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Date: Thu, 3 Sep 2009 18:07:21 +0300
Message-ID: <cc557aab0909030807i6ec3851fo7fa754b8802a3fd4@mail.gmail.com>
Subject: Re: [Qemu-devel] [PATCH v2] Build *-user targets as PIE
From: "Kirill A. Shutemov" <kirill@shutemov.name>
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To: Paul Brook <paul@codesourcery.com>
Cc: qemu-devel@nongnu.org

On Thu, Sep 3, 2009 at 5:38 PM, Paul Brook<paul@codesourcery.com> wrote:
>> PIE code usually is a bit slower. Approximately, 1% for i386 according to
>> some tests. RISC architectures should be affected less, since they have
>> more registers. On other hand we are getting rid from text relocations on
>> i386 which make executable loading slower. So...
>
> I think you've got that backwards.
> A traditional (fixed address) executable requires no load-time relocation for
> internal references because all addresses are known at static link time. PIE
> require the dynamic linker adjust all absolute addresses.

Usermode qemu on i386 is not a traditional executable, sicne it uses
-Wl,-shared for linking. In result we've got an executable which looks
like PIE, but dynamic linker have to resolve text relocations. I think
the best way it to create a true PIE without a text relocations.

P.S. I press "reply" instead "reply all" first time.