linux-toradex.git/net/bridge/br_device.c, branch v4.4.78

bridge: fix lockdep addr_list_lock false positive splat

2016-01-31T19:29:01+00:00

[ Upstream commit c6894dec8ea9ae05747124dce98b3b5c2e69b168 ]

After promisc mode management was introduced a bridge device could do
dev_set_promiscuity from its ndo_change_rx_flags() callback which in
turn can be called after the bridge's addr_list_lock has been taken
(e.g. by dev_uc_add). This causes a false positive lockdep splat because
the port interfaces' addr_list_lock is taken when br_manage_promisc()
runs after the bridge's addr list lock was already taken.
To remove the false positive introduce a custom bridge addr_list_lock
class and set it on bridge init.
A simple way to reproduce this is with the following:
$ brctl addbr br0
$ ip l add l br0 br0.100 type vlan id 100
$ ip l set br0 up
$ ip l set br0.100 up
$ echo 1 > /sys/class/net/br0/bridge/vlan_filtering
$ brctl addif br0 eth0
Splat:
[   43.684325] =============================================
[   43.684485] [ INFO: possible recursive locking detected ]
[   43.684636] 4.4.0-rc8+ #54 Not tainted
[   43.684755] ---------------------------------------------
[   43.684906] brctl/1187 is trying to acquire lock:
[   43.685047]  (_xmit_ETHER){+.....}, at: [] dev_set_rx_mode+0x1e/0x40
[   43.685460]  but task is already holding lock:
[   43.685618]  (_xmit_ETHER){+.....}, at: [] dev_uc_add+0x27/0x80
[   43.686015]  other info that might help us debug this:
[   43.686316]  Possible unsafe locking scenario:

[   43.686743]        CPU0
[   43.686967]        ----
[   43.687197]   lock(_xmit_ETHER);
[   43.687544]   lock(_xmit_ETHER);
[   43.687886] *** DEADLOCK ***

[   43.688438]  May be due to missing lock nesting notation

[   43.688882] 2 locks held by brctl/1187:
[   43.689134]  #0:  (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20
[   43.689852]  #1:  (_xmit_ETHER){+.....}, at: [] dev_uc_add+0x27/0x80
[   43.690575] stack backtrace:
[   43.690970] CPU: 0 PID: 1187 Comm: brctl Not tainted 4.4.0-rc8+ #54
[   43.691270] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014
[   43.691770]  ffffffff826a25c0 ffff8800369fb8e0 ffffffff81360ceb ffffffff826a25c0
[   43.692425]  ffff8800369fb9b8 ffffffff810d0466 ffff8800369fb968 ffffffff81537139
[   43.693071]  ffff88003a08c880 0000000000000000 00000000ffffffff 0000000002080020
[   43.693709] Call Trace:
[   43.693931]  [] dump_stack+0x4b/0x70
[   43.694199]  [] __lock_acquire+0x1e46/0x1e90
[   43.694483]  [] ? netlink_broadcast_filtered+0x139/0x3e0
[   43.694789]  [] ? nlmsg_notify+0x5a/0xc0
[   43.695064]  [] lock_acquire+0xe5/0x1f0
[   43.695340]  [] ? dev_set_rx_mode+0x1e/0x40
[   43.695623]  [] _raw_spin_lock_bh+0x45/0x80
[   43.695901]  [] ? dev_set_rx_mode+0x1e/0x40
[   43.696180]  [] dev_set_rx_mode+0x1e/0x40
[   43.696460]  [] dev_set_promiscuity+0x3c/0x50
[   43.696750]  [] br_port_set_promisc+0x25/0x50 [bridge]
[   43.697052]  [] br_manage_promisc+0x8a/0xe0 [bridge]
[   43.697348]  [] br_dev_change_rx_flags+0x1e/0x20 [bridge]
[   43.697655]  [] __dev_set_promiscuity+0x132/0x1f0
[   43.697943]  [] __dev_set_rx_mode+0x82/0x90
[   43.698223]  [] dev_uc_add+0x5e/0x80
[   43.698498]  [] vlan_device_event+0x542/0x650 [8021q]
[   43.698798]  [] notifier_call_chain+0x5d/0x80
[   43.699083]  [] raw_notifier_call_chain+0x16/0x20
[   43.699374]  [] call_netdevice_notifiers_info+0x6e/0x80
[   43.699678]  [] call_netdevice_notifiers+0x16/0x20
[   43.699973]  [] br_add_if+0x47e/0x4c0 [bridge]
[   43.700259]  [] add_del_if+0x6e/0x80 [bridge]
[   43.700548]  [] br_dev_ioctl+0xaf/0xc0 [bridge]
[   43.700836]  [] dev_ifsioc+0x30c/0x3c0
[   43.701106]  [] dev_ioctl+0xf9/0x6f0
[   43.701379]  [] ? mntput_no_expire+0x5/0x450
[   43.701665]  [] ? mntput_no_expire+0xae/0x450
[   43.701947]  [] sock_do_ioctl+0x42/0x50
[   43.702219]  [] sock_ioctl+0x1e5/0x290
[   43.702500]  [] do_vfs_ioctl+0x2cb/0x5c0
[   43.702771]  [] SyS_ioctl+0x79/0x90
[   43.703033]  [] entry_SYSCALL_64_fastpath+0x16/0x7a

CC: Vlad Yasevich 
CC: Stephen Hemminger 
CC: Bridge list 
CC: Andy Gospodarek 
CC: Roopa Prabhu 
Fixes: 2796d0c648c9 ("bridge: Automatically manage port promiscuous mode.")
Reported-by: Andy Gospodarek 
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

bridge: vlan: use proper rcu for the vlgrp member

2015-10-13T11:57:52+00:00

The bridge and port's vlgrp member is already used in RCU way, currently
we rely on the fact that it cannot disappear while the port exists but
that is error-prone and we might miss places with improper locking
(either RCU or RTNL must be held to walk the vlan_list). So make it
official and use RCU for vlgrp to catch offenders. Introduce proper vlgrp
accessors and use them consistently throughout the code.

