Andrea, Rik, please review this patch.

Thanks in advance,

Paolo

On 08/01/2015 12:59, Marc Zyngier wrote:
> From: Steve Capper <[email protected]>
> 
> ptep_clear_flush_young_notify and pmdp_clear_flush_young_notify both
> call the notifiers *after* the pte/pmd has been made young.
> 
> This can cause problems with KVM that relies on being able to block
> MMU notifiers when carrying out maintenance of second stage
> descriptors.
> 
> This patch ensures that the MMU notifiers are called before ptes and
> pmds are made old.
> 
> Signed-off-by: Steve Capper <[email protected]>
> ---
>  include/linux/mmu_notifier.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
> index 95243d2..c454c76 100644
> --- a/include/linux/mmu_notifier.h
> +++ b/include/linux/mmu_notifier.h
> @@ -290,11 +290,11 @@ static inline void mmu_notifier_mm_destroy(struct 
> mm_struct *mm)
>       int __young;                                                    \
>       struct vm_area_struct *___vma = __vma;                          \
>       unsigned long ___address = __address;                           \
> -     __young = ptep_clear_flush_young(___vma, ___address, __ptep);   \
> -     __young |= mmu_notifier_clear_flush_young(___vma->vm_mm,        \
> +     __young = mmu_notifier_clear_flush_young(___vma->vm_mm,         \
>                                                 ___address,           \
>                                                 ___address +          \
>                                                       PAGE_SIZE);     \
> +     __young |= ptep_clear_flush_young(___vma, ___address, __ptep);  \
>       __young;                                                        \
>  })
>  
> @@ -303,11 +303,11 @@ static inline void mmu_notifier_mm_destroy(struct 
> mm_struct *mm)
>       int __young;                                                    \
>       struct vm_area_struct *___vma = __vma;                          \
>       unsigned long ___address = __address;                           \
> -     __young = pmdp_clear_flush_young(___vma, ___address, __pmdp);   \
> -     __young |= mmu_notifier_clear_flush_young(___vma->vm_mm,        \
> +     __young = mmu_notifier_clear_flush_young(___vma->vm_mm,         \
>                                                 ___address,           \
>                                                 ___address +          \
>                                                       PMD_SIZE);      \
> +     __young |= pmdp_clear_flush_young(___vma, ___address, __pmdp);  \
>       __young;                                                        \
>  })
>  
> 
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