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From: Ingo Molnar <mingo@elte.hu>
To: Pavel Machek <pavel@ucw.cz>
Cc: jikos@suse.cz, kernel list <linux-kernel@vger.kernel.org>
Subject: Re: brk randomization breaks columns
Date: Mon, 4 Feb 2008 14:01:56 +0100	[thread overview]
Message-ID: <20080204130156.GA8730@elte.hu> (raw)
In-Reply-To: <20080204122837.GA1647@elf.ucw.cz>


* Pavel Machek <pavel@ucw.cz> wrote:

> Hmm, code in binfmt_elf is really strange.
> 
>         elf_bss += load_bias;
>         elf_brk += load_bias;
>         start_code += load_bias;
>         end_code += load_bias;
>         start_data += load_bias;
>         end_data += load_bias;
> 
>         /* Calling set_brk effectively mmaps the pages that we need
>          * for the bss and break sections.  We must do this before
>          * mapping in the interpreter, to make sure it doesn't wind
>          * up getting placed where the bss needs to go.
>          */
>         retval = set_brk(elf_bss, elf_brk);
> 
> ... so we allocate non-randoimzed brk, but later we just overwrite bss 
> variable with new, shiner and better randomized value... without 
> unmapping the old one... The code in binfmt_elf.c is really a mess.

hm, so it seems that it isnt even the randomization that causes the 
problem - but somehow the randomization code itself is broken, right? 

Would you be interested in figuring out how to unbreak this? [if not, 
could you send me the binary?]

	Ingo

  reply	other threads:[~2008-02-04 13:02 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-04 12:28 Pavel Machek
2008-02-04 13:01 ` Ingo Molnar [this message]
2008-02-04 13:28   ` Pavel Machek
2008-02-04 14:55     ` Jiri Kosina
2008-02-04 20:25       ` Pavel Machek
2008-02-04 14:33   ` Jiri Kosina
2008-02-04 16:12     ` Jiri Kosina
     [not found]       ` <15577be70802041016m97cddbfk43b9073408bcbce9@mail.gmail.com>
     [not found]         ` <15577be70802041029o2975ba6do34589bbdc81d1652@mail.gmail.com>
2008-02-04 19:52           ` Fwd: " Pavel Machek
2008-02-04 21:54             ` Abel Bernabeu
2008-02-04 22:48               ` Jiri Kosina
2008-02-04 23:13                 ` Abel Bernabeu
2008-02-04 23:39                   ` Pavel Machek
2008-02-04 20:31       ` Pavel Machek
2008-02-05  1:57 ` Jiri Kosina
2008-02-05 11:06   ` [regression] " Pavel Machek
2008-02-05 12:50     ` Jiri Kosina
2008-02-05 12:54       ` Ingo Molnar
2008-02-05 13:05         ` Jakub Jelinek
2008-02-05 16:18           ` Pavel Machek
2008-02-05 16:37             ` Ingo Molnar
2008-02-05 16:12       ` Pavel Machek
2008-02-05 13:08   ` Hugh Dickins
2008-02-05 15:00     ` Arjan van de Ven
2008-02-05 15:46       ` Pavel Machek
2008-02-05 15:49         ` Jiri Kosina
2008-02-05 15:55           ` Pavel Machek
2008-02-05 15:49         ` Ingo Molnar
2008-02-05 15:59           ` Pavel Machek
2008-02-05 16:06             ` Ingo Molnar
2008-02-05 22:03               ` Pavel Machek
2008-02-05 16:58         ` Arjan van de Ven
2008-02-05 17:33           ` Pavel Machek
2008-02-05 22:35           ` Jiri Kosina
2008-02-06  3:24             ` Randy Dunlap
2008-02-05 16:02   ` Pavel Machek
2008-02-05 16:09     ` Ingo Molnar
2008-02-05 22:04       ` Pavel Machek
2008-02-05 18:05   ` Pavel Machek
2008-02-05 20:42     ` Jiri Kosina

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