linux-toradex.git/net/l2tp/l2tp_eth.c, branch v4.1-rc2 Linux kernel for Apalis and Colibri modules l2tp: Use eth_<foo>_addr instead of memset 2015-03-03T22:01:38+00:00 Joe Perches joe@perches.com 2015-03-03T03:54:59+00:00 1cea7e2c9fb3bc6bec8589337a50f60a45085156 Use the built-in function instead of memset. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Use the built-in function instead of memset.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
l2tp_eth: allow to set a specific mac address 2014-11-21T19:16:38+00:00 Alexander Couzens lynxis@fe80.eu 2014-11-19T12:24:39+00:00 fe1591224a1c454f4344d59e11ccd44577c00508 Signed-off-by: Alexander Couzens <lynxis@fe80.eu> Signed-off-by: David S. Miller <davem@davemloft.net> 
Signed-off-by: Alexander Couzens <lynxis@fe80.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: set name_assign_type in alloc_netdev() 2014-07-15T23:12:48+00:00 Tom Gundersen teg@jklm.no 2014-07-14T14:37:24+00:00 c835a677331495cf137a7f8a023463afd9f032f8 Extend alloc_netdev{,_mq{,s}}() to take name_assign_type as argument, and convert all users to pass NET_NAME_UNKNOWN. Coccinelle patch: @@ expression sizeof_priv, name, setup, txqs, rxqs, count; @@ ( -alloc_netdev_mqs(sizeof_priv, name, setup, txqs, rxqs) +alloc_netdev_mqs(sizeof_priv, name, NET_NAME_UNKNOWN, setup, txqs, rxqs) | -alloc_netdev_mq(sizeof_priv, name, setup, count) +alloc_netdev_mq(sizeof_priv, name, NET_NAME_UNKNOWN, setup, count) | -alloc_netdev(sizeof_priv, name, setup) +alloc_netdev(sizeof_priv, name, NET_NAME_UNKNOWN, setup) ) v9: move comments here from the wrong commit Signed-off-by: Tom Gundersen <teg@jklm.no> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Extend alloc_netdev{,_mq{,s}}() to take name_assign_type as argument, and convert
all users to pass NET_NAME_UNKNOWN.

Coccinelle patch:

@@
expression sizeof_priv, name, setup, txqs, rxqs, count;
@@

(
-alloc_netdev_mqs(sizeof_priv, name, setup, txqs, rxqs)
+alloc_netdev_mqs(sizeof_priv, name, NET_NAME_UNKNOWN, setup, txqs, rxqs)
|
-alloc_netdev_mq(sizeof_priv, name, setup, count)
+alloc_netdev_mq(sizeof_priv, name, NET_NAME_UNKNOWN, setup, count)
|
-alloc_netdev(sizeof_priv, name, setup)
+alloc_netdev(sizeof_priv, name, NET_NAME_UNKNOWN, setup)
)

v9: move comments here from the wrong commit

Signed-off-by: Tom Gundersen <teg@jklm.no>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
l2tp: fix oops in l2tp_eth_create() error path 2012-11-03T01:56:35+00:00 Tom Parkin tparkin@katalix.com 2012-10-29T23:41:48+00:00 789336360e0a2aeb9750c16ab704a02cbe035e9e When creating an L2TPv3 Ethernet session, if register_netdev() should fail for any reason (for example, automatic naming for "l2tpeth%d" interfaces hits the 32k-interface limit), the netdev is freed in the error path. However, the l2tp_eth_sess structure's dev pointer is left uncleared, and this results in l2tp_eth_delete() then attempting to unregister the same netdev later in the session teardown. This results in an oops. To avoid this, clear the session dev pointer in the error path. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
When creating an L2TPv3 Ethernet session, if register_netdev() should fail for
any reason (for example, automatic naming for "l2tpeth%d" interfaces hits the
32k-interface limit), the netdev is freed in the error path.  However, the
l2tp_eth_sess structure's dev pointer is left uncleared, and this results in
l2tp_eth_delete() then attempting to unregister the same netdev later in the
session teardown.  This results in an oops.

To avoid this, clear the session dev pointer in the error path.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-09-15T15:43:53+00:00 David S. Miller davem@davemloft.net 2012-09-15T15:43:53+00:00 b48b63a1f6e26b0dec2c9f1690396ed4bcb66903 Conflicts: net/netfilter/nfnetlink_log.c net/netfilter/xt_LOG.c Rather easy conflict resolution, the 'net' tree had bug fixes to make sure we checked if a socket is a time-wait one or not and elide the logging code if so. Whereas on the 'net-next' side we are calculating the UID and GID from the creds using different interfaces due to the user namespace changes from Eric Biederman. Signed-off-by: David S. Miller <davem@davemloft.net> 
Conflicts:
	net/netfilter/nfnetlink_log.c
	net/netfilter/xt_LOG.c

Rather easy conflict resolution, the 'net' tree had bug fixes to make
sure we checked if a socket is a time-wait one or not and elide the
logging code if so.

Whereas on the 'net-next' side we are calculating the UID and GID from
the creds using different interfaces due to the user namespace changes
from Eric Biederman.

