Re: possible bug in libXt or libXaw

[Marco Atzeri <marco.atzeri@gmail.com>]

On 11/16/2014 10:14 AM, Mark Geisert wrote:
> Marco Atzeri writes:
>> On 11/16/2014 7:30 AM, Mark Geisert wrote:
>>> Marco Atzeri writes:
>>>> this is the pointer causing the segfault
>>>>
>>>> (gdb) p form->form.horiz_base
>>>> $2 = (Widget) 0x6275705f6779632f
>>>>
>>>> while similar pointers have a much smaller address,
>>>>
>>>> (gdb) p w
>>>> $5 = (Widget) 0x60014bd50
>>>>
>>>> so it that an assignment not clearing the upper
>>>> portion of the pointer.
>>>
>>> $2 is not a pointer that needed partial clearing, it's a character string
>>> "/cyg_pub".  Possibly a buffer overrun somewhere?  Hope the string fragment
>>> points the way to somebody.
>>>
>>> ..mark
>>>
>>
>> thanks for the hint,  "/cyg_pub" is a directory on the root
>>
>>    $ ls -l / |grep pub
>> lrwxrwxrwx   1 marco          Administrators     19 Jun 26 19:11 pub ->
>> /cygdrive/e/cyg_pub
>>
>> where the data file was stored,
>> however moving it to "/tmp" produce as result
>>
>>    p ref
>> $1 = (Widget) 0x635f7261636e5f62 aka c_racn_b
>>
>> that is not very meaningful to me, so the pointer corruption
>> can be very generic.

I was wrong. It is meaningful

(gdb) p form
$38 = (FormConstraints) 0x600000003
(gdb) x/20bs 0x600000003
0x600000003:    ""
0x600000004:    ""
0x600000005:    ""
0x600000006:    ""
0x600000007:    ""
0x600000008:    "\023\200"
0x60000000b:    ""
0x60000000c:    ""
0x60000000d:    ""
0x60000000e:    ""
0x60000000f:    ""
0x600000010:    "/tmp/sresa1b_ncar_ccsm3_0_run1_20p/es.nc"
0x600000039:    "ht_arrow"
0x600000042:    "ow"
0x600000045:    ""
0x600000046:    ""
0x600000047:    ""
0x600000048:    ""
0x600000049:    ""
0x60000004a:    ""

So it is a portion of the file name as before,
I start to feel that a pointer is not a NULL as should be...

> Good Luck,

thanks
Marco


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