From: Florian Fainelli f.fainelli@gmail.com
[ Upstream commit 1532b9778478577152201adbafa7738b1e844868 ]
DSA network devices rely on having their DSA management interface up and running otherwise their ndo_open() will return -ENETDOWN. Without doing this it would not be possible to use DSA devices as netconsole when configured on the command line. These devices also do not utilize the upper/lower linking so the check about the netpoll device having upper is not going to be a problem.
The solution adopted here is identical to the one done for net/ipv4/ipconfig.c with 728c02089a0e ("net: ipv4: handle DSA enabled master network devices"), with the network namespace scope being restricted to that of the process configuring netpoll.
Fixes: 04ff53f96a93 ("net: dsa: Add netconsole support") Tested-by: Vladimir Oltean olteanv@gmail.com Signed-off-by: Florian Fainelli f.fainelli@gmail.com Link: https://lore.kernel.org/r/20201117035236.22658-1-f.fainelli@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/netpoll.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-)
--- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -28,6 +28,7 @@ #include <linux/slab.h> #include <linux/export.h> #include <linux/if_vlan.h> +#include <net/dsa.h> #include <net/tcp.h> #include <net/udp.h> #include <net/addrconf.h> @@ -661,15 +662,15 @@ EXPORT_SYMBOL_GPL(__netpoll_setup);
int netpoll_setup(struct netpoll *np) { - struct net_device *ndev = NULL; + struct net_device *ndev = NULL, *dev = NULL; + struct net *net = current->nsproxy->net_ns; struct in_device *in_dev; int err;
rtnl_lock(); - if (np->dev_name) { - struct net *net = current->nsproxy->net_ns; + if (np->dev_name) ndev = __dev_get_by_name(net, np->dev_name); - } + if (!ndev) { np_err(np, "%s doesn't exist, aborting\n", np->dev_name); err = -ENODEV; @@ -677,6 +678,19 @@ int netpoll_setup(struct netpoll *np) } dev_hold(ndev);
+ /* bring up DSA management network devices up first */ + for_each_netdev(net, dev) { + if (!netdev_uses_dsa(dev)) + continue; + + err = dev_change_flags(dev, dev->flags | IFF_UP); + if (err < 0) { + np_err(np, "%s failed to open %s\n", + np->dev_name, dev->name); + goto put; + } + } + if (netdev_master_upper_dev_get(ndev)) { np_err(np, "%s is a slave device, aborting\n", np->dev_name); err = -EBUSY;