diff --git a/cddl/compat/opensolaris/include/libproc.h b/cddl/compat/opensolaris/include/libproc.h
--- a/cddl/compat/opensolaris/include/libproc.h
+++ b/cddl/compat/opensolaris/include/libproc.h
@@ -35,9 +35,6 @@
 #define ps_prochandle	proc_handle
 #define Lmid_t		int
 
-#define PR_RLC		0x0001
-#define PR_KLC		0x0002
-
 #include_next <libproc.h>
 
 #endif
diff --git a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_proc.h b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_proc.h
--- a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_proc.h
+++ b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_proc.h
@@ -40,6 +40,12 @@
 extern "C" {
 #endif
 
+enum dt_close_action {
+	DT_CLOSE_HANG,
+	DT_CLOSE_RUN,
+	DT_CLOSE_KILL,
+};
+
 typedef struct dt_proc {
 	dt_list_t dpr_list;		/* prev/next pointers for lru chain */
 	struct dt_proc *dpr_hash;	/* next pointer for pid hash chain */
@@ -60,6 +66,7 @@
 	uint8_t dpr_rdonly;		/* proc flag: opened read-only */
 	pthread_t dpr_tid;		/* control thread (or zero if none) */
 	dt_list_t dpr_bps;		/* list of dt_bkpt_t structures */
+	enum dt_close_action dpr_close;	/* do this to child when exiting */
 } dt_proc_t;
 
 typedef struct dt_proc_notify {
diff --git a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_proc.c b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_proc.c
--- a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_proc.c
+++ b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_proc.c
@@ -490,10 +490,11 @@
 	dt_proc_attach(dpr, B_FALSE);		/* enable rtld breakpoints */
 
 	/*
-	 * If PR_KLC is set, we created the process; otherwise we grabbed it.
-	 * Check for an appropriate stop request and wait for dt_proc_continue.
+	 * If DT_CLOSE_KILL is set, we created the process; otherwise we
+	 * grabbed it.  Check for an appropriate stop request and wait for
+	 * dt_proc_continue.
 	 */
-	if (proc_getflags(P) & PR_KLC)
+	if (dpr->dpr_close == DT_CLOSE_KILL)
 		dt_proc_stop(dpr, DT_PROC_STOP_CREATE);
 	else
 		dt_proc_stop(dpr, DT_PROC_STOP_GRAB);
@@ -586,7 +587,7 @@
 		}
 
 		if (Pstate(P) != PS_UNDEAD) {
-			if (dpr->dpr_quit && (proc_getflags(P) & PR_KLC)) {
+			if (dpr->dpr_quit && dpr->dpr_close == DT_CLOSE_KILL) {
 				/*
 				 * We're about to kill the child, so don't
 				 * bother resuming it.  In some cases, such as
@@ -679,19 +680,25 @@
 	assert(dpr != NULL);
 
 	/*
-	 * If neither PR_KLC nor PR_RLC is set, then the process is stopped by
+	 * If DT_CLOSE_HANG is set, then the process is stopped by
 	 * an external debugger and we were waiting in dt_proc_waitrun().
 	 * Leave the process in this condition using PRELEASE_HANG.
 	 */
-	if (!(proc_getflags(dpr->dpr_proc) & (PR_KLC | PR_RLC))) {
+	switch (dpr->dpr_close) {
+	case DT_CLOSE_HANG:
 		dt_dprintf("abandoning pid %d\n", (int)dpr->dpr_pid);
 		rflag = PRELEASE_HANG;
-	} else if (proc_getflags(dpr->dpr_proc) & PR_KLC) {
+		break;
+	case DT_CLOSE_KILL:
 		dt_dprintf("killing pid %d\n", (int)dpr->dpr_pid);
-		rflag = PRELEASE_KILL; /* apply kill-on-last-close */
-	} else {
+		rflag = PRELEASE_KILL;
+		break;
+	case DT_CLOSE_RUN:
 		dt_dprintf("releasing pid %d\n", (int)dpr->dpr_pid);
-		rflag = 0; /* apply run-on-last-close */
+		rflag = 0;
+		break;
+	default:
+		__unreachable();
 	}
 
 	if (dpr->dpr_tid) {
@@ -860,9 +867,7 @@
 
 	dpr->dpr_hdl = dtp;
 	dpr->dpr_pid = proc_getpid(dpr->dpr_proc);
-
-	(void) Punsetflags(dpr->dpr_proc, PR_RLC);
-	(void) Psetflags(dpr->dpr_proc, PR_KLC);
+	dpr->dpr_close = DT_CLOSE_KILL;
 
 	if (dt_proc_create_thread(dtp, dpr, dtp->dt_prcmode) != 0)
 		return (NULL); /* dt_proc_error() has been called for us */
@@ -927,9 +932,7 @@
 
 	dpr->dpr_hdl = dtp;
 	dpr->dpr_pid = pid;
-
-	(void) Punsetflags(dpr->dpr_proc, PR_KLC);
-	(void) Psetflags(dpr->dpr_proc, PR_RLC);
+	dpr->dpr_close = DT_CLOSE_RUN;
 
 	/*
 	 * If we are attempting to grab the process without a monitor
diff --git a/cddl/lib/libdtrace/libproc_compat.h b/cddl/lib/libdtrace/libproc_compat.h
--- a/cddl/lib/libdtrace/libproc_compat.h
+++ b/cddl/lib/libdtrace/libproc_compat.h
@@ -58,10 +58,8 @@
 #define	Prd_agent proc_rdagent
 #define	Prelease proc_detach
 #define	Psetbkpt proc_bkptset
-#define	Psetflags proc_setflags
 #define	Pstate proc_state
 #define	Psymbol_iter_by_addr proc_iter_symbyaddr
-#define	Punsetflags proc_clearflags
 #define	Pupdate_maps proc_rdagent
 #define	Pupdate_syms proc_updatesyms
 #define	Pxecbkpt proc_bkptexec