From 6047cdf6fcce29c21c4c6524ebafbee65c7ed27c Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 12 Jan 2024 16:46:15 +0100 Subject: [PATCH] rcu/exp: Fix RCU expedited parallel grace period kworker allocation failure recovery [ 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 Fixes: 9621fbee44df ("rcu: Move expedited grace period (GP) work to RT kthread_worker") Signed-off-by: Frederic Weisbecker Reviewed-by: Paul E. McKenney Signed-off-by: Boqun Feng Signed-off-by: Sasha Levin --- kernel/rcu/tree.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 4fe47ed95eeb..2e8d4572e862 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4677,6 +4677,7 @@ 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; }