linux_dsm_epyc7002/include
Amerigo Wang 8965779d2c ipv6,mcast: always hold idev->lock before mca_lock
dingtianhong reported the following deadlock detected by lockdep:

 ======================================================
 [ INFO: possible circular locking dependency detected ]
 3.4.24.05-0.1-default #1 Not tainted
 -------------------------------------------------------
 ksoftirqd/0/3 is trying to acquire lock:
  (&ndev->lock){+.+...}, at: [<ffffffff8147f804>] ipv6_get_lladdr+0x74/0x120

 but task is already holding lock:
  (&mc->mca_lock){+.+...}, at: [<ffffffff8149d130>] mld_send_report+0x40/0x150

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (&mc->mca_lock){+.+...}:
        [<ffffffff810a8027>] validate_chain+0x637/0x730
        [<ffffffff810a8417>] __lock_acquire+0x2f7/0x500
        [<ffffffff810a8734>] lock_acquire+0x114/0x150
        [<ffffffff814f691a>] rt_spin_lock+0x4a/0x60
        [<ffffffff8149e4bb>] igmp6_group_added+0x3b/0x120
        [<ffffffff8149e5d8>] ipv6_mc_up+0x38/0x60
        [<ffffffff81480a4d>] ipv6_find_idev+0x3d/0x80
        [<ffffffff81483175>] addrconf_notify+0x3d5/0x4b0
        [<ffffffff814fae3f>] notifier_call_chain+0x3f/0x80
        [<ffffffff81073471>] raw_notifier_call_chain+0x11/0x20
        [<ffffffff813d8722>] call_netdevice_notifiers+0x32/0x60
        [<ffffffff813d92d4>] __dev_notify_flags+0x34/0x80
        [<ffffffff813d9360>] dev_change_flags+0x40/0x70
        [<ffffffff813ea627>] do_setlink+0x237/0x8a0
        [<ffffffff813ebb6c>] rtnl_newlink+0x3ec/0x600
        [<ffffffff813eb4d0>] rtnetlink_rcv_msg+0x160/0x310
        [<ffffffff814040b9>] netlink_rcv_skb+0x89/0xb0
        [<ffffffff813eb357>] rtnetlink_rcv+0x27/0x40
        [<ffffffff81403e20>] netlink_unicast+0x140/0x180
        [<ffffffff81404a9e>] netlink_sendmsg+0x33e/0x380
        [<ffffffff813c4252>] sock_sendmsg+0x112/0x130
        [<ffffffff813c537e>] __sys_sendmsg+0x44e/0x460
        [<ffffffff813c5544>] sys_sendmsg+0x44/0x70
        [<ffffffff814feab9>] system_call_fastpath+0x16/0x1b

 -> #0 (&ndev->lock){+.+...}:
        [<ffffffff810a798e>] check_prev_add+0x3de/0x440
        [<ffffffff810a8027>] validate_chain+0x637/0x730
        [<ffffffff810a8417>] __lock_acquire+0x2f7/0x500
        [<ffffffff810a8734>] lock_acquire+0x114/0x150
        [<ffffffff814f6c82>] rt_read_lock+0x42/0x60
        [<ffffffff8147f804>] ipv6_get_lladdr+0x74/0x120
        [<ffffffff8149b036>] mld_newpack+0xb6/0x160
        [<ffffffff8149b18b>] add_grhead+0xab/0xc0
        [<ffffffff8149d03b>] add_grec+0x3ab/0x460
        [<ffffffff8149d14a>] mld_send_report+0x5a/0x150
        [<ffffffff8149f99e>] igmp6_timer_handler+0x4e/0xb0
        [<ffffffff8105705a>] call_timer_fn+0xca/0x1d0
        [<ffffffff81057b9f>] run_timer_softirq+0x1df/0x2e0
        [<ffffffff8104e8c7>] handle_pending_softirqs+0xf7/0x1f0
        [<ffffffff8104ea3b>] __do_softirq_common+0x7b/0xf0
        [<ffffffff8104f07f>] __thread_do_softirq+0x1af/0x210
        [<ffffffff8104f1c1>] run_ksoftirqd+0xe1/0x1f0
        [<ffffffff8106c7de>] kthread+0xae/0xc0
        [<ffffffff814fff74>] kernel_thread_helper+0x4/0x10

actually we can just hold idev->lock before taking pmc->mca_lock,
and avoid taking idev->lock again when iterating idev->addr_list,
since the upper callers of mld_newpack() already take
read_lock_bh(&idev->lock).

Reported-by: dingtianhong <dingtianhong@huawei.com>
Cc: dingtianhong <dingtianhong@huawei.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Tested-by: Ding Tianhong <dingtianhong@huawei.com>
Tested-by: Chen Weilong <chenweilong@huawei.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-01 23:39:21 -07:00
..
acpi ACPI / PM: Allow device power states to be used for CONFIG_PM unset 2013-05-22 00:19:28 +02:00
asm-generic Merge branch 'fixes' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2013-06-11 11:16:43 -07:00
clocksource ARM: late Exynos multiplatform changes 2013-05-07 11:28:42 -07:00
crypto
drm Merge branch 'drm-radeon-sun-hainan' of git://people.freedesktop.org/~airlied/linux 2013-05-21 08:50:57 -07:00
dt-bindings
keys
linux Merge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next 2013-07-01 13:21:17 -07:00
math-emu
media Merge branch 'topic/omap3isp' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2013-05-01 09:57:04 -07:00
memory
misc
net ipv6,mcast: always hold idev->lock before mca_lock 2013-07-01 23:39:21 -07:00
pcmcia
ras
rdma
rxrpc
scsi Merge branch 'postmerge' into for-linus 2013-05-10 07:54:01 -07:00
sound ASoC: dapm: Treat DAI widgets like AIF widgets for power 2013-06-07 15:54:50 +01:00
target target: Propigate up ->cmd_kref put return via transport_generic_free_cmd 2013-05-31 01:21:23 -07:00
trace Fixed regressions (two stability regressions and a performance 2013-05-14 09:30:54 -07:00
uapi net: Swap ver and type in pppoe_hdr 2013-07-01 18:20:33 -07:00
video Merge branch 'fbdev-3.10-fixes' of git://gitorious.org/linux-omap-dss2/linux into linux-fbdev/for-3.10-fixes 2013-05-29 17:00:34 +08:00
xen Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-06-05 16:37:30 -07:00
Kbuild UAPI: remove empty Kbuild files 2013-04-30 17:04:09 -07:00