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Date: Mon, 17 Oct 2011 08:53:44 -0700 (PDT)
From: "jan.kolar" <kolar AT math DOT cas DOT cz>
To: cygwin AT cygwin DOT com
Subject: Re: /proc/*/cmdline corrupted
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Christopher Faylor-8 wrote:
> 
> On Mon, Oct 17, 2011 at 10:27:18AM +0200, Corinna Vinschen wrote:
>>On Linux, /proc/$PID/cmdline always contains the full command line as
>>it has been when the process got started, irrespectively of changes
>>after process startup.  It looks like the loader creates a copy of the
>>argv array before calling main.
> 
> You can change the contents of what __argv[n] points to to modify what
> /proc/<pid>/cmdline displays though.
> 
> i.e.,
> 
>     strcpy (__argv[1], "a");
> 
> That's pretty risky though.
> 
>>Cygwin doesn't generate a copy of the argv array at startup, so the
>>processes __argv is the one used to call the main function.  And I'm
>>reluctant to do that since it costs just more time for a process to
>>start again.
> 
> Just creating a copy of argv without copying what it points to should be
> pretty inexpensive.  It's too bad that we export __argv and __argc.  I
> don't see Linux doing anything like that and it seems like a way for
> a Cygwin program to cause mischief.
> 
> cgf
> 
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> 
> 

See the previous post about Linux:
http://cygwin.com/ml/cygwin/2011-10/msg00314.html

And for the hell of possible solution see the link from that post:
http://cvs.rutgers.edu/cgi-bin/viewvc.cgi/tags/start/postman1.11/PsTitle.cc?revision=1806&view=markup

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