Re: [Valgrind-users] Errors with gcc -static

[Zachary T. <div...@gm...>]

On Thu, Jul 16, 2009 at 7:47 PM, Nicholas
Nethercote<n.n...@gm...> wrote:
> On Fri, Jul 17, 2009 at 2:16 AM, Zachary Turner<div...@gm...> wrote:
>> --track-origins=yes I find that the memory it's claiming is
>> uninitialized comes from sbrk().  As far as I can tell (please correct
>> me if I'm wrong) this function is guaranteed to return 0-filled
>> memory
>
> I'm not at all certain this is the case, which is why Memcheck marks
> it as undefined.  Evidence to the contrary would be welcome!
>
> Nick
>

I'm not certain either :)  When I google around it seems about 50/50
with some saying it does and some saying it doesn't.  But it might be
platform dependent.  The glibc source code's implementation of malloc
uses sbrk and has a comment that says "since sbrk() returns 0-filled
memory, we don't need to initialize the entire buffer." or something
to that effect.