Signed-off-by: David S. Miller <davem@davemloft.net>
net: qdisc busylock needs lockdep annotations 2012-09-05T21:49:27+00:00 Eric Dumazet edumazet@google.com 2012-09-05T01:02:56+00:00 23d3b8bfb8eb20e7d96afa09991e6a5ed1c83164 It seems we need to provide ability for stacked devices to use specific lock_class_key for sch->busylock We could instead default l2tpeth tx_queue_len to 0 (no qdisc), but a user might use a qdisc anyway. (So same fixes are probably needed on non LLTX stacked drivers) Noticed while stressing L2TPV3 setup : ====================================================== [ INFO: possible circular locking dependency detected ] 3.6.0-rc3+ #788 Not tainted ------------------------------------------------------- netperf/4660 is trying to acquire lock: (l2tpsock){+.-...}, at: [<ffffffffa0208db2>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core] but task is already holding lock: (&(&sch->busylock)->rlock){+.-...}, at: [<ffffffff81596595>] dev_queue_xmit+0xd75/0xe00 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&(&sch->busylock)->rlock){+.-...}: [<ffffffff810a5df0>] lock_acquire+0x90/0x200 [<ffffffff817499fc>] _raw_spin_lock_irqsave+0x4c/0x60 [<ffffffff81074872>] __wake_up+0x32/0x70 [<ffffffff8136d39e>] tty_wakeup+0x3e/0x80 [<ffffffff81378fb3>] pty_write+0x73/0x80 [<ffffffff8136cb4c>] tty_put_char+0x3c/0x40 [<ffffffff813722b2>] process_echoes+0x142/0x330 [<ffffffff813742ab>] n_tty_receive_buf+0x8fb/0x1230 [<ffffffff813777b2>] flush_to_ldisc+0x142/0x1c0 [<ffffffff81062818>] process_one_work+0x198/0x760 [<ffffffff81063236>] worker_thread+0x186/0x4b0 [<ffffffff810694d3>] kthread+0x93/0xa0 [<ffffffff81753e24>] kernel_thread_helper+0x4/0x10 -> #0 (l2tpsock){+.-...}: [<ffffffff810a5288>] __lock_acquire+0x1628/0x1b10 [<ffffffff810a5df0>] lock_acquire+0x90/0x200 [<ffffffff817498c1>] _raw_spin_lock+0x41/0x50 [<ffffffffa0208db2>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core] [<ffffffffa021a802>] l2tp_eth_dev_xmit+0x32/0x60 [l2tp_eth] [<ffffffff815952b2>] dev_hard_start_xmit+0x502/0xa70 [<ffffffff815b63ce>] sch_direct_xmit+0xfe/0x290 [<ffffffff81595a05>] dev_queue_xmit+0x1e5/0xe00 [<ffffffff815d9d60>] ip_finish_output+0x3d0/0x890 [<ffffffff815db019>] ip_output+0x59/0xf0 [<ffffffff815da36d>] ip_local_out+0x2d/0xa0 [<ffffffff815da5a3>] ip_queue_xmit+0x1c3/0x680 [<ffffffff815f4192>] tcp_transmit_skb+0x402/0xa60 [<ffffffff815f4a94>] tcp_write_xmit+0x1f4/0xa30 [<ffffffff815f5300>] tcp_push_one+0x30/0x40 [<ffffffff815e6672>] tcp_sendmsg+0xe82/0x1040 [<ffffffff81614495>] inet_sendmsg+0x125/0x230 [<ffffffff81576cdc>] sock_sendmsg+0xdc/0xf0 [<ffffffff81579ece>] sys_sendto+0xfe/0x130 [<ffffffff81752c92>] system_call_fastpath+0x16/0x1b Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&sch->busylock)->rlock); lock(l2tpsock); lock(&(&sch->busylock)->rlock); lock(l2tpsock); *** DEADLOCK *** 5 locks held by netperf/4660: #0: (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff815e581c>] tcp_sendmsg+0x2c/0x1040 #1: (rcu_read_lock){.+.+..}, at: [<ffffffff815da3e0>] ip_queue_xmit+0x0/0x680 #2: (rcu_read_lock_bh){.+....}, at: [<ffffffff815d9ac5>] ip_finish_output+0x135/0x890 #3: (rcu_read_lock_bh){.+....}, at: [<ffffffff81595820>] dev_queue_xmit+0x0/0xe00 #4: (&(&sch->busylock)->rlock){+.-...}, at: [<ffffffff81596595>] dev_queue_xmit+0xd75/0xe00 stack backtrace: Pid: 4660, comm: netperf Not tainted 3.6.0-rc3+ #788 Call Trace: [<ffffffff8173dbf8>] print_circular_bug+0x1fb/0x20c [<ffffffff810a5288>] __lock_acquire+0x1628/0x1b10 [<ffffffff810a334b>] ? check_usage+0x9b/0x4d0 [<ffffffff810a3f44>] ? __lock_acquire+0x2e4/0x1b10 [<ffffffff810a5df0>] lock_acquire+0x90/0x200 [<ffffffffa0208db2>] ? l2tp_xmit_skb+0x172/0xa50 [l2tp_core] [<ffffffff817498c1>] _raw_spin_lock+0x41/0x50 [<ffffffffa0208db2>] ? l2tp_xmit_skb+0x172/0xa50 [l2tp_core] [<ffffffffa0208db2>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core] [<ffffffffa021a802>] l2tp_eth_dev_xmit+0x32/0x60 [l2tp_eth] [<ffffffff815952b2>] dev_hard_start_xmit+0x502/0xa70 [<ffffffff81594e0e>] ? dev_hard_start_xmit+0x5e/0xa70 [<ffffffff81595961>] ? dev_queue_xmit+0x141/0xe00 [<ffffffff815b63ce>] sch_direct_xmit+0xfe/0x290 [<ffffffff81595a05>] dev_queue_xmit+0x1e5/0xe00 [<ffffffff81595820>] ? dev_hard_start_xmit+0xa70/0xa70 [<ffffffff815d9d60>] ip_finish_output+0x3d0/0x890 [<ffffffff815d9ac5>] ? ip_finish_output+0x135/0x890 [<ffffffff815db019>] ip_output+0x59/0xf0 [<ffffffff815da36d>] ip_local_out+0x2d/0xa0 [<ffffffff815da5a3>] ip_queue_xmit+0x1c3/0x680 [<ffffffff815da3e0>] ? ip_local_out+0xa0/0xa0 [<ffffffff815f4192>] tcp_transmit_skb+0x402/0xa60 [<ffffffff815fa25e>] ? tcp_md5_do_lookup+0x18e/0x1a0 [<ffffffff815f4a94>] tcp_write_xmit+0x1f4/0xa30 [<ffffffff815f5300>] tcp_push_one+0x30/0x40 [<ffffffff815e6672>] tcp_sendmsg+0xe82/0x1040 [<ffffffff81614495>] inet_sendmsg+0x125/0x230 [<ffffffff81614370>] ? inet_create+0x6b0/0x6b0 [<ffffffff8157e6e2>] ? sock_update_classid+0xc2/0x3b0 [<ffffffff8157e750>] ? sock_update_classid+0x130/0x3b0 [<ffffffff81576cdc>] sock_sendmsg+0xdc/0xf0 [<ffffffff81162579>] ? fget_light+0x3f9/0x4f0 [<ffffffff81579ece>] sys_sendto+0xfe/0x130 [<ffffffff810a69ad>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff8174a0b0>] ? _raw_spin_unlock_irq+0x30/0x50 [<ffffffff810757e3>] ? finish_task_switch+0x83/0xf0 [<ffffffff810757a6>] ? finish_task_switch+0x46/0xf0 [<ffffffff81752cb7>] ? sysret_check+0x1b/0x56 [<ffffffff81752c92>] system_call_fastpath+0x16/0x1b Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
It seems we need to provide ability for stacked devices
to use specific lock_class_key for sch->busylock

