From: Frederic Weisbecker frederic@kernel.org
[ Upstream commit a636c5e6f8fc34be520277e69c7c6ee1d4fc1d17 ]
Under CONFIG_RCU_EXP_KTHREAD=y, the nodes initialization for expedited grace periods is queued to a kworker. However if the allocation of that kworker failed, the nodes initialization is performed synchronously by the caller instead.
Now the check for kworker initialization failure relies on the kworker pointer to be NULL while its value might actually encapsulate an allocation failure error.
Make sure to handle this case.
Reviewed-by: Kalesh Singh kaleshsingh@google.com Fixes: 9621fbee44df ("rcu: Move expedited grace period (GP) work to RT kthread_worker") Signed-off-by: Frederic Weisbecker frederic@kernel.org Reviewed-by: Paul E. McKenney paulmck@kernel.org Signed-off-by: Boqun Feng boqun.feng@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/rcu/tree.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index b2bccfd37c383..38c86f2c040b5 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4749,6 +4749,7 @@ static void __init rcu_start_exp_gp_kworkers(void) rcu_exp_par_gp_kworker = kthread_create_worker(0, par_gp_kworker_name); if (IS_ERR_OR_NULL(rcu_exp_par_gp_kworker)) { pr_err("Failed to create %s!\n", par_gp_kworker_name); + rcu_exp_par_gp_kworker = NULL; kthread_destroy_worker(rcu_exp_gp_kworker); return; }