linux-stable.git/drivers/net/team, branch linux-5.6.y

team: fix hang in team_mode_get()

2020-04-29T14:34:39+00:00

[ Upstream commit 1c30fbc76b8f0c07c92a8ca4cd7c456612e17eb5 ]

When team mode is changed or set, the team_mode_get() is called to check
whether the mode module is inserted or not. If the mode module is not
inserted, it calls the request_module().
In the request_module(), it creates a child process, which is
the "modprobe" process and waits for the done of the child process.
At this point, the following locks were used.
down_read(&cb_lock()); by genl_rcv()
    genl_lock(); by genl_rcv_msc()
        rtnl_lock(); by team_nl_cmd_options_set()
            mutex_lock(&team->lock); by team_nl_team_get()

Concurrently, the team module could be removed by rmmod or "modprobe -r"
The __exit function of team module is team_module_exit(), which calls
team_nl_fini() and it tries to acquire following locks.
down_write(&cb_lock);
    genl_lock();
Because of the genl_lock() and cb_lock, this process can't be finished
earlier than request_module() routine.

The problem secenario.
CPU0                                     CPU1
team_mode_get
    request_module()
                                         modprobe -r team_mode_roundrobin
                                                     team <--(B)
        modprobe team <--(A)
            team_mode_roundrobin

By request_module(), the "modprobe team_mode_roundrobin" command
will be executed. At this point, the modprobe process will decide
that the team module should be inserted before team_mode_roundrobin.
Because the team module is being removed.

By the module infrastructure, the same module insert/remove operations
can't be executed concurrently.
So, (A) waits for (B) but (B) also waits for (A) because of locks.
So that the hang occurs at this point.

Test commands:
    while :
    do
        teamd -d &
	killall teamd &
	modprobe -rv team_mode_roundrobin &
    done

The approach of this patch is to hold the reference count of the team
module if the team module is compiled as a module. If the reference count
of the team module is not zero while request_module() is being called,
the team module will not be removed at that moment.
So that the above scenario could not occur.

Fixes: 3d249d4ca7d0 ("net: introduce ethernet teaming device")
Signed-off-by: Taehee Yoo 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

team: add missing attribute validation for array index

2020-03-03T21:28:48+00:00

Add missing attribute validation for TEAM_ATTR_OPTION_ARRAY_INDEX
to the netlink policy.

Fixes: b13033262d24 ("team: introduce array options")
Signed-off-by: Jakub Kicinski 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller

team: add missing attribute validation for port ifindex

2020-03-03T21:28:48+00:00

Add missing attribute validation for TEAM_ATTR_OPTION_PORT_IFINDEX
to the netlink policy.

Fixes: 80f7c6683fe0 ("team: add support for per-port options")
Signed-off-by: Jakub Kicinski 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2019-11-02T20:54:56+00:00

The only slightly tricky merge conflict was the netdevsim because the
mutex locking fix overlapped a lot of driver reload reorganization.

The rest were (relatively) trivial in nature.

Signed-off-by: David S. Miller

team: fix nested locking lockdep warning

2019-10-24T21:53:48+00:00

team interface could be nested and it's lock variable could be nested too.
But this lock uses static lockdep key and there is no nested locking
handling code such as mutex_lock_nested() and so on.
so the Lockdep would warn about the circular locking scenario that
couldn't happen.
In order to fix, this patch makes the team module to use dynamic lock key
instead of static key.

Test commands:
    ip link add team0 type team
    ip link add team1 type team
    ip link set team0 master team1
    ip link set team0 nomaster
    ip link set team1 master team0
    ip link set team1 nomaster

Splat that looks like:
[   40.364352] WARNING: possible recursive locking detected
[   40.364964] 5.4.0-rc3+ #96 Not tainted
[   40.365405] --------------------------------------------
[   40.365973] ip/750 is trying to acquire lock:
[   40.366542] ffff888060b34c40 (&team->lock){+.+.}, at: team_set_mac_address+0x151/0x290 [team]
[   40.367689]
	       but task is already holding lock:
[   40.368729] ffff888051201c40 (&team->lock){+.+.}, at: team_del_slave+0x29/0x60 [team]
[   40.370280]
	       other info that might help us debug this:
[   40.371159]  Possible unsafe locking scenario:

[   40.371942]        CPU0
[   40.372338]        ----
[   40.372673]   lock(&team->lock);
[   40.373115]   lock(&team->lock);
[   40.373549]
	       *** DEADLOCK ***