We could instead default l2tpeth tx_queue_len to 0 (no qdisc), but
a user might use a qdisc anyway.

(So same fixes are probably needed on non LLTX stacked drivers)

Noticed while stressing L2TPV3 setup :

======================================================
 [ INFO: possible circular locking dependency detected ]
 3.6.0-rc3+ #788 Not tainted
 -------------------------------------------------------
 netperf/4660 is trying to acquire lock:
  (l2tpsock){+.-...}, at: [<ffffffffa0208db2>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core]

 but task is already holding lock:
  (&(&sch->busylock)->rlock){+.-...}, at: [<ffffffff81596595>] dev_queue_xmit+0xd75/0xe00

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (&(&sch->busylock)->rlock){+.-...}:
        [<ffffffff810a5df0>] lock_acquire+0x90/0x200
        [<ffffffff817499fc>] _raw_spin_lock_irqsave+0x4c/0x60
        [<ffffffff81074872>] __wake_up+0x32/0x70
        [<ffffffff8136d39e>] tty_wakeup+0x3e/0x80
        [<ffffffff81378fb3>] pty_write+0x73/0x80
        [<ffffffff8136cb4c>] tty_put_char+0x3c/0x40
        [<ffffffff813722b2>] process_echoes+0x142/0x330
        [<ffffffff813742ab>] n_tty_receive_buf+0x8fb/0x1230
        [<ffffffff813777b2>] flush_to_ldisc+0x142/0x1c0
        [<ffffffff81062818>] process_one_work+0x198/0x760
        [<ffffffff81063236>] worker_thread+0x186/0x4b0
        [<ffffffff810694d3>] kthread+0x93/0xa0
        [<ffffffff81753e24>] kernel_thread_helper+0x4/0x10

 -> #0 (l2tpsock){+.-...}:
        [<ffffffff810a5288>] __lock_acquire+0x1628/0x1b10
        [<ffffffff810a5df0>] lock_acquire+0x90/0x200
        [<ffffffff817498c1>] _raw_spin_lock+0x41/0x50
        [<ffffffffa0208db2>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
        [<ffffffffa021a802>] l2tp_eth_dev_xmit+0x32/0x60 [l2tp_eth]
        [<ffffffff815952b2>] dev_hard_start_xmit+0x502/0xa70
        [<ffffffff815b63ce>] sch_direct_xmit+0xfe/0x290
        [<ffffffff81595a05>] dev_queue_xmit+0x1e5/0xe00
        [<ffffffff815d9d60>] ip_finish_output+0x3d0/0x890
        [<ffffffff815db019>] ip_output+0x59/0xf0
        [<ffffffff815da36d>] ip_local_out+0x2d/0xa0
        [<ffffffff815da5a3>] ip_queue_xmit+0x1c3/0x680
        [<ffffffff815f4192>] tcp_transmit_skb+0x402/0xa60
        [<ffffffff815f4a94>] tcp_write_xmit+0x1f4/0xa30
        [<ffffffff815f5300>] tcp_push_one+0x30/0x40
        [<ffffffff815e6672>] tcp_sendmsg+0xe82/0x1040
        [<ffffffff81614495>] inet_sendmsg+0x125/0x230
        [<ffffffff81576cdc>] sock_sendmsg+0xdc/0xf0
        [<ffffffff81579ece>] sys_sendto+0xfe/0x130
        [<ffffffff81752c92>] system_call_fastpath+0x16/0x1b
  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&(&sch->busylock)->rlock);
                                lock(l2tpsock);
                                lock(&(&sch->busylock)->rlock);
   lock(l2tpsock);

