From: "Ulrich Drepper" <drepper@gmail.com>
To: "Rik van Riel" <riel@redhat.com>
Cc: "Davide Libenzi" <davidel@xmailserver.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>
Subject: Re: [patch 2/3] MAP_NOZERO - implement sys_brk2()
Date: Tue, 26 Jun 2007 20:45:28 -0700 [thread overview]
Message-ID: <a36005b50706262045g79c4accak21fea740fdc1bffd@mail.gmail.com> (raw)
In-Reply-To: <4681D45F.7080309@redhat.com>
On 6/26/07, Rik van Riel <riel@redhat.com> wrote:
> Since programs can get back free()d memory after a malloc(),
> with the old contents of the memory intact, surely your
> MAP_NONZERO behavior could be the default for programs that
> can get away with it?
>
> Maybe we could use some magic ELF header, similar to the
> way non-executable stack is handled?
No. This is an implementation detail of the libc version. The malloc
as compiled today is expecting brk-ed memory to be zeroed. This
default can of course be changed (it's a simple define) but you cannot
make this the default behavior for brk.
next prev parent reply other threads:[~2007-06-27 3:45 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-27 2:44 Davide Libenzi
2007-06-27 3:07 ` Rik van Riel
2007-06-27 3:33 ` Davide Libenzi
2007-06-27 3:45 ` Ulrich Drepper [this message]
2007-06-27 4:11 ` Rik van Riel
2007-06-27 5:04 ` Ulrich Drepper
2007-06-27 3:48 ` Ulrich Drepper
2007-06-27 3:55 ` Davide Libenzi
2007-06-27 5:02 ` Ulrich Drepper
2007-06-27 12:32 ` Hugh Dickins
2007-06-27 15:59 ` Davide Libenzi
2007-06-27 17:01 ` Ulrich Drepper
2007-06-27 17:43 ` Hugh Dickins
2007-06-27 18:13 ` Davide Libenzi
2007-06-27 18:32 ` Hugh Dickins
2007-06-27 18:45 ` Davide Libenzi
2007-06-27 22:11 ` Nicholas Miell
2007-06-28 0:17 ` Davide Libenzi
2007-06-28 2:58 ` Davide Libenzi
2007-06-30 7:52 ` Andrew Morton
2007-06-27 18:52 ` Ulrich Drepper
2007-06-27 19:32 ` Hugh Dickins
2007-06-27 19:00 ` Rik van Riel
2007-06-27 19:22 ` Davide Libenzi
2007-06-27 16:05 ` Davide Libenzi
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