Re: [PATCH] Add a /proc/self/exedir link

From: Mike Hearn <mike@plan99.net>
To: Bodo Eggert <7eggert@gmx.de>
Cc: Neil Brown <neilb@suse.de>, linux-kernel@vger.kernel.org, akpm@osdl.org
Subject: Re: [PATCH] Add a /proc/self/exedir link
Date: Thu, 06 Apr 2006 20:36:10 +0100	[thread overview]
Message-ID: <44356DAA.90209@plan99.net> (raw)
In-Reply-To: <Pine.LNX.4.58.0604061841150.1941@be1.lrz>

> bin/foo calls bin/bar refering to /proc/self/fd/999
> bin_2/bar does dup2(open(get_my_exedir()), 999)  ***FUBAR***

So don't do that. Treat it as the same case as sending a file path via 
RPC: make sure it's resolved relative to the namespace the program is in 
and not anything under /proc/self.

In practice most desktop apps use "prefix paths" to locate their own 
data files. They don't usually send those file paths to other processes, 
not even in the case of things like GIMP plugins.

So whilst I agree you have identified a place where it breaks, I don't 
think it invalidates the scheme.

> There may be no "real path" corresponding to /proc/self/fd/4711.

Only in a pathological case like running a program that you then rm -rf 
the prefix of, in which case, you lose whatever happens.

> IMO it's still best to just symlink the program directory to the correct 
> place and make the programs search in e.g. ~/opt/ and /opt/.

That also suffers from namespace conflicts ;)

thanks -mike