  *** DEADLOCK ***

 5 locks held by netperf/4660:
  #0:  (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff815e581c>] tcp_sendmsg+0x2c/0x1040
  #1:  (rcu_read_lock){.+.+..}, at: [<ffffffff815da3e0>] ip_queue_xmit+0x0/0x680
  #2:  (rcu_read_lock_bh){.+....}, at: [<ffffffff815d9ac5>] ip_finish_output+0x135/0x890
  #3:  (rcu_read_lock_bh){.+....}, at: [<ffffffff81595820>] dev_queue_xmit+0x0/0xe00
  #4:  (&(&sch->busylock)->rlock){+.-...}, at: [<ffffffff81596595>] dev_queue_xmit+0xd75/0xe00

 stack backtrace:
 Pid: 4660, comm: netperf Not tainted 3.6.0-rc3+ #788
 Call Trace:
  [<ffffffff8173dbf8>] print_circular_bug+0x1fb/0x20c
  [<ffffffff810a5288>] __lock_acquire+0x1628/0x1b10
  [<ffffffff810a334b>] ? check_usage+0x9b/0x4d0
  [<ffffffff810a3f44>] ? __lock_acquire+0x2e4/0x1b10
  [<ffffffff810a5df0>] lock_acquire+0x90/0x200
  [<ffffffffa0208db2>] ? l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
  [<ffffffff817498c1>] _raw_spin_lock+0x41/0x50
  [<ffffffffa0208db2>] ? l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
  [<ffffffffa0208db2>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core]
  [<ffffffffa021a802>] l2tp_eth_dev_xmit+0x32/0x60 [l2tp_eth]
  [<ffffffff815952b2>] dev_hard_start_xmit+0x502/0xa70
  [<ffffffff81594e0e>] ? dev_hard_start_xmit+0x5e/0xa70
  [<ffffffff81595961>] ? dev_queue_xmit+0x141/0xe00
  [<ffffffff815b63ce>] sch_direct_xmit+0xfe/0x290
  [<ffffffff81595a05>] dev_queue_xmit+0x1e5/0xe00
  [<ffffffff81595820>] ? dev_hard_start_xmit+0xa70/0xa70
  [<ffffffff815d9d60>] ip_finish_output+0x3d0/0x890
  [<ffffffff815d9ac5>] ? ip_finish_output+0x135/0x890
  [<ffffffff815db019>] ip_output+0x59/0xf0
  [<ffffffff815da36d>] ip_local_out+0x2d/0xa0
  [<ffffffff815da5a3>] ip_queue_xmit+0x1c3/0x680
  [<ffffffff815da3e0>] ? ip_local_out+0xa0/0xa0
  [<ffffffff815f4192>] tcp_transmit_skb+0x402/0xa60
  [<ffffffff815fa25e>] ? tcp_md5_do_lookup+0x18e/0x1a0
  [<ffffffff815f4a94>] tcp_write_xmit+0x1f4/0xa30
  [<ffffffff815f5300>] tcp_push_one+0x30/0x40
  [<ffffffff815e6672>] tcp_sendmsg+0xe82/0x1040
  [<ffffffff81614495>] inet_sendmsg+0x125/0x230
  [<ffffffff81614370>] ? inet_create+0x6b0/0x6b0
  [<ffffffff8157e6e2>] ? sock_update_classid+0xc2/0x3b0
  [<ffffffff8157e750>] ? sock_update_classid+0x130/0x3b0
  [<ffffffff81576cdc>] sock_sendmsg+0xdc/0xf0
  [<ffffffff81162579>] ? fget_light+0x3f9/0x4f0
  [<ffffffff81579ece>] sys_sendto+0xfe/0x130
  [<ffffffff810a69ad>] ? trace_hardirqs_on+0xd/0x10
  [<ffffffff8174a0b0>] ? _raw_spin_unlock_irq+0x30/0x50
  [<ffffffff810757e3>] ? finish_task_switch+0x83/0xf0
  [<ffffffff810757a6>] ? finish_task_switch+0x46/0xf0
  [<ffffffff81752cb7>] ? sysret_check+0x1b/0x56
  [<ffffffff81752c92>] system_call_fastpath+0x16/0x1b

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
l2tp: fix a typo in l2tp_eth_dev_recv() 2012-09-04T19:54:55+00:00 Eric Dumazet edumazet@google.com 2012-09-04T19:54:55+00:00 c0cc88a7627c333de50b07b7c60b1d49d9d2e6cc While investigating l2tp bug, I hit a bug in eth_type_trans(), because not enough bytes were pulled in skb head. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
While investigating l2tp bug, I hit a bug in eth_type_trans(),
because not enough bytes were pulled in skb head.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: l2tp_eth: provide tx_dropped counter 2012-06-29T07:52:32+00:00 Eric Dumazet edumazet@google.com 2012-06-28T20:15:13+00:00 b8c8430726e5bd552e01dacc5a44f3f83f7446ca Change l2tp_xmit_skb() to return NET_XMIT_DROP in case skb is dropped. Use kfree_skb() instead dev_kfree_skb() for drop_monitor pleasure. Support tx_dropped counter for l2tp_eth Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Change l2tp_xmit_skb() to return NET_XMIT_DROP in case skb is dropped.

