From a2c65a9d0568b6737c02b54f00b80716a53fac61 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Thu, 27 Oct 2022 17:54:39 +0300 Subject: net: dsa: fall back to default tagger if we can't load the one from DT DSA tagging protocol drivers can be changed at runtime through sysfs and at probe time through the device tree (support for the latter was added later). When changing through sysfs, it is assumed that the module for the new tagging protocol was already loaded into the kernel (in fact this is only a concern for Ocelot/Felix switches, where we have tag_ocelot.ko and tag_ocelot_8021q.ko; for every other switch, the default and alternative protocols are compiled within the same .ko, so there is nothing for the user to load). The kernel cannot currently call request_module(), because it has no way of constructing the modalias name of the tagging protocol driver ("dsa_tag-%d", where the number is one of DSA_TAG_PROTO_*_VALUE). The device tree only contains the string name of the tagging protocol ("ocelot-8021q"), and the only mapping between the string and the DSA_TAG_PROTO_OCELOT_8021Q_VALUE is present in tag_ocelot_8021q.ko. So this is a chicken-and-egg situation and dsa_core.ko has nothing based on which it can automatically request the insertion of the module. As a consequence, if CONFIG_NET_DSA_TAG_OCELOT_8021Q is built as module, the switch will forever defer probing. The long-term solution is to make DSA call request_module() somehow, but that probably needs some refactoring. What we can do to keep operating with existing device tree blobs is to cancel the attempt to change the tagging protocol with the one specified there, and to remain operating with the default one. Depending on the situation, the default protocol might still allow some functionality (in the case of ocelot, it does), and it's better to have that than to fail to probe. Fixes: deff710703d8 ("net: dsa: Allow default tag protocol to be overridden from DT") Link: https://lore.kernel.org/lkml/20221027113248.420216-1-michael@walle.cc/ Reported-by: Heiko Thiery Reported-by: Michael Walle Signed-off-by: Vladimir Oltean Tested-by: Michael Walle Reviewed-by: Florian Fainelli Link: https://lore.kernel.org/r/20221027145439.3086017-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski --- net/dsa/dsa2.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'net/dsa') diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c index af0e2c0394ac..e504a18fc125 100644 --- a/net/dsa/dsa2.c +++ b/net/dsa/dsa2.c @@ -1409,9 +1409,9 @@ static enum dsa_tag_protocol dsa_get_tag_protocol(struct dsa_port *dp, static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master, const char *user_protocol) { + const struct dsa_device_ops *tag_ops = NULL; struct dsa_switch *ds = dp->ds; struct dsa_switch_tree *dst = ds->dst; - const struct dsa_device_ops *tag_ops; enum dsa_tag_protocol default_proto; /* Find out which protocol the switch would prefer. */ @@ -1434,10 +1434,17 @@ static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master, } tag_ops = dsa_find_tagger_by_name(user_protocol); - } else { - tag_ops = dsa_tag_driver_get(default_proto); + if (IS_ERR(tag_ops)) { + dev_warn(ds->dev, + "Failed to find a tagging driver for protocol %s, using default\n", + user_protocol); + tag_ops = NULL; + } } + if (!tag_ops) + tag_ops = dsa_tag_driver_get(default_proto); + if (IS_ERR(tag_ops)) { if (PTR_ERR(tag_ops) == -ENOPROTOOPT) return -EPROBE_DEFER; -- cgit v1.2.3 From ed1fe1bebe18884b11e5536b5ac42e3a48960835 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Fri, 11 Nov 2022 23:10:20 +0200 Subject: net: dsa: make dsa_master_ioctl() see through port_hwtstamp_get() shims MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There are multi-generational drivers like mv88e6xxx which have code like this: int mv88e6xxx_port_hwtstamp_get(struct dsa_switch *ds, int port, struct ifreq *ifr) { if (!chip->info->ptp_support) return -EOPNOTSUPP; ... } DSA wants to deny PTP timestamping on the master if the switch supports timestamping too. However it currently relies on the presence of the port_hwtstamp_get() callback to determine PTP capability, and this clearly does not work in that case (method is present but returns -EOPNOTSUPP). We should not deny PTP on the DSA master for those switches which truly do not support hardware timestamping. Create a dsa_port_supports_hwtstamp() method which actually probes for support by calling port_hwtstamp_get() and