user/sven/linux.git/net/core/dev.c, branch v3.10.93

net: call rcu_read_lock early in process_backlog

2015-10-01T10:07:35Z

[ Upstream commit 2c17d27c36dcce2b6bf689f41a46b9e909877c21 ] Incoming packet should be either in backlog queue or in RCU read-side section. Otherwise, the final sequence of flush_backlog() and synchronize_net() may miss packets that can run without device reference: CPU 1 CPU 2 skb->dev: no reference process_backlog:__skb_dequeue process_backlog:local_irq_enable on_each_cpu for flush_backlog => IPI(hardirq): flush_backlog - packet not found in backlog CPU delayed ... synchronize_net - no ongoing RCU read-side sections netdev_run_todo, rcu_barrier: no ongoing callbacks __netif_receive_skb_core:rcu_read_lock - too late free dev process packet for freed dev Fixes: 6e583ce5242f ("net: eliminate refcounting in backlog queue") Cc: Eric W. Biederman Cc: Stephen Hemminger Signed-off-by: Julian Anastasov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: reject creation of netdev names with colons

2015-03-18T12:22:27Z

[ Upstream commit a4176a9391868bfa87705bcd2e3b49e9b9dd2996 ] colons are used as a separator in netdev device lookup in dev_ioctl.c Specific functions are SIOCGIFTXQLEN SIOCETHTOOL SIOCSIFNAME Signed-off-by: Matthew Thode Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: rps: fix cpu unplug

2015-02-27T01:48:47Z

[ Upstream commit ac64da0b83d82abe62f78b3d0e21cca31aea24fa ] softnet_data.input_pkt_queue is protected by a spinlock that we must hold when transferring packets from victim queue to an active one. This is because other cpus could still be trying to enqueue packets into victim queue. A second problem is that when we transfert the NAPI poll_list from victim to current cpu, we absolutely need to special case the percpu backlog, because we do not want to add complex locking to protect process_queue : Only owner cpu is allowed to manipulate it, unless cpu is offline. Based on initial patch from Prasad Sodagudi & Subash Abhinov Kasiviswanathan. This version is better because we do not slow down packet processing, only make migration safer. Reported-by: Prasad Sodagudi Reported-by: Subash Abhinov Kasiviswanathan Signed-off-by: Eric Dumazet Cc: Tom Herbert Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: force a list_del() in unregister_netdevice_many()

2014-06-26T19:12:38Z

[ Upstream commit 87757a917b0b3c0787e0563c679762152be81312 ] unregister_netdevice_many() API is error prone and we had too many bugs because of dangling LIST_HEAD on stacks. See commit f87e6f47933e3e ("net: dont leave active on stack LIST_HEAD") In fact, instead of making sure no caller leaves an active list_head, just force a list_del() in the callee. No one seems to need to access the list after unregister_netdevice_many() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net-gro: reset skb->truesize in napi_reuse_skb()

2014-05-31T04:52:16Z

[ Upstream commit e33d0ba8047b049c9262fdb1fcafb93cb52ceceb ] Recycling skb always had been very tough... This time it appears GRO layer can accumulate skb->truesize adjustments made by drivers when they attach a fragment to skb. skb_gro_receive() can only subtract from skb->truesize the used part of a fragment. I spotted this problem seeing TcpExtPruneCalled and TcpExtTCPRcvCollapsed that were unexpected with a recent kernel, where TCP receive window should be sized properly to accept traffic coming from a driver not overshooting skb->truesize. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

