Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Sun, 16 Jun 2013 19:39:43 +0200
From: Jens Gustedt <>
Subject: Re: valgrind problems

Am Sonntag, den 16.06.2013, 12:04 -0400 schrieb Rich Felker:
> It's not an indeterminate value. It's simply a value. Because malloc
> is not special here. It's just like any other function defined in C
> code on a freestanding implementation.

I agree that malloc is not special here, because it is freestanding,
no problem. But malloc also gets the memory from some system calls, if
you don't have a fixed static pool.

These system calls guarantee you that the value of the memory is
determined. So this is a platform specific guarantee, and valgrind
doesn't seem to share that information.

In particular, valgrind claimed that calloc was using memory
unitialized that was received with brk. It is platform specific to
assume that memory returned by brk is initialized to some value, be it
0 or not. If this is a linux specific guarantee, valgrind seems to be
missing it.


:: INRIA Nancy Grand Est ::   ::
:: AlGorille ::::::::::::::: office Nancy : +33 383593090   ::
:: ICube :::::::::::::: office Strasbourg : +33 368854536   ::
:: ::::::::::::::::::::::::::: gsm France : +33 651400183   ::
:: :::::::::::::::::::: gsm international : +49 15737185122 ::

Download attachment "signature.asc" of type "application/pgp-signature" (199 bytes)

Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.