From: Andrea Arcangeli <aarcange@xxxxxxxxxx> Subject: userfaultfd: wp: userfaultfd_pte/huge_pmd_wp() helpers Implement helpers methods to invoke userfaultfd wp faults more selectively: not only when a wp fault triggers on a vma with vma->vm_flags VM_UFFD_WP set, but only if the _PAGE_UFFD_WP bit is set in the pagetable too. Link: http://lkml.kernel.org/r/20200220163112.11409-5-peterx@xxxxxxxxxx Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> Reviewed-by: Jerome Glisse <jglisse@xxxxxxxxxx> Reviewed-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> Cc: Bobby Powers <bobbypowers@xxxxxxxxx> Cc: Brian Geffon <bgeffon@xxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Denis Plotnikov <dplotnikov@xxxxxxxxxxxxx> Cc: "Dr . David Alan Gilbert" <dgilbert@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: "Kirill A . Shutemov" <kirill@xxxxxxxxxxxxx> Cc: Martin Cracauer <cracauer@xxxxxxxx> Cc: Marty McFadden <mcfadden8@xxxxxxxx> Cc: Maya Gokhale <gokhale2@xxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Pavel Emelyanov <xemul@xxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Shaohua Li <shli@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/userfaultfd_k.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) --- a/include/linux/userfaultfd_k.h~userfaultfd-wp-userfaultfd_pte-huge_pmd_wp-helpers +++ a/include/linux/userfaultfd_k.h @@ -14,6 +14,8 @@ #include <linux/userfaultfd.h> /* linux/include/uapi/linux/userfaultfd.h */ #include <linux/fcntl.h> +#include <linux/mm.h> +#include <asm-generic/pgtable_uffd.h> /* * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining @@ -57,6 +59,18 @@ static inline bool userfaultfd_wp(struct return vma->vm_flags & VM_UFFD_WP; } +static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma, + pte_t pte) +{ + return userfaultfd_wp(vma) && pte_uffd_wp(pte); +} + +static inline bool userfaultfd_huge_pmd_wp(struct vm_area_struct *vma, + pmd_t pmd) +{ + return userfaultfd_wp(vma) && pmd_uffd_wp(pmd); +} + static inline bool userfaultfd_armed(struct vm_area_struct *vma) { return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP); @@ -106,6 +120,19 @@ static inline bool userfaultfd_wp(struct return false; } +static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma, + pte_t pte) +{ + return false; +} + +static inline bool userfaultfd_huge_pmd_wp(struct vm_area_struct *vma, + pmd_t pmd) +{ + return false; +} + + static inline bool userfaultfd_armed(struct vm_area_struct *vma) { return false; _
