linux-stable.git/drivers/net/dummy.c, branch linux-3.2.y

dummy: fix oops when loading the dummy failed

2013-08-02T20:14:49+00:00

[ Upstream commit 2c8a01894a12665d8059fad8f0a293c98a264121 ]

We rename the dummy in modprobe.conf like this:

install dummy0 /sbin/modprobe -o dummy0 --ignore-install dummy
install dummy1 /sbin/modprobe -o dummy1 --ignore-install dummy

We got oops when we run the command:

modprobe dummy0
modprobe dummy1

------------[ cut here ]------------

[ 3302.187584] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[ 3302.195411] IP: [] __rtnl_link_unregister+0x9a/0xd0
[ 3302.201844] PGD 85c94a067 PUD 8517bd067 PMD 0
[ 3302.206305] Oops: 0002 [#1] SMP
[ 3302.299737] task: ffff88105ccea300 ti: ffff880eba4a0000 task.ti: ffff880eba4a0000
[ 3302.307186] RIP: 0010:[]  [] __rtnl_link_unregister+0x9a/0xd0
[ 3302.316044] RSP: 0018:ffff880eba4a1dd8  EFLAGS: 00010246
[ 3302.321332] RAX: 0000000000000000 RBX: ffffffff81a9d738 RCX: 0000000000000002
[ 3302.328436] RDX: 0000000000000000 RSI: ffffffffa04d602c RDI: ffff880eba4a1dd8
[ 3302.335541] RBP: ffff880eba4a1e18 R08: dead000000200200 R09: dead000000100100
[ 3302.342644] R10: 0000000000000080 R11: 0000000000000003 R12: ffffffff81a9d788
[ 3302.349748] R13: ffffffffa04d7020 R14: ffffffff81a9d670 R15: ffff880eba4a1dd8
[ 3302.364910] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 3302.370630] CR2: 0000000000000008 CR3: 000000085e15e000 CR4: 00000000000427e0
[ 3302.377734] DR0: 0000000000000003 DR1: 00000000000000b0 DR2: 0000000000000001
[ 3302.384838] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 3302.391940] Stack:
[ 3302.393944]  ffff880eba4a1dd8 ffff880eba4a1dd8 ffff880eba4a1e18 ffffffffa04d70c0
[ 3302.401350]  00000000ffffffef ffffffffa01a8000 0000000000000000 ffffffff816111c8
[ 3302.408758]  ffff880eba4a1e48 ffffffffa01a80be ffff880eba4a1e48 ffffffffa04d70c0
[ 3302.416164] Call Trace:
[ 3302.418605]  [] ? 0xffffffffa01a7fff
[ 3302.423727]  [] dummy_init_module+0xbe/0x1000 [dummy0]
[ 3302.430405]  [] ? 0xffffffffa01a7fff
[ 3302.435535]  [] do_one_initcall+0x152/0x1b0
[ 3302.441263]  [] do_init_module+0x7b/0x200
[ 3302.446824]  [] load_module+0x4e2/0x530
[ 3302.452215]  [] ? ddebug_dyndbg_boot_param_cb+0x60/0x60
[ 3302.458979]  [] SyS_init_module+0xd1/0x130
[ 3302.464627]  [] system_call_fastpath+0x16/0x1b
[ 3302.490090] RIP  [] __rtnl_link_unregister+0x9a/0xd0
[ 3302.496607]  RSP 
[ 3302.500084] CR2: 0000000000000008
[ 3302.503466] ---[ end trace 8342d49cd49f78ed ]---

The reason is that when loading dummy, if __rtnl_link_register() return failed,
the init_module should return and avoid take the wrong path.

Signed-off-by: Tan Xiaojun 
Signed-off-by: Ding Tianhong 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

dummy: fix rcu_sched self-detected stalls

2012-07-12T03:32:14+00:00

[ Upstream commit 16b0dc29c1af9df341428f4c49ada4f626258082 ]

Trying to "modprobe dummy numdummies=30000" triggers :

INFO: rcu_sched self-detected stall on CPU { 8} (t=60000 jiffies)

After this splat, RTNL is locked and reboot is needed.

We must call cond_resched() to avoid this, even holding RTNL.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

dummy: Add ndo_uninit().

2012-05-11T12:14:25+00:00

commit 890fdf2a0cb88202d1427589db2cf29c1bdd3c1d upstream.

In register_netdevice(), when ndo_init() is successful and later
some error occurred, ndo_uninit() will be called.
So dummy deivce is desirable to implement ndo_uninit() method
to free percpu stats for this case.
And, ndo_uninit() is also called along with dev->destructor() when
device is unregistered, so in order to prevent dev->dstats from
being freed twice, dev->destructor is modified to free_netdev().

Signed-off-by: Hiroaki SHIMODA 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: remove use of ndo_set_multicast_list in drivers

2011-08-18T03:22:03+00:00

replace it by ndo_set_rx_mode

Signed-off-by: Jiri Pirko 
Signed-off-by: David S. Miller

net: call dev_alloc_name from register_netdevice

2011-05-05T17:57:45+00:00

Force dev_alloc_name() to be called from register_netdevice() by
dev_get_valid_name(). That allows to remove multiple explicit
dev_alloc_name() calls.

The possibility to call dev_alloc_name in advance remains.

This also fixes veth creation regresion caused by
84c49d8c3e4abefb0a41a77b25aa37ebe8d6b743

Signed-off-by: Jiri Pirko 
Signed-off-by: David S. Miller

dummy: percpu stats and lockless xmit

2010-09-29T20:23:30+00:00

Converts dummy network device driver to :

- percpu stats

- 64bit stats

- lockless xmit (NETIF_F_LLTX)

- performance features added (NETIF_F_SG | NETIF_F_FRAGLIST |
NETIF_F_TSO | NETIF_F_NO_CSUM | NETIF_F_HIGHDMA)

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

netdev: convert pseudo drivers to netdev_tx_t

2009-09-01T08:13:40+00:00

These are all drivers that don't touch real hardware.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

net: use NETDEV_TX_OK instead of 0 in ndo_start_xmit() functions

2009-07-06T02:16:04+00:00

This patch is the result of an automatic spatch transformation to convert
all ndo_start_xmit() return values of 0 to NETDEV_TX_OK.

Some occurences are missed by the automatic conversion, those will be
handled in a seperate patch.

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

dummy: convert to net_device_ops

2008-11-21T04:28:00+00:00

Convert to new network device ops interface.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

[NET]: Nuke SET_MODULE_OWNER macro.

2007-10-10T23:51:13+00:00

It's been a useless no-op for long enough in 2.6 so I figured it's time to
remove it.  The number of people that could object because they're
maintaining unified 2.4 and 2.6 drivers is probably rather small.

[ Handled drivers added by netdev tree and some missed IRDA cases... -DaveM ]

Signed-off-by: Ralf Baechle 
Signed-off-by: Jeff Garzik 
Signed-off-by: David S. Miller