From d24458e43b103c7eb7b2fd57bcac392fd7750438 Mon Sep 17 00:00:00 2001 From: Björn Töpel Date: Mon, 23 Jul 2018 11:43:03 +0200 Subject: xsk: fix poll/POLLIN premature returns MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Polling for the ingress queues relies on reading the producer/consumer pointers of the Rx queue. Prior this commit, a cached consumer pointer could be used, instead of the actual consumer pointer and therefore report POLLIN prematurely. This patch makes sure that the non-cached consumer pointer is used instead. Reported-by: Qi Zhang Tested-by: Qi Zhang Fixes: c497176cb2e4 ("xsk: add Rx receive functions and poll support") Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann --- net/xdp/xsk_queue.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/xdp') diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h index 52ecaf770642..8a64b150be54 100644 --- a/net/xdp/xsk_queue.h +++ b/net/xdp/xsk_queue.h @@ -250,7 +250,7 @@ static inline bool xskq_full_desc(struct xsk_queue *q) static inline bool xskq_empty_desc(struct xsk_queue *q) { - return xskq_nb_free(q, q->prod_tail, 1) == q->nentries; + return xskq_nb_free(q, q->prod_tail, q->nentries) == q->nentries; } void xskq_set_umem(struct xsk_queue *q, struct xdp_umem_props *umem_props); -- cgit v1.2.3-59-g8ed1b