diff --git a/gdb/testsuite/gdb.threads/ia64-sigill.c b/gdb/testsuite/gdb.threads/ia64-sigill.c
index 4833e47..a685fb0 100644
--- a/gdb/testsuite/gdb.threads/ia64-sigill.c
+++ b/gdb/testsuite/gdb.threads/ia64-sigill.c
@@ -44,6 +44,8 @@ static pthread_mutex_t thread2_tid_mutex = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_
 
 static pthread_mutex_t terminate_mutex = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP;
 
+static pthread_barrier_t threads_started_barrier;
+
 /* Do not use alarm as it would create a ptrace event which would hang up us if
    we are being traced by GDB which we stopped ourselves.  */
 
@@ -78,6 +80,8 @@ thread_func (void *threadno_voidp)
   int threadno = (intptr_t) threadno_voidp;
   int i;
 
+  pthread_barrier_wait (&threads_started_barrier);
+
   switch (threadno)
   {
     case 1:
@@ -272,6 +276,8 @@ main (int argc, char **argv)
 
   timed_mutex_lock (&terminate_mutex);
 
+  pthread_barrier_init (&threads_started_barrier, NULL, 3);
+
   i = pthread_create (&thread1, NULL, thread_func, (void *) (intptr_t) 1);
   assert (i == 0);
 
@@ -298,6 +304,11 @@ main (int argc, char **argv)
 
   atexit (cleanup);
 
+  /* Wait until all threads are seen running.  On Linux (at least),
+     new threads start stopped, and the debugger must resume them.
+     Need to wait for that before stopping GDB.  */
+  pthread_barrier_wait (&threads_started_barrier);
+
   printf ("Stopping GDB PID %lu.\n", (unsigned long) tracer);
 
   if (tracer)
diff --git a/gdb/testsuite/gdb.threads/siginfo-threads.c b/gdb/testsuite/gdb.threads/siginfo-threads.c
index 7aa1ea2..b86df54 100644
--- a/gdb/testsuite/gdb.threads/siginfo-threads.c
+++ b/gdb/testsuite/gdb.threads/siginfo-threads.c
@@ -54,6 +54,8 @@ static int thread2_sigusr2_hit;
 static pthread_mutex_t terminate_mutex
   = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP;
 
+static pthread_barrier_t threads_started_barrier;
+
 /* Do not use alarm as it would create a ptrace event which would hang
    us up if we are being traced by GDB, which we stopped
    ourselves.  */
@@ -128,6 +130,8 @@ thread1_func (void *unused)
 {
   int i;
 
+  pthread_barrier_wait (&threads_started_barrier);
+
   timed_mutex_lock (&thread1_tid_mutex);
 
   /* THREAD1_TID_MUTEX must be already locked to avoid a race.  */
@@ -163,6 +167,8 @@ thread2_func (void *unused)
 {
   int i;
 
+  pthread_barrier_wait (&threads_started_barrier);
+
   timed_mutex_lock (&thread2_tid_mutex);
 
   /* THREAD2_TID_MUTEX must be already locked to avoid a race.  */
@@ -354,6 +360,8 @@ main (int argc, char **argv)
   assert_perror (errno);
   assert (i == 0);
 
+  pthread_barrier_init (&threads_started_barrier, NULL, 3);
+
   i = pthread_create (&thread1, NULL, thread1_func, NULL);
   assert (i == 0);
 
@@ -380,6 +388,11 @@ main (int argc, char **argv)
 
   atexit (cleanup);
 
+  /* Wait until all threads are seen running.  On Linux (at least),
+     new threads start stopped, and the debugger must resume them.
+     Need to wait for that before stopping GDB.  */
+  pthread_barrier_wait (&threads_started_barrier);
+
   printf ("Stopping GDB PID %lu.\n", (unsigned long) tracer);
 
   if (tracer)
diff --git a/gdb/testsuite/gdb.threads/watchthreads-reorder.c b/gdb/testsuite/gdb.threads/watchthreads-reorder.c
index 315104a..05b200c 100644
--- a/gdb/testsuite/gdb.threads/watchthreads-reorder.c
+++ b/gdb/testsuite/gdb.threads/watchthreads-reorder.c
@@ -44,6 +44,8 @@ static pthread_mutex_t thread2_tid_mutex = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_
 
 static pthread_mutex_t terminate_mutex = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP;
 
+static pthread_barrier_t threads_started_barrier;
+
 /* These variables must have lower in-memory addresses than thread1_rwatch and
    thread2_rwatch so that they take their watchpoint slots.  */
 
@@ -87,6 +89,8 @@ thread1_func (void *unused)
   int i;
   volatile int rwatch_store;
 
+  pthread_barrier_wait (&threads_started_barrier);
+
   timed_mutex_lock (&thread1_tid_mutex);
 
   /* THREAD1_TID_MUTEX must be already locked to avoid race.  */
@@ -113,6 +117,8 @@ thread2_func (void *unused)
   int i;
   volatile int rwatch_store;
 
+  pthread_barrier_wait (&threads_started_barrier);
+
   timed_mutex_lock (&thread2_tid_mutex);
 
   /* THREAD2_TID_MUTEX must be already locked to avoid race.  */
@@ -279,6 +285,8 @@ main (int argc, char **argv)
 
   timed_mutex_lock (&terminate_mutex);
 
+  pthread_barrier_init (&threads_started_barrier, NULL, 3);
+
   i = pthread_create (&thread1, NULL, thread1_func, NULL);
   assert (i == 0);
 
@@ -305,6 +313,11 @@ main (int argc, char **argv)
 
   atexit (cleanup);
 
+  /* Wait until all threads are seen running.  On Linux (at least),
+     new threads start stopped, and the debugger must resume them.
+     Need to wait for that before stopping GDB.  */
+  pthread_barrier_wait (&threads_started_barrier);
+
   printf ("Stopping GDB PID %lu.\n", (unsigned long) tracer);
 
   if (tracer)
