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From: dconway@hpldsla.sid.hp.com (Dan Conway)
Newsgroups: comp.lang.c
Subject: Re: Failure INSIDE malloc() ??
Message-ID: <2170006@hpldsla.sid.hp.com>
Date: 20 Jun 91 15:37:37 GMT
References: <1991Jun19.131709.13260@risky.ecs.umass.edu>
Organization: HP Scientific Instruments Division - Palo Alto, CA
Lines: 26

jog@ganzer.ecs.umass.edu (Ashwini ) writes:
> Hello Everyone, 
> 
> I'm having a problem with malloc routine. I have a large program,
> so I may run out of memory (im using free wherever possible) 
> but my program still crashes INSIDE malloc. Isnt this routine 
> supposed to return a null pointer if it runs out of allocatable
> memory? The program crashes at the following statement which is
> inside malloc.(got by running through dbx).
> 
> movb $ffffffff, (r10)
> 
> I couldnt find anything in the faq list.
> ANY help would be greatly appreciated.
> Thanks
> Ashwini			jog@ecs.umass.edu
> ----------
> 

Two possibilities come to mind: you may have freed the same pointer twice
without an intervening malloc, or you may have assigned through a pointer
after freeing it.  Either way, you might have messed up malloc's internal data
structures enough to cause it to crash.

Dan Conway
dconway@hpsid.sid.hp.com