right list for SIGABRT python binary question ?

[Karsten Hilbert]

On Sat, Oct 21, 2017 at 09:31:54AM +0200, dieter wrote:

> > 	Debug memory block at address p=0x717b7c: API ''
> > 	    0 bytes originally requested
> > 	    The 3 pad bytes at p-3 are not all FORBIDDENBYTE (0xfb):
> > 	        at p-3: 0x03 *** OUCH
> > 	        at p-2: 0x4e *** OUCH
> > 	        at p-1: 0x00 *** OUCH
> > 	    Because memory is corrupted at the start, the count of bytes requested
> > 	       may be bogus, and checking the trailing pad bytes may segfault.
> > 	    The 4 pad bytes at tail=0x717b7c are not all FORBIDDENBYTE (0xfb):
> > 	        at tail+0: 0x00 *** OUCH
> > 	        at tail+1: 0x00 *** OUCH
> > 	        at tail+2: 0x00 *** OUCH
> > 	        at tail+3: 0x00 *** OUCH
> > 	    The block was made by call #0 to debug malloc/realloc.
> > 	Fatal Python error: bad ID: Allocated using API '', verified using API 'o'
> > ...
> > Can anyone give more guidance on what the above python debug
> > output might vaguely point to ?
> 
> It points to a memory corruption.
> 
> I would approach the problem by means of debugging: put a write
> breakpoint at the corrupted address "0x717b7c" and check what part
> of the system accesses it (this assumes you are using a CPU
> supporting write breakpoints).
> It may be very tedious as the address might be accessed very often
> legally before it gets corrupted.
> 
> Another approach may be to use a tool designed for memory debugging,
> e.g. "valgrind".

Hi Dieter,

thanks for your guidance. I fear this approach is out of my class.

Karsten
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