Commit 7d4a101c authored by Vincent Mailhol's avatar Vincent Mailhol Committed by Marc Kleine-Budde
Browse files

can: dev: add sanity check in can_set_static_ctrlmode() 

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().

Link: https://lore.kernel.org/all/20211213160226.56219-3-mailhol.vincent@wanadoo.fr


Signed-off-by: default avatarVincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent c9e1d8ed

drivers/net/can/m_can/m_can.c

+7 −3
Original line number Diff line number Diff line
@@ -1456,7 +1456,7 @@ 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 */
@@ -1486,7 +1486,9 @@ 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 = cdev->bit_timing ?

			cdev->bit_timing : &m_can_bittiming_const_30X;
@@ -1496,7 +1498,9 @@ static int m_can_dev_setup(struct m_can_classdev *cdev) 
		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 = cdev->bit_timing ?

			cdev->bit_timing : &m_can_bittiming_const_31X;

drivers/net/can/rcar/rcar_canfd.c

+3 −1
Original line number Diff line number Diff line
@@ -1699,7 +1699,9 @@ 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 */

include/linux/can/dev.h

+9 −2
Original line number Diff line number Diff line
@@ -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,

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)