From 3d6e43c75d6bab212e8bc142585ee36eb8e2e5d9 Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@kernel.org>
Date: Tue, 3 Mar 2020 15:02:50 -0800
Subject: [PATCH] rcutorture: Add torture tests for RCU Tasks Rude

This commit adds the definitions required to torture the rude flavor of
RCU tasks.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/Kconfig.debug                      |  2 ++
 kernel/rcu/rcu.h                              |  1 +
 kernel/rcu/rcutorture.c                       | 31 +++++++++++++++++--
 .../selftests/rcutorture/configs/rcu/CFLIST   |  1 +
 .../selftests/rcutorture/configs/rcu/RUDE01   | 10 ++++++
 .../rcutorture/configs/rcu/RUDE01.boot        |  1 +
 6 files changed, 44 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/RUDE01
 create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/RUDE01.boot

diff --git a/kernel/rcu/Kconfig.debug b/kernel/rcu/Kconfig.debug
index 4aa02eee8f6c..b5f3545b0cfb 100644
--- a/kernel/rcu/Kconfig.debug
+++ b/kernel/rcu/Kconfig.debug
@@ -29,6 +29,7 @@ config RCU_PERF_TEST
 	select TORTURE_TEST
 	select SRCU
 	select TASKS_RCU
+	select TASKS_RUDE_RCU
 	default n
 	help
 	  This option provides a kernel module that runs performance
@@ -46,6 +47,7 @@ config RCU_TORTURE_TEST
 	select TORTURE_TEST
 	select SRCU
 	select TASKS_RCU
+	select TASKS_RUDE_RCU
 	default n
 	help
 	  This option provides a kernel module that runs torture tests
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 00ddc92c5774..c5746202e124 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -441,6 +441,7 @@ void rcu_request_urgent_qs_task(struct task_struct *t);
 enum rcutorture_type {
 	RCU_FLAVOR,
 	RCU_TASKS_FLAVOR,
+	RCU_TASKS_RUDE_FLAVOR,
 	RCU_TRIVIAL_FLAVOR,
 	SRCU_FLAVOR,
 	INVALID_RCU_FLAVOR
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index fbb3e6247443..6b0663801a82 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -730,6 +730,33 @@ static struct rcu_torture_ops trivial_ops = {
 	.name		= "trivial"
 };
 
+/*
+ * Definitions for rude RCU-tasks torture testing.
+ */
+
+static void rcu_tasks_rude_torture_deferred_free(struct rcu_torture *p)
+{
+	call_rcu_tasks_rude(&p->rtort_rcu, rcu_torture_cb);
+}
+
+static struct rcu_torture_ops tasks_rude_ops = {
+	.ttype		= RCU_TASKS_RUDE_FLAVOR,
+	.init		= rcu_sync_torture_init,
+	.readlock	= rcu_torture_read_lock_trivial,
+	.read_delay	= rcu_read_delay,  /* just reuse rcu's version. */
+	.readunlock	= rcu_torture_read_unlock_trivial,
+	.get_gp_seq	= rcu_no_completed,
+	.deferred_free	= rcu_tasks_rude_torture_deferred_free,
+	.sync		= synchronize_rcu_tasks_rude,
+	.exp_sync	= synchronize_rcu_tasks_rude,
+	.call		= call_rcu_tasks_rude,
+	.cb_barrier	= rcu_barrier_tasks_rude,
+	.fqs		= NULL,
+	.stats		= NULL,
+	.irq_capable	= 1,
+	.name		= "tasks-rude"
+};
+
 static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old)
 {
 	if (!cur_ops->gp_diff)
@@ -739,7 +766,7 @@ static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old)
 
 static bool __maybe_unused torturing_tasks(void)
 {
-	return cur_ops == &tasks_ops;
+	return cur_ops == &tasks_ops || cur_ops == &tasks_rude_ops;
 }
 
 /*
@@ -2413,7 +2440,7 @@ rcu_torture_init(void)
 	int firsterr = 0;
 	static struct rcu_torture_ops *torture_ops[] = {
 		&rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
-		&busted_srcud_ops, &tasks_ops, &trivial_ops,
+		&busted_srcud_ops, &tasks_ops, &tasks_rude_ops, &trivial_ops,
 	};
 
 	if (!torture_init_begin(torture_type, verbose))
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/CFLIST b/tools/testing/selftests/rcutorture/configs/rcu/CFLIST
index c3c1fb5a9e1f..ec0c72f4ccba 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/CFLIST
+++ b/tools/testing/selftests/rcutorture/configs/rcu/CFLIST
@@ -14,3 +14,4 @@ TINY02
 TASKS01
 TASKS02
 TASKS03
+RUDE01
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/RUDE01 b/tools/testing/selftests/rcutorture/configs/rcu/RUDE01
new file mode 100644
index 000000000000..bafe94cbd739
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/configs/rcu/RUDE01
@@ -0,0 +1,10 @@
+CONFIG_SMP=y
+CONFIG_NR_CPUS=2
+CONFIG_HOTPLUG_CPU=y
+CONFIG_PREEMPT_NONE=n
+CONFIG_PREEMPT_VOLUNTARY=n
+CONFIG_PREEMPT=y
+CONFIG_DEBUG_LOCK_ALLOC=y
+CONFIG_PROVE_LOCKING=y
+#CHECK#CONFIG_PROVE_RCU=y
+CONFIG_RCU_EXPERT=y
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/RUDE01.boot b/tools/testing/selftests/rcutorture/configs/rcu/RUDE01.boot
new file mode 100644
index 000000000000..9363708c9075
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/configs/rcu/RUDE01.boot
@@ -0,0 +1 @@
+rcutorture.torture_type=tasks-rude