Merging upstream version 6.9.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 17 insertions, 12 deletions

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 7567ca8e74..cf2e907534 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1368,9 +1368,13 @@ rcu_torture_writer(void *arg)
 	struct rcu_torture *rp;
 	struct rcu_torture *old_rp;
 	static DEFINE_TORTURE_RANDOM(rand);
+	unsigned long stallsdone = jiffies;
 	bool stutter_waited;
 	unsigned long ulo[NUM_ACTIVE_RCU_POLL_OLDSTATE];
 
+	// If a new stall test is added, this must be adjusted.
+	if (stall_cpu_holdoff + stall_gp_kthread + stall_cpu)
+		stallsdone += (stall_cpu_holdoff + stall_gp_kthread + stall_cpu + 60) * HZ;
 	VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
 	if (!can_expedite)
 		pr_alert("%s" TORTURE_FLAG
@@ -1576,11 +1580,11 @@ rcu_torture_writer(void *arg)
 		    !atomic_read(&rcu_fwd_cb_nodelay) &&
 		    !cur_ops->slow_gps &&
 		    !torture_must_stop() &&
-		    boot_ended)
+		    boot_ended &&
+		    time_after(jiffies, stallsdone))
 			for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++)
 				if (list_empty(&rcu_tortures[i].rtort_free) &&
-				    rcu_access_pointer(rcu_torture_current) !=
-				    &rcu_tortures[i]) {
+				    rcu_access_pointer(rcu_torture_current) != &rcu_tortures[i]) {
 					tracing_off();
 					show_rcu_gp_kthreads();
 					WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count);
@@ -1993,7 +1997,8 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid)
 	preempt_disable();
 	pipe_count = READ_ONCE(p->rtort_pipe_count);
 	if (pipe_count > RCU_TORTURE_PIPE_LEN) {
-		/* Should not happen, but... */
+		// Should not happen in a correct RCU implementation,
+		// happens quite often for torture_type=busted.
 		pipe_count = RCU_TORTURE_PIPE_LEN;
 	}
 	completed = cur_ops->get_gp_seq();
@@ -2441,7 +2446,8 @@ static struct notifier_block rcu_torture_stall_block = {
 
 /*
  * CPU-stall kthread.  It waits as specified by stall_cpu_holdoff, then
- * induces a CPU stall for the time specified by stall_cpu.
+ * induces a CPU stall for the time specified by stall_cpu.  If a new
+ * stall test is added, stallsdone in rcu_torture_writer() must be adjusted.
  */
 static int rcu_torture_stall(void *args)
 {
@@ -2481,8 +2487,8 @@ static int rcu_torture_stall(void *args)
 			preempt_disable();
 		pr_alert("%s start on CPU %d.\n",
 			  __func__, raw_smp_processor_id());
-		while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(),
-				    stop_at))
+		while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(), stop_at) &&
+		       !kthread_should_stop())
 			if (stall_cpu_block) {
 #ifdef CONFIG_PREEMPTION
 				preempt_schedule();
@@ -3035,11 +3041,12 @@ static void rcu_torture_barrier_cbf(struct rcu_head *rcu)
 }
 
 /* IPI handler to get callback posted on desired CPU, if online. */
-static void rcu_torture_barrier1cb(void *rcu_void)
+static int rcu_torture_barrier1cb(void *rcu_void)
 {
 	struct rcu_head *rhp = rcu_void;
 
 	cur_ops->call(rhp, rcu_torture_barrier_cbf);
+	return 0;
 }
 
 /* kthread function to register callbacks used to test RCU barriers. */
@@ -3065,11 +3072,9 @@ static int rcu_torture_barrier_cbs(void *arg)
 		 * The above smp_load_acquire() ensures barrier_phase load
 		 * is ordered before the following ->call().
 		 */
-		if (smp_call_function_single(myid, rcu_torture_barrier1cb,
-					     &rcu, 1)) {
-			// IPI failed, so use direct call from current CPU.
+		if (smp_call_on_cpu(myid, rcu_torture_barrier1cb, &rcu, 1))
 			cur_ops->call(&rcu, rcu_torture_barrier_cbf);
-		}
+
 		if (atomic_dec_and_test(&barrier_cbs_count))
 			wake_up(&barrier_wq);
 	} while (!torture_must_stop());