Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
Date: Thu, 11 Aug 2005 13:05:47 -0500
From: Brian Ford <Brian DOT Ford AT flightsafety DOT com>
X-X-Sender: ford AT PC1163-8460-XP DOT flightsafety DOT com
Reply-To: cygwin AT cygwin DOT com
To: cygwin AT cygwin DOT com
Subject: Re: "Segmentation fault" CygWin tools with code Injection-MS Detours
In-Reply-To: <20050811143645.GF16476@trixie.casa.cgf.cx>
Message-ID: <Pine.CYG.4.58.0508111302150.2696@PC1163-8460-XP.flightsafety.com>
References: <42FB4856 DOT 9060808 AT club-internet DOT fr> <42FB4B92 DOT 4060101 AT le-resistant DOT com>  <20050811143645 DOT GF16476 AT trixie DOT casa DOT cgf DOT cx>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
X-IsSubscribed: yes

On Thu, 11 Aug 2005, Christopher Faylor wrote:

> On Thu, Aug 11, 2005 at 02:58:58PM +0200, Louis Lecaroz wrote:
> >Having (if possible ;) ) a patch & a standard modification in cygwin to
> >allow this type of programming will be really great !
>
> Cygwin has its own (currently undocumented) hooking mechanism.  Setting
> the LD_PRELOAD environment variable to the name of a DLL will cause any
> function in the DLL to override the similarly named cygwin function.  It
> works similarly to linux:
>
>  LD_PRELOAD
>   A whitespace-separated list of additional, user-specified, ELF shared
>   libraries to be loaded before all others.  This can be used to
>   selectively override functions in other shared libraries.
>
> except that it uses DLLs rather than "ELF shared libraries".

Just to add a useless speculation that I don't currently have time to
follow up on...

I'd bet this is the mechanism used by SysInternals Process Explorer for
the currently broken (on Cygwin) DLL list and thread list features.  If
and when I have time to confirm this useless speculation, I'll report
back.  Unless someone else gets to it first... ;-).

-- 
Brian Ford
Senior Realtime Software Engineer
VITAL - Visual Simulation Systems
FlightSafety International
the best safety device in any aircraft is a well-trained pilot...

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/