From patchwork Mon Jul 23 09:43:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= X-Patchwork-Id: 947667 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=gmail.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 41YxPh6nl5z9s3N for ; Mon, 23 Jul 2018 19:43:20 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388211AbeGWKnj (ORCPT ); Mon, 23 Jul 2018 06:43:39 -0400 Received: from mga17.intel.com ([192.55.52.151]:21666 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388128AbeGWKni (ORCPT ); Mon, 23 Jul 2018 06:43:38 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 Jul 2018 02:43:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,393,1526367600"; d="scan'208";a="59893766" Received: from leyk-mobl.ger.corp.intel.com (HELO localhost.localdomain) ([10.252.50.153]) by orsmga006.jf.intel.com with ESMTP; 23 Jul 2018 02:43:08 -0700 From: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= To: bjorn.topel@gmail.com, magnus.karlsson@intel.com, ast@fb.com, daniel@iogearbox.net, netdev@vger.kernel.org Cc: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , qi.z.zhang@intel.com Subject: [PATCH bpf] xsk: fix poll/POLLIN premature returns Date: Mon, 23 Jul 2018 11:43:03 +0200 Message-Id: <20180723094303.6632-1-bjorn.topel@gmail.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Björn Töpel 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 --- net/xdp/xsk_queue.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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);