From a94720bf821dd63e72176da5f423ba7935dde67d Mon Sep 17 00:00:00 2001
From: Andrea Arcangeli <aarcange@redhat.com>
Date: Wed, 22 Feb 2017 15:42:15 -0800
Subject: [PATCH] userfaultfd: use vma_is_anonymous

Cleanup the vma->vm_ops usage.

Side note: it would be more robust if vma_is_anonymous() would also
check that vm_flags hasn't VM_PFNMAP set.

Link: http://lkml.kernel.org/r/20161216144821.5183-5-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Michael Rapoport <RAPOPORT@il.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 fs/userfaultfd.c | 8 ++++----
 mm/userfaultfd.c | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 71e917387ec38..7e8f0d60718d8 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -830,7 +830,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
 
 		/* check not compatible vmas */
 		ret = -EINVAL;
-		if (cur->vm_ops)
+		if (!vma_is_anonymous(cur))
 			goto out_unlock;
 
 		/*
@@ -855,7 +855,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
 	do {
 		cond_resched();
 
-		BUG_ON(vma->vm_ops);
+		BUG_ON(!vma_is_anonymous(vma));
 		BUG_ON(vma->vm_userfaultfd_ctx.ctx &&
 		       vma->vm_userfaultfd_ctx.ctx != ctx);
 
@@ -981,7 +981,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
 		 * provides for more strict behavior to notice
 		 * unregistration errors.
 		 */
-		if (cur->vm_ops)
+		if (!vma_is_anonymous(cur))
 			goto out_unlock;
 
 		found = true;
@@ -995,7 +995,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
 	do {
 		cond_resched();
 
-		BUG_ON(vma->vm_ops);
+		BUG_ON(!vma_is_anonymous(vma));
 
 		/*
 		 * Nothing to do: this vma is already registered into this
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index af817e5060fbf..9c2ed70ac78de 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -197,7 +197,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
 	 * FIXME: only allow copying on anonymous vmas, tmpfs should
 	 * be added.
 	 */
-	if (dst_vma->vm_ops)
+	if (!vma_is_anonymous(dst_vma))
 		goto out_unlock;
 
 	/*
-- 
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