Use kfree_skb() instead dev_kfree_skb() for drop_monitor pleasure.

Support tx_dropped counter for l2tp_eth

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: l2tp_eth: use LLTX to avoid LOCKDEP splats 2012-06-26T23:42:33+00:00 Eric Dumazet edumazet@google.com 2012-06-25T05:35:45+00:00 a2842a1e66329798d66563b52faec1a299ec4f73 Denys Fedoryshchenko reported a LOCKDEP issue with l2tp code. [ 8683.927442] ====================================================== [ 8683.927555] [ INFO: possible circular locking dependency detected ] [ 8683.927672] 3.4.1-build-0061 #14 Not tainted [ 8683.927782] ------------------------------------------------------- [ 8683.927895] swapper/0/0 is trying to acquire lock: [ 8683.928007] (slock-AF_INET){+.-...}, at: [<e0fc73ec>] l2tp_xmit_skb+0x173/0x47e [l2tp_core] [ 8683.928121] [ 8683.928121] but task is already holding lock: [ 8683.928121] (_xmit_ETHER#2){+.-...}, at: [<c02f062d>] sch_direct_xmit+0x36/0x119 [ 8683.928121] [ 8683.928121] which lock already depends on the new lock. [ 8683.928121] [ 8683.928121] [ 8683.928121] the existing dependency chain (in reverse order) is: [ 8683.928121] [ 8683.928121] -> #1 (_xmit_ETHER#2){+.-...}: [ 8683.928121] [<c015a561>] lock_acquire+0x71/0x85 [ 8683.928121] [<c034da2d>] _raw_spin_lock+0x33/0x40 [ 8683.928121] [<c0304e0c>] ip_send_reply+0xf2/0x1ce [ 8683.928121] [<c0317dbc>] tcp_v4_send_reset+0x153/0x16f [ 8683.928121] [<c0317f4a>] tcp_v4_do_rcv+0x172/0x194 [ 8683.928121] [<c031929b>] tcp_v4_rcv+0x387/0x5a0 [ 8683.928121] [<c03001d0>] ip_local_deliver_finish+0x13a/0x1e9 [ 8683.928121] [<c0300645>] NF_HOOK.clone.11+0x46/0x4d [ 8683.928121] [<c030075b>] ip_local_deliver+0x41/0x45 [ 8683.928121] [<c03005dd>] ip_rcv_finish+0x31a/0x33c [ 8683.928121] [<c0300645>] NF_HOOK.clone.11+0x46/0x4d [ 8683.928121] [<c0300960>] ip_rcv+0x201/0x23d [ 8683.928121] [<c02de91b>] __netif_receive_skb+0x329/0x378 [ 8683.928121] [<c02deae8>] netif_receive_skb+0x4e/0x7d [ 8683.928121] [<e08d5ef3>] rtl8139_poll+0x243/0x33d [8139too] [ 8683.928121] [<c02df103>] net_rx_action+0x90/0x15d [ 8683.928121] [<c012b2b5>] __do_softirq+0x7b/0x118 [ 8683.928121] [ 8683.928121] -> #0 (slock-AF_INET){+.-...}: [ 8683.928121] [<c0159f1b>] __lock_acquire+0x9a3/0xc27 [ 8683.928121] [<c015a561>] lock_acquire+0x71/0x85 [ 8683.928121] [<c034da2d>] _raw_spin_lock+0x33/0x40 [ 8683.928121] [<e0fc73ec>] l2tp_xmit_skb+0x173/0x47e [l2tp_core] [ 8683.928121] [<e0fe31fb>] l2tp_eth_dev_xmit+0x1a/0x2f [l2tp_eth] [ 8683.928121] [<c02e01e7>] dev_hard_start_xmit+0x333/0x3f2 [ 8683.928121] [<c02f064c>] sch_direct_xmit+0x55/0x119 [ 8683.928121] [<c02e0528>] dev_queue_xmit+0x282/0x418 [ 8683.928121] [<c031f4fb>] NF_HOOK.clone.19+0x45/0x4c [ 8683.928121] [<c031f524>] arp_xmit+0x22/0x24 [ 8683.928121] [<c031f567>] arp_send+0x41/0x48 [ 8683.928121] [<c031fa7d>] arp_process+0x289/0x491 [ 8683.928121] [<c031f4fb>] NF_HOOK.clone.19+0x45/0x4c [ 8683.928121] [<c031f7a0>] arp_rcv+0xb1/0xc3 [ 8683.928121] [<c02de91b>] __netif_receive_skb+0x329/0x378 [ 8683.928121] [<c02de9d3>] process_backlog+0x69/0x130 [ 8683.928121] [<c02df103>] net_rx_action+0x90/0x15d [ 8683.928121] [<c012b2b5>] __do_softirq+0x7b/0x118 [ 8683.928121] [ 8683.928121] other info that might help us debug this: [ 8683.928121] [ 8683.928121] Possible unsafe locking scenario: [ 8683.928121] [ 8683.928121] CPU0 CPU1 [ 8683.928121] ---- ---- [ 8683.928121] lock(_xmit_ETHER#2); [ 8683.928121] lock(slock-AF_INET); [ 8683.928121] lock(_xmit_ETHER#2); [ 8683.928121] lock(slock-AF_INET); [ 8683.928121] [ 8683.928121] *** DEADLOCK *** [ 8683.928121] [ 8683.928121] 3 locks held by swapper/0/0: [ 8683.928121] #0: (rcu_read_lock){.