From ff6ac4d013e680a5e7a38ee83ca59ffe1846915d Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sun, 2 Apr 2023 15:37:54 +0300 Subject: [PATCH] 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 Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- net/dsa/master.c | 2 +- net/dsa/port.c | 10 ++++++---- net/dsa/port.h | 2 +- 3 files changed, 8 insertions(+), 6 deletions(-) diff --git a/net/dsa/master.c b/net/dsa/master.c index 22d3f16b0e6d..e397641382ca 100644 --- a/net/dsa/master.c +++ b/net/dsa/master.c @@ -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; } diff --git a/net/dsa/port.c b/net/dsa/port.c index 15cee17769e9..71ba30538411 100644 --- a/net/dsa/port.c +++ b/net/dsa/port.c @@ -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; } diff --git a/net/dsa/port.h b/net/dsa/port.h index 9c218660d223..dc812512fd0e 100644 --- a/net/dsa/port.h +++ b/net/dsa/port.h @@ -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);