malloc: bug or feature ?

Peter Wemm peter at
Wed Apr 7 08:39:09 PDT 2004

On Wednesday 07 April 2004 05:55 am, Marc Olzheim wrote:
> On Wed, Apr 07, 2004 at 02:39:53PM +0200, Georges-Andre Silber wrote:
> > Is it a 'normal' behaviour of malloc()? Shouldn't malloc() return
> > NULL?
> It should return NULL indeed. I can reproduce this on my -CURRENT
> machine, while 5.2.1-RELEASE is ok.

In -current, this is normal.  The default MALLOC_OPTIONS setting is 
'AJ', which intentionally fills new malloc'ed data area with junk, and 
has all the assertions turned on.

The SEGV looks suspicious though.  I wonder if malloc is trying to put 
the junk in without checking if malloc failed.

Anyway, try "env MALLOC_OPTIONS=aj ./a.out"  See 'man malloc.conf' etc 
for more info.
Peter Wemm - peter at; peter at; peter at
"All of this is for nothing if we don't go to the stars" - JMS/B5

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