linux-stable.git/net/phonet/pn_dev.c, branch v3.4

phonet: Sort out initiailziation and cleanup code.

2012-04-13T15:01:43+00:00

Recently an oops was reported in phonet if there was a failure during
network namespace creation.

[  163.733755] ------------[ cut here ]------------
[  163.734501] kernel BUG at include/net/netns/generic.h:45!
[  163.734501] invalid opcode: 0000 [#1] PREEMPT SMP
[  163.734501] CPU 2
[  163.734501] Pid: 19145, comm: trinity Tainted: G        W 3.4.0-rc1-next-20120405-sasha-dirty #57
[  163.734501] RIP: 0010:[]  [] phonet_pernet+0x182/0x1a0
[  163.734501] RSP: 0018:ffff8800674d5ca8  EFLAGS: 00010246
[  163.734501] RAX: 000000003fffffff RBX: 0000000000000000 RCX: ffff8800678c88d8
[  163.734501] RDX: 00000000003f4000 RSI: ffff8800678c8910 RDI: 0000000000000282
[  163.734501] RBP: ffff8800674d5cc8 R08: 0000000000000000 R09: 0000000000000000
[  163.734501] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880068bec920
[  163.734501] R13: ffffffff836b90c0 R14: 0000000000000000 R15: 0000000000000000
[  163.734501] FS:  00007f055e8de700(0000) GS:ffff88007d000000(0000) knlGS:0000000000000000
[  163.734501] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  163.734501] CR2: 00007f055e6bb518 CR3: 0000000070c16000 CR4: 00000000000406e0
[  163.734501] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  163.734501] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  163.734501] Process trinity (pid: 19145, threadinfo ffff8800674d4000, task ffff8800678c8000)
[  163.734501] Stack:
[  163.734501]  ffffffff824d5f00 ffffffff810e2ec1 ffff880067ae0000 00000000ffffffd4
[  163.734501]  ffff8800674d5cf8 ffffffff824d667a ffff880067ae0000 00000000ffffffd4
[  163.734501]  ffffffff836b90c0 0000000000000000 ffff8800674d5d18 ffffffff824d707d
[  163.734501] Call Trace:
[  163.734501]  [] ? phonet_pernet+0x20/0x1a0
[  163.734501]  [] ? get_parent_ip+0x11/0x50
[  163.734501]  [] phonet_device_destroy+0x1a/0x100
[  163.734501]  [] phonet_device_notify+0x3d/0x50
[  163.734501]  [] notifier_call_chain+0xee/0x130
[  163.734501]  [] raw_notifier_call_chain+0x11/0x20
[  163.734501]  [] call_netdevice_notifiers+0x52/0x60
[  163.734501]  [] rollback_registered_many+0x185/0x270
[  163.734501]  [] unregister_netdevice_many+0x14/0x60
[  163.734501]  [] ipip_exit_net+0x1b3/0x1d0
[  163.734501]  [] ? ipip_rcv+0x420/0x420
[  163.734501]  [] ops_exit_list+0x35/0x70
[  163.734501]  [] setup_net+0xab/0xe0
[  163.734501]  [] copy_net_ns+0x76/0x100
[  163.734501]  [] create_new_namespaces+0xfb/0x190
[  163.734501]  [] unshare_nsproxy_namespaces+0x61/0x80
[  163.734501]  [] sys_unshare+0xff/0x290
[  163.734501]  [] ? trace_hardirqs_on_thunk+0x3a/0x3f
[  163.734501]  [] system_call_fastpath+0x16/0x1b
[  163.734501] Code: e0 c3 fe 66 0f 1f 44 00 00 48 c7 c2 40 60 4d 82 be 01 00 00 00 48 c7 c7 80 d1 23 83 e8 48 2a c4 fe e8 73 06 c8 fe 48 85 db 75 0e <0f> 0b 0f 1f 40 00 eb fe 66 0f 1f 44 00 00 48 83 c4 10 48 89 d8
[  163.734501] RIP  [] phonet_pernet+0x182/0x1a0
[  163.734501]  RSP 
[  163.861289] ---[ end trace fb5615826c548066 ]---

After investigation it turns out there were two issues.
1) Phonet was not implementing network devices but was using register_pernet_device
   instead of register_pernet_subsys.

   This was allowing there to be cases when phonenet was not initialized and
   the phonet net_generic was not set for a network namespace when network
   device events were being reported on the netdevice_notifier for a network
   namespace leading to the oops above.

2) phonet_exit_net was implementing a confusing and special case of handling all
   network devices from going away that it was hard to see was correct, and would
   only occur when the phonet module was removed.

   Now that unregister_netdevice_notifier has been modified to synthesize unregistration
   events for the network devices that are extant when called this confusing special
   case in phonet_exit_net is no longer needed.

