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Re: LD_PRELOAD problem

From: LS Cheng <exriscer_at_gmail.com>
Date: Fri, 1 Sep 2006 14:13:25 +0200
Message-ID: <6e9345580609010513w6fa37062m4363295fdfce934e@mail.gmail.com>


Hi all

I have more information, I did a chatr to check differences between working server oracle binary and the non working.

I see two differences, in the server which LD_PRELOAD doesnt cause problem oracle binary has these two attributes:

explicit unloading disabled
linkage table protection disabled

Does anyone know how can I change these attributes with chatr?

Cheers

On 8/31/06, Tanel Poder <tanel.poder.003_at_mail.ee> wrote:
>
> LD_PRELOAD allows you to hijack dynamicly loaded library functions. If
> sqlplus calls function X, then if this function X is exported from your
> /sbl/xxx.sl then this function X is called from /sbl/xxx.sl even if it
> exists in some other dll against which the executable is linked (like
> libclntsh* libraries).
>
> Run: nm /sbl/xxx.sl to see which functions may be hijacked there, this
> could give some more indication what's going on.
>
> And of course, the library's word-size has to match word-size of the
> executable. If the word sizes are different, you have to recompile the
> library.
>
> Tanel.
>
> ------------------------------
> *From:* oracle-l-bounce_at_freelists.org [mailto:
> oracle-l-bounce_at_freelists.org] *On Behalf Of *LS Cheng
> *Sent:* Thursday, August 31, 2006 04:45
>
> *To:* Jesse, Rich
> *Cc:* oracle-l
> *Subject:* Re: LD_PRELOAD problem
>
>
>
> However when I unset LD_PRELOAD sqlplus works but of course the
> application specific program fails.
>
>

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Received on Fri Sep 01 2006 - 07:13:25 CDT

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