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 BC0FAC0032E for ; Wed, 25 Oct 2023 22:40:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230416AbjJYWk2 (ORCPT ); Wed, 25 Oct 2023 18:40:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229576AbjJYWk1 (ORCPT ); Wed, 25 Oct 2023 18:40:27 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9AAC1CC for ; Wed, 25 Oct 2023 15:40:25 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3367C433C7; Wed, 25 Oct 2023 22:40:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698273625; bh=qfels1GYMTPfnHoxUp0H97xy17t+4MpcMZslcbdXlTU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Z8l6OsMGIrBIB1ROCA2X/RxkK0jc9MA4OXyVteCFe/oFT+HDvYrQMymtXnhMDxFva kls3WJ1IEuuleQujkDmi9oe7qwd4Fd/dakjSeOeavZjGyp8ovUwnt4sABCeg/uBxuP 8/ARvVtNmeq1Insw+oAdbJg3x4p3NsOC87W2FdHMAblx0DShIzvY6COZnO84N37XAF 717r/5Ihc4yHEvzZHit/YnaUbUJFTbpYJerrXB0tCrzuL/MlhDqjN8Z8i7FOjVuTjF iks7d6HCVAhdiBRSzZxxSsZmnvP3Sfzl7+ITC8IThqdBm9c/sO8pJirlMUrzTPW0Vk 2IUXy2kn8noWQ== Date: Wed, 25 Oct 2023 15:40:23 -0700 From: Jakub Kicinski To: "Radu Pirea (NXP OSS)" Cc: sd@queasysnail.net, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, andrew@lunn.ch, hkallweit1@gmail.com, linux@armlinux.org.uk, richardcochran@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, sebastian.tobuschat@oss.nxp.com Subject: Re: [PATCH net-next v8 4/7] net: macsec: introduce mdo_insert_tx_tag Message-ID: <20231025154023.576a2f7b@kernel.org> In-Reply-To: <20231023094327.565297-5-radu-nicolae.pirea@oss.nxp.com> References: <20231023094327.565297-1-radu-nicolae.pirea@oss.nxp.com> <20231023094327.565297-5-radu-nicolae.pirea@oss.nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 23 Oct 2023 12:43:24 +0300 Radu Pirea (NXP OSS) wrote: > + if (unlikely(skb_headroom(skb) < ops->needed_headroom || > + skb_tailroom(skb) < ops->needed_tailroom)) { This sort of "if head / tail room is to small, realloc" helper would be more widely applicable, we should factor it out. > + struct sk_buff *nskb = skb_copy_expand(skb, And this should perhaps be pskb_expand_head(). > + ops->needed_headroom, > + ops->needed_tailroom, > + GFP_ATOMIC); > + if (likely(nskb)) { > + consume_skb(skb); > + skb = nskb; > + } else { > + err = -ENOMEM; > + goto cleanup; > + } > + } else { > + skb = skb_unshare(skb, GFP_ATOMIC); You don't need to unshare if tailroom is 0, you just need to call skb_cow_head(). I think we have this sort of code in DSA already, IIRC Vladimir wrote it. dsa_realloc_skb() ? Can we factor out / reuse that? > + if (!skb) > + return ERR_PTR(-ENOMEM); > + } > + > + err = ops->mdo_insert_tx_tag(phydev, skb); > + if (unlikely(err)) > + goto cleanup; > + > + if (unlikely(skb->len - ETH_HLEN > macsec_priv(dev)->real_dev->mtu)) { You can check that first, if the packet is going to be dropped no point doing the expansions. > + err = -EINVAL; > + goto cleanup; > + }