Michael S. Tsirkin wrote:
> vhost net module wants to do copy to/from user from a kernel thread,
> which needs use_mm. Export it to modules.
> 
> Acked-by: Andrea Arcangeli <aarcange@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

I need this too:

Acked-by: Gregory Haskins <ghaskins@novell.com>

> ---
>  mm/mmu_context.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/mm/mmu_context.c b/mm/mmu_context.c
> index ded9081..0777654 100644
> --- a/mm/mmu_context.c
> +++ b/mm/mmu_context.c
> @@ -5,6 +5,7 @@
>  
>  #include <linux/mm.h>
>  #include <linux/mmu_context.h>
> +#include <linux/module.h>
>  #include <linux/sched.h>
>  
>  #include <asm/mmu_context.h>
> @@ -37,6 +38,7 @@ void use_mm(struct mm_struct *mm)
>  	if (active_mm != mm)
>  		mmdrop(active_mm);
>  }
> +EXPORT_SYMBOL_GPL(use_mm);
>  
>  /*
>   * unuse_mm
> @@ -56,3 +58,4 @@ void unuse_mm(struct mm_struct *mm)
>  	enter_lazy_tlb(mm, tsk);
>  	task_unlock(tsk);
>  }
> +EXPORT_SYMBOL_GPL(unuse_mm);