mirror of
https://github.com/torvalds/linux.git
synced 2025-04-06 09:13:43 +00:00
5a562b8b3f
Switch for using of get_state_synchronize_rcu_full() and poll_state_synchronize_rcu_full() pair to debug a normal synchronize_rcu() call. Just using "not" full APIs to identify if a grace period is passed or not might lead to a false-positive kernel splat. It can happen, because get_state_synchronize_rcu() compresses both normal and expedited states into one single unsigned long value, so a poll_state_synchronize_rcu() can miss GP-completion when synchronize_rcu()/synchronize_rcu_expedited() concurrently run. To address this, switch to poll_state_synchronize_rcu_full() and get_state_synchronize_rcu_full() APIs, which use separate variables for expedited and normal states. Reported-by: cheung wall <zzqq0103.hey@gmail.com> Closes: https://lore.kernel.org/lkml/Z5ikQeVmVdsWQrdD@pc636/T/ Fixes: 988f569ae041 ("rcu: Reduce synchronize_rcu() latency") Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/20250227131613.52683-3-urezki@gmail.com Signed-off-by: Boqun Feng <boqun.feng@gmail.com>