Re: [PATCH] [POWERPC] Fix oops related to 4xx flush_tlb_page modification

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Fri, 2007-11-09 at 03:58 -0600, Kumar Gala wrote:
> kmap_atomic calls flush_tlb_page with a NULL VMA and thus we end
> up dereferencing a NULL pointer to try and get the context.id.
> 
> If the VMA is null use the global pid value of 0.

Ack.

> ---
>  include/asm-powerpc/tlbflush.h |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/asm-powerpc/tlbflush.h b/include/asm-powerpc/tlbflush.h
> index e7b4c0d..5c91081 100644
> --- a/include/asm-powerpc/tlbflush.h
> +++ b/include/asm-powerpc/tlbflush.h
> @@ -44,13 +44,13 @@ static inline void flush_tlb_mm(struct mm_struct *mm)
>  static inline void flush_tlb_page(struct vm_area_struct *vma,
>  				  unsigned long vmaddr)
>  {
> -	_tlbie(vmaddr, vma->vm_mm->context.id);
> +	_tlbie(vmaddr, vma ? vma->vm_mm->context.id : 0);
>  }
> 
>  static inline void flush_tlb_page_nohash(struct vm_area_struct *vma,
>  					 unsigned long vmaddr)
>  {
> -	_tlbie(vmaddr, vma->vm_mm->context.id);
> +	_tlbie(vmaddr, vma ? vma->vm_mm->context.id : 0);
>  }
> 
>  static inline void flush_tlb_range(struct vm_area_struct *vma,