Re: LD_PRELOAD problem

  • From: "LS Cheng" <exriscer@xxxxxxxxx>
  • To: "Tanel Poder" <tanel.poder.003@xxxxxxx>
  • Date: Fri, 1 Sep 2006 08:42:41 +0200

I just compared function name for both library and sqlplus NM output and
there are 381 which are used in both cases. Now what does this mean...?

Ah, the funny thing is they just told me 5 minutes ago that the same
configuration works in other servers and in some doesnt. Puzzled...


On 8/31/06, Tanel Poder <tanel.poder.003@xxxxxxx> 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/ then this function X is called from /sbl/ even if it exists in some other dll against which the executable is linked (like libclntsh* libraries).

Run: nm /sbl/ 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


*From:* oracle-l-bounce@xxxxxxxxxxxxx [mailto:
oracle-l-bounce@xxxxxxxxxxxxx] *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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