From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Jan Beulich" <JBeulich@suse.com>
Subject: Re: [V7 PATCH 3/7] pvh dom0: implement
 XENMEM_add_to_physmap_range for x86
Date: Tue, 17 Dec 2013 16:56:55 +0000
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References: <1387247911-28846-1-git-send-email-mukesh.rathor@oracle.com>
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To: Mukesh Rathor <mukesh.rathor@oracle.com>
Cc: george.dunlap@eu.citrix.com, xen-devel <xen-devel@lists.xenproject.org>, keir.xen@gmail.com, tim@xen.org
List-Id: xen-devel@lists.xenproject.org

>>> On 17.12.13 at 03:38, Mukesh Rathor <mukesh.rathor@oracle.com> wrote:
> +    case XENMEM_add_to_physmap_range:
> +    {
> +        struct xen_add_to_physmap_range xatpr;
> +        struct domain *d;
> +
> +        if ( copy_from_guest(&xatpr, arg, 1) )
> +            return -EFAULT;
> +
> +        /* This mapspace is redundant for this hypercall */
> +        if ( xatpr.space == XENMAPSPACE_gmfn_range )
> +            return -EINVAL;
> +
> +        d = rcu_lock_domain_by_any_id(xatpr.domid);
> +        if ( d == NULL )
> +            return -ESRCH;
> +
> +        if ( (rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d)) == 0 )
> +            rc = xenmem_add_to_physmap_range(d, &xatpr);
> +
> +        rcu_unlock_domain(d);
> +
> +        if ( rc == -EAGAIN )
> +            rc = hypercall_create_continuation(
> +                __HYPERVISOR_memory_op, "ih", op, arg);

There's another bug here: You don't copy back xatpr, and hence
when the hypercall gets resumed, you'll again find the original
size rather than the reduced one.

Jan

> +
> +        return rc;
> +    }