slight cleanup of single-threading code for KSE processes

4 files changed, 53 insertions, 6 deletions

diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index c01f4fa..02af5ee 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -162,11 +162,19 @@ execve(td, uap)
 	PROC_LOCK(p);
 	KASSERT((p->p_flag & P_INEXEC) == 0,
 	    ("%s(): process already has P_INEXEC flag", __func__));
-	if ((p->p_flag & P_KSES) && thread_single(SNGLE_EXIT)) {
-		PROC_UNLOCK(p);
-		return (ERESTART);	/* Try again later. */
+	if (p->p_flag & P_KSES) {
+		if (thread_single(SNGLE_EXIT)) {
+			PROC_UNLOCK(p);
+			return (ERESTART);	/* Try again later. */
+		}
+		/*
+		 * If we get here all other threads are dead,
+		 * so unset the associated flags and lose KSE mode.
+		 */
+		p->p_flag &= ~P_KSES;
+		td->td_flags &= ~TDF_UNBOUND;
+		thread_single_end();
 	}
-	/* If we get here all other threads are dead. */
 	p->p_flag |= P_INEXEC;
 	PROC_UNLOCK(p);
 
diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index e09e98d..5f9d1bd 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -768,6 +768,15 @@ again:
 	PROC_UNLOCK(p2);
 
 	/*
+	 * If other threads are waiting, let them continue now
+	 */
+	if (p1->p_flag & P_KSES) {
+		PROC_LOCK(p1);
+		thread_single_end();
+		PROC_UNLOCK(p1);
+	}
+
+	/*
 	 * Return child proc pointer to parent.
 	 */
 	*procp = p2;
diff --git a/sys/kern/kern_kse.c b/sys/kern/kern_kse.c
index 664dde4..0214237 100644
--- a/sys/kern/kern_kse.c
+++ b/sys/kern/kern_kse.c
@@ -804,6 +804,21 @@ thread_single_end(void)
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	p->p_flag &= ~P_STOPPED_SNGL;
 	p->p_singlethread = NULL;
-	thread_unsuspend(p);
+	/*
+	 * If there are other threads they mey now run,
+	 * unless of course there is a blanket 'stop order'
+	 * on the process. The single threader must be allowed
+	 * to continue however as this is a bad place to stop.
+	 */
+	if ((p->p_numthreads != 1) && (!P_SHOULDSTOP(p))) {
+		mtx_lock_spin(&sched_lock);
+		while (( td = TAILQ_FIRST(&p->p_suspended))) {
+			TAILQ_REMOVE(&p->p_suspended, td, td_runq);
+			p->p_suspcount--;
+			setrunqueue(td);
+		}
+		mtx_unlock_spin(&sched_lock);
+	}
 }
 
+
diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c
index 664dde4..0214237 100644
--- a/sys/kern/kern_thread.c
+++ b/sys/kern/kern_thread.c
@@ -804,6 +804,21 @@ thread_single_end(void)
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	p->p_flag &= ~P_STOPPED_SNGL;
 	p->p_singlethread = NULL;
-	thread_unsuspend(p);
+	/*
+	 * If there are other threads they mey now run,
+	 * unless of course there is a blanket 'stop order'
+	 * on the process. The single threader must be allowed
+	 * to continue however as this is a bad place to stop.
+	 */
+	if ((p->p_numthreads != 1) && (!P_SHOULDSTOP(p))) {
+		mtx_lock_spin(&sched_lock);
+		while (( td = TAILQ_FIRST(&p->p_suspended))) {
+			TAILQ_REMOVE(&p->p_suspended, td, td_runq);
+			p->p_suspcount--;
+			setrunqueue(td);
+		}
+		mtx_unlock_spin(&sched_lock);
+	}
 }
 
+