diff options
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index cd7ba50eac15..e02d2363347e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -940,6 +940,18 @@ struct net_device *dev_get_by_napi_id(unsigned int napi_id) } EXPORT_SYMBOL(dev_get_by_napi_id); +static DEFINE_SEQLOCK(netdev_rename_lock); + +void netdev_copy_name(struct net_device *dev, char *name) +{ + unsigned int seq; + + do { + seq = read_seqbegin(&netdev_rename_lock); + strscpy(name, dev->name, IFNAMSIZ); + } while (read_seqretry(&netdev_rename_lock, seq)); +} + /** * netdev_get_name - get a netdevice name, knowing its ifindex. * @net: network namespace @@ -951,7 +963,6 @@ int netdev_get_name(struct net *net, char *name, int ifindex) struct net_device *dev; int ret; - down_read(&devnet_rename_sem); rcu_read_lock(); dev = dev_get_by_index_rcu(net, ifindex); @@ -960,12 +971,11 @@ int netdev_get_name(struct net *net, char *name, int ifindex) goto out; } - strcpy(name, dev->name); + netdev_copy_name(dev, name); ret = 0; out: rcu_read_unlock(); - up_read(&devnet_rename_sem); return ret; } @@ -1217,7 +1227,10 @@ int dev_change_name(struct net_device *dev, const char *newname) memcpy(oldname, dev->name, IFNAMSIZ); + write_seqlock(&netdev_rename_lock); err = dev_get_valid_name(net, dev, newname); + write_sequnlock(&netdev_rename_lock); + if (err < 0) { up_write(&devnet_rename_sem); return err; @@ -1257,7 +1270,9 @@ rollback: if (err >= 0) { err = ret; down_write(&devnet_rename_sem); + write_seqlock(&netdev_rename_lock); memcpy(dev->name, oldname, IFNAMSIZ); + write_sequnlock(&netdev_rename_lock); memcpy(oldname, newname, IFNAMSIZ); WRITE_ONCE(dev->name_assign_type, old_assign_type); old_assign_type = NET_NAME_RENAMED; @@ -11403,8 +11418,12 @@ int __dev_change_net_namespace(struct net_device *dev, struct net *net, dev_net_set(dev, net); dev->ifindex = new_ifindex; - if (new_name[0]) /* Rename the netdev to prepared name */ + if (new_name[0]) { + /* Rename the netdev to prepared name */ + write_seqlock(&netdev_rename_lock); strscpy(dev->name, new_name, IFNAMSIZ); + write_sequnlock(&netdev_rename_lock); + } /* Fixup kobjects */ dev_set_uevent_suppress(&dev->dev, 1); |