From: "Paul E. McKenney" <paul...@linux.vnet.ibm.com>
This commit adds a object_debug option to rcutorture to allow the
debug-object-based checks for duplicate call_rcu() invocations to
be deterministically tested.
Signed-off-by: Paul E. McKenney <paul...@linux.vnet.ibm.com>
Cc: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
Cc: Sedat Dilek <sedat.di...@gmail.com>
Cc: Davidlohr Bueso <davidlohr.bu...@hp.com>
Cc: Rik van Riel <r...@surriel.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Tested-by: Sedat Dilek <sedat.di...@gmail.com>
[ paulmck: Banish mid-function ifdef, more or less per Josh Triplett. ]
---
kernel/rcutorture.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 3d936f0f..f5cf2bb 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -66,6 +66,7 @@ static int fqs_duration; /* Duration of bursts (us), 0
to disable. */
static int fqs_holdoff; /* Hold time within burst (us). */
static int fqs_stutter = 3; /* Wait time between bursts (s). */
static int n_barrier_cbs; /* Number of callbacks to test RCU barriers. */
+static int object_debug; /* Test object-debug double call_rcu()?. */
static int onoff_interval; /* Wait time between CPU hotplugs, 0=disable. */
static int onoff_holdoff; /* Seconds after boot before CPU hotplugs. */
static int shutdown_secs; /* Shutdown time (s). <=0 for no shutdown. */
@@ -100,6 +101,8 @@ module_param(fqs_stutter, int, 0444);
MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)");
module_param(n_barrier_cbs, int, 0444);
MODULE_PARM_DESC(n_barrier_cbs, "# of callbacks/kthreads for barrier testing");
+module_param(object_debug, int, 0444);
+MODULE_PARM_DESC(object_debug, "Enable debug-object double call_rcu()
testing");
module_param(onoff_interval, int, 0444);
MODULE_PARM_DESC(onoff_interval, "Time between CPU hotplugs (s), 0=disable");
module_param(onoff_holdoff, int, 0444);
@@ -1934,6 +1937,46 @@ rcu_torture_cleanup(void)
rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
}
+#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
+static void rcu_torture_leak_cb(struct rcu_head *rhp)
+{
+}
+
+static void rcu_torture_err_cb(struct rcu_head *rhp)
+{
+ /* This -might- happen due to race conditions, but is unlikely. */
+ pr_alert("rcutorture: duplicated callback was invoked.\n");
+}
+#endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+
+/*
+ * Verify that double-free causes debug-objects to complain, but only
+ * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
+ * cannot be carried out.
+ */
+static void rcu_test_debug_objects(void)
+{
+#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
+ struct rcu_head rh1;
+ struct rcu_head rh2;
+
+ init_rcu_head_on_stack(&rh1);
+ init_rcu_head_on_stack(&rh2);
+ pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n");
+ local_irq_disable(); /* Make it hard to finish grace period. */
+ call_rcu(&rh1, rcu_torture_leak_cb); /* start grace period. */
+ call_rcu(&rh2, rcu_torture_err_cb);
+ call_rcu(&rh2, rcu_torture_err_cb); /* duplicate callback. */
+ local_irq_enable();
+ rcu_barrier();
+ pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n");
+ destroy_rcu_head_on_stack(&rh1);
+ destroy_rcu_head_on_stack(&rh2);
+#else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+ pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing
duplicate call_rcu()\n");
+#endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+}
+
static int __init
rcu_torture_init(void)
{
@@ -2163,6 +2206,8 @@ rcu_torture_init(void)
firsterr = retval;
goto unwind;
}
+ if (object_debug)
+ rcu_test_debug_objects();
rcutorture_record_test_transition();
mutex_unlock(&fullstop_mutex);
return 0;
--
1.8.1.5
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