6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Paul E. McKenney <paulmck@xxxxxxxxxx>
[ Upstream commit 0ae9942f03d0d034fdb0a4f44fc99f62a3107987 ]
When using rcutorture as a module, there are a number of conditions that
can abort the modprobe operation, for example, when attempting to run
both RCU CPU stall warning tests and forward-progress tests. This can
cause rcu_torture_cleanup() to be invoked on the unwind path out of
rcu_rcu_torture_init(), which will mean that rcu_gp_slow_unregister()
is invoked without a matching rcu_gp_slow_register(). This will cause
a splat because rcu_gp_slow_unregister() is passed rcu_fwd_cb_nodelay,
which does not match a NULL pointer.
This commit therefore forgives a mismatch involving a NULL pointer, thus
avoiding this false-positive splat.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
kernel/rcu/tree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 86923a8914007..dd6e15ca63b0c 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1336,7 +1336,7 @@ EXPORT_SYMBOL_GPL(rcu_gp_slow_register);
/* Unregister a counter, with NULL for not caring which. */
void rcu_gp_slow_unregister(atomic_t *rgssp)
{
- WARN_ON_ONCE(rgssp && rgssp != rcu_gp_slow_suppress);
+ WARN_ON_ONCE(rgssp && rgssp != rcu_gp_slow_suppress && rcu_gp_slow_suppress != NULL);
WRITE_ONCE(rcu_gp_slow_suppress, NULL);
}
--
2.43.0
