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Date: Tue, 6 Mar 2007 22:23:22 -0800
From: Gary Johnson <garyjohn AT spk DOT agilent DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: [Testcase] Memory returned by malloc not always zeroed.
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On 2007-03-07, Buzz wrote:
> Hi,
> 
> On three different cygwin 1.5.24-2 systems, attached testprogram
> (compile with ``gcc -o mall-test mall-test.c'')
> returns many lines like:
> 
> n1 S13 p12 is 0x81, not 0
> n1 S14 p0 is 0x8c, not 0
> n1 S14 p1 is 0x7f, not 0
> n1 S14 p2 is 0x14, not 0
> n1 S14 p3 is 0x61, not 0
> n1 S14 p4 is 0x8c, not 0
> n1 S14 p5 is 0x7f, not 0
> n1 S14 p6 is 0x14, not 0
> n1 S14 p7 is 0x61, not 0
> n1 S14 p12 is 0x81, not 0
> 
> This indicates malloc returning non-zeroed memory.
> 
> Has anybody got a clue as to what's going on?

Malloc() returns a pointer to a block of memory.  Other than size 
and alignment, the contents of that memory is not specified.  If you 
want a block of memory initialized to zero, use calloc().

Regards,
Gary

-- 
Gary Johnson                 | Agilent Technologies
garyjohn AT spk DOT agilent DOT com     | Mobile Broadband Division
                             | Spokane, Washington, USA

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