diff options
| author | Alan Huang <mmpgouride@gmail.com> | 2023-07-06 10:28:48 +0000 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2023-08-16 14:27:41 -0700 |
| commit | efd04f8a8b45b8b98704b5860e363bab239b8bae (patch) | |
| tree | ccfaab884686930f555c931a7fa48d58e8965f8b | |
| parent | 3292ba0229dbe5f3e79b78b230354ada2888dc29 (diff) | |
rcu: Use WRITE_ONCE() for assignments to ->next for rculist_nulls
When the objects managed by rculist_nulls are allocated with
SLAB_TYPESAFE_BY_RCU, old readers may still hold references to an object
even though it is just now being added, which means the modification of
->next is visible to readers. This patch therefore uses WRITE_ONCE()
for assignments to ->next.
Signed-off-by: Alan Huang <mmpgouride@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
| -rw-r--r-- | include/linux/rculist_nulls.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/rculist_nulls.h b/include/linux/rculist_nulls.h index ba4c00dd8005..89186c499dd4 100644 --- a/include/linux/rculist_nulls.h +++ b/include/linux/rculist_nulls.h @@ -101,7 +101,7 @@ static inline void hlist_nulls_add_head_rcu(struct hlist_nulls_node *n, { struct hlist_nulls_node *first = h->first; - n->next = first; + WRITE_ONCE(n->next, first); WRITE_ONCE(n->pprev, &h->first); rcu_assign_pointer(hlist_nulls_first_rcu(h), n); if (!is_a_nulls(first)) @@ -137,7 +137,7 @@ static inline void hlist_nulls_add_tail_rcu(struct hlist_nulls_node *n, last = i; if (last) { - n->next = last->next; + WRITE_ONCE(n->next, last->next); n->pprev = &last->next; rcu_assign_pointer(hlist_nulls_next_rcu(last), n); } else { |