[PATCH tip/core/rcu 13/17] rcutorture: Make object_debug also double call_rcu() heap object

paulmck
2021-01-06T17:19:10Z

This commit provides a test for call_rcu() printing the allocation address
of a double-freed callback by double-freeing a callback allocated via
kmalloc(). However, this commit does not depend on any other commit.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/rcutorture.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 4a0c6e6..72fd6bb 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -2782,6 +2782,7 @@ static void rcu_test_debug_objects(void)
#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
struct rcu_head rh1;
struct rcu_head rh2;
+ struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);

init_rcu_head_on_stack(&rh1);
init_rcu_head_on_stack(&rh2);
@@ -2794,6 +2795,10 @@ static void rcu_test_debug_objects(void)
local_irq_disable(); /* Make it harder to start a new grace period. */
call_rcu(&rh2, rcu_torture_leak_cb);
call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
+ if (rhp) {
+ call_rcu(rhp, rcu_torture_leak_cb);
+ call_rcu(rhp, rcu_torture_err_cb); /* Another duplicate callback. */
+ }
local_irq_enable();
rcu_read_unlock();
preempt_enable();
--
2.9.5