64-bit emacs crashes a lot

[Ryan Johnson]

On 02/08/2013 7:04 AM, Ken Brown wrote:
> On 8/2/2013 4:02 AM, Corinna Vinschen wrote:
>> On Aug  1 22:46, Ryan Johnson wrote:
>>> On 26/07/2013 11:32 PM, Ryan Johnson wrote:
>>>> On 26/07/2013 10:50 PM, Ken Brown wrote:
>>>>> On 7/26/2013 8:32 PM, Ryan Johnson wrote:
>>>>>> Hi all,
>>>>>>
>>>>>> Running 64-bit cygwin 1.7.22(0.268/5/3), with emacs-nox 24.3-4 
>>>>>> inside
>>>>>> mintty 1.2-beta1-1, I keep getting seg faults and "Fatal error
>>>>>> 6: Aborted"
>>>>
>>>>>> It happens at strange times, invariably during I/O of some kind 
>>>>>> (either
>>>>>> keyboard input or output from some compilation window); I don't 
>>>>>> get the
>>>>>> impression it's fork-related. I don't know how to get a backtrace 
>>>>>> from
>>>>>> emacs, given the way any exception or signal always loses the
>>>>>> "userland"
>>>>>> stack (suggestions welcome).
>>>>>>
>>>>>> Anyone else seeing this?
>>>>>
>>>>> This doesn't really answer your question since I don't use
>>>>> emacs-nox, but I've been running 64-bit emacs-X11 and finding it
>>>>> very stable.  I typically keep it running for several days at a
>>>>> time.
>>>>>
>>>>> You say you don't know how to get a backtrace from emacs. I
>>>>> assume you've installed emacs-debuginfo and run emacs under gdb.
>>>>> Are you saying you can never get a backtrace after it crashes?
>>>> I do have the emacs-debuginfo. I meant that the stack dump didn't
>>>> have any emacs frames in it (they were all cygwin1.dll), and my
>>>> experience with cygwin/gdb is that once you've taken a signal or
>>>> exception you lose the cygwin stack and just see a bunch of
>>>> threads mucking around in various low-level Windows dlls.
>>>>
>>>> I have tried attaching gdb to emacs and setting a breakpoint on
>>>> abort(), but it didn't catch anything yet. I'm also hampered by
>>>> gdb constantly getting confused, breaking partway into emacs, and
>>>> having to detach/reattach it. I've started a new thread for that
>>>> issue.
>>>
>>> Here's a new one... I started a compilation, but before it actually
>>> invoked the command it started pegging the CPU. After ^G^G^G, it
>>> crashed with the following:
>>>> Auto-save? (y or n) y
>>>>       0 [main] emacs 5076 C:\cygwin64\bin\emacs-nox.exe: *** fatal
>>>> error - Internal error: TP_NUM_W_BUFS too small 2268032 >= 10.
>>
>> That looks like a memory overwrite.  2268032 is 0x229b80, which looks
>> suspiciously like a stack address.  And the overwritten value is on the
>> stack, too, well within the cygwin TLS area.  If *this* value gets
>> overwritten, the TLS is probbaly totally hosed at this point. There's
>> just no way to infer the culprit from this limited info.
>
> Could this be BLODA?  Ryan, I noticed that you wrote in a different 
> thread, "I recently migrated to 64-bit cygwin...and so far have not 
> had to disable Windows Defender; the latter was a recurring source of 
> trouble for my previous 32-bit cygwin install on Win7/64."
This would be a whole new level of nasty from a BLODA... I thought they 
only interfered with fork()?

However, this *is* Windows Defender we're talking about... service 
disabled and all cygwin processes restarted. I'll let you know in a day 
or so if the crashes go away.

Thanks,
Ryan


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