From: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> Subject: userfaultfd: introduce vma_can_userfault Check whether a VMA can be used with userfault in more compact way Link: http://lkml.kernel.org/r/20161216144821.5183-28-aarcange@xxxxxxxxxx Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> Acked-by: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx> Cc: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx> Cc: Michael Rapoport <RAPOPORT@xxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/userfaultfd.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff -puN fs/userfaultfd.c~userfaultfd-introduce-vma_can_userfault fs/userfaultfd.c --- a/fs/userfaultfd.c~userfaultfd-introduce-vma_can_userfault +++ a/fs/userfaultfd.c @@ -1096,6 +1096,11 @@ static __always_inline int validate_rang return 0; } +static inline bool vma_can_userfault(struct vm_area_struct *vma) +{ + return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma); +} + static int userfaultfd_register(struct userfaultfd_ctx *ctx, unsigned long arg) { @@ -1185,7 +1190,7 @@ static int userfaultfd_register(struct u /* check not compatible vmas */ ret = -EINVAL; - if (!vma_is_anonymous(cur) && !is_vm_hugetlb_page(cur)) + if (!vma_can_userfault(cur)) goto out_unlock; /* * If this vma contains ending address, and huge pages @@ -1229,7 +1234,7 @@ static int userfaultfd_register(struct u do { cond_resched(); - BUG_ON(!vma_is_anonymous(vma) && !is_vm_hugetlb_page(vma)); + BUG_ON(!vma_can_userfault(vma)); BUG_ON(vma->vm_userfaultfd_ctx.ctx && vma->vm_userfaultfd_ctx.ctx != ctx); @@ -1367,7 +1372,7 @@ static int userfaultfd_unregister(struct * provides for more strict behavior to notice * unregistration errors. */ - if (!vma_is_anonymous(cur) && !is_vm_hugetlb_page(cur)) + if (!vma_can_userfault(cur)) goto out_unlock; found = true; @@ -1381,7 +1386,7 @@ static int userfaultfd_unregister(struct do { cond_resched(); - BUG_ON(!vma_is_anonymous(vma) && !is_vm_hugetlb_page(vma)); + BUG_ON(!vma_can_userfault(vma)); /* * Nothing to do: this vma is already registered into this _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
