[PATCH 4.17 245/324] sfp: ensure we clean up properly on bus registration failure

Greg Kroah-Hartman
2018-08-23T09:01:13Z

From: Russell King <rmk+kernel@armlinux.org.uk>

[ Upstream commit f20a4c46b984331a509528fa2b84125c617ef98b ]

We fail to correctly clean up after a bus registration failure, which
can lead to an incorrect assumption about the registration state of
the upstream or sfp cage.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/phy/sfp-bus.c | 31 ++++++++++++++++++++++++-------
1 file changed, 24 insertions(+), 7 deletions(-)

--- a/drivers/net/phy/sfp-bus.c
+++ b/drivers/net/phy/sfp-bus.c
@@ -436,6 +436,13 @@ void sfp_upstream_stop(struct sfp_bus *b
}
EXPORT_SYMBOL_GPL(sfp_upstream_stop);

+static void sfp_upstream_clear(struct sfp_bus *bus)
+{
+ bus->upstream_ops = NULL;
+ bus->upstream = NULL;
+ bus->netdev = NULL;
+}
+
/**
* sfp_register_upstream() - Register the neighbouring device
* @fwnode: firmware node for the SFP bus
@@ -462,8 +469,11 @@ struct sfp_bus *sfp_register_upstream(st
bus->upstream = upstream;
bus->netdev = ndev;

- if (bus->sfp)
+ if (bus->sfp) {
ret = sfp_register_bus(bus);
+ if (ret)
+ sfp_upstream_clear(bus);
+ }
rtnl_unlock();
}

@@ -488,8 +498,7 @@ void sfp_unregister_upstream(struct sfp_
rtnl_lock();
if (bus->sfp)
sfp_unregister_bus(bus);
- bus->upstream = NULL;
- bus->netdev = NULL;
+ sfp_upstream_clear(bus);
rtnl_unlock();

sfp_bus_put(bus);
@@ -561,6 +570,13 @@ void sfp_module_remove(struct sfp_bus *b
}
EXPORT_SYMBOL_GPL(sfp_module_remove);

+static void sfp_socket_clear(struct sfp_bus *bus)
+{
+ bus->sfp_dev = NULL;
+ bus->sfp = NULL;
+ bus->socket_ops = NULL;
+}
+
struct sfp_bus *sfp_register_socket(struct device *dev, struct sfp *sfp,
const struct sfp_socket_ops *ops)
{
@@ -573,8 +589,11 @@ struct sfp_bus *sfp_register_socket(stru
bus->sfp = sfp;
bus->socket_ops = ops;

- if (bus->netdev)
+ if (bus->netdev) {
ret = sfp_register_bus(bus);
+ if (ret)
+ sfp_socket_clear(bus);
+ }
rtnl_unlock();
}

@@ -592,9 +611,7 @@ void sfp_unregister_socket(struct sfp_bu
rtnl_lock();
if (bus->netdev)
sfp_unregister_bus(bus);
- bus->sfp_dev = NULL;
- bus->sfp = NULL;
- bus->socket_ops = NULL;
+ sfp_socket_clear(bus);
rtnl_unlock();

sfp_bus_put(bus);