sshd fork failure

[marco atzeri]

On 10/13/2012 8:24 PM, Christopher Faylor wrote:
> On Sat, Oct 13, 2012 at 08:21:01PM +0200, marco atzeri wrote:
>> On 10/13/2012 6:54 PM, Christopher Faylor wrote:
>>> On Sat, Oct 13, 2012 at 06:10:23PM +0200, marco atzeri wrote:
>>>> On 10/13/2012 5:39 PM, Christopher Faylor wrote:
>>>>> On Thu, Aug 30, 2012 at 06:44:39PM +0200, marco atzeri wrote:
>>>>>> Hi,
>>>>>> tracing the sshd process on latest cygwin shapshot ,
>>>>>> I see that the fork is failing due to exception C0000005
>>>>>>
>>>>>>        1       1 [main] sshd (4644)
>>>>>> **********************************************
>>>>>>     5921    5922 [main] sshd (4644) Program name:
>>>>>> E:\cygwin\usr\sbin\sshd.exe (windows pid 4644)
>>>>>>       30    5952 [main] sshd (4644) OS version:   Windows NT-6.1
>>>>>>       25    5977 [main] sshd (4644)
>>>>>> **********************************************
>>>>>>      636    6613 [main] sshd (4644) sigprocmask: 0 = sigprocmask (0,
>>>>>> 0x6123D428, 0x610FBB30)
>>>>>>      122    6735 [main] sshd 4644 child_copy: cygheap - hp 0x20C low
>>>>>> 0x612708D0, high 0x61277640, res 1
>>>>>>     1368    8103 [main] sshd 4644 child_copy: done
>>>>>> --- Process 4644, exception C0000005 at 61137277
>>>>>>
>>>>>>
>>>>>>
>>>>>> $ addr2line.exe 61137277 -e /usr/bin/cygwin1.dll
>>>>>> /netrel/src/cygwin-snapshot-20120827-1/newlib/libc/stdlib/mbtowc_r.c:323
>>>>>>
>>>>>> that should be:
>>>>>>
>>>>>>     ch = (state->__count == 1) ? t[i++] : state->__value.__wchb[1];
>>>>>>
>>>>>> inside __utf8_mbtowc .
>>>>>> It looks a strange place for a fork failure, but it is used in
>>>>>> winsup/cygwin/cygheap.cc so it could make sense.
>>>>>>
>>>>>> Any suggestion how to follow/debug the child portion of fork ?
>>>>>
>>>>> Is this still failing?  We're looking to release 1.7.17 soon.
>>>>
>>>> on  20121012 similar but in another location.
>>>>
>>>> --- Process 6280, exception C0000005 at 61137DC8
>>>>     427  147466 [main] sshd 6280 exception::handle: In
>>>> cygwin_except_handler exception 0xC0000005 at 0x61137DC8 sp 0x289270
>>>>      67  147533 [main] sshd 6280 exception::handle: In
>>>> cygwin_except_handler signal 11 at 0x61137DC8
>>>>      38  147571 [main] sshd 6280 exception::handle: In
>>>> cygwin_except_handler calling 0x0
>>>>      37  147608 [main] sshd 6280 exception::handle: Exception:
>>>> STATUS_ACCESS_VIOLATION
>>>>
>>>>    addr2line.exe 61137DC8 -e /usr/bin/cygwin1.dll
>>>> /netrel/src/cygwin-snapshot-20121012-1/newlib/libc/stdio/findfp.c:296
>>>
>>> You seem to be the only person reporting this problem.  Everyone else
>>> updates to a snapshot to cure ssh problems.  FWIW, that instruction
>>> shouldn't even be executed.
>>
>> I have such issue only on sshd forking and for long time,
>> so it is not relative to last snapshots.
>
> Corinna fixed an issue which could have manifested as ssh SIGSEGVing.
> Given the fact that the 61137DC8 doesn't make any sense, are you sure
> you're actually using a snapshot?  Could there be an old version of
> cygwin1.dll sitting around somewhere?
>
> cgf
>


$ uname -a
CYGWIN_NT-6.1-WOW64 MARCOATZERI 1.7.17s(0.262/5/3) 20121012 01:20:45 
i686 Cygwin

could be that the cygwin1.dbg of 20121012 is not correct ?




--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple