The patch titled
Subject: userfaultfd: wrap the common dst_vma check into an inlined function
has been added to the -mm tree. Its filename is
userfaultfd-wrap-the-common-dst_vma-check-into-an-inlined-function.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/userfaultfd-wrap-the-common-dst_vma-check-into-an-inlined-function.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/userfaultfd-wrap-the-common-dst_vma-check-into-an-inlined-function.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
Subject: userfaultfd: wrap the common dst_vma check into an inlined function
When doing UFFDIO_COPY, it is necessary to find the correct destination
vma and make sure fault range is in it.
Since there are two places need to do the same task, just wrap those
common check into an inlined function.
Link: http://lkml.kernel.org/r/20190927070032.2129-3-richardw.yang@xxxxxxxxxxxxxxx
Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/userfaultfd.c | 56 +++++++++++++++++++++++++--------------------
1 file changed, 32 insertions(+), 24 deletions(-)
--- a/mm/userfaultfd.c~userfaultfd-wrap-the-common-dst_vma-check-into-an-inlined-function
+++ a/mm/userfaultfd.c
@@ -18,6 +18,36 @@
#include <asm/tlbflush.h>
#include "internal.h"
+static __always_inline
+struct vm_area_struct *find_dst_vma(struct mm_struct *dst_mm,
+ unsigned long dst_start,
+ unsigned long len)
+{
+ /*
+ * Make sure that the dst range is both valid and fully within a
+ * single existing vma.
+ */
+ struct vm_area_struct *dst_vma;
+
+ dst_vma = find_vma(dst_mm, dst_start);
+ if (!dst_vma)
+ return NULL;
+
+ if (dst_start < dst_vma->vm_start ||
+ dst_start + len > dst_vma->vm_end)
+ return NULL;
+
+ /*
+ * Check the vma is registered in uffd, this is required to
+ * enforce the VM_MAYWRITE check done at uffd registration
+ * time.
+ */
+ if (!dst_vma->vm_userfaultfd_ctx.ctx)
+ return NULL;
+
+ return dst_vma;
+}
+
static int mcopy_atomic_pte(struct mm_struct *dst_mm,
pmd_t *dst_pmd,
struct vm_area_struct *dst_vma,
@@ -221,20 +251,9 @@ retry:
*/
if (!dst_vma) {
err = -ENOENT;
- dst_vma = find_vma(dst_mm, dst_start);
+ dst_vma = find_dst_vma(dst_mm, dst_start, len);
if (!dst_vma || !is_vm_hugetlb_page(dst_vma))
goto out_unlock;
- /*
- * Check the vma is registered in uffd, this is
- * required to enforce the VM_MAYWRITE check done at
- * uffd registration time.
- */
- if (!dst_vma->vm_userfaultfd_ctx.ctx)
- goto out_unlock;
-
- if (dst_start < dst_vma->vm_start ||
- dst_start + len > dst_vma->vm_end)
- goto out_unlock;
err = -EINVAL;
if (vma_hpagesize != vma_kernel_pagesize(dst_vma))
@@ -471,20 +490,9 @@ retry:
* both valid and fully within a single existing vma.
*/
err = -ENOENT;
- dst_vma = find_vma(dst_mm, dst_start);
+ dst_vma = find_dst_vma(dst_mm, dst_start, len);
if (!dst_vma)
goto out_unlock;
- /*
- * Check the vma is registered in uffd, this is required to
- * enforce the VM_MAYWRITE check done at uffd registration
- * time.
- */
- if (!dst_vma->vm_userfaultfd_ctx.ctx)
- goto out_unlock;
-
- if (dst_start < dst_vma->vm_start ||
- dst_start + len > dst_vma->vm_end)
- goto out_unlock;
err = -EINVAL;
/*
_
Patches currently in -mm which might be from richardw.yang@xxxxxxxxxxxxxxx are
userfaultfd-use-vma_pagesize-for-all-huge-page-size-calculation.patch
userfaultfd-remove-unnecessary-warn_on-in-__mcopy_atomic_hugetlb.patch
userfaultfd-wrap-the-common-dst_vma-check-into-an-inlined-function.patch