+.+..}, at: [<c02dbc10>] rcu_lock_acquire+0x0/0x30 [ 8683.928121] #1: (rcu_read_lock_bh){.+....}, at: [<c02dbc10>] rcu_lock_acquire+0x0/0x30 [ 8683.928121] #2: (_xmit_ETHER#2){+.-...}, at: [<c02f062d>] sch_direct_xmit+0x36/0x119 [ 8683.928121] [ 8683.928121] stack backtrace: [ 8683.928121] Pid: 0, comm: swapper/0 Not tainted 3.4.1-build-0061 #14 [ 8683.928121] Call Trace: [ 8683.928121] [<c034bdd2>] ? printk+0x18/0x1a [ 8683.928121] [<c0158904>] print_circular_bug+0x1ac/0x1b6 [ 8683.928121] [<c0159f1b>] __lock_acquire+0x9a3/0xc27 [ 8683.928121] [<c015a561>] lock_acquire+0x71/0x85 [ 8683.928121] [<e0fc73ec>] ? l2tp_xmit_skb+0x173/0x47e [l2tp_core] [ 8683.928121] [<c034da2d>] _raw_spin_lock+0x33/0x40 [ 8683.928121] [<e0fc73ec>] ? l2tp_xmit_skb+0x173/0x47e [l2tp_core] [ 8683.928121] [<e0fc73ec>] l2tp_xmit_skb+0x173/0x47e [l2tp_core] [ 8683.928121] [<e0fe31fb>] l2tp_eth_dev_xmit+0x1a/0x2f [l2tp_eth] [ 8683.928121] [<c02e01e7>] dev_hard_start_xmit+0x333/0x3f2 [ 8683.928121] [<c02f064c>] sch_direct_xmit+0x55/0x119 [ 8683.928121] [<c02e0528>] dev_queue_xmit+0x282/0x418 [ 8683.928121] [<c02e02a6>] ? dev_hard_start_xmit+0x3f2/0x3f2 [ 8683.928121] [<c031f4fb>] NF_HOOK.clone.19+0x45/0x4c [ 8683.928121] [<c031f524>] arp_xmit+0x22/0x24 [ 8683.928121] [<c02e02a6>] ? dev_hard_start_xmit+0x3f2/0x3f2 [ 8683.928121] [<c031f567>] arp_send+0x41/0x48 [ 8683.928121] [<c031fa7d>] arp_process+0x289/0x491 [ 8683.928121] [<c031f7f4>] ? __neigh_lookup.clone.20+0x42/0x42 [ 8683.928121] [<c031f4fb>] NF_HOOK.clone.19+0x45/0x4c [ 8683.928121] [<c031f7a0>] arp_rcv+0xb1/0xc3 [ 8683.928121] [<c031f7f4>] ? __neigh_lookup.clone.20+0x42/0x42 [ 8683.928121] [<c02de91b>] __netif_receive_skb+0x329/0x378 [ 8683.928121] [<c02de9d3>] process_backlog+0x69/0x130 [ 8683.928121] [<c02df103>] net_rx_action+0x90/0x15d [ 8683.928121] [<c012b2b5>] __do_softirq+0x7b/0x118 [ 8683.928121] [<c012b23a>] ? local_bh_enable+0xd/0xd [ 8683.928121] <IRQ> [<c012b4d0>] ? irq_exit+0x41/0x91 [ 8683.928121] [<c0103c6f>] ? do_IRQ+0x79/0x8d [ 8683.928121] [<c0157ea1>] ? trace_hardirqs_off_caller+0x2e/0x86 [ 8683.928121] [<c034ef6e>] ? common_interrupt+0x2e/0x34 [ 8683.928121] [<c0108a33>] ? default_idle+0x23/0x38 [ 8683.928121] [<c01091a8>] ? cpu_idle+0x55/0x6f [ 8683.928121] [<c033df25>] ? rest_init+0xa1/0xa7 [ 8683.928121] [<c033de84>] ? __read_lock_failed+0x14/0x14 [ 8683.928121] [<c0498745>] ? start_kernel+0x303/0x30a [ 8683.928121] [<c0498209>] ? repair_env_string+0x51/0x51 [ 8683.928121] [<c04980a8>] ? i386_start_kernel+0xa8/0xaf It appears that like most virtual devices, l2tp should be converted to LLTX mode. This patch takes care of statistics using atomic_long in both RX and TX paths, and fix a bug in l2tp_eth_dev_recv(), which was caching skb->data before a pskb_may_pull() call. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Denys Fedoryshchenko <denys@visp.net.lb> Cc: James Chapman <jchapman@katalix.com> Cc: Hong zhi guo <honkiko@gmail.com> Cc: Francois Romieu <romieu@fr.zoreil.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Denys Fedoryshchenko reported a LOCKDEP issue with l2tp code.

