From 049dfe96baf97228a9e98eaf50a8a7386ec7a483 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 2 Oct 2024 16:57:38 +0200 Subject: [PATCH] rcu: Report callbacks enqueued on offline CPU blind spot Callbacks enqueued after rcutree_report_cpu_dead() fall into RCU barrier blind spot. Report any potential misuse. Reported-by: Paul E. McKenney Signed-off-by: Frederic Weisbecker Signed-off-by: Paul E. McKenney Signed-off-by: Uladzislau Rezki (Sony) --- kernel/rcu/tree.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index ff98233d4aa5..24f1cb292a92 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3084,8 +3084,11 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in) head->func = func; head->next = NULL; kasan_record_aux_stack_noalloc(head); + local_irq_save(flags); rdp = this_cpu_ptr(&rcu_data); + RCU_LOCKDEP_WARN(!rcu_rdp_cpu_online(rdp), "Callback enqueued on offline CPU!"); + lazy = lazy_in && !rcu_async_should_hurry(); /* Add the callback to our list. */ -- 2.25.1