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: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Vladimir Oltean 2023-04-02 15:37:54 +03:00 committed by David S. Miller
parent c4bffeaa8d
commit ff6ac4d013
3 changed files with 8 additions and 6 deletions

View file

@ -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;
}

View file

@ -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;
}

View file

@ -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);