Signed-off-by: Eric W. Biederman 
Acked-by: Rémi Denis-Courmont 
Signed-off-by: David S. Miller

net: reintroduce missing rcu_assign_pointer() calls

2012-01-12T20:26:56+00:00

commit a9b3cd7f32 (rcu: convert uses of rcu_assign_pointer(x, NULL) to
RCU_INIT_POINTER) did a lot of incorrect changes, since it did a
complete conversion of rcu_assign_pointer(x, y) to RCU_INIT_POINTER(x,
y).

We miss needed barriers, even on x86, when y is not NULL.

Signed-off-by: Eric Dumazet 
CC: Stephen Hemminger 
CC: Paul E. McKenney 
Signed-off-by: David S. Miller

rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER

2011-08-02T11:29:23+00:00

When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.

Convert all rcu_assign_pointer of NULL value.

//smpl
@@ expression P; @@

- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)

// 

Signed-off-by: Stephen Hemminger 
Acked-by: Paul E. McKenney 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6

2011-05-20T20:43:21+00:00

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1446 commits)
  macvlan: fix panic if lowerdev in a bond
  tg3: Add braces around 5906 workaround.
  tg3: Fix NETIF_F_LOOPBACK error
  macvlan: remove one synchronize_rcu() call
  networking: NET_CLS_ROUTE4 depends on INET
  irda: Fix error propagation in ircomm_lmp_connect_response()
  irda: Kill set but unused variable 'bytes' in irlan_check_command_param()
  irda: Kill set but unused variable 'clen' in ircomm_connect_indication()
  rxrpc: Fix set but unused variable 'usage' in rxrpc_get_transport()
  be2net: Kill set but unused variable 'req' in lancer_fw_download()
  irda: Kill set but unused vars 'saddr' and 'daddr' in irlan_provider_connect_indication()
  atl1c: atl1c_resume() is only used when CONFIG_PM_SLEEP is defined.
  rxrpc: Fix set but unused variable 'usage' in rxrpc_get_peer().
  rxrpc: Kill set but unused variable 'local' in rxrpc_UDP_error_handler()
  rxrpc: Kill set but unused variable 'sp' in rxrpc_process_connection()
  rxrpc: Kill set but unused variable 'sp' in rxrpc_rotate_tx_window()
  pkt_sched: Kill set but unused variable 'protocol' in tc_classify()
  isdn: capi: Use pr_debug() instead of ifdefs.
  tg3: Update version to 3.119
  tg3: Apply rx_discards fix to 5719/5720
  ...

Fix up trivial conflicts in arch/x86/Kconfig and net/mac80211/agg-tx.c
as per Davem.

net,rcu: convert call_rcu(phonet_device_rcu_free) to kfree_rcu()

2011-05-08T05:51:10+00:00

The rcu callback phonet_device_rcu_free() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(phonet_device_rcu_free).

Signed-off-by: Lai Jiangshan 
Acked-by: David S. Miller 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

net: dont hold rtnl mutex during netlink dump callbacks

2011-05-02T22:26:28+00:00

Four years ago, Patrick made a change to hold rtnl mutex during netlink
dump callbacks.

I believe it was a wrong move. This slows down concurrent dumps, making
good old /proc/net/ files faster than rtnetlink in some situations.

This occurred to me because one "ip link show dev ..." was _very_ slow
on a workload adding/removing network devices in background.

All dump callbacks are able to use RCU locking now, so this patch does
roughly a revert of commits :

1c2d670f366 : [RTNETLINK]: Hold rtnl_mutex during netlink dump callbacks
6313c1e0992 : [RTNETLINK]: Remove unnecessary locking in dump callbacks

This let writers fight for rtnl mutex and readers going full speed.

It also takes care of phonet : phonet_route_get() is now called from rcu
read section. I renamed it to phonet_route_get_rcu()

Signed-off-by: Eric Dumazet 
Cc: Patrick McHardy 
Cc: Remi Denis-Courmont 
Acked-by: Stephen Hemminger 
Signed-off-by: David S. Miller

Phonet: list subscribed resources via proc_fs

2010-09-16T04:31:33+00:00

Signed-off-by: Rémi Denis-Courmont 
Signed-off-by: David S. Miller

phonet: use for_each_set_bit

2010-08-28T22:37:04+00:00

Replace open-coded loop with for_each_set_bit().

Signed-off-by: Akinobu Mita 
Cc: "David S. Miller" 
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller

phonet: use call_rcu for phonet device free

2010-06-09T23:14:25+00:00

Use call_rcu rather than synchronize_rcu.

Signed-off-by: Jiri Pirko 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

phonet: use phonet_pernet instead of directly net_generic

2010-04-26T18:18:44+00:00

As in for example pppoe introduce phonet_pernet and use it instead of calling
net_generic directly.

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