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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D7CD9C4332F for ; Mon, 25 Oct 2021 17:23:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BCBD660D07 for ; Mon, 25 Oct 2021 17:23:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233662AbhJYR0F (ORCPT ); Mon, 25 Oct 2021 13:26:05 -0400 Received: from smtp02.smtpout.orange.fr ([80.12.242.124]:53584 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233986AbhJYRZy (ORCPT ); Mon, 25 Oct 2021 13:25:54 -0400 Received: from tomoyo.flets-east.jp ([114.149.34.46]) by smtp.orange.fr with ESMTPA id f3gYmY0E4niuxf3h3mufGm; Mon, 25 Oct 2021 19:23:31 +0200 X-ME-Helo: tomoyo.flets-east.jp X-ME-Auth: MDU0YmViZGZmMDIzYiBlMiM2NTczNTRjNWZkZTMwOGRiOGQ4ODf3NWI1ZTMyMzdiODlhOQ== X-ME-Date: Mon, 25 Oct 2021 19:23:31 +0200 X-ME-IP: 114.149.34.46 From: Vincent Mailhol To: Marc Kleine-Budde , linux-can@vger.kernel.org Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Vincent Mailhol Subject: [PATCH v3 2/4] can: dev: add sanity check in can_set_static_ctrlmode() Date: Tue, 26 Oct 2021 02:22:45 +0900 Message-Id: <20211025172247.1774451-3-mailhol.vincent@wanadoo.fr> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211025172247.1774451-1-mailhol.vincent@wanadoo.fr> References: <20211025172247.1774451-1-mailhol.vincent@wanadoo.fr> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org Previous patch removed can_priv::ctrlmode_static to replace it with can_get_static_ctrlmode(). A condition sine qua non for this to work is that the controller static modes should never be set in can_priv::ctrlmode_supported (c.f. the comment on can_priv::ctrlmode_supported which states that it is for "options that can be *modified* by netlink"). Also, this condition is already correctly fulfilled by all existing drivers which rely on the ctrlmode_static feature. Nonetheless, we added an extra safeguard in can_set_static_ctrlmode() to return an error value and to warn the developer who would be adventurous enough to set to static a given feature that is already set to supported. The drivers which rely on the static controller mode are then updated to check the return value of can_set_static_ctrlmode(). Signed-off-by: Vincent Mailhol --- Some few comments on how the rcar_canfd and m_can drivers free their allocated resources when an error occurs during probing. The function rcar_canfd_channel_probe() is quite inconsistent with the way it handles errors. After the call to alloc_candev, there are several "goto fail" statements that would directly exit without calling free_candev()! Nonetheless, later on the driver will check the return value of rcar_canfd_channel_probe() and call rcar_canfd_channel_remove() which will correctly call free_candev(). Even if this is inconsistent, there is no sign of a memory leak. So I just applied the change the can_set_static_ctrlmode() without bothering more (N.B. I do not own that device so I am not willing to take the risk of making bigger changes because I can not test). On the other hand, m_can_dev_setup() is fine: the return value is checked by the caller and necessary actions are taken. As such, for both driver, we did a minimal change. --- drivers/net/can/m_can/m_can.c | 10 +++++++--- drivers/net/can/rcar/rcar_canfd.c | 4 +++- include/linux/can/dev.h | 11 +++++++++-- 3 files changed, 19 insertions(+), 6 deletions(-) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index 2470c47b2e31..ab4371aa4ff1 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -1463,7 +1463,7 @@ static bool m_can_niso_supported(struct m_can_classdev *cdev) static int m_can_dev_setup(struct m_can_classdev *cdev) { struct net_device *dev = cdev->net; - int m_can_version; + int m_can_version, err; m_can_version = m_can_check_core_release(cdev); /* return if unsupported version */ @@ -1493,13 +1493,17 @@ static int m_can_dev_setup(struct m_can_classdev *cdev) switch (cdev->version) { case 30: /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */ - can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO); + err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO); + if (err) + return err; cdev->can.bittiming_const = &m_can_bittiming_const_30X; cdev->can.data_bittiming_const = &m_can_data_bittiming_const_30X; break; case 31: /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */ - can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO); + err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO); + if (err) + return err; cdev->can.bittiming_const = &m_can_bittiming_const_31X; cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X; break; diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c index ff9d0f5ae0dd..e225c1c03812 100644 --- a/drivers/net/can/rcar/rcar_canfd.c +++ b/drivers/net/can/rcar/rcar_canfd.c @@ -1706,7 +1706,9 @@ static int rcar_canfd_channel_probe(struct rcar_canfd_global *gpriv, u32 ch, &rcar_canfd_data_bittiming_const; /* Controller starts in CAN FD only mode */ - can_set_static_ctrlmode(ndev, CAN_CTRLMODE_FD); + err = can_set_static_ctrlmode(ndev, CAN_CTRLMODE_FD); + if (err) + goto fail; priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING; } else { /* Controller starts in Classical CAN only mode */ diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index 92e2d69462f0..fff3f70df697 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -131,17 +131,24 @@ static inline s32 can_get_relative_tdco(const struct can_priv *priv) } /* helper to define static CAN controller features at device creation time */ -static inline void can_set_static_ctrlmode(struct net_device *dev, - u32 static_mode) +static inline int __must_check can_set_static_ctrlmode(struct net_device *dev, + u32 static_mode) { struct can_priv *priv = netdev_priv(dev); /* alloc_candev() succeeded => netdev_priv() is valid at this point */ + if (priv->ctrlmode_supported & static_mode) { + netdev_warn(dev, + "Controller features can not be supported and static at the same time\n"); + return -EINVAL; + } priv->ctrlmode = static_mode; /* override MTU which was set by default in can_setup()? */ if (static_mode & CAN_CTRLMODE_FD) dev->mtu = CANFD_MTU; + + return 0; } static inline u32 can_get_static_ctrlmode(struct can_priv *priv) -- 2.32.0