ -71,6 +71,9 @@
 .Xr mmap 2 .
 .It Ar kpti
 Controls the KPTI enable, AMD64 only.
+.It Ar logsigexit
+Controls the logging of exits due to a signal that would normally cause a core
+dump.
 .El
 .Pp
 The
Index: usr.bin/proccontrol/proccontrol.c
===================================================================
--- usr.bin/proccontrol/proccontrol.c
+++ usr.bin/proccontrol/proccontrol.c
@@ -48,6 +48,7 @@
 #ifdef PROC_KPTI_CTL
 	MODE_KPTI,
 #endif
+	MODE_LOGSIGEXIT,
 };
 
 static pid_t
@@ -75,7 +76,7 @@
 {
 
 	fprintf(stderr, "Usage: proccontrol -m (aslr|protmax|trace|trapcap|"
-	    "stackgap"KPTI_USAGE") [-q] "
+	    "stackgap"KPTI_USAGE"|logsigexit) [-q] "
 	    "[-s (enable|disable)] [-p pid | command]\n");
 	exit(1);
 }
@@ -108,6 +109,8 @@
 			else if (strcmp(optarg, "kpti") == 0)
 				mode = MODE_KPTI;
 #endif
+			else if (strcmp(optarg, "logsigexit") == 0)
+				mode = MODE_LOGSIGEXIT;
 			else
 				usage();
 			break;
@@ -164,6 +167,10 @@
 			error = procctl(P_PID, pid, PROC_KPTI_STATUS, &arg);
 			break;
 #endif
+		case MODE_LOGSIGEXIT:
+			error = procctl(P_PID, pid, PROC_LOGSIGEXIT_STATUS,
+			    &arg);
+			break;
 		default:
 			usage();
 			break;
@@ -259,6 +266,19 @@
 				printf(", not active\n");
 			break;
 #endif
+		case MODE_LOGSIGEXIT:
+			switch (arg) {
+			case PROC_LOGSIGEXIT_CTL_NOFORCE:
+				printf("not forced\n");
+				break;
+			case PROC_LOGSIGEXIT_CTL_FORCE_ENABLE:
+				printf("force enabled\n");
+				break;
+			case PROC_LOGSIGEXIT_CTL_FORCE_DISABLE:
+				printf("force disabled\n");
+				break;
+			}
+			break;
 		}
 	} else {
 		switch (mode) {
@@ -295,6 +315,11 @@
 			error = procctl(P_PID, pid, PROC_KPTI_CTL, &arg);
 			break;
 #endif
+		case MODE_LOGSIGEXIT:
+			arg = enable ? PROC_LOGSIGEXIT_CTL_FORCE_ENABLE :
+			    PROC_LOGSIGEXIT_CTL_FORCE_DISABLE;
+			error = procctl(P_PID, pid, PROC_LOGSIGEXIT_CTL, &arg);
+			break;
 		default:
 			usage();
 			break;