vlan: Fix lockdep warning when vlan dev handle notification

2014-05-31T04:52:15Z

[ Upstream commit dc8eaaa006350d24030502a4521542e74b5cb39f ] When I open the LOCKDEP config and run these steps: modprobe 8021q vconfig add eth2 20 vconfig add eth2.20 30 ifconfig eth2 xx.xx.xx.xx then the Call Trace happened: [32524.386288] ============================================= [32524.386293] [ INFO: possible recursive locking detected ] [32524.386298] 3.14.0-rc2-0.7-default+ #35 Tainted: G O [32524.386302] --------------------------------------------- [32524.386306] ifconfig/3103 is trying to acquire lock: [32524.386310] (&vlan_netdev_addr_lock_key/1){+.....}, at: [] dev_mc_sync+0x64/0xb0 [32524.386326] [32524.386326] but task is already holding lock: [32524.386330] (&vlan_netdev_addr_lock_key/1){+.....}, at: [] dev_set_rx_mode+0x23/0x40 [32524.386341] [32524.386341] other info that might help us debug this: [32524.386345] Possible unsafe locking scenario: [32524.386345] [32524.386350] CPU0 [32524.386352] ---- [32524.386354] lock(&vlan_netdev_addr_lock_key/1); [32524.386359] lock(&vlan_netdev_addr_lock_key/1); [32524.386364] [32524.386364] *** DEADLOCK *** [32524.386364] [32524.386368] May be due to missing lock nesting notation [32524.386368] [32524.386373] 2 locks held by ifconfig/3103: [32524.386376] #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x12/0x20 [32524.386387] #1: (&vlan_netdev_addr_lock_key/1){+.....}, at: [] dev_set_rx_mode+0x23/0x40 [32524.386398] [32524.386398] stack backtrace: [32524.386403] CPU: 1 PID: 3103 Comm: ifconfig Tainted: G O 3.14.0-rc2-0.7-default+ #35 [32524.386409] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [32524.386414] ffffffff81ffae40 ffff8800d9625ae8 ffffffff814f68a2 ffff8800d9625bc8 [32524.386421] ffffffff810a35fb ffff8800d8a8d9d0 00000000d9625b28 ffff8800d8a8e5d0 [32524.386428] 000003cc00000000 0000000000000002 ffff8800d8a8e5f8 0000000000000000 [32524.386435] Call Trace: [32524.386441] [] dump_stack+0x6a/0x78 [32524.386448] [] __lock_acquire+0x7ab/0x1940 [32524.386454] [] ? __lock_acquire+0x3ea/0x1940 [32524.386459] [] lock_acquire+0xe4/0x110 [32524.386464] [] ? dev_mc_sync+0x64/0xb0 [32524.386471] [] _raw_spin_lock_nested+0x2a/0x40 [32524.386476] [] ? dev_mc_sync+0x64/0xb0 [32524.386481] [] dev_mc_sync+0x64/0xb0 [32524.386489] [] vlan_dev_set_rx_mode+0x2b/0x50 [8021q] [32524.386495] [] __dev_set_rx_mode+0x5f/0xb0 [32524.386500] [] dev_set_rx_mode+0x2b/0x40 [32524.386506] [] __dev_open+0xef/0x150 [32524.386511] [] __dev_change_flags+0xa7/0x190 [32524.386516] [] dev_change_flags+0x32/0x80 [32524.386524] [] devinet_ioctl+0x7d6/0x830 [32524.386532] [] ? dev_ioctl+0x34b/0x660 [32524.386540] [] inet_ioctl+0x80/0xa0 [32524.386550] [] sock_do_ioctl+0x2d/0x60 [32524.386558] [] sock_ioctl+0x82/0x2a0 [32524.386568] [] do_vfs_ioctl+0x93/0x590 [32524.386578] [] ? rcu_read_lock_held+0x45/0x50 [32524.386586] [] ? __fget_light+0x105/0x110 [32524.386594] [] SyS_ioctl+0x91/0xb0 [32524.386604] [] system_call_fastpath+0x16/0x1b ======================================================================== The reason is that all of the addr_lock_key for vlan dev have the same class, so if we change the status for vlan dev, the vlan dev and its real dev will hold the same class of addr_lock_key together, so the warning happened. we should distinguish the lock depth for vlan dev and its real dev. v1->v2: Convert the vlan_netdev_addr_lock_key to an array of eight elements, which could support to add 8 vlan id on a same vlan dev, I think it is enough for current scene, because a netdev's name is limited to IFNAMSIZ which could not hold 8 vlan id, and the vlan dev would not meet the same class key with its real dev. The new function vlan_dev_get_lockdep_subkey() will return the subkey and make the vlan dev could get a suitable class key. v2->v3: According David's suggestion, I use the subclass to distinguish the lock key for vlan dev and its real dev, but it make no sense, because the difference for subclass in the lock_class_key doesn't mean that the difference class for lock_key, so I use lock_depth to distinguish the different depth for every vlan dev, the same depth of the vlan dev could have the same lock_class_key, I import the MAX_LOCK_DEPTH from the include/linux/sched.h, I think it is enough here, the lockdep should never exceed that value. v3->v4: Add a huge array of locking keys will waste static kernel memory and is not a appropriate method, we could use _nested() variants to fix the problem, calculate the depth for every vlan dev, and use the depth as the subclass for addr_lock_key. Signed-off-by: Ding Tianhong Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: core: introduce netif_skb_dev_features

