Re: [PATCH net-next] net:set valid name before calling ndo_init()

[Jiri Pirko <jpirko@redhat.com>]

Fri, May 13, 2011 at 03:46:56AM CEST, panweiping3@gmail.com wrote:
>In commit 1c5cae815d19 (net: call dev_alloc_name from register_netdevice),
>a bug of bonding was invloved, see example 1 and 2.
>
>In register_netdevice(), the name of net_device is not valid until
>dev_get_valid_name() is called. But dev->netdev_ops->ndo_init(that is
>bond_init) is called before dev_get_valid_name(),
>and it uses the invalid name of net_device.
>
>I think register_netdevice() should make sure that the name of net_device is
>valid before calling ndo_init().
>
>example 1:
>modprobe bonding
>ls  /proc/net/bonding/bond%d
>
>ps -eLf
>root      3398     2  3398  0    1 21:34 ?        00:00:00 [bond%d]
>
>example 2:
>modprobe bonding max_bonds=3
>
>[  170.100292] bonding: Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)
>[  170.101090] bonding: Warning: either miimon or arp_interval and arp_ip_target module parameters must be specified, otherwise bonding will not detect link failures! see bonding.txt for details.
>[  170.102469] ------------[ cut here ]------------
>[  170.103150] WARNING: at /home/pwp/net-next-2.6/fs/proc/generic.c:586 proc_register+0x126/0x157()
>[  170.104075] Hardware name: VirtualBox
>[  170.105065] proc_dir_entry 'bonding/bond%d' already registered
>[  170.105613] Modules linked in: bonding(+) sunrpc ipv6 uinput microcode ppdev parport_pc parport joydev e1000 pcspkr i2c_piix4 i2c_core [last unloaded: bonding]
>[  170.108397] Pid: 3457, comm: modprobe Not tainted 2.6.39-rc2+ #14
>[  170.108935] Call Trace:
>[  170.109382]  [<c0438f3b>] warn_slowpath_common+0x6a/0x7f
>[  170.109911]  [<c051a42a>] ? proc_register+0x126/0x157
>[  170.110329]  [<c0438fc3>] warn_slowpath_fmt+0x2b/0x2f
>[  170.110846]  [<c051a42a>] proc_register+0x126/0x157
>[  170.111870]  [<c051a4dd>] proc_create_data+0x82/0x98
>[  170.112335]  [<f94e6af6>] bond_create_proc_entry+0x3f/0x73 [bonding]
>[  170.112905]  [<f94dd806>] bond_init+0x77/0xa5 [bonding]
>[  170.113319]  [<c0721ac6>] register_netdevice+0x8c/0x1d3
>[  170.113848]  [<f94e0e30>] bond_create+0x6c/0x90 [bonding]
>[  170.114322]  [<f94f4763>] bonding_init+0x763/0x7b1 [bonding]
>[  170.114879]  [<c0401240>] do_one_initcall+0x76/0x122
>[  170.115317]  [<f94f4000>] ? 0xf94f3fff
>[  170.115799]  [<c0463f1e>] sys_init_module+0x1286/0x140d
>[  170.116879]  [<c07c6d9f>] sysenter_do_call+0x12/0x28
>[  170.117404] ---[ end trace 64e4fac3ae5fff1a ]---
>[  170.117924] bond%d: Warning: failed to register to debugfs
>[  170.128728] ------------[ cut here ]------------
>[  170.129360] WARNING: at /home/pwp/net-next-2.6/fs/proc/generic.c:586 proc_register+0x126/0x157()
>[  170.130323] Hardware name: VirtualBox
>[  170.130797] proc_dir_entry 'bonding/bond%d' already registered
>[  170.131315] Modules linked in: bonding(+) sunrpc ipv6 uinput microcode ppdev parport_pc parport joydev e1000 pcspkr i2c_piix4 i2c_core [last unloaded: bonding]
>[  170.133731] Pid: 3457, comm: modprobe Tainted: G        W   2.6.39-rc2+ #14
>[  170.134308] Call Trace:
>[  170.134743]  [<c0438f3b>] warn_slowpath_common+0x6a/0x7f
>[  170.135305]  [<c051a42a>] ? proc_register+0x126/0x157
>[  170.135820]  [<c0438fc3>] warn_slowpath_fmt+0x2b/0x2f
>[  170.137168]  [<c051a42a>] proc_register+0x126/0x157
>[  170.137700]  [<c051a4dd>] proc_create_data+0x82/0x98
>[  170.138174]  [<f94e6af6>] bond_create_proc_entry+0x3f/0x73 [bonding]
>[  170.138745]  [<f94dd806>] bond_init+0x77/0xa5 [bonding]
>[  170.139278]  [<c0721ac6>] register_netdevice+0x8c/0x1d3
>[  170.139828]  [<f94e0e30>] bond_create+0x6c/0x90 [bonding]
>[  170.140361]  [<f94f4763>] bonding_init+0x763/0x7b1 [bonding]
>[  170.140927]  [<c0401240>] do_one_initcall+0x76/0x122
>[  170.141494]  [<f94f4000>] ? 0xf94f3fff
>[  170.141975]  [<c0463f1e>] sys_init_module+0x1286/0x140d
>[  170.142463]  [<c07c6d9f>] sysenter_do_call+0x12/0x28
>[  170.142974] ---[ end trace 64e4fac3ae5fff1b ]---
>[  170.144949] bond%d: Warning: failed to register to debugfs
>
>Signed-off-by: Weiping Pan <panweiping3@gmail.com>
>---
> net/core/dev.c |    8 ++++----
> 1 files changed, 4 insertions(+), 4 deletions(-)
>
>diff --git a/net/core/dev.c b/net/core/dev.c
>index ea23353..3ed09f8 100644
>--- a/net/core/dev.c
>+++ b/net/core/dev.c
>@@ -5437,6 +5437,10 @@ int register_netdevice(struct net_device *dev)
> 
> 	dev->iflink = -1;
> 
>+	ret = dev_get_valid_name(dev, dev->name);
>+	if (ret < 0)
>+		goto out;
>+
> 	/* Init, if this function is available */
> 	if (dev->netdev_ops->ndo_init) {
> 		ret = dev->netdev_ops->ndo_init(dev);
>@@ -5447,10 +5451,6 @@ int register_netdevice(struct net_device *dev)
> 		}
> 	}
> 
>-	ret = dev_get_valid_name(dev, dev->name);
>-	if (ret < 0)
>-		goto err_uninit;
>-
> 	dev->ifindex = dev_new_index(net);
> 	if (dev->iflink == -1)
> 		dev->iflink = dev->ifindex;
>-- 
>1.7.4.4
>
>--
>To unsubscribe from this list: send the line "unsubscribe netdev" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html


Reviewed-by: Jiri Pirko <jpirko@redhat.com>