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From: Denis Vlasenko <vda.linux@googlemail.com>
To: ray-gmail@madrabbit.org
Cc: "Rob Landley" <rob@landley.net>,
	linux-kernel@vger.kernel.org,
	"David McCullough" <david_mccullough@au.securecomputing.com>
Subject: Re: Feature request: exec self for NOMMU.
Date: Wed, 27 Dec 2006 19:35:07 +0100
Message-ID: <200612271935.07835.vda.linux@googlemail.com> (raw)
In-Reply-To: <2c0942db0612262113v5b504aecmdd922193415b60de@mail.gmail.com>

On Wednesday 27 December 2006 06:13, Ray Lee wrote:
> On 12/26/06, Rob Landley <rob@landley.net> wrote:
> > I'm trying to make some nommu-friendly busybox-like tools, which means using
> > vfork() instead of fork().  This means that after I fork I have to exec in
> > the child to unblock the parent, and if I want to exec my current executable
> > I have to find out where it lives so I can feed the path to exec().  This is
> > nontrivial.
> >
> > Worse, it's not always possible.  If chroot() has happened since the program
> > started, there may not _be_ a path to my current executable available from
> > this process's current or root directories.
> 
> How about openning an fd to yourself at the beginning of execution, then calling
> fexecve later?

This solves chroot problem. How to find path-to-yourself reliably
(for one, without using /proc/self/exe) is not obvious to me.
--
vda

  parent reply index

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-12-26 23:23 Rob Landley
2006-12-26 23:55 ` David Lang
2006-12-27  0:39   ` Rob Landley
2006-12-27  4:24   ` Denis Vlasenko
2006-12-27  5:44     ` Rob Landley
2006-12-27  5:13 ` Ray Lee
2006-12-27  5:51   ` Rob Landley
2006-12-27  6:08     ` Vadim Lobanov
2006-12-27  8:29       ` Rob Landley
2006-12-27 18:49         ` Ray Lee
2006-12-27 21:13           ` Rob Landley
2006-12-27 18:35   ` Denis Vlasenko [this message]
2006-12-27 21:03     ` Rob Landley
2006-12-28  2:48       ` Denis Vlasenko
2006-12-28  5:32         ` Rob Landley

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