Re: lib/49816: rtld internal lock vs fork

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

The following reply was made to PR lib/49816; it has been noted by GNATS.

From: Joerg Sonnenberger <joerg%britannica.bec.de@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: lib/49816: rtld internal lock vs fork
Date: Mon, 6 Apr 2015 15:50:34 +0200

 On Mon, Apr 06, 2015 at 09:20:00AM +0000, yamt%NetBSD.org@localhost wrote:
 > >Description:
 > 	when a thread does fork(2), some other thread might hold _rtld_mutex.
 > 	in that case, the child process will likely deadlock soon because
 > 	of non-zero _rtld_mutex.  i've observed the problem with open vswitch.
 
 Non-zero _rtld_mutex by itself should not be problem. The problem exists
 if another thread requires the exclusive lock. I do plan to rewrite rtld
 at some point to never require an exclusive lock for symbol look up, but
 that's far from trivial. In the old world before locking, you would just
 hit race conditions or not.
 
 Joerg