diff mbox series

[v4,09/27] userfaultfd: wp: userfaultfd_pte/huge_pmd_wp() helpers

Message ID 20190426045151.19556-10-peterx@redhat.com (mailing list archive)
State New, archived
Headers show
Series userfaultfd: write protection support | expand

Commit Message

Peter Xu April 26, 2019, 4:51 a.m. UTC 
From: Andrea Arcangeli <aarcange@redhat.com>

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.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 include/linux/userfaultfd_k.h | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
diff mbox series

Patch

diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index 38f748e7186e..c6590c58ce28 100644
--- a/include/linux/userfaultfd_k.h
+++ b/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
@@ -55,6 +57,18 @@  static inline bool userfaultfd_wp(struct vm_area_struct *vma)
 	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);
@@ -104,6 +118,19 @@  static inline bool userfaultfd_wp(struct vm_area_struct *vma)
 	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;