From: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Check whether a VMA can be used with userfault in more compact way
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
---
fs/userfaultfd.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 9552734..387fe77 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1060,6 +1060,11 @@ 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)
{
@@ -1149,7 +1154,7 @@ 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
@@ -1193,7 +1198,7 @@ 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);
@@ -1331,7 +1336,7 @@ 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;
@@ -1345,7 +1350,7 @@ 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
--
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