Subject: Re: disabling PTHREAD_CONCURRENCY for 3.0
To: Manuel Bouyer <>
From: Chuck Silvers <>
List: tech-kern
Date: 12/13/2005 06:17:17
On Mon, Dec 12, 2005 at 08:18:49PM +0100, Manuel Bouyer wrote:
> On Mon, Dec 12, 2005 at 09:09:24AM -0800, Chuck Silvers wrote:
> > > If PTHREAD_CONCURRENCY > 1 can cause kernel panics, just removing it from
> > > libpthread isn't enouth. The kernel has to be patched as well, otherwise a
> > > local user could start an application linked with a bad libpthread and
> > > cause a local DOS.
> > 
> > I was more worried about us advertising a feature that crashes the system
> > than a malicious user.  but disabling the sa_setconcurrency() syscall
> > as well is easy enough, I'll add that to the patch.
> Maybe not disable it (possible backward compat issues ?) but return error
> if the value is not 1.

this setup is in pthread_init(), which returns void.
this is called before main() as the constructor for the pthread library.
"return an error" in this case would mean "cause the process to exit".

what compatibility issue are you concerned about?