Commit d24458e4 authored Jul 23, 2018 by Björn Töpel Committed by Daniel Borkmann Jul 26, 2018

xsk: fix poll/POLLIN premature returns



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 <qi.z.zhang@intel.com>
Tested-by: Qi Zhang <qi.z.zhang@intel.com>
Fixes: c497176c ("xsk: add Rx receive functions and poll support")
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

parent 9e4e5b5c

net/xdp/xsk_queue.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);

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