From 55adf4de30346e0ec6b988cb9b885a5dddc954af Mon Sep 17 00:00:00 2001
From: Andrea Arcangeli <aarcange@redhat.com>
Date: Mon, 6 Apr 2020 20:05:37 -0700
Subject: [PATCH] userfaultfd: wp: userfaultfd_pte/huge_pmd_wp() helpers
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>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Link: http://lkml.kernel.org/r/20200220163112.11409-5-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/userfaultfd_k.h | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index 5dc247af0f2ef..7b91b76aac580 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
@@ -57,6 +59,18 @@ 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);
@@ -106,6 +120,19 @@ 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;
--
2.30.2