From 03478756b1b9298686ca9c8793e484ae39eb4649 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 6 Apr 2012 15:35:39 +0000 Subject: phonet: Sort out initiailziation and cleanup code. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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/phonet/pn_dev.c | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-) (limited to 'net') diff --git a/net/phonet/pn_dev.c b/net/phonet/pn_dev.c index 9b9a85ecc4c..bf5cf69c820 100644 --- a/net/phonet/pn_dev.c +++ b/net/phonet/pn_dev.c @@ -331,23 +331,6 @@ static int __net_init phonet_init_net(struct net *net) static void __net_exit phonet_exit_net(struct net *net) { - struct phonet_net *pnn = phonet_pernet(net); - struct net_device *dev; - unsigned i; - - rtnl_lock(); - for_each_netdev(net, dev) - phonet_device_destroy(dev); - - for (i = 0; i < 64; i++) { - dev = pnn->routes.table[i]; - if (dev) { - rtm_phonet_notify(RTM_DELROUTE, dev, i); - dev_put(dev); - } - } - rtnl_unlock(); - proc_net_remove(net, "phonet"); } @@ -361,7 +344,7 @@ static struct pernet_operations phonet_net_ops = { /* Initialize Phonet devices list */ int __init phonet_device_init(void) { - int err = register_pernet_device(&phonet_net_ops); + int err = register_pernet_subsys(&phonet_net_ops); if (err) return err; @@ -377,7 +360,7 @@ void phonet_device_exit(void) { rtnl_unregister_all(PF_PHONET); unregister_netdevice_notifier(&phonet_device_notifier); - unregister_pernet_device(&phonet_net_ops); + unregister_pernet_subsys(&phonet_net_ops); proc_net_remove(&init_net, "pnresource"); } -- cgit v1.2.3-70-g09d2