From patchwork Thu Nov 25 17:20:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincent Mailhol X-Patchwork-Id: 12693691 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9CED7C4332F for ; Thu, 25 Nov 2021 17:23:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ghrHzKWU1ZLq1FRYzl/3HlvNH2HlfR4W7XfSmgiN92o=; b=RaqW+P7M7BNnxp hrvRIxtKH4ueTmIQtCjdxqPToEcTK1Vp3lDj4p/+TdS6qvA4JxWv9M/YPa0jKIr+ThYeXCrVoQ+4c IAam6aDYtC3HbTbvGjxDJ3yt/belzd0NLA2pqn+sIasWFDfJAXb8I3h/l97d8ZtCCJuCHWG8PZrP/ Zc3mEaMliIrvspaNgIXkBvtIByVAqEX17GOKD6u2yW4w8KwRKQxZ7OUObWymU++4JYgShi4/HEvEk 7orBUz6xPjirkfiyrWLTadQ+piiBEfQoeTM5vELIAIZoJ4Fuk1CUNqGf+INIusWV1EgCkTKPgEdDV lFpqTLeYT3K33ujUvJFw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mqIRR-008MOP-Qe; Thu, 25 Nov 2021 17:21:50 +0000 Received: from smtp09.smtpout.orange.fr ([80.12.242.131] helo=smtp.smtpout.orange.fr) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mqIRA-008MIa-Ea for linux-arm-kernel@lists.infradead.org; Thu, 25 Nov 2021 17:21:33 +0000 Received: from tomoyo.flets-east.jp ([114.149.34.46]) by smtp.orange.fr with ESMTPA id qIQDm0ronE8xTqIR2m0krN; Thu, 25 Nov 2021 18:21:27 +0100 X-ME-Helo: tomoyo.flets-east.jp X-ME-Auth: MDU0YmViZGZmMDIzYiBlMiM2NTczNTRjNWZkZTMwOGRiOGQ4ODf3NWI1ZTMyMzdiODlhOQ== X-ME-Date: Thu, 25 Nov 2021 18:21:27 +0100 X-ME-IP: 114.149.34.46 From: Vincent Mailhol To: Marc Kleine-Budde , linux-can@vger.kernel.org Cc: Oliver Hartkopp , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, Vincent Mailhol , Yasushi SHOJI Subject: [PATCH v2 3/5] can: do not copy the payload of RTR frames Date: Fri, 26 Nov 2021 02:20:19 +0900 Message-Id: <20211125172021.976384-4-mailhol.vincent@wanadoo.fr> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211125172021.976384-1-mailhol.vincent@wanadoo.fr> References: <20211125172021.976384-1-mailhol.vincent@wanadoo.fr> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211125_092132_675640_0EF7252B X-CRM114-Status: GOOD ( 13.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The actual payload length of the CAN Remote Transmission Request (RTR) frames is always 0, i.e. nothing is transmitted on the wire. However, those RTR frames still use the DLC to indicate the length of the requested frame. For this reason, it is incorrect to copy the payload of RTR frames (the payload buffer would only contain garbage data). This patch encapsulates the payload copy in a check toward the RTR flag. CC: Yasushi SHOJI Signed-off-by: Vincent Mailhol --- drivers/net/can/pch_can.c | 15 ++++++++------- drivers/net/can/spi/mcp251x.c | 3 ++- drivers/net/can/usb/mcba_usb.c | 8 ++++---- 3 files changed, 14 insertions(+), 12 deletions(-) diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c index 6b45840db1f9..4bf9bfc4de72 100644 --- a/drivers/net/can/pch_can.c +++ b/drivers/net/can/pch_can.c @@ -677,16 +677,17 @@ static int pch_can_rx_normal(struct net_device *ndev, u32 obj_num, int quota) cf->can_id = id; } - if (id2 & PCH_ID2_DIR) - cf->can_id |= CAN_RTR_FLAG; - cf->len = can_cc_dlc2len((ioread32(&priv->regs-> ifregs[0].mcont)) & 0xF); - for (i = 0; i < cf->len; i += 2) { - data_reg = ioread16(&priv->regs->ifregs[0].data[i / 2]); - cf->data[i] = data_reg; - cf->data[i + 1] = data_reg >> 8; + if (id2 & PCH_ID2_DIR) { + cf->can_id |= CAN_RTR_FLAG; + } else { + for (i = 0; i < cf->len; i += 2) { + data_reg = ioread16(&priv->regs->ifregs[0].data[i / 2]); + cf->data[i] = data_reg; + cf->data[i + 1] = data_reg >> 8; + } } rcv_pkts++; diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index 0579ab74f728..db3fa98569c4 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -733,7 +733,8 @@ static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx) } /* Data length */ frame->len = can_cc_dlc2len(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK); - memcpy(frame->data, buf + RXBDAT_OFF, frame->len); + if (!(frame->can_id & CAN_RTR_FLAG)) + memcpy(frame->data, buf + RXBDAT_OFF, frame->len); priv->net->stats.rx_packets++; priv->net->stats.rx_bytes += frame->len; diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c index a1a154c08b7f..162d2e11cadd 100644 --- a/drivers/net/can/usb/mcba_usb.c +++ b/drivers/net/can/usb/mcba_usb.c @@ -450,12 +450,12 @@ static void mcba_usb_process_can(struct mcba_priv *priv, cf->can_id = (sid & 0xffe0) >> 5; } - if (msg->dlc & MCBA_DLC_RTR_MASK) - cf->can_id |= CAN_RTR_FLAG; - cf->len = can_cc_dlc2len(msg->dlc & MCBA_DLC_MASK); - memcpy(cf->data, msg->data, cf->len); + if (msg->dlc & MCBA_DLC_RTR_MASK) + cf->can_id |= CAN_RTR_FLAG; + else + memcpy(cf->data, msg->data, cf->len); stats->rx_packets++; stats->rx_bytes += cf->len;