Signed-off-by: Nikolay Aleksandrov 
Reviewed-by: Ido Schimmel 
Signed-off-by: David S. Miller

bridge: vlan: move pvid inside net_bridge_vlan_group

2015-10-02T01:24:04+00:00

One obvious way to converge more code (which was also used by the
previous vlan code) is to move pvid inside net_bridge_vlan_group. This
allows us to simplify some and remove other port-specific functions.
Also gives us the ability to simply pass the vlan group and use all of the
contained information.

Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

bridge: vlan: add per-vlan struct and move to rhashtables

2015-09-29T20:36:06+00:00

This patch changes the bridge vlan implementation to use rhashtables
instead of bitmaps. The main motivation behind this change is that we
need extensible per-vlan structures (both per-port and global) so more
advanced features can be introduced and the vlan support can be
extended. I've tried to break this up but the moment net_port_vlans is
changed and the whole API goes away, thus this is a larger patch.
A few short goals of this patch are:
- Extensible per-vlan structs stored in rhashtables and a sorted list
- Keep user-visible behaviour (compressed vlans etc)
- Keep fastpath ingress/egress logic the same (optimizations to come
  later)

Here's a brief list of some of the new features we'd like to introduce:
- per-vlan counters
- vlan ingress/egress mapping
- per-vlan igmp configuration
- vlan priorities
- avoid fdb entries replication (e.g. local fdb scaling issues)

The structure is kept single for both global and per-port entries so to
avoid code duplication where possible and also because we'll soon introduce
"port0 / aka bridge as port" which should simplify things further
(thanks to Vlad for the suggestion!).

Now we have per-vlan global rhashtable (bridge-wide) and per-vlan port
rhashtable, if an entry is added to a port it'll get a pointer to its
global context so it can be quickly accessed later. There's also a
sorted vlan list which is used for stable walks and some user-visible
behaviour such as the vlan ranges, also for error paths.
VLANs are stored in a "vlan group" which currently contains the
rhashtable, sorted vlan list and the number of "real" vlan entries.
A good side-effect of this change is that it resembles how hw keeps
per-vlan data.
One important note after this change is that if a VLAN is being looked up
in the bridge's rhashtable for filtering purposes (or to check if it's an
existing usable entry, not just a global context) then the new helper
br_vlan_should_use() needs to be used if the vlan is found. In case the
lookup is done only with a port's vlan group, then this check can be
skipped.

Things tested so far:
- basic vlan ingress/egress
- pvids
- untagged vlans
- undef CONFIG_BRIDGE_VLAN_FILTERING
- adding/deleting vlans in different scenarios (with/without global ctx,
  while transmitting traffic, in ranges etc)
- loading/removing the module while having/adding/deleting vlans
- extracting bridge vlan information (user ABI), compressed requests
- adding/deleting fdbs on vlans
- bridge mac change, promisc mode
- default pvid change
- kmemleak ON during the whole time

Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

bridge: define some min/max/default ageing time constants

2015-09-23T21:35:58+00:00

Signed-off-by: Scott Feldman 
Acked-by: Jiri Pirko 
Signed-off-by: David S. Miller

net: bridge: convert to using IFF_NO_QUEUE

2015-08-18T18:55:06+00:00

Signed-off-by: Phil Sutter 
Cc: Stephen Hemminger 
Signed-off-by: David S. Miller

bridge: Don't segment multiple tagged packets on bridge device

2015-08-03T21:24:50+00:00

Bridge devices don't need to segment multiple tagged packets since thier
ports can segment them.

Signed-off-by: Toshiaki Makita 
Signed-off-by: David S. Miller

netfilter: bridge: use rcu hook to resolve br_netfilter dependency

2015-03-10T14:03:02+00:00

e5de75b ("netfilter: bridge: move DNAT helper to br_netfilter") results
in the following link problem:

net/bridge/br_device.c:29: undefined reference to `br_nf_prerouting_finish_bridge`

Moreover it creates a hard dependency between br_netfilter and the
bridge core, which is what we've been trying to avoid so far.

Resolve this problem by using a hook structure so we reduce #ifdef
pollution and keep bridge netfilter specific code under br_netfilter.c
which was the original intention.

Reported-by: Simon Horman 
Signed-off-by: Pablo Neira Ayuso

netfilter: bridge: move DNAT helper to br_netfilter

2015-03-09T16:56:07+00:00

Only one caller, there is no need to keep this in a header.
Move it to br_netfilter.c where this belongs to.

Based on patch from Florian Westphal.

Signed-off-by: Pablo Neira Ayuso

bridge: Add filtering support for default_pvid

2014-10-06T01:21:37+00:00

Currently when vlan filtering is turned on on the bridge, the bridge
will drop all traffic untill the user configures the filter.  This
isn't very nice for ports that don't care about vlans and just
want untagged traffic.

A concept of a default_pvid was recently introduced.  This patch
adds filtering support for default_pvid.   Now, ports that don't
care about vlans and don't define there own filter will belong
to the VLAN of the default_pvid and continue to receive untagged
traffic.

This filtering can be disabled by setting default_pvid to 0.

Signed-off-by: Vladislav Yasevich 
Signed-off-by: David S. Miller