[ 8683.927442] ======================================================
[ 8683.927555] [ INFO: possible circular locking dependency detected ]
[ 8683.927672] 3.4.1-build-0061 #14 Not tainted
[ 8683.927782] -------------------------------------------------------
[ 8683.927895] swapper/0/0 is trying to acquire lock:
[ 8683.928007]  (slock-AF_INET){+.-...}, at: [<e0fc73ec>]
l2tp_xmit_skb+0x173/0x47e [l2tp_core]
[ 8683.928121]
[ 8683.928121] but task is already holding lock:
[ 8683.928121]  (_xmit_ETHER#2){+.-...}, at: [<c02f062d>]
sch_direct_xmit+0x36/0x119
[ 8683.928121]
[ 8683.928121] which lock already depends on the new lock.
[ 8683.928121]
[ 8683.928121]
[ 8683.928121] the existing dependency chain (in reverse order) is:
[ 8683.928121]
[ 8683.928121] -> #1 (_xmit_ETHER#2){+.-...}:
[ 8683.928121]        [<c015a561>] lock_acquire+0x71/0x85
[ 8683.928121]        [<c034da2d>] _raw_spin_lock+0x33/0x40
[ 8683.928121]        [<c0304e0c>] ip_send_reply+0xf2/0x1ce
[ 8683.928121]        [<c0317dbc>] tcp_v4_send_reset+0x153/0x16f
[ 8683.928121]        [<c0317f4a>] tcp_v4_do_rcv+0x172/0x194
[ 8683.928121]        [<c031929b>] tcp_v4_rcv+0x387/0x5a0
[ 8683.928121]        [<c03001d0>] ip_local_deliver_finish+0x13a/0x1e9
[ 8683.928121]        [<c0300645>] NF_HOOK.clone.11+0x46/0x4d
[ 8683.928121]        [<c030075b>] ip_local_deliver+0x41/0x45
[ 8683.928121]        [<c03005dd>] ip_rcv_finish+0x31a/0x33c
[ 8683.928121]        [<c0300645>] NF_HOOK.clone.11+0x46/0x4d
[ 8683.928121]        [<c0300960>] ip_rcv+0x201/0x23d
[ 8683.928121]        [<c02de91b>] __netif_receive_skb+0x329/0x378
[ 8683.928121]        [<c02deae8>] netif_receive_skb+0x4e/0x7d
[ 8683.928121]        [<e08d5ef3>] rtl8139_poll+0x243/0x33d [8139too]
[ 8683.928121]        [<c02df103>] net_rx_action+0x90/0x15d
[ 8683.928121]        [<c012b2b5>] __do_softirq+0x7b/0x118
[ 8683.928121]
[ 8683.928121] -> #0 (slock-AF_INET){+.-...}:
[ 8683.928121]        [<c0159f1b>] __lock_acquire+0x9a3/0xc27
[ 8683.928121]        [<c015a561>] lock_acquire+0x71/0x85
[ 8683.928121]        [<c034da2d>] _raw_spin_lock+0x33/0x40
[ 8683.928121]        [<e0fc73ec>] l2tp_xmit_skb+0x173/0x47e
[l2tp_core]
[ 8683.928121]        [<e0fe31fb>] l2tp_eth_dev_xmit+0x1a/0x2f
[l2tp_eth]
[ 8683.928121]        [<c02e01e7>] dev_hard_start_xmit+0x333/0x3f2
[ 8683.928121]        [<c02f064c>] sch_direct_xmit+0x55/0x119
[ 8683.928121]        [<c02e0528>] dev_queue_xmit+0x282/0x418
[ 8683.928121]        [<c031f4fb>] NF_HOOK.clone.19+0x45/0x4c
[ 8683.928121]        [<c031f524>] arp_xmit+0x22/0x24
[ 8683.928121]        [<c031f567>] arp_send+0x41/0x48
[ 8683.928121]        [<c031fa7d>] arp_process+0x289/0x491
[ 8683.928121]        [<c031f4fb>] NF_HOOK.clone.19+0x45/0x4c
[ 8683.928121]        [<c031f7a0>] arp_rcv+0xb1/0xc3
[ 8683.928121]        [<c02de91b>] __netif_receive_skb+0x329/0x378
[ 8683.928121]        [<c02de9d3>] process_backlog+0x69/0x130
[ 8683.928121]        [<c02df103>] net_rx_action+0x90/0x15d
[ 8683.928121]        [<c012b2b5>] __do_softirq+0x7b/0x118
[ 8683.928121]
[ 8683.928121] other info that might help us debug this:
[ 8683.928121]
[ 8683.928121]  Possible unsafe locking scenario:
[ 8683.928121]
[ 8683.928121]        CPU0                    CPU1
[ 8683.928121]        ----                    ----
[ 8683.928121]   lock(_xmit_ETHER#2);
[ 8683.928121]                                lock(slock-AF_INET);
[ 8683.928121]                                lock(_xmit_ETHER#2);
[ 8683.928121]   lock(slock-AF_INET);
[ 8683.928121]
[ 8683.928121]  *** DEADLOCK ***
[ 8683.928121]
[ 8683.928121] 3 locks held by swapper/0/0:
