[sr-dev] TM possible deadlock

Jason Penton jason.penton at gmail.com
Thu Apr 10 10:51:25 CEST 2014 

Nice work Daniel!! - Works perfectly! ;)

Cheers
Jason


On Thu, Apr 10, 2014 at 9:06 AM, Jason Penton <jason.penton at gmail.com>wrote:

> oh excellent, I will look at it right away - was just getting ready to
> jump in myself ;)
>
> Cheers
> Jason
>
>
> On Thu, Apr 10, 2014 at 9:01 AM, Daniel-Constantin Mierla <
> miconda at gmail.com> wrote:
>
>>  Hello Jason,
>>
>> I pushed a patch trying to fix this case, it is only on git master
>> branch. Can you test it? If all goes fine, we can consider backporting it.
>>
>> Cheers,
>> Daniel
>>
>>
>> On 09/04/14 23:26, Jason Penton wrote:
>>
>> Hey Daniel,
>>
>>  nothing extraordinary...
>>
>>  # -- TM params --
>> modparam("tm", "fr_timer", 20000);
>> modparam("tm", "fr_inv_timer", 10000)
>>
>>
>>  Cheers
>> Jason
>>
>>
>> On Wed, Apr 9, 2014 at 10:32 PM, Jason Penton <jason.penton at gmail.com>wrote:
>>
>>> Hey Daniel,
>>>
>>>  Yes I did a test with a very basic config file and I am not able to
>>> re-create. However, with my *complex* cfg file I can re-create every time.
>>> Tomorrow I will compare what is different and report back... hopefully with
>>> fix ;)
>>>
>>>  here is bt of timer process deadlocking itself:
>>>
>>>  #0  syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:39
>>> #1  0x00007f5009f22004 in futex_get (lock=0x7f4fc55030d8) at
>>> ../../mem/../futexlock.h:123
>>> #2  0x00007f5009f223e1 in _lock (s=0x7f4fc55030d8, file=0x7f5009f90fd1
>>> "t_cancel.c", function=0x7f5009f91980 "cancel_branch", line=250) at
>>> lock.h:99
>>> #3  0x00007f5009f23271 in cancel_branch (t=0x7f4fc5501b40, branch=0,
>>> reason=0x7fff646d03a8, flags=3) at t_cancel.c:250
>>> #4  0x00007f5009f22c02 in cancel_uacs (t=0x7f4fc5501b40,
>>> cancel_data=0x7fff646d03a0, flags=1) at t_cancel.c:123
>>> #5  0x00007f5009f718c4 in _reply_light (trans=0x7f4fc5501b40,
>>>     buf=0x7f500a24dc68 "SIP/2.0 500 Server error on LIR select next
>>> S-CSCF\r\nVia: SIP/2.0/UDP 10.0.1.167:6060;branch=z9hG4bKb7.2ae09f29ffbd0034cd6d58483053603b.1\r\nVia:
>>> SIP/2.0/UDP 10.0.1.166:4060;branch=z9hG4bKb7.3faa03ddea80"..., len=778,
>>> code=500, to_tag=0x7f500a1c7ae0 "c82b15d7f12ef185f95fe4945457d449-8bab",
>>> to_tag_len=37, lock=0, bm=0x7fff646d0b60) at t_reply.c:660
>>> #6  0x00007f5009f7244c in _reply (trans=0x7f4fc5501b40,
>>> p_msg=0x7f500a1c6bc0, code=500, text=0x7f500a249a48 "Server error on LIR
>>> select next S-CSCF", lock=0) at t_reply.c:795
>>> #7  0x00007f5009f76436 in t_reply_unsafe (t=0x7f4fc5501b40,
>>> p_msg=0x7f500a1c6bc0, code=500, text=0x7f500a249a48 "Server error on LIR
>>> select next S-CSCF") at t_reply.c:1643
>>> #8  0x00007f5009f57621 in w_t_reply (msg=0x7f500a1c6bc0,
>>> p1=0x7f500a2497d8 "\340\332$\nP\177", p2=0x7f500a249870 "h\321$\nP\177") at
>>> tm.c:1324
>>> #9  0x000000000041a700 in do_action (h=0x7fff646d1d30, a=0x7f500a24cee8,
>>> msg=0x7f500a1c6bc0) at action.c:1119
>>> #10 0x0000000000423831 in run_actions (h=0x7fff646d1d30,
>>> a=0x7f500a24cee8, msg=0x7f500a1c6bc0) at action.c:1607
>>> #11 0x000000000041a5a4 in do_action (h=0x7fff646d1d30, a=0x7f500a24d478,
>>> msg=0x7f500a1c6bc0) at action.c:1102
>>> #12 0x0000000000423831 in run_actions (h=0x7fff646d1d30,
>>> a=0x7f500a249148, msg=0x7f500a1c6bc0) at action.c:1607
>>> #13 0x000000000041a54e in do_action (h=0x7fff646d1d30, a=0x7f500a24c500,
>>> msg=0x7f500a1c6bc0) at action.c:1098
>>> #14 0x0000000000423831 in run_actions (h=0x7fff646d1d30,
>>> a=0x7f500a247a28, msg=0x7f500a1c6bc0) at action.c:1607
