In a threaded process, don't kill off all the other threads until we have a

reasonable chance that the eceve() is going to succeeed. I.e.
wait until we've done the permission checks etc.

MFC after:	1 week

1 files changed, 17 insertions, 11 deletions

diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index 1a79f48a3273..16dd5e62042d 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -254,17 +254,6 @@ kern_execve(td, fname, argv, envv, mac_p)
 	PROC_LOCK(p);
 	KASSERT((p->p_flag & P_INEXEC) == 0,
 	    ("%s(): process already has P_INEXEC flag", __func__));
-	if (p->p_flag & P_HADTHREADS) {
-		if (thread_single(SINGLE_EXIT)) {
-			PROC_UNLOCK(p);
-			mtx_unlock(&Giant);
-			return (ERESTART);	/* Try again later. */
-		}
-		/*
-		 * If we get here all other threads are dead,
-		 * and threading mode has been turned off
-		 */
-	}
 	p->p_flag |= P_INEXEC;
 	PROC_UNLOCK(p);
 
@@ -356,6 +345,23 @@ interpret:
 	if (error)
 		goto exec_fail_dealloc;
 
+	PROC_LOCK(p);
+	if (p->p_flag & P_HADTHREADS) {
+		if (thread_single(SINGLE_EXIT)) {
+			PROC_UNLOCK(p);
+			error = ERESTART;
+			goto exec_fail_dealloc;
+		}
+		/*
+		 * If we get here all other threads are dead,
+		 * and threading mode has been turned off.
+		 * Returning to the user from this point on
+		 * may confuse the thread library as some threads
+		 * will have just "died".
+		 */
+	}
+	PROC_UNLOCK(p);
+
 	/*
 	 *	If the current process has a special image activator it
 	 *	wants to try first, call it.   For example, emulating shell