diff --git a/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c b/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c
index c803a01..fc6be8a 100644
--- a/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c
+++ b/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c
@@ -1001,6 +1001,9 @@ int
 fasttrap_pid_probe(struct reg *rp)
 {
 	proc_t *p = curproc;
+#if !defined(sun)
+	proc_t *pp;
+#endif
 	uintptr_t pc = rp->r_rip - 1;
 	uintptr_t new_pc = 0;
 	fasttrap_bucket_t *bucket;
@@ -1036,24 +1039,31 @@ fasttrap_pid_probe(struct reg *rp)
 	curthread->t_dtrace_regv = 0;
 #endif
 
-#if defined(sun)
 	/*
 	 * Treat a child created by a call to vfork(2) as if it were its
 	 * parent. We know that there's only one thread of control in such a
 	 * process: this one.
 	 */
+#if defined(sun)
 	while (p->p_flag & SVFORK) {
 		p = p->p_parent;
 	}
-#endif
 
-	PROC_LOCK(p);
-	_PHOLD(p);
 	pid = p->p_pid;
-#if defined(sun)
 	pid_mtx = &cpu_core[CPU->cpu_id].cpuc_pid_lock;
 	mutex_enter(pid_mtx);
+#else
+	pp = p;
+	sx_slock(&proctree_lock);
+	while (pp->p_vmspace == pp->p_pptr->p_vmspace)
+		pp = pp->p_pptr;
+	pid = pp->p_pid;
+	sx_sunlock(&proctree_lock);
+
+	PROC_LOCK(p);
+	_PHOLD(p);
 #endif
+
 	bucket = &fasttrap_tpoints.fth_table[FASTTRAP_TPOINTS_INDEX(pid, pc)];
 
 	/*
@@ -1073,9 +1083,10 @@ fasttrap_pid_probe(struct reg *rp)
 	if (tp == NULL) {
 #if defined(sun)
 		mutex_exit(pid_mtx);
-#endif
+#else
 		_PRELE(p);
 		PROC_UNLOCK(p);
+#endif
 		return (-1);
 	}
 
@@ -1197,9 +1208,10 @@ fasttrap_pid_probe(struct reg *rp)
 	 * tracepoint again later if we need to light up any return probes.
 	 */
 	tp_local = *tp;
-	PROC_UNLOCK(p);
 #if defined(sun)
 	mutex_exit(pid_mtx);
+#else
+	PROC_UNLOCK(p);
 #endif
 	tp = &tp_local;
 
@@ -1749,7 +1761,7 @@ fasttrap_pid_probe(struct reg *rp)
 #if defined(sun)
 		if (fasttrap_copyout(scratch, (char *)addr, i)) {
 #else
-		if (uwrite(curproc, scratch, i, addr)) {
+		if (uwrite(p, scratch, i, addr)) {
 #endif
 			fasttrap_sigtrap(p, curthread, pc);
 			new_pc = pc;
@@ -1808,10 +1820,12 @@ done:
 
 	rp->r_rip = new_pc;
 
+#if !defined(sun)
 	PROC_LOCK(p);
 	proc_write_regs(curthread, rp);
 	_PRELE(p);
 	PROC_UNLOCK(p);
+#endif
 
 	return (0);
 }
diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index 3198bd5..b3d9c24 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -676,12 +676,12 @@ do_fork(struct thread *td, int flags, struct proc *p2, struct thread *td2,
 
 #ifdef KDTRACE_HOOKS
 	/*
-	 * Tell the DTrace fasttrap provider about the new process
-	 * if it has registered an interest. We have to do this only after
-	 * p_state is PRS_NORMAL since the fasttrap module will use pfind()
-	 * later on.
+	 * Tell the DTrace fasttrap provider about the new process so that any
+	 * tracepoints inherited from the parent can be removed. We have to do
+	 * this only after p_state is PRS_NORMAL since the fasttrap module will
+	 * use pfind() later on.
 	 */
-	if (dtrace_fasttrap_fork)
+	if ((flags & RFMEM) == 0 && dtrace_fasttrap_fork)
 		dtrace_fasttrap_fork(p1, p2);
 #endif
 	if ((p1->p_flag & (P_TRACED | P_FOLLOWFORK)) == (P_TRACED |