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Subject: LD_PRELOAD regression on 1.5.19-4  ? no more loaded library in child process
Date: Thu, 26 Jan 2006 11:37:18 +0100
Message-ID: <5CD8C8F9F151D142922161D4CF32F9400573F5EF@exch-lv03.intl.businessobjects.com>
From: "Louis Lecaroz" <louis DOT lecaroz AT businessobjects DOT com>
To: <cygwin AT cygwin DOT com>
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Hi all CygWin champions developers ;)

Since this version, the LD_PRELOAD tag is no more replicated to subprocess (Win32 version of cygwin).
That means, if I set the LD_PRELOAD variable, only the parent process calls the LoadLibrary & load the DLL defined in LD_PRELOAD.

In this case, when starting bash, the LD_PRELOAD command is executed. but when starting a cp.exe, cat.exe or another cygwin command from the bash shell, the LD_PRELOAD is no more executed !
If I performed :
SET LD_PRELOAD=/cygdrive/d/mydll.dll
c:\bash (mydll.dll loaded correctly)
$cp toto.txt titi.txt (no mydll.dll loaded !)

If I performed :
SET LD_PRELOAD=/cygdrive/d/mydll.dll
c:\bash (mydll.dll loaded correctly)
$cmd
c:\cp toto.txt titi.txt (mydll.dll loaded)

So, it works now in this last build of cygwin as it was working previously the snapshot #20050811

To correct this, a snapshot has been provided, snapshot #20050811, See ChangeLog in winsup\cygwinChangeLog :
2005-08-11  Christopher Faylor  <cgf AT timesys DOT com>

 * dcrt0.cc: Remove ld_preload declaration.
 * winsup.h: Move ld_preload declaration here.
 * fork.cc (fork_child): Call ld_preload() before returning.

So this issue was corrected by ffork.cc version 1.158 of ffork.ccd
I took a quick look into the ffork.cc, & I saw that the fixup_hooks_after_fork () &  _my_tls.fixup_after_fork () are now called after ld_preload instead of before as deliverd in snapshot #20050811.
I don't know exactly if this is the reason of my issue.

This is not maybe a regression as I suppose this because it does not work now as it has been designed since this snapshot to work.
Did this behavior has been since modified to work by another way ?

Thx in advance for all the help you will be able to provide me,
Louis
  

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