Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH rcu 2/3] rcu: Mark ->expmask access in synchronize_rcu_expedited_wait() | Date | Fri, 4 Feb 2022 14:55:06 -0800 |
| |
This commit adds a READ_ONCE() to an access to the rcu_node structure's ->expmask field to prevent compiler mischief. Detected by KCSAN.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org> --- kernel/rcu/tree_exp.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 1568c8ef185b2..60197ea24ceb9 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -502,7 +502,8 @@ static void synchronize_rcu_expedited_wait(void) if (synchronize_rcu_expedited_wait_once(1)) return; rcu_for_each_leaf_node(rnp) { - for_each_leaf_node_cpu_mask(rnp, cpu, rnp->expmask) { + mask = READ_ONCE(rnp->expmask); + for_each_leaf_node_cpu_mask(rnp, cpu, mask) { rdp = per_cpu_ptr(&rcu_data, cpu); if (rdp->rcu_forced_tick_exp) continue; -- 2.31.1.189.g2e36527f23
| |