From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C838C387 for ; Wed, 8 May 2024 00:41:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715128912; cv=none; b=Q29BgRSvKkNoswfHXeuGfFx2H3nXJoZ47GUSFvVQ/+CPiYBJ7dcvPNQvMLoPwTXkKY0eqCW83LP9n6Q39gca1Jw0xp/drOvwSkCvve17ELTkii8hHh8ORyxaVUYn6w9TOC3MJV5VTvN+sY4/CJInLS9UY09zAxajieoyAe8zHbA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715128912; c=relaxed/simple; bh=nSgzNkhefaPXx9os5W6lvwSXgN69B9Mv7zaCXBCS1UA=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=UTByeAHXHB95Uc3ybt7J42reIYC5W84J+noP2A6qs0Ixa+RN6zhZ0NBoq9WdgceYP/gkNLQ2UyPxOGTVyf814tbXTteyBGbpY2yVFMEZ4pEgOU2dyc3rMj3f6Yge6+ESn/qj8UuLSAYYPeIE2GmvebTXcnBkzfNk7Nl7yXCZm1w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XS+ZWWAv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="XS+ZWWAv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E92FC3277B; Wed, 8 May 2024 00:41:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1715128912; bh=nSgzNkhefaPXx9os5W6lvwSXgN69B9Mv7zaCXBCS1UA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=XS+ZWWAvHEvNISJ57QTyotEENTuPDso31BbRwTDBoKlXxNdGmUYn/8ebT190g388p eAMlTHddPW+GGpodoAcJYnQXSwWv/H1EIhyN31aFjB5OKTPy7gS+MY83/m1Fe7cCIt 4Sz18dcY5g2HecTKqd9141f3eMC9ZpNwAMZxEBt/xg9+nUWqmHarapGyJl0Wp0ezCg kg8HNRzz4RGeaS5CwDbyCjYeQebO1sfl5U6/eVaAEelNdW/JKu+oXDMspPG7MMcrrS 0OnyEIJtqJnWxSfVmLhzECD3dQFH1h+9eCoqpwIHpKv7m0h3UJ8j0rdHhYWvOzhn9J WmhwqEa2xcWXA== Date: Tue, 7 May 2024 17:41:51 -0700 From: Jakub Kicinski To: Eric Dumazet Cc: "David S . Miller" , Paolo Abeni , netdev@vger.kernel.org, eric.dumazet@gmail.com, Steve Glendinning , UNGLinuxDriver@microchip.com Subject: Re: [PATCH net-next] net: usb: smsc95xx: stop lying about skb->truesize Message-ID: <20240507174151.477792ac@kernel.org> In-Reply-To: <20240506142835.3665037-1-edumazet@google.com> References: <20240506142835.3665037-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 6 May 2024 14:28:35 +0000 Eric Dumazet wrote: > - ax_skb->len = size; > - ax_skb->data = packet; > - skb_set_tail_pointer(ax_skb, size); > + skb_put(ax_skb, size - 4); > + memcpy(ax_skb->data, packet, size - 4); > > if (dev->net->features & NETIF_F_RXCSUM) > smsc95xx_rx_csum_offload(ax_skb); > - skb_trim(ax_skb, ax_skb->len - 4); /* remove fcs */ > - ax_skb->truesize = size + sizeof(struct sk_buff); I think this one's off: static void smsc95xx_rx_csum_offload(struct sk_buff *skb) { skb->csum = *(u16 *)(skb_tail_pointer(skb) - 2); skb->ip_summed = CHECKSUM_COMPLETE; skb_trim(skb, skb->len - 2); }