[ 8683.928121]  #0:  (rcu_read_lock){.+.+..}, at: [<c02dbc10>]
rcu_lock_acquire+0x0/0x30
[ 8683.928121]  #1:  (rcu_read_lock_bh){.+....}, at: [<c02dbc10>]
rcu_lock_acquire+0x0/0x30
[ 8683.928121]  #2:  (_xmit_ETHER#2){+.-...}, at: [<c02f062d>]
sch_direct_xmit+0x36/0x119
[ 8683.928121]
[ 8683.928121] stack backtrace:
[ 8683.928121] Pid: 0, comm: swapper/0 Not tainted 3.4.1-build-0061 #14
[ 8683.928121] Call Trace:
[ 8683.928121]  [<c034bdd2>] ? printk+0x18/0x1a
[ 8683.928121]  [<c0158904>] print_circular_bug+0x1ac/0x1b6
[ 8683.928121]  [<c0159f1b>] __lock_acquire+0x9a3/0xc27
[ 8683.928121]  [<c015a561>] lock_acquire+0x71/0x85
[ 8683.928121]  [<e0fc73ec>] ? l2tp_xmit_skb+0x173/0x47e [l2tp_core]
[ 8683.928121]  [<c034da2d>] _raw_spin_lock+0x33/0x40
[ 8683.928121]  [<e0fc73ec>] ? l2tp_xmit_skb+0x173/0x47e [l2tp_core]
[ 8683.928121]  [<e0fc73ec>] l2tp_xmit_skb+0x173/0x47e [l2tp_core]
[ 8683.928121]  [<e0fe31fb>] l2tp_eth_dev_xmit+0x1a/0x2f [l2tp_eth]
[ 8683.928121]  [<c02e01e7>] dev_hard_start_xmit+0x333/0x3f2
[ 8683.928121]  [<c02f064c>] sch_direct_xmit+0x55/0x119
[ 8683.928121]  [<c02e0528>] dev_queue_xmit+0x282/0x418
[ 8683.928121]  [<c02e02a6>] ? dev_hard_start_xmit+0x3f2/0x3f2
[ 8683.928121]  [<c031f4fb>] NF_HOOK.clone.19+0x45/0x4c
[ 8683.928121]  [<c031f524>] arp_xmit+0x22/0x24
[ 8683.928121]  [<c02e02a6>] ? dev_hard_start_xmit+0x3f2/0x3f2
[ 8683.928121]  [<c031f567>] arp_send+0x41/0x48
[ 8683.928121]  [<c031fa7d>] arp_process+0x289/0x491
[ 8683.928121]  [<c031f7f4>] ? __neigh_lookup.clone.20+0x42/0x42
[ 8683.928121]  [<c031f4fb>] NF_HOOK.clone.19+0x45/0x4c
[ 8683.928121]  [<c031f7a0>] arp_rcv+0xb1/0xc3
[ 8683.928121]  [<c031f7f4>] ? __neigh_lookup.clone.20+0x42/0x42
[ 8683.928121]  [<c02de91b>] __netif_receive_skb+0x329/0x378
[ 8683.928121]  [<c02de9d3>] process_backlog+0x69/0x130
[ 8683.928121]  [<c02df103>] net_rx_action+0x90/0x15d
[ 8683.928121]  [<c012b2b5>] __do_softirq+0x7b/0x118
[ 8683.928121]  [<c012b23a>] ? local_bh_enable+0xd/0xd
[ 8683.928121]  <IRQ>  [<c012b4d0>] ? irq_exit+0x41/0x91
[ 8683.928121]  [<c0103c6f>] ? do_IRQ+0x79/0x8d
[ 8683.928121]  [<c0157ea1>] ? trace_hardirqs_off_caller+0x2e/0x86
[ 8683.928121]  [<c034ef6e>] ? common_interrupt+0x2e/0x34
[ 8683.928121]  [<c0108a33>] ? default_idle+0x23/0x38
[ 8683.928121]  [<c01091a8>] ? cpu_idle+0x55/0x6f
[ 8683.928121]  [<c033df25>] ? rest_init+0xa1/0xa7
[ 8683.928121]  [<c033de84>] ? __read_lock_failed+0x14/0x14
[ 8683.928121]  [<c0498745>] ? start_kernel+0x303/0x30a
[ 8683.928121]  [<c0498209>] ? repair_env_string+0x51/0x51
[ 8683.928121]  [<c04980a8>] ? i386_start_kernel+0xa8/0xaf

It appears that like most virtual devices, l2tp should be converted to
LLTX mode.

This patch takes care of statistics using atomic_long in both RX and TX
paths, and fix a bug in l2tp_eth_dev_recv(), which was caching skb->data
before a pskb_may_pull() call.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Denys Fedoryshchenko <denys@visp.net.lb>
Cc: James Chapman <jchapman@katalix.com>
Cc: Hong zhi guo <honkiko@gmail.com>
Cc: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: l2tp_eth: fix l2tp_eth_dev_xmit race 2012-06-25T23:30:54+00:00 Eric Dumazet edumazet@google.com 2012-06-25T00:45:14+00:00 aa214de0595eecf5079a172a16333fa638b64915 Its illegal to dereference skb after giving it to l2tp_xmit_skb() as it might be already freed/reused. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Its illegal to dereference skb after giving it to l2tp_xmit_skb()
as it might be already freed/reused.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>