Re: [Qemu-devel] linux-user crashes on clone(2) when run on ppc host

["Emilio G. Cota" <cota@braap.org>]

On Wed, Jun 17, 2015 at 09:58:27 +0100, Peter Maydell wrote:
> On 17 June 2015 at 01:52, Emilio G. Cota <cota@braap.org> wrote:
> > I'm having trouble running a simple multithreaded program on a PowerPC host machine.
> >
> > The machine I'm using is a ppc VM--I think it's running under KVM (I'm using
> > OVH's RunAbove Power8 service):
> >   admin@adsf:~/qemu$ uname -a
> >   Linux adsf 3.13.0-37-generic #64-Ubuntu SMP Mon Sep 22 21:27:09 UTC 2014 ppc64le ppc64le ppc64le GNU/Linux
> >
> > admin@adsf:~/qemu$ ppc64le-linux-user/qemu-ppc64le foo
> 
> Multithreaded binaries don't work with linux-user; there are a bunch
> of known race conditions involving data structures we don't correctly
> lock or make per-thread.
> 
> This is a long-standing issue; we're hoping we might get to fixing
> it some time this year.

I don't think this is a race because it also breaks when
run on a single core (with taskset -c 0).

What data structures are you referring to? Are they ppc-specific?
On x86 hosts linux-user works reliably with multithreaded apps.
I'd expect any races on common code to show up on x86 as well.

Thanks,

		Emilio