2014-03-07T05:30:05Z

commit d206940319c41df4299db75ed56142177bb2e5f6 upstream. Will be used by upcoming ipv4 forward path change that needs to determine feature mask using skb->dst->dev instead of skb->dev. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: core: Always propagate flag changes to interfaces

2013-12-08T15:29:26Z

[ Upstream commit d2615bf450694c1302d86b9cc8a8958edfe4c3a4 ] The following commit: b6c40d68ff6498b7f63ddf97cf0aa818d748dee7 net: only invoke dev->change_rx_flags when device is UP tried to fix a problem with VLAN devices and promiscuouse flag setting. The issue was that VLAN device was setting a flag on an interface that was down, thus resulting in bad promiscuity count. This commit blocked flag propagation to any device that is currently down. A later commit: deede2fabe24e00bd7e246eb81cd5767dc6fcfc7 vlan: Don't propagate flag changes on down interfaces fixed VLAN code to only propagate flags when the VLAN interface is up, thus fixing the same issue as above, only localized to VLAN. The problem we have now is that if we have create a complex stack involving multiple software devices like bridges, bonds, and vlans, then it is possible that the flags would not propagate properly to the physical devices. A simple examle of the scenario is the following: eth0----> bond0 ----> bridge0 ---> vlan50 If bond0 or eth0 happen to be down at the time bond0 is added to the bridge, then eth0 will never have promisc mode set which is currently required for operation as part of the bridge. As a result, packets with vlan50 will be dropped by the interface. The only 2 devices that implement the special flag handling are VLAN and DSA and they both have required code to prevent incorrect flag propagation. As a result we can remove the generic solution introduced in b6c40d68ff6498b7f63ddf97cf0aa818d748dee7 and leave it to the individual devices to decide whether they will block flag propagation or not. Reported-by: Stefan Priebe Suggested-by: Veaceslav Falico Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

vlan: mask vlan prio bits

2013-07-28T23:30:05Z

[ Upstream commit d4b812dea4a236f729526facf97df1a9d18e191c ] In commit 48cc32d38a52d0b68f91a171a8d00531edc6a46e ("vlan: don't deliver frames for unknown vlans to protocols") Florian made sure we set pkt_type to PACKET_OTHERHOST if the vlan id is set and we could find a vlan device for this particular id. But we also have a problem if prio bits are set. Steinar reported an issue on a router receiving IPv6 frames with a vlan tag of 4000 (id 0, prio 2), and tunneled into a sit device, because skb->vlan_tci is set. Forwarded frame is completely corrupted : We can see (8100:4000) being inserted in the middle of IPv6 source address : 16:48:00.780413 IP6 2001:16d8:8100:4000:ee1c:0:9d9:bc87 > 9f94:4d95:2001:67c:29f4::: ICMP6, unknown icmp6 type (0), length 64 0x0000: 0000 0029 8000 c7c3 7103 0001 a0ae e651 0x0010: 0000 0000 ccce 0b00 0000 0000 1011 1213 0x0020: 1415 1617 1819 1a1b 1c1d 1e1f 2021 2223 0x0030: 2425 2627 2829 2a2b 2c2d 2e2f 3031 3233 It seems we are not really ready to properly cope with this right now. We can probably do better in future kernels : vlan_get_ingress_priority() should be a netdev property instead of a per vlan_dev one. For stable kernels, lets clear vlan_tci to fix the bugs. Reported-by: Steinar H. Gunderson Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: fix kernel deadlock with interface rename and netdev name retrieval.

2013-06-26T20:42:54Z

When the kernel (compiled with CONFIG_PREEMPT=n) is performing the rename of a network interface, it can end up waiting for a workqueue to complete. If userland is able to invoke a SIOCGIFNAME ioctl or a SO_BINDTODEVICE getsockopt in between, the kernel will deadlock due to the fact that read_secklock_begin() will spin forever waiting for the writer process (the one doing the interface rename) to update the devnet_rename_seq sequence. This patch fixes the problem by adding a helper (netdev_get_name()) and using it in the code handling the SIOCGIFNAME ioctl and SO_BINDTODEVICE setsockopt. The netdev_get_name() helper uses raw_seqcount_begin() to avoid spinning forever, waiting for devnet_rename_seq->sequence to become even. cond_resched() is used in the contended case, before retrying the access to give the writer process a chance to finish. The use of raw_seqcount_begin() will incur some unneeded work in the reader process in the contended case, but this is better than deadlocking the system. Signed-off-by: Nicolas Schichan Acked-by: Eric Dumazet Signed-off-by: David S. Miller