From ba6907db6de17cf90c4fc67f3eb1d1d37dd0b7ac Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Wed, 22 Feb 2017 15:43:22 -0800 Subject: [PATCH] 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@redhat.com Signed-off-by: Mike Rapoport Signed-off-by: Andrea Arcangeli Acked-by: Hillf Danton Cc: "Dr. David Alan Gilbert" Cc: Michael Rapoport Cc: Mike Kravetz Cc: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/userfaultfd.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 11b5e65e8fba..593135c296bc 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1096,6 +1096,11 @@ static __always_inline int validate_range(struct mm_struct *mm, 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 userfaultfd_ctx *ctx, /* 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 userfaultfd_ctx *ctx, 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 userfaultfd_ctx *ctx, * 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 userfaultfd_ctx *ctx, 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 -- 2.20.1