Commit ff6ac4d0 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by David S. Miller
Browse files

net: dsa: make dsa_port_supports_hwtstamp() construct a fake ifreq 



dsa_master_ioctl() is in the process of getting converted to a different
API, where we won't have access to a struct ifreq * anymore, but rather,
to a struct kernel_hwtstamp_config.

Since ds->ops->port_hwtstamp_get() still uses struct ifreq *, this
creates a difficult situation where we have to make up such a dummy
pointer.

The conversion is a bit messy, because it forces a "good" implementation
of ds->ops->port_hwtstamp_get() to return -EFAULT in copy_to_user()
because of the NULL ifr->ifr_data pointer. However, it works, and it is
only a transient step until ds->ops->port_hwtstamp_get() gets converted
to the new API which passes struct kernel_hwtstamp_config and does not
call copy_to_user().

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c4bffeaa

net/dsa/master.c

+1 −1
Original line number Diff line number Diff line
@@ -212,7 +212,7 @@ static int dsa_master_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 
		 * switch in the tree that is PTP capable.

		 */

		list_for_each_entry(dp, &dst->ports, list)

			if (dsa_port_supports_hwtstamp(dp, ifr))

			if (dsa_port_supports_hwtstamp(dp))

				return -EBUSY;

		break;

	}

net/dsa/port.c

+6 −4
Original line number Diff line number Diff line
@@ -114,19 +114,21 @@ static bool dsa_port_can_configure_learning(struct dsa_port *dp) 
	return !err;

}



bool dsa_port_supports_hwtstamp(struct dsa_port *dp, struct ifreq *ifr)

bool dsa_port_supports_hwtstamp(struct dsa_port *dp)

{

	struct dsa_switch *ds = dp->ds;

	struct ifreq ifr = {};

	int err;



	if (!ds->ops->port_hwtstamp_get || !ds->ops->port_hwtstamp_set)

		return false;



	/* "See through" shim implementations of the "get" method.

	 * This will clobber the ifreq structure, but we will either return an

	 * error, or the master will overwrite it with proper values.

	 * Since we can't cook up a complete ioctl request structure, this will

	 * fail in copy_to_user() with -EFAULT, which hopefully is enough to

	 * detect a valid implementation.

	 */

	err = ds->ops->port_hwtstamp_get(ds, dp->index, ifr);

	err = ds->ops->port_hwtstamp_get(ds, dp->index, &ifr);

	return err != -EOPNOTSUPP;

}

net/dsa/port.h

+1 −1
Original line number Diff line number Diff line
@@ -15,7 +15,7 @@ struct switchdev_obj_port_mdb; 
struct switchdev_vlan_msti;

struct phy_device;



bool dsa_port_supports_hwtstamp(struct dsa_port *dp, struct ifreq *ifr);

bool dsa_port_supports_hwtstamp(struct dsa_port *dp);

void dsa_port_set_tag_protocol(struct dsa_port *cpu_dp,

			       const struct dsa_device_ops *tag_ops);

int dsa_port_set_state(struct dsa_port *dp, u8 state, bool do_fast_age);