Re: Runtime trouble with commit dbd952127d (seccomp: introduce writer locking)

From: Oleg Nesterov
Date: Sun Aug 10 2014 - 15:35:19 EST


On 08/09, Kees Cook wrote:
>
> On Sat, Aug 9, 2014 at 6:47 PM, Guenter Roeck <private@xxxxxxxxxxxx> wrote:
> > Hi folks,
> >
> > I am having some trouble with commit dbd952127d (seccomp: introduce
> > writer locking) when running my qemu tests on the upstream kernel.
>
> Eek, sorry this is causing you trouble!
>
> > With powerpc, I get the following crash.
> >
> > ftrace: allocating 20093 entries in 59 pages
> > ------------[ cut here ]------------
> > kernel BUG at kernel/fork.c:1108!
>
> For your tree, does this resolve to copy_seccomp()'s
>
> BUG_ON(!spin_is_locked(&current->sighand->siglock));
>
> line?

This is almost off-topic, and I too do not understand whats going on...

But I'd suggest to change this check to use lockdep_is_held() in any
case.

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/