From: John Reiser <jreiser@BitWagon.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Potential bug in fs/binfmt_elf.c?
Date: Sun, 07 Mar 2004 21:57:43 -0800 [thread overview]
Message-ID: <404C0B57.6030607@BitWagon.com> (raw)
In-Reply-To: <m1brn8us96.fsf@ebiederm.dsl.xmission.com>
>> LOAD 0x001000 0x00400000 0x00400000 0x00000 0x10000000 R 0x1000
>
>
> What is the purpose of allocating 256MB of read-only zeros?
To prevent the kernel from placing any shared libraries there [via mmap()
from ld-linux.so.2], especially under the influence of exec-shield.
This is 'wine', which wants to reserve that address space for mapping
executables that were built for some other operating system. For this
purpose, the .p_flags of PF_R instead could be 0 [==> PROT_NONE]; but
do_brk() still turns either one into 'prw.' which has potential memory
[over-]commit charges. The expected 'pr--' [or 'p---'] should have
a memory commit cost of zero.
--
next prev parent reply other threads:[~2004-03-08 5:58 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-05 17:38 Potential bug in fs/binfmt_elf.c? Mike Hearn
2004-03-05 18:28 ` John Reiser
2004-03-06 18:46 ` Ulrich Drepper
2004-03-06 21:10 ` Mike Hearn
2004-03-07 6:11 ` Ulrich Drepper
2004-03-07 9:58 ` Mike Hearn
2004-03-07 10:46 ` Ulrich Drepper
2004-03-07 11:53 ` Mike Hearn
2004-03-07 21:32 ` Ulrich Drepper
2004-03-07 23:55 ` Eric W. Biederman
2004-03-08 5:57 ` John Reiser [this message]
2004-03-08 8:06 ` Jakub Jelinek
2004-03-11 6:17 ` [PATCH] binfmt_elf.c allow .bss with no access (p---) John Reiser
2004-03-11 14:23 ` Mike Hearn
2004-03-11 19:18 ` John Reiser
2004-03-12 16:42 ` Mike Hearn
[not found] ` <20040412185317.79ac7d7d.akpm@osdl.org>
2004-04-13 17:33 ` John Reiser
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