Re: [Xen-devel] [PATCH] xen/xen_initial_domain: check thatxen_start_info is initialized

From: Jan Beulich
Date: Thu Oct 04 2012 - 03:43:40 EST


>>> On 03.10.12 at 19:08, Stefano Stabellini <Stefano.Stabellini@xxxxxxxxxxxxx>
wrote:
> Since commit commit 4c071ee5268f7234c3d084b6093bebccc28cdcba ("arm:
> initial Xen support") PV on HVM guests can be xen_initial_domain.
> However PV on HVM guests might have an unitialized xen_start_info, so
> check before accessing its fields.
>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> Acked-by: Ian Campbell <Ian.Campbell@xxxxxxxxxx>
> Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
>
> diff --git a/include/xen/xen.h b/include/xen/xen.h
> index 9a39ca5..e7101bb 100644
> --- a/include/xen/xen.h
> +++ b/include/xen/xen.h
> @@ -28,7 +28,7 @@ extern enum xen_domain_type xen_domain_type;
> #include <asm/xen/hypervisor.h>
>
> #define xen_initial_domain() (xen_domain() && \
> - xen_start_info->flags & SIF_INITDOMAIN)
> + xen_start_info && xen_start_info->flags & SIF_INITDOMAIN)
> #else /* !CONFIG_XEN_DOM0 */
> #define xen_initial_domain() (0)
> #endif /* CONFIG_XEN_DOM0 */

Didn't your other patch statically initialize it?

Jan

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