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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42AF8C4332F for ; Mon, 20 Dec 2021 14:16:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233527AbhLTOQe (ORCPT ); Mon, 20 Dec 2021 09:16:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54560 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233487AbhLTOQd (ORCPT ); Mon, 20 Dec 2021 09:16:33 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF54EC061574; Mon, 20 Dec 2021 06:16:32 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7CD896116D; Mon, 20 Dec 2021 14:16:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26E6FC36AE8; Mon, 20 Dec 2021 14:16:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1640009791; bh=7sGEbzlUMwIOcKcozCdxOdT+mDoelkMEDXmoiUlQOVE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=R0Vf0MB+Tw+29zYUdgx7tCRafPSTzaVDYi9ZNCBZo3VguStkdHBbdLzLY0/jb/EAu SyGEIeOxRZSWkwLiOcYF4LVJ6NVsEQH4ORdYNygBi/l9HZjw4J52SMTBZy5lUOpXZY IBCoq/2RCeXC/NrQ4mDifKCH5FDz5b27NvVXH/BI= Date: Mon, 20 Dec 2021 15:16:28 +0100 From: Greg KH To: Jiasheng Jiang Cc: ecree.xilinx@gmail.com, habetsm.xilinx@gmail.com, davem@davemloft.net, kuba@kernel.org, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH] sfc: Check null pointer of rx_queue->page_ring Message-ID: References: <20211220135603.954944-1-jiasheng@iscas.ac.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211220135603.954944-1-jiasheng@iscas.ac.cn> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 20, 2021 at 09:56:03PM +0800, Jiasheng Jiang wrote: > Because of the possible failure of the kcalloc, it should be better to > set rx_queue->page_ptr_mask to 0 when it happens in order to maintain > the consistency. > > Fixes: 5a6681e22c14 ("sfc: separate out SFC4000 ("Falcon") support into new sfc-falcon driver") > Signed-off-by: Jiasheng Jiang > --- > drivers/net/ethernet/sfc/rx_common.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/sfc/rx_common.c b/drivers/net/ethernet/sfc/rx_common.c > index 68fc7d317693..0983abc0cc5f 100644 > --- a/drivers/net/ethernet/sfc/rx_common.c > +++ b/drivers/net/ethernet/sfc/rx_common.c > @@ -150,7 +150,10 @@ static void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue) > efx->rx_bufs_per_page); > rx_queue->page_ring = kcalloc(page_ring_size, > sizeof(*rx_queue->page_ring), GFP_KERNEL); > - rx_queue->page_ptr_mask = page_ring_size - 1; > + if (!rx_queue->page_ring) > + rx_queue->page_ptr_mask = 0; > + else > + rx_queue->page_ptr_mask = page_ring_size - 1; > } Why not return an error?