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| author | Paul E. McKenney <paulmck@kernel.org> | 2020-01-04 21:44:41 +0300 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-04-27 21:01:16 +0300 |
| commit | 5822b8126ff01e0baaf7d5168adc4ac8aeae088c (patch) | |
| tree | 8d908940c9a3cfa446b01d68465814795c7fa6de /kernel/rcu/tree_plugin.h | |
| parent | b68c6146512d92f6d570d26e1873497ade2cc4cb (diff) | |
| download | linux-5822b8126ff01e0baaf7d5168adc4ac8aeae088c.tar.xz | |
rcu: Add WRITE_ONCE() to rcu_node ->boost_tasks
The rcu_node structure's ->boost_tasks field is read locklessly, so this
commit adds the WRITE_ONCE() to an update in order to provide proper
documentation and READ_ONCE()/WRITE_ONCE() pairing.
This data race was reported by KCSAN. Not appropriate for backporting
due to failure being unlikely.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/tree_plugin.h')
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index ed6bb460c7c6..664d0aa48edb 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -505,7 +505,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) /* Snapshot ->boost_mtx ownership w/rnp->lock held. */ drop_boost_mutex = rt_mutex_owner(&rnp->boost_mtx) == t; if (&t->rcu_node_entry == rnp->boost_tasks) - rnp->boost_tasks = np; + WRITE_ONCE(rnp->boost_tasks, np); } /* @@ -1082,7 +1082,7 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags) rnp->qsmask == 0 && (ULONG_CMP_GE(jiffies, rnp->boost_time) || rcu_state.cbovld))) { if (rnp->exp_tasks == NULL) - rnp->boost_tasks = rnp->gp_tasks; + WRITE_ONCE(rnp->boost_tasks, rnp->gp_tasks); raw_spin_unlock_irqrestore_rcu_node(rnp, flags); rcu_wake_cond(rnp->boost_kthread_task, READ_ONCE(rnp->boost_kthread_status)); |