[   40.374432]  May be due to missing lock nesting notation

[   40.375338] 2 locks held by ip/750:
[   40.375851]  #0: ffffffffabcc42b0 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0
[   40.376927]  #1: ffff888051201c40 (&team->lock){+.+.}, at: team_del_slave+0x29/0x60 [team]
[   40.377989]
	       stack backtrace:
[   40.378650] CPU: 0 PID: 750 Comm: ip Not tainted 5.4.0-rc3+ #96
[   40.379368] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   40.380574] Call Trace:
[   40.381208]  dump_stack+0x7c/0xbb
[   40.381959]  __lock_acquire+0x269d/0x3de0
[   40.382817]  ? register_lock_class+0x14d0/0x14d0
[   40.383784]  ? check_chain_key+0x236/0x5d0
[   40.384518]  lock_acquire+0x164/0x3b0
[   40.385074]  ? team_set_mac_address+0x151/0x290 [team]
[   40.385805]  __mutex_lock+0x14d/0x14c0
[   40.386371]  ? team_set_mac_address+0x151/0x290 [team]
[   40.387038]  ? team_set_mac_address+0x151/0x290 [team]
[   40.387632]  ? mutex_lock_io_nested+0x1380/0x1380
[   40.388245]  ? team_del_slave+0x60/0x60 [team]
[   40.388752]  ? rcu_read_lock_sched_held+0x90/0xc0
[   40.389304]  ? rcu_read_lock_bh_held+0xa0/0xa0
[   40.389819]  ? lock_acquire+0x164/0x3b0
[   40.390285]  ? lockdep_rtnl_is_held+0x16/0x20
[   40.390797]  ? team_port_get_rtnl+0x90/0xe0 [team]
[   40.391353]  ? __module_text_address+0x13/0x140
[   40.391886]  ? team_set_mac_address+0x151/0x290 [team]
[   40.392547]  team_set_mac_address+0x151/0x290 [team]
[   40.393111]  dev_set_mac_address+0x1f0/0x3f0
[ ... ]

Fixes: 3d249d4ca7d0 ("net: introduce ethernet teaming device")
Signed-off-by: Taehee Yoo 
Signed-off-by: David S. Miller

net: core: add generic lockdep keys

2019-10-24T21:53:48+00:00

Some interface types could be nested.
(VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, VIRT_WIFI, VXLAN, etc..)
These interface types should set lockdep class because, without lockdep
class key, lockdep always warn about unexisting circular locking.

In the current code, these interfaces have their own lockdep class keys and
these manage itself. So that there are so many duplicate code around the
/driver/net and /net/.
This patch adds new generic lockdep keys and some helper functions for it.

This patch does below changes.
a) Add lockdep class keys in struct net_device
   - qdisc_running, xmit, addr_list, qdisc_busylock
   - these keys are used as dynamic lockdep key.
b) When net_device is being allocated, lockdep keys are registered.
   - alloc_netdev_mqs()
c) When net_device is being free'd llockdep keys are unregistered.
   - free_netdev()
d) Add generic lockdep key helper function
   - netdev_register_lockdep_key()
   - netdev_unregister_lockdep_key()
   - netdev_update_lockdep_key()
e) Remove unnecessary generic lockdep macro and functions
f) Remove unnecessary lockdep code of each interfaces.

After this patch, each interface modules don't need to maintain
their lockdep keys.

Signed-off-by: Taehee Yoo 
Signed-off-by: David S. Miller

team: call RCU read lock when walking the port_list

2019-10-10T04:13:59+00:00

Before reading the team port list, we need to acquire the RCU read lock.
Also change list_for_each_entry() to list_for_each_entry_rcu().

v2:
repost the patch to net-next and remove fixes flag as this is a cosmetic
change.

Suggested-by: Paolo Abeni 
Signed-off-by: Hangbin Liu 
Acked-by: Paolo Abeni 
Acked-by: Jiri Pirko 
Signed-off-by: Jakub Kicinski

team: Add vlan tx offload to hw_enc_features

2019-08-09T05:41:41+00:00

We should also enable team's vlan tx offload in hw_enc_features,
pass the vlan packets to the slave devices with vlan tci, let the
slave handle vlan tunneling offload implementation.

Fixes: 3268e5cb494d ("team: Advertise tunneling offload features")
Signed-off-by: YueHaibing 
Signed-off-by: David S. Miller

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

2019-06-28T04:06:39+00:00

The new route handling in ip_mc_finish_output() from 'net' overlapped
with the new support for returning congestion notifications from BPF
programs.

In order to handle this I had to take the dev_loopback_xmit() calls
out of the switch statement.

The aquantia driver conflicts were simple overlapping changes.

Signed-off-by: David S. Miller

team: Always enable vlan tx offload

2019-06-26T17:14:08+00:00

We should rather have vlan_tci filled all the way down
to the transmitting netdevice and let it do the hw/sw
vlan implementation.

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