net: add {READ|WRITE}_ONCE() annotations on ->rskq_accept_head

reqsk_queue_empty() is called from inet_csk_listen_poll() while
other cpus might write ->rskq_accept_head value.

Use {READ|WRITE}_ONCE() to avoid compiler tricks
and potential KCSAN splats.

Fixes: fff1f3001c ("tcp: add a spinlock to protect struct request_sock_queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
This commit is contained in:
Eric Dumazet 2019-10-09 14:51:20 -07:00 committed by Jakub Kicinski
parent 503978aca4
commit 60b173ca3d
3 changed files with 4 additions and 4 deletions

View File

@ -775,7 +775,7 @@ static int pvcalls_back_poll(struct xenbus_device *dev,
mappass->reqcopy = *req;
icsk = inet_csk(mappass->sock->sk);
queue = &icsk->icsk_accept_queue;
data = queue->rskq_accept_head != NULL;
data = READ_ONCE(queue->rskq_accept_head) != NULL;
if (data) {
mappass->reqcopy.cmd = 0;
ret = 0;

View File

@ -185,7 +185,7 @@ void reqsk_fastopen_remove(struct sock *sk, struct request_sock *req,
static inline bool reqsk_queue_empty(const struct request_sock_queue *queue)
{
return queue->rskq_accept_head == NULL;
return READ_ONCE(queue->rskq_accept_head) == NULL;
}
static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue,
@ -197,7 +197,7 @@ static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue
req = queue->rskq_accept_head;
if (req) {
sk_acceptq_removed(parent);
queue->rskq_accept_head = req->dl_next;
WRITE_ONCE(queue->rskq_accept_head, req->dl_next);
if (queue->rskq_accept_head == NULL)
queue->rskq_accept_tail = NULL;
}

View File

@ -934,7 +934,7 @@ struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
req->sk = child;
req->dl_next = NULL;
if (queue->rskq_accept_head == NULL)
queue->rskq_accept_head = req;
WRITE_ONCE(queue->rskq_accept_head, req);
else
queue->rskq_accept_tail->dl_next = req;
queue->rskq_accept_tail = req;