seeing whether that returned -EOPNOTSUPP or not. Fixes: f685e609a301 ("net: dsa: Deny PTP on master if switch supports it") Link: https://patchwork.kernel.org/project/netdevbpf/patch/20221110124345.3901389-1-festevam@gmail.com/ Reported-by: Fabio Estevam Reported-by: Steffen Bätz Signed-off-by: Vladimir Oltean Tested-by: Fabio Estevam Signed-off-by: David S. Miller --- net/dsa/dsa_priv.h | 1 + net/dsa/master.c | 3 +-- net/dsa/port.c | 16 ++++++++++++++++ 3 files changed, 18 insertions(+), 2 deletions(-) (limited to 'net/dsa') diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h index 6e65c7ffd6f3..71e9707d11d4 100644 --- a/net/dsa/dsa_priv.h +++ b/net/dsa/dsa_priv.h @@ -210,6 +210,7 @@ static inline struct net_device *dsa_master_find_slave(struct net_device *dev, extern struct rtnl_link_ops dsa_link_ops __read_mostly; /* port.c */ +bool dsa_port_supports_hwtstamp(struct dsa_port *dp, struct ifreq *ifr); 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); diff --git a/net/dsa/master.c b/net/dsa/master.c index 40367ab41cf8..421de166515f 100644 --- a/net/dsa/master.c +++ b/net/dsa/master.c @@ -204,8 +204,7 @@ 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 (dp->ds->ops->port_hwtstamp_get || - dp->ds->ops->port_hwtstamp_set) + if (dsa_port_supports_hwtstamp(dp, ifr)) return -EBUSY; break; } diff --git a/net/dsa/port.c b/net/dsa/port.c index 208168276995..750fe68d9b2a 100644 --- a/net/dsa/port.c +++ b/net/dsa/port.c @@ -110,6 +110,22 @@ 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) +{ + struct dsa_switch *ds = dp->ds; + 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. + */ + err = ds->ops->port_hwtstamp_get(ds, dp->index, ifr); + return err != -EOPNOTSUPP; +} + int dsa_port_set_state(struct dsa_port *dp, u8 state, bool do_fast_age) { struct dsa_switch *ds = dp->ds; -- cgit v1.2.3 From 4e0c19fcb8b5323716140fa82b79aa9f60e60407 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Mon, 14 Nov 2022 16:35:51 +0200 Subject: net: dsa: don't leak tagger-owned storage on switch driver unbind In the initial commit dc452a471dba ("net: dsa: introduce tagger-owned storage for private and shared data"), we had a call to tag_ops->disconnect(dst) issued from dsa_tree_free(), which is called at tree teardown time. There were problems with connecting to a switch tree as a whole, so this got reworked to connecting to individual switches within the tree. In this process, tag_ops->disconnect(ds) was made to be called only from switch.c (cross-chip notifiers emitted as a result of dynamic tag proto changes), but the normal driver teardown code path wasn't replaced with anything. Solve this problem by adding a function that does the opposite of dsa_switch_setup_tag_protocol(), which is called from the equivalent spot in dsa_switch_teardown(). The positioning here also ensures that we won't have any use-after-free in tagging protocol (*rcv) ops, since the teardown sequence is as follows: dsa_tree_teardown -> dsa_tree_teardown_master -> dsa_master_teardown -> unsets master->dsa_ptr, making no further packets match the ETH_P_XDSA packet type handler -> dsa_tree_teardown_ports -> dsa_port_teardown -> dsa_slave_destroy -> unregisters DSA net devices, there is even a synchronize_net() in unregister_netdevice_many() -> dsa_tree_teardown_switches -> dsa_switch_teardown -> dsa_switch_teardown_tag_protocol -> finally frees the tagger-owned storage Fixes: 7f2973149c22 ("net: dsa: make tagging protocols connect to individual switches from a tree") Signed-off-by: Vladimir Oltean Reviewed-by: Saeed Mahameed Reviewed-by: Florian Fainelli Link: https://lore.kernel.org/r/20221114143551.1906361-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski --- net/dsa/dsa2.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'net/dsa') diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c index e504a18fc125..5417f7b1187c 100644 --- a/net/dsa/dsa2.c +++ b/net/dsa/dsa2.c @@ -864,6 +864,14 @@ disconnect: return err; } +static void dsa_switch_teardown_tag_protocol(struct dsa_switch *ds) +{ + const struct dsa_device_ops *tag_ops = ds->dst->tag_ops; + + if (tag_ops->disconnect) + tag_ops->disconnect(ds); +} + static int dsa_switch_setup(struct dsa_switch *ds) { struct dsa_devlink_priv *dl_priv; @@ -953,6 +961,8 @@ static void dsa_switch_teardown(struct dsa_switch *ds) ds->slave_mii_bus = NULL; } + dsa_switch_teardown_tag_protocol(ds); + if (ds->ops->teardown) ds->ops->teardown(ds); -- cgit v1.2.3