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Re: dynamically written code problem

From: Paolo Bonzini <paolo dot bonzini at polimi dot it>
To: Jakub Jelinek <jakub at redhat dot com>
Cc: Bob Wilkinson <bob dot wilkinson at sbcglobal dot net>, gcc at gcc dot gnu dot org
Date: Mon, 11 Oct 2004 10:10:43 +0200
Subject: Re: dynamically written code problem
References: <002801c4af13$83537260$6401a8c0@bwdesk> <416A3480.5020409@gnu.org> <20041011072528.GL30497@sunsite.ms.mff.cuni.cz> <416A3881.6080507@polimi.it> <20041011074454.GB31909@devserv.devel.redhat.com>

> on my system, mmap is allocating in the 0x40000000 range, and malloc > is allocating at the brk (around 0x08000000). Is this different when > exec-shield is activated?
Yes.  mmap with PROT_EXEC set attempts to allocate as low as possible,
usually below the executable.
mmap without PROT_EXEC allocates as high as possible, below the stack.

So at least my function does not lose execute protection if mmap was used with PROT_EXEC. Thank you very much,

Paolo

Follow-Ups:
- Re: dynamically written code problem
  - From: Tolga Dalman

References:
- dynamically written code problem
  - From: Bob Wilkinson
- Re: dynamically written code problem
  - From: Paolo Bonzini
- Re: dynamically written code problem
  - From: Jakub Jelinek
- Re: dynamically written code problem
  - From: Paolo Bonzini
- Re: dynamically written code problem
  - From: Jakub Jelinek

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