>>> #15 0x0000000000423fdf in run_top_route (a=0x7f500a247a28,
>>> msg=0x7f500a1c6bc0, c=0x0) at action.c:1693
>>> #16 0x00007f5009f73815 in run_failure_handlers (t=0x7f4fc5501b40,
>>> rpl=0xffffffffffffffff, code=408, extra_flags=96) at t_reply.c:1061
>>> #17 0x00007f5009f7527a in t_should_relay_response (Trans=0x7f4fc5501b40,
>>> new_code=408, branch=1, should_store=0x7fff646d201c,
>>> should_relay=0x7fff646d2018, cancel_data=0x7fff646d2070,
>>>     reply=0xffffffffffffffff) at t_reply.c:1416
>>> #18 0x00007f5009f76ede in relay_reply (t=0x7f4fc5501b40,
>>> p_msg=0xffffffffffffffff, branch=1, msg_status=408,
>>> cancel_data=0x7fff646d2070, do_put_on_wait=0) at t_reply.c:1819
>>> #19 0x00007f5009f44c88 in fake_reply (t=0x7f4fc5501b40, branch=1,
>>> code=408) at timer.c:354
>>> #20 0x00007f5009f450e7 in final_response_handler (r_buf=0x7f4fc5501e60,
>>> t=0x7f4fc5501b40) at timer.c:526
>>>  #21 0x00007f5009f4518d in retr_buf_handler (ticks=260027386,
>>> tl=0x7f4fc5501e80, p=0x3e8) at timer.c:584
>>> #22 0x0000000000544119 in timer_list_expire (t=260027386,
>>> h=0x7f4fc527cbe0, slow_l=0x7f4fc527cdf0, slow_mark=0) at timer.c:894
>>> #23 0x0000000000544418 in timer_handler () at timer.c:959
>>> #24 0x00000000005446b2 in timer_main () at timer.c:998
>>> #25 0x0000000000471ddf in main_loop () at main.c:1689
>>>
>>>
>>>
>>> On Wed, Apr 9, 2014 at 9:34 PM, Daniel-Constantin Mierla <
>>> miconda at gmail.com> wrote:
>>>
>>>>  Hello,
>>>>
>>>> that should not be a very rare case and I would expect to be caught so
>>>> far, anyhow ... this looks like easy to reproduce, have you tried it?
>>>>
>>>> You can have two kamailio, one relying the invite to the second, which
>>>> will reply with 100, then wait for the timeout on the first instance. You
>>>> can add some debug messages in the code to see if the lock is called twice.
>>>>
>>>> Cheers,
>>>> Daniel
>>>>
>>>>
>>>> On 09/04/14 17:51, Jason Penton wrote:
>>>>
>>>>  Hi All,
>>>>
>>>>  I have been experiencing a deadlock when a timeout occurs on a
>>>> t_relayed() INVITE. Going through the code I have noticed a possible chance
>>>> of deadlock (without re-entrant enabled). Here is my thinking:
>>>>
>>>>  t_should_relay_response() is called with REPLY_LOCK when the timer
>>>> process fires on the fr_inv_timer (no response from the INVITE that was
>>>> relayed, other than 100 provisional) and a 408 is generated. However, from
>>>> within that function there are calls to run_failure_handlers() which in
>>>> turn *could* try and lock the reply (viz. somebody having a t_reply() call
>>>> in the cfg file - in failure route block). This would result in another
>>>> lock on the same transaction's REPLY_LOCK....
>>>>
>>>>  Has anybody else experienced something like this?
>>>>
>>>>  this is on master btw.
>>>>
>>>>  Cheers
>>>> Jason
>>>>
>>>>
>>>>  _______________________________________________
>>>> sr-dev mailing listsr-dev at lists.sip-router.orghttp://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-dev
>>>>
>>>>
>>>> --
>>>> Daniel-Constantin Mierla - http://www.asipto.comhttp://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
>>>>
>>>>
>>>> _______________________________________________
>>>> sr-dev mailing list
>>>> sr-dev at lists.sip-router.org
>>>> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-dev
>>>>
>>>>
>>>
>>
>> --
>> Daniel-Constantin Mierla - http://www.asipto.comhttp://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sip-router.org/pipermail/sr-dev/attachments/20140410/9ff2880a/attachment-0001.html>

More information about the sr-dev mailing list