lkml.org 
[lkml]   [2014]   [Jul]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
Subjectnet, phonet, rcu: rcu hang within gprs_attach
Hi all,

While fuzzing with trinity inside a KVM tools guest running the latest -next
kernel I've stumbled on the following stack trace (full log attached):

[ 370.662014] INFO: task trinity-main:8727 blocked for more than 120 seconds.
[ 370.662891] Not tainted 3.16.0-rc6-next-20140724-sasha-00046-g7324c87-dirty #932
[ 370.663655] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 370.664562] trinity-main D ffff88053cc80000 13064 8727 8714 0x00000000
[ 370.665328] ffff88053da6fc10 0000000000000002 ffff8805483e2dc8 ffff880541873000
[ 370.666147] 000000276ed30787 ffff88053da6c010 ffff88053da6c000 ffff8805452a0000
[ 370.667243] ffff880541873000 0000000000000000 7fffffffffffffff ffffffffb3ec51d8
[ 370.668788] Call Trace:
[ 370.669118] schedule (kernel/sched/core.c:2847)
[ 370.670538] schedule_timeout (kernel/time/timer.c:1476)
[ 370.671524] ? mark_lock (kernel/locking/lockdep.c:2894)
[ 370.672299] ? __this_cpu_preempt_check (lib/smp_processor_id.c:63)
[ 370.673227] ? get_parent_ip (kernel/sched/core.c:2561)
[ 370.674085] wait_for_completion (include/linux/spinlock.h:328 kernel/sched/completion.c:76 kernel/sched/completion.c:93 kernel/sched/completion.c:101 kernel/sched/completion.c:122)
[ 370.674960] ? wake_up_state (kernel/sched/core.c:2942)
[ 370.675576] _rcu_barrier (kernel/rcu/tree.c:3325 (discriminator 8))
[ 370.676109] rcu_barrier (kernel/rcu/tree_plugin.h:920)
[ 370.676627] netdev_run_todo (net/core/dev.c:6323)
[ 370.677202] rtnl_unlock (net/core/rtnetlink.c:80)
[ 370.677714] unregister_netdev (net/core/dev.c:6687)
[ 370.678266] gprs_attach (net/phonet/pep-gprs.c:311)
[ 370.679641] pep_setsockopt (net/phonet/pep.c:1016)
[ 370.681082] sock_common_setsockopt (net/core/sock.c:2603)
[ 370.682048] SyS_setsockopt (net/socket.c:1914 net/socket.c:1894)
[ 370.682854] tracesys (arch/x86/kernel/entry_64.S:541)
[ 370.683586] 1 lock held by trinity-main/8727:
[ 370.684232] #0: (rcu_preempt_state.barrier_mutex){+.+...}, at: _rcu_barrier (kernel/rcu/tree.c:3233)

This has reproduced couple of times, and has always originated from gprs_attach. I don't see any obvious
issues with the code there, so I'm not sure if it's a fault of the phonet or the rcu code.


Thanks,
Sasha
[unhandled content-type:application/x-xz]
\
 
 \ /
  Last update: 2014-07-25 01:01    [W:0.066 / U:5.676 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site