linux/net/dsa
Vladimir Oltean cf5ca4ddc3 net: dsa: don't leave dangling pointers in dp->pl when failing
There is a desire to simplify the dsa_port registration path with
devlink, and this involves reworking a bit how user ports which fail to
connect to their PHY (because it's missing) get reinitialized as UNUSED
devlink ports.

The desire is for the change to look something like this; basically
dsa_port_setup() has failed, we just change dp->type and call
dsa_port_setup() again.

-/* Destroy the current devlink port, and create a new one which has the UNUSED
- * flavour.
- */
-static int dsa_port_reinit_as_unused(struct dsa_port *dp)
+static int dsa_port_setup_as_unused(struct dsa_port *dp)
 {
-	dsa_port_devlink_teardown(dp);
 	dp->type = DSA_PORT_TYPE_UNUSED;
-	return dsa_port_devlink_setup(dp);
+	return dsa_port_setup(dp);
 }

For an UNUSED port, dsa_port_setup() mostly only calls dsa_port_devlink_setup()
anyway, so we could get away with calling just that. But if we call the
full blown dsa_port_setup(dp) (which will be needed to properly set
dp->setup = true), the callee will have the tendency to go through this
code block too, and call dsa_port_disable(dp):

	switch (dp->type) {
	case DSA_PORT_TYPE_UNUSED:
		dsa_port_disable(dp);
		break;

That is not very good, because dsa_port_disable() has this hidden inside
of it:

	if (dp->pl)
		phylink_stop(dp->pl);

Fact is, we are not prepared to handle a call to dsa_port_disable() with
a struct dsa_port that came from a previous (and failed) call to
dsa_port_setup(). We do not clean up dp->pl, and this will make the
second call to dsa_port_setup() call phylink_stop() on a dangling dp->pl
pointer.

Solve this by creating an API for phylink destruction which is symmetric
to the phylink creation, and never leave dp->pl set to anything except
NULL or a valid phylink structure.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-30 18:17:16 -07:00
..
dsa2.c net: dsa: move port_setup/teardown to be called outside devlink port registered area 2022-09-30 18:17:16 -07:00
dsa_priv.h net: dsa: don't leave dangling pointers in dp->pl when failing 2022-09-30 18:17:16 -07:00
dsa.c net: dsa: allow the DSA master to be seen and changed through rtnetlink 2022-09-20 10:32:35 +02:00
Kconfig net: dsa: tag_ksz: add tag handling for Microchip LAN937x 2022-07-02 16:34:05 +01:00
Makefile net: dsa: allow the DSA master to be seen and changed through rtnetlink 2022-09-20 10:32:35 +02:00
master.c net: dsa: allow masters to join a LAG 2022-09-20 10:32:36 +02:00
netlink.c net: dsa: make user ports return to init_net on netns deletion 2022-09-26 11:28:57 -07:00
port.c net: dsa: don't leave dangling pointers in dp->pl when failing 2022-09-30 18:17:16 -07:00
slave.c net: dsa: don't leave dangling pointers in dp->pl when failing 2022-09-30 18:17:16 -07:00
switch.c net: dsa: allow masters to join a LAG 2022-09-20 10:32:36 +02:00
tag_8021q.c net: dsa: introduce dsa_port_get_master() 2022-09-20 10:32:35 +02:00
tag_ar9331.c net: dsa: remove the struct packet_type argument from dsa_device_ops::rcv() 2021-08-02 15:13:15 +01:00
tag_brcm.c net: dsa: Fix spelling mistakes and cleanup code 2022-08-01 12:23:06 -07:00
tag_dsa.c net: dsa: tag_dsa: Fix tx from VLAN uppers on non-filtering bridges 2022-03-08 11:12:28 +01:00
tag_gswip.c net: dsa: remove the struct packet_type argument from dsa_device_ops::rcv() 2021-08-02 15:13:15 +01:00
tag_hellcreek.c net: dsa: hellcreek: Print warning only once 2022-08-31 19:54:04 -07:00
tag_ksz.c net: dsa: tag_ksz: add tag handling for Microchip LAN937x 2022-07-02 16:34:05 +01:00
tag_lan9303.c net: dsa: lan9303: handle hwaccel VLAN tags 2022-02-17 09:32:06 -08:00
tag_mtk.c net: dsa: create a helper for locating EtherType DSA headers on TX 2021-08-11 14:44:58 +01:00
tag_ocelot_8021q.c net: dsa: tag_8021q: merge RX and TX VLANs 2022-02-27 11:06:14 +00:00
tag_ocelot.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-12-23 16:09:58 -08:00
tag_qca.c net: dsa: tag_qca: add support for handling mgmt and MIB Ethernet packet 2022-02-02 14:43:59 +00:00
tag_rtl4_a.c net: dsa: tag_rtl4_a: Drop bit 9 from egress frames 2021-09-14 19:34:03 -07:00
tag_rtl8_4.c net: dsa: tag_rtl8_4: fix typo in modalias name 2022-03-09 20:36:24 -08:00
tag_rzn1_a5psw.c net: dsa: add Renesas RZ/N1 switch tag driver 2022-06-27 11:37:55 +01:00
tag_sja1105.c net: dsa: tag_8021q: rename dsa_8021q_bridge_tx_fwd_offload_vid 2022-02-27 11:06:14 +00:00
tag_trailer.c net: dsa: remove the struct packet_type argument from dsa_device_ops::rcv() 2021-08-02 15:13:15 +01:00
tag_xrs700x.c net: dsa: remove the struct packet_type argument from dsa_device_ops::rcv() 2021-08-02 15:13:15 +01:00