Re: inheriting the lwp private area

[Matt Thomas <matt%3am-software.com@localhost>]

On Mar 22, 2011, at 8:51 PM, Antti Kantee wrote:

> Hi,
> 
> On Julio's request I was looking at the now-failing tests and resulting
> hanging processes.  Basically at least on i386 the failures are a
> result of fork() + setcontext() (plus some voodoo) after which calling
> pthread_mutex_lock() with signals masked causes a busyloop due to
> pthread__self() causing a segv but the signal never getting delivered
> (that in itself seems like stinky business, but not the motivating factor
> of this mail).
> 
> Per 4am intuition it seems pretty obvious that a child should inherit
> the forking lwp's private data.  Does that make sense to everyone else?
> At least patching fork1() to do so fixes the hanging processes and
> failing tests and a quick roll around qemu hasn't caused any problems.
> 
> If it doesn't make sense, I'll disable the pthread bits (per commit
> guideline clause 5) until support is fully fixed so that others don't have
> to suffer from untested half-baked commits causing juju hangs and crashes.

You mean l->l_private should be copied on fork?  Absolutely.