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

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

On Thu, Jun 18, 2015 at 08:42:40 +0100, Peter Maydell wrote:
> > What data structures are you referring to? Are they ppc-specific?
> 
> None of the code generation data structures are locked at all --
> if two threads try to generate code at the same time they'll
> tend to clobber each other.

AFAICT tb_gen_code is called with a mutex held (the sequence is
mutex->tb_find_fast->tb_find_slow->tb_gen_code in cpu-exec.c)

The only call to tb_gen_code that in usermode is not holding
the lock is in cpu_breakpoint_insert->breakpoint_invalidate->
tb_invalidate_phys_page_range->tb_gen_code. I'm not using
gdb so I guess I cannot trigger this.

Am I missing something?

> On 17 June 2015 at 22:36, Emilio G. Cota <cota@braap.org> wrote:
> > I don't think this is a race because it also breaks when
> > run on a single core (with taskset -c 0).

As I said, this problem doesn't seem to be a race.

Thanks,

		Emilio