From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B377AC468BD for ; Sat, 8 Jun 2019 11:44:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D5BC214AF for ; Sat, 8 Jun 2019 11:44:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559994270; bh=VGQ3nTj9VgA/BJ8LC7D+7GRpevYOXm3z1Gff8jlbOEU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fVFxPLv/bHVnYSuJhbDmCkj115rnjovJjKFtS+rMYkaZQBJYX+1zG53ENn4BYI8dA shAeQ+k2TnDFGfiNTK35I51y3J3JvePzBrJ00xHhXyRY+vCgIVH9hVlHBfcn8ILzk6 pywJAXKwghJumWvPb/oCUkklz/QS+cBLIB4GEKA4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728840AbfFHLnl (ORCPT ); Sat, 8 Jun 2019 07:43:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:60948 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728801AbfFHLnf (ORCPT ); Sat, 8 Jun 2019 07:43:35 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D40542168B; Sat, 8 Jun 2019 11:43:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559994214; bh=VGQ3nTj9VgA/BJ8LC7D+7GRpevYOXm3z1Gff8jlbOEU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zHMFqCTX+zgKUb2rVdSMzKCnXWcbnL599pXTcni/iy9vYIDU3I0klDdbf56+qxZJf 70wNshqjJ/KwXVVgiz2Mg56U5NpFlji508c8L3Vm4dUE9AXqI6QXR2CSYXLhx0Ocvv eH/bv/0PtM2Nr7nxAyA9JIeDjMwDYTtS3P1OZblg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Igor Russkikh , Igor Russkikh , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 24/49] net: aquantia: tx clean budget logic error Date: Sat, 8 Jun 2019 07:42:05 -0400 Message-Id: <20190608114232.8731-24-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190608114232.8731-1-sashal@kernel.org> References: <20190608114232.8731-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Igor Russkikh [ Upstream commit 31bafc49a7736989e4c2d9f7280002c66536e590 ] In case no other traffic happening on the ring, full tx cleanup may not be completed. That may cause socket buffer to overflow and tx traffic to stuck until next activity on the ring happens. This is due to logic error in budget variable decrementor. Variable is compared with zero, and then post decremented, causing it to become MAX_INT. Solution is remove decrementor from the `for` statement and rewrite it in a clear way. Fixes: b647d3980948e ("net: aquantia: Add tx clean budget and valid budget handling logic") Signed-off-by: Igor Russkikh Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/aquantia/atlantic/aq_ring.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c index 6f3312350cac..b3c7994d73eb 100644 --- a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c +++ b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c @@ -139,10 +139,10 @@ void aq_ring_queue_stop(struct aq_ring_s *ring) bool aq_ring_tx_clean(struct aq_ring_s *self) { struct device *dev = aq_nic_get_dev(self->aq_nic); - unsigned int budget = AQ_CFG_TX_CLEAN_BUDGET; + unsigned int budget; - for (; self->sw_head != self->hw_head && budget--; - self->sw_head = aq_ring_next_dx(self, self->sw_head)) { + for (budget = AQ_CFG_TX_CLEAN_BUDGET; + budget && self->sw_head != self->hw_head; budget--) { struct aq_ring_buff_s *buff = &self->buff_ring[self->sw_head]; if (likely(buff->is_mapped)) { @@ -167,6 +167,7 @@ bool aq_ring_tx_clean(struct aq_ring_s *self) buff->pa = 0U; buff->eop_index = 0xffffU; + self->sw_head = aq_ring_next_dx(self, self->sw_head); } return !!budget; -- 2.20.1